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1 : : /*-------------------------------------------------------------------------
2 : : *
3 : : * xlog.c
4 : : * PostgreSQL write-ahead log manager
5 : : *
6 : : * The Write-Ahead Log (WAL) functionality is split into several source
7 : : * files, in addition to this one:
8 : : *
9 : : * xloginsert.c - Functions for constructing WAL records
10 : : * xlogrecovery.c - WAL recovery and standby code
11 : : * xlogreader.c - Facility for reading WAL files and parsing WAL records
12 : : * xlogutils.c - Helper functions for WAL redo routines
13 : : *
14 : : * This file contains functions for coordinating database startup and
15 : : * checkpointing, and managing the write-ahead log buffers when the
16 : : * system is running.
17 : : *
18 : : * StartupXLOG() is the main entry point of the startup process. It
19 : : * coordinates database startup, performing WAL recovery, and the
20 : : * transition from WAL recovery into normal operations.
21 : : *
22 : : * XLogInsertRecord() inserts a WAL record into the WAL buffers. Most
23 : : * callers should not call this directly, but use the functions in
24 : : * xloginsert.c to construct the WAL record. XLogFlush() can be used
25 : : * to force the WAL to disk.
26 : : *
27 : : * In addition to those, there are many other functions for interrogating
28 : : * the current system state, and for starting/stopping backups.
29 : : *
30 : : *
31 : : * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
32 : : * Portions Copyright (c) 1994, Regents of the University of California
33 : : *
34 : : * src/backend/access/transam/xlog.c
35 : : *
36 : : *-------------------------------------------------------------------------
37 : : */
38 : :
39 : : #include "postgres.h"
40 : :
41 : : #include <ctype.h>
42 : : #include <math.h>
43 : : #include <time.h>
44 : : #include <fcntl.h>
45 : : #include <sys/stat.h>
46 : : #include <sys/time.h>
47 : : #include <unistd.h>
48 : :
49 : : #include "access/clog.h"
50 : : #include "access/commit_ts.h"
51 : : #include "access/heaptoast.h"
52 : : #include "access/multixact.h"
53 : : #include "access/rewriteheap.h"
54 : : #include "access/subtrans.h"
55 : : #include "access/timeline.h"
56 : : #include "access/transam.h"
57 : : #include "access/twophase.h"
58 : : #include "access/xact.h"
59 : : #include "access/xlog_internal.h"
60 : : #include "access/xlogarchive.h"
61 : : #include "access/xloginsert.h"
62 : : #include "access/xlogreader.h"
63 : : #include "access/xlogrecovery.h"
64 : : #include "access/xlogutils.h"
65 : : #include "access/xlogwait.h"
66 : : #include "backup/basebackup.h"
67 : : #include "catalog/catversion.h"
68 : : #include "catalog/pg_control.h"
69 : : #include "catalog/pg_database.h"
70 : : #include "common/controldata_utils.h"
71 : : #include "common/file_utils.h"
72 : : #include "executor/instrument.h"
73 : : #include "miscadmin.h"
74 : : #include "pg_trace.h"
75 : : #include "pgstat.h"
76 : : #include "port/atomics.h"
77 : : #include "postmaster/bgwriter.h"
78 : : #include "postmaster/datachecksum_state.h"
79 : : #include "postmaster/startup.h"
80 : : #include "postmaster/walsummarizer.h"
81 : : #include "postmaster/walwriter.h"
82 : : #include "replication/origin.h"
83 : : #include "replication/slot.h"
84 : : #include "replication/slotsync.h"
85 : : #include "replication/snapbuild.h"
86 : : #include "replication/walreceiver.h"
87 : : #include "replication/walsender.h"
88 : : #include "storage/bufmgr.h"
89 : : #include "storage/fd.h"
90 : : #include "storage/ipc.h"
91 : : #include "storage/large_object.h"
92 : : #include "storage/latch.h"
93 : : #include "storage/predicate.h"
94 : : #include "storage/proc.h"
95 : : #include "storage/procarray.h"
96 : : #include "storage/procsignal.h"
97 : : #include "storage/reinit.h"
98 : : #include "storage/spin.h"
99 : : #include "storage/subsystems.h"
100 : : #include "storage/sync.h"
101 : : #include "utils/guc_hooks.h"
102 : : #include "utils/guc_tables.h"
103 : : #include "utils/injection_point.h"
104 : : #include "utils/pgstat_internal.h"
105 : : #include "utils/ps_status.h"
106 : : #include "utils/relmapper.h"
107 : : #include "utils/snapmgr.h"
108 : : #include "utils/timeout.h"
109 : : #include "utils/timestamp.h"
110 : : #include "utils/varlena.h"
111 : : #include "utils/wait_event.h"
112 : :
113 : : #ifdef WAL_DEBUG
114 : : #include "utils/memutils.h"
115 : : #endif
116 : :
117 : : /* timeline ID to be used when bootstrapping */
118 : : #define BootstrapTimeLineID 1
119 : :
120 : : /* User-settable parameters */
121 : : int max_wal_size_mb = 1024; /* 1 GB */
122 : : int min_wal_size_mb = 80; /* 80 MB */
123 : : int wal_keep_size_mb = 0;
124 : : int XLOGbuffers = -1;
125 : : int XLogArchiveTimeout = 0;
126 : : int XLogArchiveMode = ARCHIVE_MODE_OFF;
127 : : char *XLogArchiveCommand = NULL;
128 : : bool EnableHotStandby = false;
129 : : bool fullPageWrites = true;
130 : : bool wal_log_hints = false;
131 : : int wal_compression = WAL_COMPRESSION_NONE;
132 : : char *wal_consistency_checking_string = NULL;
133 : : bool *wal_consistency_checking = NULL;
134 : : bool wal_init_zero = true;
135 : : bool wal_recycle = true;
136 : : bool log_checkpoints = true;
137 : : int wal_sync_method = DEFAULT_WAL_SYNC_METHOD;
138 : : int wal_level = WAL_LEVEL_REPLICA;
139 : : int CommitDelay = 0; /* precommit delay in microseconds */
140 : : int CommitSiblings = 5; /* # concurrent xacts needed to sleep */
141 : : int wal_retrieve_retry_interval = 5000;
142 : : int max_slot_wal_keep_size_mb = -1;
143 : : int wal_decode_buffer_size = 512 * 1024;
144 : : bool track_wal_io_timing = false;
145 : :
146 : : #ifdef WAL_DEBUG
147 : : bool XLOG_DEBUG = false;
148 : : #endif
149 : :
150 : : int wal_segment_size = DEFAULT_XLOG_SEG_SIZE;
151 : :
152 : : /*
153 : : * Number of WAL insertion locks to use. A higher value allows more insertions
154 : : * to happen concurrently, but adds some CPU overhead to flushing the WAL,
155 : : * which needs to iterate all the locks.
156 : : */
157 : : #define NUM_XLOGINSERT_LOCKS 8
158 : :
159 : : /*
160 : : * Max distance from last checkpoint, before triggering a new xlog-based
161 : : * checkpoint.
162 : : */
163 : : int CheckPointSegments;
164 : :
165 : : /* Estimated distance between checkpoints, in bytes */
166 : : static double CheckPointDistanceEstimate = 0;
167 : : static double PrevCheckPointDistance = 0;
168 : :
169 : : /*
170 : : * Track whether there were any deferred checks for custom resource managers
171 : : * specified in wal_consistency_checking.
172 : : */
173 : : static bool check_wal_consistency_checking_deferred = false;
174 : :
175 : : /*
176 : : * GUC support
177 : : */
178 : : const struct config_enum_entry wal_sync_method_options[] = {
179 : : {"fsync", WAL_SYNC_METHOD_FSYNC, false},
180 : : #ifdef HAVE_FSYNC_WRITETHROUGH
181 : : {"fsync_writethrough", WAL_SYNC_METHOD_FSYNC_WRITETHROUGH, false},
182 : : #endif
183 : : {"fdatasync", WAL_SYNC_METHOD_FDATASYNC, false},
184 : : #ifdef O_SYNC
185 : : {"open_sync", WAL_SYNC_METHOD_OPEN, false},
186 : : #endif
187 : : #ifdef O_DSYNC
188 : : {"open_datasync", WAL_SYNC_METHOD_OPEN_DSYNC, false},
189 : : #endif
190 : : {NULL, 0, false}
191 : : };
192 : :
193 : :
194 : : /*
195 : : * Although only "on", "off", and "always" are documented,
196 : : * we accept all the likely variants of "on" and "off".
197 : : */
198 : : const struct config_enum_entry archive_mode_options[] = {
199 : : {"always", ARCHIVE_MODE_ALWAYS, false},
200 : : {"on", ARCHIVE_MODE_ON, false},
201 : : {"off", ARCHIVE_MODE_OFF, false},
202 : : {"true", ARCHIVE_MODE_ON, true},
203 : : {"false", ARCHIVE_MODE_OFF, true},
204 : : {"yes", ARCHIVE_MODE_ON, true},
205 : : {"no", ARCHIVE_MODE_OFF, true},
206 : : {"1", ARCHIVE_MODE_ON, true},
207 : : {"0", ARCHIVE_MODE_OFF, true},
208 : : {NULL, 0, false}
209 : : };
210 : :
211 : : /*
212 : : * Statistics for current checkpoint are collected in this global struct.
213 : : * Because only the checkpointer or a stand-alone backend can perform
214 : : * checkpoints, this will be unused in normal backends.
215 : : */
216 : : CheckpointStatsData CheckpointStats;
217 : :
218 : : /*
219 : : * During recovery, lastFullPageWrites keeps track of full_page_writes that
220 : : * the replayed WAL records indicate. It's initialized with full_page_writes
221 : : * that the recovery starting checkpoint record indicates, and then updated
222 : : * each time XLOG_FPW_CHANGE record is replayed.
223 : : */
224 : : static bool lastFullPageWrites;
225 : :
226 : : /*
227 : : * Local copy of the state tracked by SharedRecoveryState in shared memory,
228 : : * It is false if SharedRecoveryState is RECOVERY_STATE_DONE. True actually
229 : : * means "not known, need to check the shared state".
230 : : */
231 : : static bool LocalRecoveryInProgress = true;
232 : :
233 : : /*
234 : : * Local state for XLogInsertAllowed():
235 : : * 1: unconditionally allowed to insert XLOG
236 : : * 0: unconditionally not allowed to insert XLOG
237 : : * -1: must check RecoveryInProgress(); disallow until it is false
238 : : * Most processes start with -1 and transition to 1 after seeing that recovery
239 : : * is not in progress. But we can also force the value for special cases.
240 : : * The coding in XLogInsertAllowed() depends on the first two of these states
241 : : * being numerically the same as bool true and false.
242 : : */
243 : : static int LocalXLogInsertAllowed = -1;
244 : :
245 : : /*
246 : : * ProcLastRecPtr points to the start of the last XLOG record inserted by the
247 : : * current backend. It is updated for all inserts. XactLastRecEnd points to
248 : : * end+1 of the last record, and is reset when we end a top-level transaction,
249 : : * or start a new one; so it can be used to tell if the current transaction has
250 : : * created any XLOG records.
251 : : *
252 : : * While in parallel mode, this may not be fully up to date. When committing,
253 : : * a transaction can assume this covers all xlog records written either by the
254 : : * user backend or by any parallel worker which was present at any point during
255 : : * the transaction. But when aborting, or when still in parallel mode, other
256 : : * parallel backends may have written WAL records at later LSNs than the value
257 : : * stored here. The parallel leader advances its own copy, when necessary,
258 : : * in WaitForParallelWorkersToFinish.
259 : : */
260 : : XLogRecPtr ProcLastRecPtr = InvalidXLogRecPtr;
261 : : XLogRecPtr XactLastRecEnd = InvalidXLogRecPtr;
262 : : XLogRecPtr XactLastCommitEnd = InvalidXLogRecPtr;
263 : :
264 : : /*
265 : : * RedoRecPtr is this backend's local copy of the REDO record pointer
266 : : * (which is almost but not quite the same as a pointer to the most recent
267 : : * CHECKPOINT record). We update this from the shared-memory copy,
268 : : * XLogCtl->Insert.RedoRecPtr, whenever we can safely do so (ie, when we
269 : : * hold an insertion lock). See XLogInsertRecord for details. We are also
270 : : * allowed to update from XLogCtl->RedoRecPtr if we hold the info_lck;
271 : : * see GetRedoRecPtr.
272 : : *
273 : : * NB: Code that uses this variable must be prepared not only for the
274 : : * possibility that it may be arbitrarily out of date, but also for the
275 : : * possibility that it might be set to InvalidXLogRecPtr. We used to
276 : : * initialize it as a side effect of the first call to RecoveryInProgress(),
277 : : * which meant that most code that might use it could assume that it had a
278 : : * real if perhaps stale value. That's no longer the case.
279 : : */
280 : : static XLogRecPtr RedoRecPtr;
281 : :
282 : : /*
283 : : * doPageWrites is this backend's local copy of (fullPageWrites ||
284 : : * runningBackups > 0). It is used together with RedoRecPtr to decide whether
285 : : * a full-page image of a page need to be taken.
286 : : *
287 : : * NB: Initially this is false, and there's no guarantee that it will be
288 : : * initialized to any other value before it is first used. Any code that
289 : : * makes use of it must recheck the value after obtaining a WALInsertLock,
290 : : * and respond appropriately if it turns out that the previous value wasn't
291 : : * accurate.
292 : : */
293 : : static bool doPageWrites;
294 : :
295 : : /*----------
296 : : * Shared-memory data structures for XLOG control
297 : : *
298 : : * LogwrtRqst indicates a byte position that we need to write and/or fsync
299 : : * the log up to (all records before that point must be written or fsynced).
300 : : * The positions already written/fsynced are maintained in logWriteResult
301 : : * and logFlushResult using atomic access.
302 : : * In addition to the shared variable, each backend has a private copy of
303 : : * both in LogwrtResult, which is updated when convenient.
304 : : *
305 : : * The request bookkeeping is simpler: there is a shared XLogCtl->LogwrtRqst
306 : : * (protected by info_lck), but we don't need to cache any copies of it.
307 : : *
308 : : * info_lck is only held long enough to read/update the protected variables,
309 : : * so it's a plain spinlock. The other locks are held longer (potentially
310 : : * over I/O operations), so we use LWLocks for them. These locks are:
311 : : *
312 : : * WALBufMappingLock: must be held to replace a page in the WAL buffer cache.
313 : : * It is only held while initializing and changing the mapping. If the
314 : : * contents of the buffer being replaced haven't been written yet, the mapping
315 : : * lock is released while the write is done, and reacquired afterwards.
316 : : *
317 : : * WALWriteLock: must be held to write WAL buffers to disk (XLogWrite or
318 : : * XLogFlush).
319 : : *
320 : : * ControlFileLock: must be held to read/update control file or create
321 : : * new log file.
322 : : *
323 : : *----------
324 : : */
325 : :
326 : : typedef struct XLogwrtRqst
327 : : {
328 : : XLogRecPtr Write; /* last byte + 1 to write out */
329 : : XLogRecPtr Flush; /* last byte + 1 to flush */
330 : : } XLogwrtRqst;
331 : :
332 : : typedef struct XLogwrtResult
333 : : {
334 : : XLogRecPtr Write; /* last byte + 1 written out */
335 : : XLogRecPtr Flush; /* last byte + 1 flushed */
336 : : } XLogwrtResult;
337 : :
338 : : /*
339 : : * Inserting to WAL is protected by a small fixed number of WAL insertion
340 : : * locks. To insert to the WAL, you must hold one of the locks - it doesn't
341 : : * matter which one. To lock out other concurrent insertions, you must hold
342 : : * of them. Each WAL insertion lock consists of a lightweight lock, plus an
343 : : * indicator of how far the insertion has progressed (insertingAt).
344 : : *
345 : : * The insertingAt values are read when a process wants to flush WAL from
346 : : * the in-memory buffers to disk, to check that all the insertions to the
347 : : * region the process is about to write out have finished. You could simply
348 : : * wait for all currently in-progress insertions to finish, but the
349 : : * insertingAt indicator allows you to ignore insertions to later in the WAL,
350 : : * so that you only wait for the insertions that are modifying the buffers
351 : : * you're about to write out.
352 : : *
353 : : * This isn't just an optimization. If all the WAL buffers are dirty, an
354 : : * inserter that's holding a WAL insert lock might need to evict an old WAL
355 : : * buffer, which requires flushing the WAL. If it's possible for an inserter
356 : : * to block on another inserter unnecessarily, deadlock can arise when two
357 : : * inserters holding a WAL insert lock wait for each other to finish their
358 : : * insertion.
359 : : *
360 : : * Small WAL records that don't cross a page boundary never update the value,
361 : : * the WAL record is just copied to the page and the lock is released. But
362 : : * to avoid the deadlock-scenario explained above, the indicator is always
363 : : * updated before sleeping while holding an insertion lock.
364 : : *
365 : : * lastImportantAt contains the LSN of the last important WAL record inserted
366 : : * using a given lock. This value is used to detect if there has been
367 : : * important WAL activity since the last time some action, like a checkpoint,
368 : : * was performed - allowing to not repeat the action if not. The LSN is
369 : : * updated for all insertions, unless the XLOG_MARK_UNIMPORTANT flag was
370 : : * set. lastImportantAt is never cleared, only overwritten by the LSN of newer
371 : : * records. Tracking the WAL activity directly in WALInsertLock has the
372 : : * advantage of not needing any additional locks to update the value.
373 : : */
374 : : typedef struct
375 : : {
376 : : LWLock lock;
377 : : pg_atomic_uint64 insertingAt;
378 : : XLogRecPtr lastImportantAt;
379 : : } WALInsertLock;
380 : :
381 : : /*
382 : : * All the WAL insertion locks are allocated as an array in shared memory. We
383 : : * force the array stride to be a power of 2, which saves a few cycles in
384 : : * indexing, but more importantly also ensures that individual slots don't
385 : : * cross cache line boundaries. (Of course, we have to also ensure that the
386 : : * array start address is suitably aligned.)
387 : : */
388 : : typedef union WALInsertLockPadded
389 : : {
390 : : WALInsertLock l;
391 : : char pad[PG_CACHE_LINE_SIZE];
392 : : } WALInsertLockPadded;
393 : :
394 : : /*
395 : : * Session status of running backup, used for sanity checks in SQL-callable
396 : : * functions to start and stop backups.
397 : : */
398 : : static SessionBackupState sessionBackupState = SESSION_BACKUP_NONE;
399 : :
400 : : /*
401 : : * Shared state data for WAL insertion.
402 : : */
403 : : typedef struct XLogCtlInsert
404 : : {
405 : : slock_t insertpos_lck; /* protects CurrBytePos and PrevBytePos */
406 : :
407 : : /*
408 : : * CurrBytePos is the end of reserved WAL. The next record will be
409 : : * inserted at that position. PrevBytePos is the start position of the
410 : : * previously inserted (or rather, reserved) record - it is copied to the
411 : : * prev-link of the next record. These are stored as "usable byte
412 : : * positions" rather than XLogRecPtrs (see XLogBytePosToRecPtr()).
413 : : */
414 : : uint64 CurrBytePos;
415 : : uint64 PrevBytePos;
416 : :
417 : : /*
418 : : * Make sure the above heavily-contended spinlock and byte positions are
419 : : * on their own cache line. In particular, the RedoRecPtr and full page
420 : : * write variables below should be on a different cache line. They are
421 : : * read on every WAL insertion, but updated rarely, and we don't want
422 : : * those reads to steal the cache line containing Curr/PrevBytePos.
423 : : */
424 : : char pad[PG_CACHE_LINE_SIZE];
425 : :
426 : : /*
427 : : * fullPageWrites is the authoritative value used by all backends to
428 : : * determine whether to write full-page image to WAL. This shared value,
429 : : * instead of the process-local fullPageWrites, is required because, when
430 : : * full_page_writes is changed by SIGHUP, we must WAL-log it before it
431 : : * actually affects WAL-logging by backends. Checkpointer sets at startup
432 : : * or after SIGHUP.
433 : : *
434 : : * To read these fields, you must hold an insertion lock. To modify them,
435 : : * you must hold ALL the locks.
436 : : */
437 : : XLogRecPtr RedoRecPtr; /* current redo point for insertions */
438 : : bool fullPageWrites;
439 : :
440 : : /*
441 : : * runningBackups is a counter indicating the number of backups currently
442 : : * in progress. lastBackupStart is the latest checkpoint redo location
443 : : * used as a starting point for an online backup.
444 : : */
445 : : int runningBackups;
446 : : XLogRecPtr lastBackupStart;
447 : :
448 : : /*
449 : : * WAL insertion locks.
450 : : */
451 : : WALInsertLockPadded *WALInsertLocks;
452 : : } XLogCtlInsert;
453 : :
454 : : /*
455 : : * Total shared-memory state for XLOG.
456 : : */
457 : : typedef struct XLogCtlData
458 : : {
459 : : XLogCtlInsert Insert;
460 : :
461 : : /* Protected by info_lck: */
462 : : XLogwrtRqst LogwrtRqst;
463 : : XLogRecPtr RedoRecPtr; /* a recent copy of Insert->RedoRecPtr */
464 : : XLogRecPtr asyncXactLSN; /* LSN of newest async commit/abort */
465 : : XLogRecPtr replicationSlotMinLSN; /* oldest LSN needed by any slot */
466 : :
467 : : XLogSegNo lastRemovedSegNo; /* latest removed/recycled XLOG segment */
468 : :
469 : : /* Fake LSN counter, for unlogged relations. */
470 : : pg_atomic_uint64 unloggedLSN;
471 : :
472 : : /* Time and LSN of last xlog segment switch. Protected by WALWriteLock. */
473 : : pg_time_t lastSegSwitchTime;
474 : : XLogRecPtr lastSegSwitchLSN;
475 : :
476 : : /* These are accessed using atomics -- info_lck not needed */
477 : : pg_atomic_uint64 logInsertResult; /* last byte + 1 inserted to buffers */
478 : : pg_atomic_uint64 logWriteResult; /* last byte + 1 written out */
479 : : pg_atomic_uint64 logFlushResult; /* last byte + 1 flushed */
480 : :
481 : : /*
482 : : * Latest initialized page in the cache (last byte position + 1).
483 : : *
484 : : * To change the identity of a buffer (and InitializedUpTo), you need to
485 : : * hold WALBufMappingLock. To change the identity of a buffer that's
486 : : * still dirty, the old page needs to be written out first, and for that
487 : : * you need WALWriteLock, and you need to ensure that there are no
488 : : * in-progress insertions to the page by calling
489 : : * WaitXLogInsertionsToFinish().
490 : : */
491 : : XLogRecPtr InitializedUpTo;
492 : :
493 : : /*
494 : : * These values do not change after startup, although the pointed-to pages
495 : : * and xlblocks values certainly do. xlblocks values are protected by
496 : : * WALBufMappingLock.
497 : : */
498 : : char *pages; /* buffers for unwritten XLOG pages */
499 : : pg_atomic_uint64 *xlblocks; /* 1st byte ptr-s + XLOG_BLCKSZ */
500 : : int XLogCacheBlck; /* highest allocated xlog buffer index */
501 : :
502 : : /*
503 : : * InsertTimeLineID is the timeline into which new WAL is being inserted
504 : : * and flushed. It is zero during recovery, and does not change once set.
505 : : *
506 : : * If we create a new timeline when the system was started up,
507 : : * PrevTimeLineID is the old timeline's ID that we forked off from.
508 : : * Otherwise it's equal to InsertTimeLineID.
509 : : *
510 : : * We set these fields while holding info_lck. Most that reads these
511 : : * values knows that recovery is no longer in progress and so can safely
512 : : * read the value without a lock, but code that could be run either during
513 : : * or after recovery can take info_lck while reading these values.
514 : : */
515 : : TimeLineID InsertTimeLineID;
516 : : TimeLineID PrevTimeLineID;
517 : :
518 : : /*
519 : : * SharedRecoveryState indicates if we're still in crash or archive
520 : : * recovery. Protected by info_lck.
521 : : */
522 : : RecoveryState SharedRecoveryState;
523 : :
524 : : /*
525 : : * InstallXLogFileSegmentActive indicates whether the checkpointer should
526 : : * arrange for future segments by recycling and/or PreallocXlogFiles().
527 : : * Protected by ControlFileLock. Only the startup process changes it. If
528 : : * true, anyone can use InstallXLogFileSegment(). If false, the startup
529 : : * process owns the exclusive right to install segments, by reading from
530 : : * the archive and possibly replacing existing files.
531 : : */
532 : : bool InstallXLogFileSegmentActive;
533 : :
534 : : /*
535 : : * WalWriterSleeping indicates whether the WAL writer is currently in
536 : : * low-power mode (and hence should be nudged if an async commit occurs).
537 : : * Protected by info_lck.
538 : : */
539 : : bool WalWriterSleeping;
540 : :
541 : : /*
542 : : * During recovery, we keep a copy of the latest checkpoint record here.
543 : : * lastCheckPointRecPtr points to start of checkpoint record and
544 : : * lastCheckPointEndPtr points to end+1 of checkpoint record. Used by the
545 : : * checkpointer when it wants to create a restartpoint.
546 : : *
547 : : * Protected by info_lck.
548 : : */
549 : : XLogRecPtr lastCheckPointRecPtr;
550 : : XLogRecPtr lastCheckPointEndPtr;
551 : : CheckPoint lastCheckPoint;
552 : :
553 : : /*
554 : : * lastFpwDisableRecPtr points to the start of the last replayed
555 : : * XLOG_FPW_CHANGE record that instructs full_page_writes is disabled.
556 : : */
557 : : XLogRecPtr lastFpwDisableRecPtr;
558 : :
559 : : /* last data_checksum_version we've seen */
560 : : uint32 data_checksum_version;
561 : :
562 : : slock_t info_lck; /* locks shared variables shown above */
563 : : } XLogCtlData;
564 : :
565 : : /*
566 : : * Classification of XLogInsertRecord operations.
567 : : */
568 : : typedef enum
569 : : {
570 : : WALINSERT_NORMAL,
571 : : WALINSERT_SPECIAL_SWITCH,
572 : : WALINSERT_SPECIAL_CHECKPOINT
573 : : } WalInsertClass;
574 : :
575 : : static XLogCtlData *XLogCtl = NULL;
576 : :
577 : : /* a private copy of XLogCtl->Insert.WALInsertLocks, for convenience */
578 : : static WALInsertLockPadded *WALInsertLocks = NULL;
579 : :
580 : : /*
581 : : * We maintain an image of pg_control in shared memory.
582 : : */
583 : : static ControlFileData *LocalControlFile = NULL;
584 : : static ControlFileData *ControlFile = NULL;
585 : :
586 : : static void XLOGShmemRequest(void *arg);
587 : : static void XLOGShmemInit(void *arg);
588 : : static void XLOGShmemAttach(void *arg);
589 : :
590 : : const ShmemCallbacks XLOGShmemCallbacks = {
591 : : .request_fn = XLOGShmemRequest,
592 : : .init_fn = XLOGShmemInit,
593 : : .attach_fn = XLOGShmemAttach,
594 : : };
595 : :
596 : : /*
597 : : * Calculate the amount of space left on the page after 'endptr'. Beware
598 : : * multiple evaluation!
599 : : */
600 : : #define INSERT_FREESPACE(endptr) \
601 : : (((endptr) % XLOG_BLCKSZ == 0) ? 0 : (XLOG_BLCKSZ - (endptr) % XLOG_BLCKSZ))
602 : :
603 : : /* Macro to advance to next buffer index. */
604 : : #define NextBufIdx(idx) \
605 : : (((idx) == XLogCtl->XLogCacheBlck) ? 0 : ((idx) + 1))
606 : :
607 : : /*
608 : : * XLogRecPtrToBufIdx returns the index of the WAL buffer that holds, or
609 : : * would hold if it was in cache, the page containing 'recptr'.
610 : : */
611 : : #define XLogRecPtrToBufIdx(recptr) \
612 : : (((recptr) / XLOG_BLCKSZ) % (XLogCtl->XLogCacheBlck + 1))
613 : :
614 : : /*
615 : : * These are the number of bytes in a WAL page usable for WAL data.
616 : : */
617 : : #define UsableBytesInPage (XLOG_BLCKSZ - SizeOfXLogShortPHD)
618 : :
619 : : /*
620 : : * Convert values of GUCs measured in megabytes to equiv. segment count.
621 : : * Rounds down.
622 : : */
623 : : #define ConvertToXSegs(x, segsize) XLogMBVarToSegs((x), (segsize))
624 : :
625 : : /* The number of bytes in a WAL segment usable for WAL data. */
626 : : static int UsableBytesInSegment;
627 : :
628 : : /*
629 : : * Private, possibly out-of-date copy of shared LogwrtResult.
630 : : * See discussion above.
631 : : */
632 : : static XLogwrtResult LogwrtResult = {0, 0};
633 : :
634 : : /*
635 : : * Update local copy of shared XLogCtl->log{Write,Flush}Result
636 : : *
637 : : * It's critical that Flush always trails Write, so the order of the reads is
638 : : * important, as is the barrier. See also XLogWrite.
639 : : */
640 : : #define RefreshXLogWriteResult(_target) \
641 : : do { \
642 : : _target.Flush = pg_atomic_read_u64(&XLogCtl->logFlushResult); \
643 : : pg_read_barrier(); \
644 : : _target.Write = pg_atomic_read_u64(&XLogCtl->logWriteResult); \
645 : : } while (0)
646 : :
647 : : /*
648 : : * openLogFile is -1 or a kernel FD for an open log file segment.
649 : : * openLogSegNo identifies the segment, and openLogTLI the corresponding TLI.
650 : : * These variables are only used to write the XLOG, and so will normally refer
651 : : * to the active segment.
652 : : *
653 : : * Note: call Reserve/ReleaseExternalFD to track consumption of this FD.
654 : : */
655 : : static int openLogFile = -1;
656 : : static XLogSegNo openLogSegNo = 0;
657 : : static TimeLineID openLogTLI = 0;
658 : :
659 : : /*
660 : : * Local copies of equivalent fields in the control file. When running
661 : : * crash recovery, LocalMinRecoveryPoint is set to InvalidXLogRecPtr as we
662 : : * expect to replay all the WAL available, and updateMinRecoveryPoint is
663 : : * switched to false to prevent any updates while replaying records.
664 : : * Those values are kept consistent as long as crash recovery runs.
665 : : */
666 : : static XLogRecPtr LocalMinRecoveryPoint;
667 : : static TimeLineID LocalMinRecoveryPointTLI;
668 : : static bool updateMinRecoveryPoint = true;
669 : :
670 : : /*
671 : : * Local state for ControlFile data_checksum_version. After initialization
672 : : * this is only updated when absorbing a procsignal barrier during interrupt
673 : : * processing. The reason for keeping a copy in backend-private memory is to
674 : : * avoid locking for interrogating the data checksum state. Possible values
675 : : * are the data checksum versions defined in storage/checksum.h.
676 : : */
677 : : static ChecksumStateType LocalDataChecksumState = 0;
678 : :
679 : : /*
680 : : * Variable backing the GUC, keep it in sync with LocalDataChecksumState.
681 : : * See SetLocalDataChecksumState().
682 : : */
683 : : int data_checksums = 0;
684 : :
685 : : /* For WALInsertLockAcquire/Release functions */
686 : : static int MyLockNo = 0;
687 : : static bool holdingAllLocks = false;
688 : :
689 : : #ifdef WAL_DEBUG
690 : : static MemoryContext walDebugCxt = NULL;
691 : : #endif
692 : :
693 : : static void CleanupAfterArchiveRecovery(TimeLineID EndOfLogTLI,
694 : : XLogRecPtr EndOfLog,
695 : : TimeLineID newTLI);
696 : : static void CheckRequiredParameterValues(void);
697 : : static void XLogReportParameters(void);
698 : : static int LocalSetXLogInsertAllowed(void);
699 : : static void CreateEndOfRecoveryRecord(void);
700 : : static XLogRecPtr CreateOverwriteContrecordRecord(XLogRecPtr aborted_lsn,
701 : : XLogRecPtr pagePtr,
702 : : TimeLineID newTLI);
703 : : static void CheckPointGuts(XLogRecPtr checkPointRedo, int flags);
704 : : static void KeepLogSeg(XLogRecPtr recptr, XLogSegNo *logSegNo);
705 : :
706 : : static void AdvanceXLInsertBuffer(XLogRecPtr upto, TimeLineID tli,
707 : : bool opportunistic);
708 : : static void XLogWrite(XLogwrtRqst WriteRqst, TimeLineID tli, bool flexible);
709 : : static bool InstallXLogFileSegment(XLogSegNo *segno, char *tmppath,
710 : : bool find_free, XLogSegNo max_segno,
711 : : TimeLineID tli);
712 : : static void XLogFileClose(void);
713 : : static void PreallocXlogFiles(XLogRecPtr endptr, TimeLineID tli);
714 : : static void RemoveTempXlogFiles(void);
715 : : static void RemoveOldXlogFiles(XLogSegNo segno, XLogRecPtr lastredoptr,
716 : : XLogRecPtr endptr, TimeLineID insertTLI);
717 : : static void RemoveXlogFile(const struct dirent *segment_de,
718 : : XLogSegNo recycleSegNo, XLogSegNo *endlogSegNo,
719 : : TimeLineID insertTLI);
720 : : static void UpdateLastRemovedPtr(char *filename);
721 : : static void ValidateXLOGDirectoryStructure(void);
722 : : static void CleanupBackupHistory(void);
723 : : static void UpdateMinRecoveryPoint(XLogRecPtr lsn, bool force);
724 : : static bool PerformRecoveryXLogAction(void);
725 : : static void InitControlFile(uint64 sysidentifier, uint32 data_checksum_version);
726 : : static void WriteControlFile(void);
727 : : static void ReadControlFile(void);
728 : : static void UpdateControlFile(void);
729 : : static char *str_time(pg_time_t tnow, char *buf, size_t bufsize);
730 : :
731 : : static int get_sync_bit(int method);
732 : :
733 : : static void CopyXLogRecordToWAL(int write_len, bool isLogSwitch,
734 : : XLogRecData *rdata,
735 : : XLogRecPtr StartPos, XLogRecPtr EndPos,
736 : : TimeLineID tli);
737 : : static void ReserveXLogInsertLocation(int size, XLogRecPtr *StartPos,
738 : : XLogRecPtr *EndPos, XLogRecPtr *PrevPtr);
739 : : static bool ReserveXLogSwitch(XLogRecPtr *StartPos, XLogRecPtr *EndPos,
740 : : XLogRecPtr *PrevPtr);
741 : : static XLogRecPtr WaitXLogInsertionsToFinish(XLogRecPtr upto);
742 : : static char *GetXLogBuffer(XLogRecPtr ptr, TimeLineID tli);
743 : : static XLogRecPtr XLogBytePosToRecPtr(uint64 bytepos);
744 : : static XLogRecPtr XLogBytePosToEndRecPtr(uint64 bytepos);
745 : : static uint64 XLogRecPtrToBytePos(XLogRecPtr ptr);
746 : :
747 : : static void WALInsertLockAcquire(void);
748 : : static void WALInsertLockAcquireExclusive(void);
749 : : static void WALInsertLockRelease(void);
750 : : static void WALInsertLockUpdateInsertingAt(XLogRecPtr insertingAt);
751 : :
752 : : static void XLogChecksums(uint32 new_type);
753 : :
754 : : /*
755 : : * Insert an XLOG record represented by an already-constructed chain of data
756 : : * chunks. This is a low-level routine; to construct the WAL record header
757 : : * and data, use the higher-level routines in xloginsert.c.
758 : : *
759 : : * If 'fpw_lsn' is valid, it is the oldest LSN among the pages that this
760 : : * WAL record applies to, that were not included in the record as full page
761 : : * images. If fpw_lsn <= RedoRecPtr, the function does not perform the
762 : : * insertion and returns InvalidXLogRecPtr. The caller can then recalculate
763 : : * which pages need a full-page image, and retry. If fpw_lsn is invalid, the
764 : : * record is always inserted.
765 : : *
766 : : * 'flags' gives more in-depth control on the record being inserted. See
767 : : * XLogSetRecordFlags() for details.
768 : : *
769 : : * 'topxid_included' tells whether the top-transaction id is logged along with
770 : : * current subtransaction. See XLogRecordAssemble().
771 : : *
772 : : * The first XLogRecData in the chain must be for the record header, and its
773 : : * data must be MAXALIGNed. XLogInsertRecord fills in the xl_prev and
774 : : * xl_crc fields in the header, the rest of the header must already be filled
775 : : * by the caller.
776 : : *
777 : : * Returns XLOG pointer to end of record (beginning of next record).
778 : : * This can be used as LSN for data pages affected by the logged action.
779 : : * (LSN is the XLOG point up to which the XLOG must be flushed to disk
780 : : * before the data page can be written out. This implements the basic
781 : : * WAL rule "write the log before the data".)
782 : : */
783 : : XLogRecPtr
784 : 24793029 : XLogInsertRecord(XLogRecData *rdata,
785 : : XLogRecPtr fpw_lsn,
786 : : uint8 flags,
787 : : int num_fpi,
788 : : uint64 fpi_bytes,
789 : : bool topxid_included)
790 : : {
791 : 24793029 : XLogCtlInsert *Insert = &XLogCtl->Insert;
792 : : pg_crc32c rdata_crc;
793 : : bool inserted;
794 : 24793029 : XLogRecord *rechdr = (XLogRecord *) rdata->data;
795 : 24793029 : uint8 info = rechdr->xl_info & ~XLR_INFO_MASK;
796 : 24793029 : WalInsertClass class = WALINSERT_NORMAL;
797 : : XLogRecPtr StartPos;
798 : : XLogRecPtr EndPos;
799 : 24793029 : bool prevDoPageWrites = doPageWrites;
800 : : TimeLineID insertTLI;
801 : :
802 : : /* Does this record type require special handling? */
803 [ + + ]: 24793029 : if (unlikely(rechdr->xl_rmid == RM_XLOG_ID))
804 : : {
805 [ + + ]: 323369 : if (info == XLOG_SWITCH)
806 : 818 : class = WALINSERT_SPECIAL_SWITCH;
807 [ + + ]: 322551 : else if (info == XLOG_CHECKPOINT_REDO)
808 : 999 : class = WALINSERT_SPECIAL_CHECKPOINT;
809 : : }
810 : :
811 : : /* we assume that all of the record header is in the first chunk */
812 : : Assert(rdata->len >= SizeOfXLogRecord);
813 : :
814 : : /* cross-check on whether we should be here or not */
815 [ - + ]: 24793029 : if (!XLogInsertAllowed())
816 [ # # ]: 0 : elog(ERROR, "cannot make new WAL entries during recovery");
817 : :
818 : : /*
819 : : * Given that we're not in recovery, InsertTimeLineID is set and can't
820 : : * change, so we can read it without a lock.
821 : : */
822 : 24793029 : insertTLI = XLogCtl->InsertTimeLineID;
823 : :
824 : : /*----------
825 : : *
826 : : * We have now done all the preparatory work we can without holding a
827 : : * lock or modifying shared state. From here on, inserting the new WAL
828 : : * record to the shared WAL buffer cache is a two-step process:
829 : : *
830 : : * 1. Reserve the right amount of space from the WAL. The current head of
831 : : * reserved space is kept in Insert->CurrBytePos, and is protected by
832 : : * insertpos_lck.
833 : : *
834 : : * 2. Copy the record to the reserved WAL space. This involves finding the
835 : : * correct WAL buffer containing the reserved space, and copying the
836 : : * record in place. This can be done concurrently in multiple processes.
837 : : *
838 : : * To keep track of which insertions are still in-progress, each concurrent
839 : : * inserter acquires an insertion lock. In addition to just indicating that
840 : : * an insertion is in progress, the lock tells others how far the inserter
841 : : * has progressed. There is a small fixed number of insertion locks,
842 : : * determined by NUM_XLOGINSERT_LOCKS. When an inserter crosses a page
843 : : * boundary, it updates the value stored in the lock to the how far it has
844 : : * inserted, to allow the previous buffer to be flushed.
845 : : *
846 : : * Holding onto an insertion lock also protects RedoRecPtr and
847 : : * fullPageWrites from changing until the insertion is finished.
848 : : *
849 : : * Step 2 can usually be done completely in parallel. If the required WAL
850 : : * page is not initialized yet, you have to grab WALBufMappingLock to
851 : : * initialize it, but the WAL writer tries to do that ahead of insertions
852 : : * to avoid that from happening in the critical path.
853 : : *
854 : : *----------
855 : : */
856 : 24793029 : START_CRIT_SECTION();
857 : :
858 [ + + ]: 24793029 : if (likely(class == WALINSERT_NORMAL))
859 : : {
860 : 24791212 : WALInsertLockAcquire();
861 : :
862 : : /*
863 : : * Check to see if my copy of RedoRecPtr is out of date. If so, may
864 : : * have to go back and have the caller recompute everything. This can
865 : : * only happen just after a checkpoint, so it's better to be slow in
866 : : * this case and fast otherwise.
867 : : *
868 : : * Also check to see if fullPageWrites was just turned on or there's a
869 : : * running backup (which forces full-page writes); if we weren't
870 : : * already doing full-page writes then go back and recompute.
871 : : *
872 : : * If we aren't doing full-page writes then RedoRecPtr doesn't
873 : : * actually affect the contents of the XLOG record, so we'll update
874 : : * our local copy but not force a recomputation. (If doPageWrites was
875 : : * just turned off, we could recompute the record without full pages,
876 : : * but we choose not to bother.)
877 : : */
878 [ + + ]: 24791212 : if (RedoRecPtr != Insert->RedoRecPtr)
879 : : {
880 : : Assert(RedoRecPtr < Insert->RedoRecPtr);
881 : 8128 : RedoRecPtr = Insert->RedoRecPtr;
882 : : }
883 [ + + + + ]: 24791212 : doPageWrites = (Insert->fullPageWrites || Insert->runningBackups > 0);
884 : :
885 [ + + ]: 24791212 : if (doPageWrites &&
886 [ + + + + ]: 22478695 : (!prevDoPageWrites ||
887 [ + + ]: 21030052 : (XLogRecPtrIsValid(fpw_lsn) && fpw_lsn <= RedoRecPtr)))
888 : : {
889 : : /*
890 : : * Oops, some buffer now needs to be backed up that the caller
891 : : * didn't back up. Start over.
892 : : */
893 : 8800 : WALInsertLockRelease();
894 : 8800 : END_CRIT_SECTION();
895 : 8800 : return InvalidXLogRecPtr;
896 : : }
897 : :
898 : : /*
899 : : * Reserve space for the record in the WAL. This also sets the xl_prev
900 : : * pointer.
901 : : */
902 : 24782412 : ReserveXLogInsertLocation(rechdr->xl_tot_len, &StartPos, &EndPos,
903 : : &rechdr->xl_prev);
904 : :
905 : : /* Normal records are always inserted. */
906 : 24782412 : inserted = true;
907 : : }
908 [ + + ]: 1817 : else if (class == WALINSERT_SPECIAL_SWITCH)
909 : : {
910 : : /*
911 : : * In order to insert an XLOG_SWITCH record, we need to hold all of
912 : : * the WAL insertion locks, not just one, so that no one else can
913 : : * begin inserting a record until we've figured out how much space
914 : : * remains in the current WAL segment and claimed all of it.
915 : : *
916 : : * Nonetheless, this case is simpler than the normal cases handled
917 : : * below, which must check for changes in doPageWrites and RedoRecPtr.
918 : : * Those checks are only needed for records that can contain buffer
919 : : * references, and an XLOG_SWITCH record never does.
920 : : */
921 : : Assert(!XLogRecPtrIsValid(fpw_lsn));
922 : 818 : WALInsertLockAcquireExclusive();
923 : 818 : inserted = ReserveXLogSwitch(&StartPos, &EndPos, &rechdr->xl_prev);
924 : : }
925 : : else
926 : : {
927 : : Assert(class == WALINSERT_SPECIAL_CHECKPOINT);
928 : :
929 : : /*
930 : : * We need to update both the local and shared copies of RedoRecPtr,
931 : : * which means that we need to hold all the WAL insertion locks.
932 : : * However, there can't be any buffer references, so as above, we need
933 : : * not check RedoRecPtr before inserting the record; we just need to
934 : : * update it afterwards.
935 : : */
936 : : Assert(!XLogRecPtrIsValid(fpw_lsn));
937 : 999 : WALInsertLockAcquireExclusive();
938 : 999 : ReserveXLogInsertLocation(rechdr->xl_tot_len, &StartPos, &EndPos,
939 : : &rechdr->xl_prev);
940 : 999 : RedoRecPtr = Insert->RedoRecPtr = StartPos;
941 : 999 : inserted = true;
942 : : }
943 : :
944 [ + + ]: 24784229 : if (inserted)
945 : : {
946 : : /*
947 : : * Now that xl_prev has been filled in, calculate CRC of the record
948 : : * header.
949 : : */
950 : 24784170 : rdata_crc = rechdr->xl_crc;
951 : 24784170 : COMP_CRC32C(rdata_crc, rechdr, offsetof(XLogRecord, xl_crc));
952 : 24784170 : FIN_CRC32C(rdata_crc);
953 : 24784170 : rechdr->xl_crc = rdata_crc;
954 : :
955 : : /*
956 : : * All the record data, including the header, is now ready to be
957 : : * inserted. Copy the record in the space reserved.
958 : : */
959 : 24784170 : CopyXLogRecordToWAL(rechdr->xl_tot_len,
960 : : class == WALINSERT_SPECIAL_SWITCH, rdata,
961 : : StartPos, EndPos, insertTLI);
962 : :
963 : : /*
964 : : * Unless record is flagged as not important, update LSN of last
965 : : * important record in the current slot. When holding all locks, just
966 : : * update the first one.
967 : : */
968 [ + + ]: 24784170 : if ((flags & XLOG_MARK_UNIMPORTANT) == 0)
969 : : {
970 [ + + ]: 24623637 : int lockno = holdingAllLocks ? 0 : MyLockNo;
971 : :
972 : 24623637 : WALInsertLocks[lockno].l.lastImportantAt = StartPos;
973 : : }
974 : : }
975 : : else
976 : : {
977 : : /*
978 : : * This was an xlog-switch record, but the current insert location was
979 : : * already exactly at the beginning of a segment, so there was no need
980 : : * to do anything.
981 : : */
982 : : }
983 : :
984 : : /*
985 : : * Done! Let others know that we're finished.
986 : : */
987 : 24784229 : WALInsertLockRelease();
988 : :
989 : 24784229 : END_CRIT_SECTION();
990 : :
991 : 24784229 : MarkCurrentTransactionIdLoggedIfAny();
992 : :
993 : : /*
994 : : * Mark top transaction id is logged (if needed) so that we should not try
995 : : * to log it again with the next WAL record in the current subtransaction.
996 : : */
997 [ + + ]: 24784229 : if (topxid_included)
998 : 223 : MarkSubxactTopXidLogged();
999 : :
1000 : : /*
1001 : : * Update shared LogwrtRqst.Write, if we crossed page boundary.
1002 : : */
1003 [ + + ]: 24784229 : if (StartPos / XLOG_BLCKSZ != EndPos / XLOG_BLCKSZ)
1004 : : {
1005 : 1897757 : SpinLockAcquire(&XLogCtl->info_lck);
1006 : : /* advance global request to include new block(s) */
1007 [ + + ]: 1897757 : if (XLogCtl->LogwrtRqst.Write < EndPos)
1008 : 1827779 : XLogCtl->LogwrtRqst.Write = EndPos;
1009 : 1897757 : SpinLockRelease(&XLogCtl->info_lck);
1010 : 1897757 : RefreshXLogWriteResult(LogwrtResult);
1011 : : }
1012 : :
1013 : : /*
1014 : : * If this was an XLOG_SWITCH record, flush the record and the empty
1015 : : * padding space that fills the rest of the segment, and perform
1016 : : * end-of-segment actions (eg, notifying archiver).
1017 : : */
1018 [ + + ]: 24784229 : if (class == WALINSERT_SPECIAL_SWITCH)
1019 : : {
1020 : : TRACE_POSTGRESQL_WAL_SWITCH();
1021 : 818 : XLogFlush(EndPos);
1022 : :
1023 : : /*
1024 : : * Even though we reserved the rest of the segment for us, which is
1025 : : * reflected in EndPos, we return a pointer to just the end of the
1026 : : * xlog-switch record.
1027 : : */
1028 [ + + ]: 818 : if (inserted)
1029 : : {
1030 : 759 : EndPos = StartPos + SizeOfXLogRecord;
1031 [ + + ]: 759 : if (StartPos / XLOG_BLCKSZ != EndPos / XLOG_BLCKSZ)
1032 : : {
1033 : 2 : uint64 offset = XLogSegmentOffset(EndPos, wal_segment_size);
1034 : :
1035 [ - + ]: 2 : if (offset == EndPos % XLOG_BLCKSZ)
1036 : 0 : EndPos += SizeOfXLogLongPHD;
1037 : : else
1038 : 2 : EndPos += SizeOfXLogShortPHD;
1039 : : }
1040 : : }
1041 : : }
1042 : :
1043 : : #ifdef WAL_DEBUG
1044 : : if (XLOG_DEBUG)
1045 : : {
1046 : : static XLogReaderState *debug_reader = NULL;
1047 : : XLogRecord *record;
1048 : : DecodedXLogRecord *decoded;
1049 : : StringInfoData buf;
1050 : : StringInfoData recordBuf;
1051 : : char *errormsg = NULL;
1052 : : MemoryContext oldCxt;
1053 : :
1054 : : oldCxt = MemoryContextSwitchTo(walDebugCxt);
1055 : :
1056 : : initStringInfo(&buf);
1057 : : appendStringInfo(&buf, "INSERT @ %X/%08X: ", LSN_FORMAT_ARGS(EndPos));
1058 : :
1059 : : /*
1060 : : * We have to piece together the WAL record data from the XLogRecData
1061 : : * entries, so that we can pass it to the rm_desc function as one
1062 : : * contiguous chunk.
1063 : : */
1064 : : initStringInfo(&recordBuf);
1065 : : for (; rdata != NULL; rdata = rdata->next)
1066 : : appendBinaryStringInfo(&recordBuf, rdata->data, rdata->len);
1067 : :
1068 : : /* We also need temporary space to decode the record. */
1069 : : record = (XLogRecord *) recordBuf.data;
1070 : : decoded = (DecodedXLogRecord *)
1071 : : palloc(DecodeXLogRecordRequiredSpace(record->xl_tot_len));
1072 : :
1073 : : if (!debug_reader)
1074 : : debug_reader = XLogReaderAllocate(wal_segment_size, NULL,
1075 : : XL_ROUTINE(.page_read = NULL,
1076 : : .segment_open = NULL,
1077 : : .segment_close = NULL),
1078 : : NULL);
1079 : : if (!debug_reader)
1080 : : {
1081 : : appendStringInfoString(&buf, "error decoding record: out of memory while allocating a WAL reading processor");
1082 : : }
1083 : : else if (!DecodeXLogRecord(debug_reader,
1084 : : decoded,
1085 : : record,
1086 : : EndPos,
1087 : : &errormsg))
1088 : : {
1089 : : appendStringInfo(&buf, "error decoding record: %s",
1090 : : errormsg ? errormsg : "no error message");
1091 : : }
1092 : : else
1093 : : {
1094 : : appendStringInfoString(&buf, " - ");
1095 : :
1096 : : debug_reader->record = decoded;
1097 : : xlog_outdesc(&buf, debug_reader);
1098 : : debug_reader->record = NULL;
1099 : : }
1100 : : elog(LOG, "%s", buf.data);
1101 : :
1102 : : pfree(decoded);
1103 : : pfree(buf.data);
1104 : : pfree(recordBuf.data);
1105 : : MemoryContextSwitchTo(oldCxt);
1106 : : }
1107 : : #endif
1108 : :
1109 : : /*
1110 : : * Update our global variables
1111 : : */
1112 : 24784229 : ProcLastRecPtr = StartPos;
1113 : 24784229 : XactLastRecEnd = EndPos;
1114 : :
1115 : : /* Report WAL traffic to the instrumentation. */
1116 [ + + ]: 24784229 : if (inserted)
1117 : : {
1118 : 24784170 : pgWalUsage.wal_bytes += rechdr->xl_tot_len;
1119 : 24784170 : pgWalUsage.wal_records++;
1120 : 24784170 : pgWalUsage.wal_fpi += num_fpi;
1121 : 24784170 : pgWalUsage.wal_fpi_bytes += fpi_bytes;
1122 : :
1123 : : /* Required for the flush of pending stats WAL data */
1124 : 24784170 : pgstat_report_fixed = true;
1125 : : }
1126 : :
1127 : 24784229 : return EndPos;
1128 : : }
1129 : :
1130 : : /*
1131 : : * Reserves the right amount of space for a record of given size from the WAL.
1132 : : * *StartPos is set to the beginning of the reserved section, *EndPos to
1133 : : * its end+1. *PrevPtr is set to the beginning of the previous record; it is
1134 : : * used to set the xl_prev of this record.
1135 : : *
1136 : : * This is the performance critical part of XLogInsert that must be serialized
1137 : : * across backends. The rest can happen mostly in parallel. Try to keep this
1138 : : * section as short as possible, insertpos_lck can be heavily contended on a
1139 : : * busy system.
1140 : : *
1141 : : * NB: The space calculation here must match the code in CopyXLogRecordToWAL,
1142 : : * where we actually copy the record to the reserved space.
1143 : : *
1144 : : * NB: Testing shows that XLogInsertRecord runs faster if this code is inlined;
1145 : : * however, because there are two call sites, the compiler is reluctant to
1146 : : * inline. We use pg_attribute_always_inline here to try to convince it.
1147 : : */
1148 : : static pg_attribute_always_inline void
1149 : 24783411 : ReserveXLogInsertLocation(int size, XLogRecPtr *StartPos, XLogRecPtr *EndPos,
1150 : : XLogRecPtr *PrevPtr)
1151 : : {
1152 : 24783411 : XLogCtlInsert *Insert = &XLogCtl->Insert;
1153 : : uint64 startbytepos;
1154 : : uint64 endbytepos;
1155 : : uint64 prevbytepos;
1156 : :
1157 : 24783411 : size = MAXALIGN(size);
1158 : :
1159 : : /* All (non xlog-switch) records should contain data. */
1160 : : Assert(size > SizeOfXLogRecord);
1161 : :
1162 : : /*
1163 : : * The duration the spinlock needs to be held is minimized by minimizing
1164 : : * the calculations that have to be done while holding the lock. The
1165 : : * current tip of reserved WAL is kept in CurrBytePos, as a byte position
1166 : : * that only counts "usable" bytes in WAL, that is, it excludes all WAL
1167 : : * page headers. The mapping between "usable" byte positions and physical
1168 : : * positions (XLogRecPtrs) can be done outside the locked region, and
1169 : : * because the usable byte position doesn't include any headers, reserving
1170 : : * X bytes from WAL is almost as simple as "CurrBytePos += X".
1171 : : */
1172 : 24783411 : SpinLockAcquire(&Insert->insertpos_lck);
1173 : :
1174 : 24783411 : startbytepos = Insert->CurrBytePos;
1175 : 24783411 : endbytepos = startbytepos + size;
1176 : 24783411 : prevbytepos = Insert->PrevBytePos;
1177 : 24783411 : Insert->CurrBytePos = endbytepos;
1178 : 24783411 : Insert->PrevBytePos = startbytepos;
1179 : :
1180 : 24783411 : SpinLockRelease(&Insert->insertpos_lck);
1181 : :
1182 : 24783411 : *StartPos = XLogBytePosToRecPtr(startbytepos);
1183 : 24783411 : *EndPos = XLogBytePosToEndRecPtr(endbytepos);
1184 : 24783411 : *PrevPtr = XLogBytePosToRecPtr(prevbytepos);
1185 : :
1186 : : /*
1187 : : * Check that the conversions between "usable byte positions" and
1188 : : * XLogRecPtrs work consistently in both directions.
1189 : : */
1190 : : Assert(XLogRecPtrToBytePos(*StartPos) == startbytepos);
1191 : : Assert(XLogRecPtrToBytePos(*EndPos) == endbytepos);
1192 : : Assert(XLogRecPtrToBytePos(*PrevPtr) == prevbytepos);
1193 : 24783411 : }
1194 : :
1195 : : /*
1196 : : * Like ReserveXLogInsertLocation(), but for an xlog-switch record.
1197 : : *
1198 : : * A log-switch record is handled slightly differently. The rest of the
1199 : : * segment will be reserved for this insertion, as indicated by the returned
1200 : : * *EndPos value. However, if we are already at the beginning of the current
1201 : : * segment, *StartPos and *EndPos are set to the current location without
1202 : : * reserving any space, and the function returns false.
1203 : : */
1204 : : static bool
1205 : 818 : ReserveXLogSwitch(XLogRecPtr *StartPos, XLogRecPtr *EndPos, XLogRecPtr *PrevPtr)
1206 : : {
1207 : 818 : XLogCtlInsert *Insert = &XLogCtl->Insert;
1208 : : uint64 startbytepos;
1209 : : uint64 endbytepos;
1210 : : uint64 prevbytepos;
1211 : 818 : uint32 size = MAXALIGN(SizeOfXLogRecord);
1212 : : XLogRecPtr ptr;
1213 : : uint32 segleft;
1214 : :
1215 : : /*
1216 : : * These calculations are a bit heavy-weight to be done while holding a
1217 : : * spinlock, but since we're holding all the WAL insertion locks, there
1218 : : * are no other inserters competing for it. GetXLogInsertRecPtr() does
1219 : : * compete for it, but that's not called very frequently.
1220 : : */
1221 : 818 : SpinLockAcquire(&Insert->insertpos_lck);
1222 : :
1223 : 818 : startbytepos = Insert->CurrBytePos;
1224 : :
1225 : 818 : ptr = XLogBytePosToEndRecPtr(startbytepos);
1226 [ + + ]: 818 : if (XLogSegmentOffset(ptr, wal_segment_size) == 0)
1227 : : {
1228 : 59 : SpinLockRelease(&Insert->insertpos_lck);
1229 : 59 : *EndPos = *StartPos = ptr;
1230 : 59 : return false;
1231 : : }
1232 : :
1233 : 759 : endbytepos = startbytepos + size;
1234 : 759 : prevbytepos = Insert->PrevBytePos;
1235 : :
1236 : 759 : *StartPos = XLogBytePosToRecPtr(startbytepos);
1237 : 759 : *EndPos = XLogBytePosToEndRecPtr(endbytepos);
1238 : :
1239 : 759 : segleft = wal_segment_size - XLogSegmentOffset(*EndPos, wal_segment_size);
1240 [ + - ]: 759 : if (segleft != wal_segment_size)
1241 : : {
1242 : : /* consume the rest of the segment */
1243 : 759 : *EndPos += segleft;
1244 : 759 : endbytepos = XLogRecPtrToBytePos(*EndPos);
1245 : : }
1246 : 759 : Insert->CurrBytePos = endbytepos;
1247 : 759 : Insert->PrevBytePos = startbytepos;
1248 : :
1249 : 759 : SpinLockRelease(&Insert->insertpos_lck);
1250 : :
1251 : 759 : *PrevPtr = XLogBytePosToRecPtr(prevbytepos);
1252 : :
1253 : : Assert(XLogSegmentOffset(*EndPos, wal_segment_size) == 0);
1254 : : Assert(XLogRecPtrToBytePos(*EndPos) == endbytepos);
1255 : : Assert(XLogRecPtrToBytePos(*StartPos) == startbytepos);
1256 : : Assert(XLogRecPtrToBytePos(*PrevPtr) == prevbytepos);
1257 : :
1258 : 759 : return true;
1259 : : }
1260 : :
1261 : : /*
1262 : : * Subroutine of XLogInsertRecord. Copies a WAL record to an already-reserved
1263 : : * area in the WAL.
1264 : : */
1265 : : static void
1266 : 24784170 : CopyXLogRecordToWAL(int write_len, bool isLogSwitch, XLogRecData *rdata,
1267 : : XLogRecPtr StartPos, XLogRecPtr EndPos, TimeLineID tli)
1268 : : {
1269 : : char *currpos;
1270 : : int freespace;
1271 : : int written;
1272 : : XLogRecPtr CurrPos;
1273 : : XLogPageHeader pagehdr;
1274 : :
1275 : : /*
1276 : : * Get a pointer to the right place in the right WAL buffer to start
1277 : : * inserting to.
1278 : : */
1279 : 24784170 : CurrPos = StartPos;
1280 : 24784170 : currpos = GetXLogBuffer(CurrPos, tli);
1281 [ + - ]: 24784170 : freespace = INSERT_FREESPACE(CurrPos);
1282 : :
1283 : : /*
1284 : : * there should be enough space for at least the first field (xl_tot_len)
1285 : : * on this page.
1286 : : */
1287 : : Assert(freespace >= sizeof(uint32));
1288 : :
1289 : : /* Copy record data */
1290 : 24784170 : written = 0;
1291 [ + + ]: 113097609 : while (rdata != NULL)
1292 : : {
1293 : 88313439 : const char *rdata_data = rdata->data;
1294 : 88313439 : int rdata_len = rdata->len;
1295 : :
1296 [ + + ]: 90321487 : while (rdata_len > freespace)
1297 : : {
1298 : : /*
1299 : : * Write what fits on this page, and continue on the next page.
1300 : : */
1301 : : Assert(CurrPos % XLOG_BLCKSZ >= SizeOfXLogShortPHD || freespace == 0);
1302 : 2008048 : memcpy(currpos, rdata_data, freespace);
1303 : 2008048 : rdata_data += freespace;
1304 : 2008048 : rdata_len -= freespace;
1305 : 2008048 : written += freespace;
1306 : 2008048 : CurrPos += freespace;
1307 : :
1308 : : /*
1309 : : * Get pointer to beginning of next page, and set the xlp_rem_len
1310 : : * in the page header. Set XLP_FIRST_IS_CONTRECORD.
1311 : : *
1312 : : * It's safe to set the contrecord flag and xlp_rem_len without a
1313 : : * lock on the page. All the other flags were already set when the
1314 : : * page was initialized, in AdvanceXLInsertBuffer, and we're the
1315 : : * only backend that needs to set the contrecord flag.
1316 : : */
1317 : 2008048 : currpos = GetXLogBuffer(CurrPos, tli);
1318 : 2008048 : pagehdr = (XLogPageHeader) currpos;
1319 : 2008048 : pagehdr->xlp_rem_len = write_len - written;
1320 : 2008048 : pagehdr->xlp_info |= XLP_FIRST_IS_CONTRECORD;
1321 : :
1322 : : /* skip over the page header */
1323 [ + + ]: 2008048 : if (XLogSegmentOffset(CurrPos, wal_segment_size) == 0)
1324 : : {
1325 : 1283 : CurrPos += SizeOfXLogLongPHD;
1326 : 1283 : currpos += SizeOfXLogLongPHD;
1327 : : }
1328 : : else
1329 : : {
1330 : 2006765 : CurrPos += SizeOfXLogShortPHD;
1331 : 2006765 : currpos += SizeOfXLogShortPHD;
1332 : : }
1333 [ + - ]: 2008048 : freespace = INSERT_FREESPACE(CurrPos);
1334 : : }
1335 : :
1336 : : Assert(CurrPos % XLOG_BLCKSZ >= SizeOfXLogShortPHD || rdata_len == 0);
1337 : 88313439 : memcpy(currpos, rdata_data, rdata_len);
1338 : 88313439 : currpos += rdata_len;
1339 : 88313439 : CurrPos += rdata_len;
1340 : 88313439 : freespace -= rdata_len;
1341 : 88313439 : written += rdata_len;
1342 : :
1343 : 88313439 : rdata = rdata->next;
1344 : : }
1345 : : Assert(written == write_len);
1346 : :
1347 : : /*
1348 : : * If this was an xlog-switch, it's not enough to write the switch record,
1349 : : * we also have to consume all the remaining space in the WAL segment. We
1350 : : * have already reserved that space, but we need to actually fill it.
1351 : : */
1352 [ + + + - ]: 24784170 : if (isLogSwitch && XLogSegmentOffset(CurrPos, wal_segment_size) != 0)
1353 : : {
1354 : : /* An xlog-switch record doesn't contain any data besides the header */
1355 : : Assert(write_len == SizeOfXLogRecord);
1356 : :
1357 : : /* Assert that we did reserve the right amount of space */
1358 : : Assert(XLogSegmentOffset(EndPos, wal_segment_size) == 0);
1359 : :
1360 : : /* Use up all the remaining space on the current page */
1361 : 759 : CurrPos += freespace;
1362 : :
1363 : : /*
1364 : : * Cause all remaining pages in the segment to be flushed, leaving the
1365 : : * XLog position where it should be, at the start of the next segment.
1366 : : * We do this one page at a time, to make sure we don't deadlock
1367 : : * against ourselves if wal_buffers < wal_segment_size.
1368 : : */
1369 [ + + ]: 760775 : while (CurrPos < EndPos)
1370 : : {
1371 : : /*
1372 : : * The minimal action to flush the page would be to call
1373 : : * WALInsertLockUpdateInsertingAt(CurrPos) followed by
1374 : : * AdvanceXLInsertBuffer(...). The page would be left initialized
1375 : : * mostly to zeros, except for the page header (always the short
1376 : : * variant, as this is never a segment's first page).
1377 : : *
1378 : : * The large vistas of zeros are good for compressibility, but the
1379 : : * headers interrupting them every XLOG_BLCKSZ (with values that
1380 : : * differ from page to page) are not. The effect varies with
1381 : : * compression tool, but bzip2 for instance compresses about an
1382 : : * order of magnitude worse if those headers are left in place.
1383 : : *
1384 : : * Rather than complicating AdvanceXLInsertBuffer itself (which is
1385 : : * called in heavily-loaded circumstances as well as this lightly-
1386 : : * loaded one) with variant behavior, we just use GetXLogBuffer
1387 : : * (which itself calls the two methods we need) to get the pointer
1388 : : * and zero most of the page. Then we just zero the page header.
1389 : : */
1390 : 760016 : currpos = GetXLogBuffer(CurrPos, tli);
1391 [ + - + - : 3040064 : MemSet(currpos, 0, SizeOfXLogShortPHD);
+ - + - +
+ ]
1392 : :
1393 : 760016 : CurrPos += XLOG_BLCKSZ;
1394 : : }
1395 : : }
1396 : : else
1397 : : {
1398 : : /* Align the end position, so that the next record starts aligned */
1399 : 24783411 : CurrPos = MAXALIGN64(CurrPos);
1400 : : }
1401 : :
1402 [ - + ]: 24784170 : if (CurrPos != EndPos)
1403 [ # # ]: 0 : ereport(PANIC,
1404 : : errcode(ERRCODE_DATA_CORRUPTED),
1405 : : errmsg_internal("space reserved for WAL record does not match what was written"));
1406 : 24784170 : }
1407 : :
1408 : : /*
1409 : : * Acquire a WAL insertion lock, for inserting to WAL.
1410 : : */
1411 : : static void
1412 : 24792222 : WALInsertLockAcquire(void)
1413 : : {
1414 : : bool immed;
1415 : :
1416 : : /*
1417 : : * It doesn't matter which of the WAL insertion locks we acquire, so try
1418 : : * the one we used last time. If the system isn't particularly busy, it's
1419 : : * a good bet that it's still available, and it's good to have some
1420 : : * affinity to a particular lock so that you don't unnecessarily bounce
1421 : : * cache lines between processes when there's no contention.
1422 : : *
1423 : : * If this is the first time through in this backend, pick a lock
1424 : : * (semi-)randomly. This allows the locks to be used evenly if you have a
1425 : : * lot of very short connections.
1426 : : */
1427 : : static int lockToTry = -1;
1428 : :
1429 [ + + ]: 24792222 : if (lockToTry == -1)
1430 : 9283 : lockToTry = MyProcNumber % NUM_XLOGINSERT_LOCKS;
1431 : 24792222 : MyLockNo = lockToTry;
1432 : :
1433 : : /*
1434 : : * The insertingAt value is initially set to 0, as we don't know our
1435 : : * insert location yet.
1436 : : */
1437 : 24792222 : immed = LWLockAcquire(&WALInsertLocks[MyLockNo].l.lock, LW_EXCLUSIVE);
1438 [ + + ]: 24792222 : if (!immed)
1439 : : {
1440 : : /*
1441 : : * If we couldn't get the lock immediately, try another lock next
1442 : : * time. On a system with more insertion locks than concurrent
1443 : : * inserters, this causes all the inserters to eventually migrate to a
1444 : : * lock that no-one else is using. On a system with more inserters
1445 : : * than locks, it still helps to distribute the inserters evenly
1446 : : * across the locks.
1447 : : */
1448 : 16536 : lockToTry = (lockToTry + 1) % NUM_XLOGINSERT_LOCKS;
1449 : : }
1450 : 24792222 : }
1451 : :
1452 : : /*
1453 : : * Acquire all WAL insertion locks, to prevent other backends from inserting
1454 : : * to WAL.
1455 : : */
1456 : : static void
1457 : 4847 : WALInsertLockAcquireExclusive(void)
1458 : : {
1459 : : int i;
1460 : :
1461 : : /*
1462 : : * When holding all the locks, all but the last lock's insertingAt
1463 : : * indicator is set to 0xFFFFFFFFFFFFFFFF, which is higher than any real
1464 : : * XLogRecPtr value, to make sure that no-one blocks waiting on those.
1465 : : */
1466 [ + + ]: 38776 : for (i = 0; i < NUM_XLOGINSERT_LOCKS - 1; i++)
1467 : : {
1468 : 33929 : LWLockAcquire(&WALInsertLocks[i].l.lock, LW_EXCLUSIVE);
1469 : 33929 : LWLockUpdateVar(&WALInsertLocks[i].l.lock,
1470 : 33929 : &WALInsertLocks[i].l.insertingAt,
1471 : : PG_UINT64_MAX);
1472 : : }
1473 : : /* Variable value reset to 0 at release */
1474 : 4847 : LWLockAcquire(&WALInsertLocks[i].l.lock, LW_EXCLUSIVE);
1475 : :
1476 : 4847 : holdingAllLocks = true;
1477 : 4847 : }
1478 : :
1479 : : /*
1480 : : * Release our insertion lock (or locks, if we're holding them all).
1481 : : *
1482 : : * NB: Reset all variables to 0, so they cause LWLockWaitForVar to block the
1483 : : * next time the lock is acquired.
1484 : : */
1485 : : static void
1486 : 24797069 : WALInsertLockRelease(void)
1487 : : {
1488 [ + + ]: 24797069 : if (holdingAllLocks)
1489 : : {
1490 : : int i;
1491 : :
1492 [ + + ]: 43623 : for (i = 0; i < NUM_XLOGINSERT_LOCKS; i++)
1493 : 38776 : LWLockReleaseClearVar(&WALInsertLocks[i].l.lock,
1494 : 38776 : &WALInsertLocks[i].l.insertingAt,
1495 : : 0);
1496 : :
1497 : 4847 : holdingAllLocks = false;
1498 : : }
1499 : : else
1500 : : {
1501 : 24792222 : LWLockReleaseClearVar(&WALInsertLocks[MyLockNo].l.lock,
1502 : 24792222 : &WALInsertLocks[MyLockNo].l.insertingAt,
1503 : : 0);
1504 : : }
1505 : 24797069 : }
1506 : :
1507 : : /*
1508 : : * Update our insertingAt value, to let others know that we've finished
1509 : : * inserting up to that point.
1510 : : */
1511 : : static void
1512 : 2629755 : WALInsertLockUpdateInsertingAt(XLogRecPtr insertingAt)
1513 : : {
1514 [ + + ]: 2629755 : if (holdingAllLocks)
1515 : : {
1516 : : /*
1517 : : * We use the last lock to mark our actual position, see comments in
1518 : : * WALInsertLockAcquireExclusive.
1519 : : */
1520 : 754673 : LWLockUpdateVar(&WALInsertLocks[NUM_XLOGINSERT_LOCKS - 1].l.lock,
1521 : 754673 : &WALInsertLocks[NUM_XLOGINSERT_LOCKS - 1].l.insertingAt,
1522 : : insertingAt);
1523 : : }
1524 : : else
1525 : 1875082 : LWLockUpdateVar(&WALInsertLocks[MyLockNo].l.lock,
1526 : 1875082 : &WALInsertLocks[MyLockNo].l.insertingAt,
1527 : : insertingAt);
1528 : 2629755 : }
1529 : :
1530 : : /*
1531 : : * Wait for any WAL insertions < upto to finish.
1532 : : *
1533 : : * Returns the location of the oldest insertion that is still in-progress.
1534 : : * Any WAL prior to that point has been fully copied into WAL buffers, and
1535 : : * can be flushed out to disk. Because this waits for any insertions older
1536 : : * than 'upto' to finish, the return value is always >= 'upto'.
1537 : : *
1538 : : * Note: When you are about to write out WAL, you must call this function
1539 : : * *before* acquiring WALWriteLock, to avoid deadlocks. This function might
1540 : : * need to wait for an insertion to finish (or at least advance to next
1541 : : * uninitialized page), and the inserter might need to evict an old WAL buffer
1542 : : * to make room for a new one, which in turn requires WALWriteLock.
1543 : : */
1544 : : static XLogRecPtr
1545 : 2500337 : WaitXLogInsertionsToFinish(XLogRecPtr upto)
1546 : : {
1547 : : uint64 bytepos;
1548 : : XLogRecPtr inserted;
1549 : : XLogRecPtr reservedUpto;
1550 : : XLogRecPtr finishedUpto;
1551 : 2500337 : XLogCtlInsert *Insert = &XLogCtl->Insert;
1552 : : int i;
1553 : :
1554 [ - + ]: 2500337 : if (MyProc == NULL)
1555 [ # # ]: 0 : elog(PANIC, "cannot wait without a PGPROC structure");
1556 : :
1557 : : /*
1558 : : * Check if there's any work to do. Use a barrier to ensure we get the
1559 : : * freshest value.
1560 : : */
1561 : 2500337 : inserted = pg_atomic_read_membarrier_u64(&XLogCtl->logInsertResult);
1562 [ + + ]: 2500337 : if (upto <= inserted)
1563 : 1959664 : return inserted;
1564 : :
1565 : : /* Read the current insert position */
1566 : 540673 : SpinLockAcquire(&Insert->insertpos_lck);
1567 : 540673 : bytepos = Insert->CurrBytePos;
1568 : 540673 : SpinLockRelease(&Insert->insertpos_lck);
1569 : 540673 : reservedUpto = XLogBytePosToEndRecPtr(bytepos);
1570 : :
1571 : : /*
1572 : : * No-one should request to flush a piece of WAL that hasn't even been
1573 : : * reserved yet. However, it can happen if there is a block with a bogus
1574 : : * LSN on disk, for example. XLogFlush checks for that situation and
1575 : : * complains, but only after the flush. Here we just assume that to mean
1576 : : * that all WAL that has been reserved needs to be finished. In this
1577 : : * corner-case, the return value can be smaller than 'upto' argument.
1578 : : */
1579 [ - + ]: 540673 : if (upto > reservedUpto)
1580 : : {
1581 [ # # ]: 0 : ereport(LOG,
1582 : : errmsg("request to flush past end of generated WAL; request %X/%08X, current position %X/%08X",
1583 : : LSN_FORMAT_ARGS(upto), LSN_FORMAT_ARGS(reservedUpto)));
1584 : 0 : upto = reservedUpto;
1585 : : }
1586 : :
1587 : : /*
1588 : : * Loop through all the locks, sleeping on any in-progress insert older
1589 : : * than 'upto'.
1590 : : *
1591 : : * finishedUpto is our return value, indicating the point upto which all
1592 : : * the WAL insertions have been finished. Initialize it to the head of
1593 : : * reserved WAL, and as we iterate through the insertion locks, back it
1594 : : * out for any insertion that's still in progress.
1595 : : */
1596 : 540673 : finishedUpto = reservedUpto;
1597 [ + + ]: 4866057 : for (i = 0; i < NUM_XLOGINSERT_LOCKS; i++)
1598 : : {
1599 : 4325384 : XLogRecPtr insertingat = InvalidXLogRecPtr;
1600 : :
1601 : : do
1602 : : {
1603 : : /*
1604 : : * See if this insertion is in progress. LWLockWaitForVar will
1605 : : * wait for the lock to be released, or for the 'value' to be set
1606 : : * by a LWLockUpdateVar call. When a lock is initially acquired,
1607 : : * its value is 0 (InvalidXLogRecPtr), which means that we don't
1608 : : * know where it's inserting yet. We will have to wait for it. If
1609 : : * it's a small insertion, the record will most likely fit on the
1610 : : * same page and the inserter will release the lock without ever
1611 : : * calling LWLockUpdateVar. But if it has to sleep, it will
1612 : : * advertise the insertion point with LWLockUpdateVar before
1613 : : * sleeping.
1614 : : *
1615 : : * In this loop we are only waiting for insertions that started
1616 : : * before WaitXLogInsertionsToFinish was called. The lack of
1617 : : * memory barriers in the loop means that we might see locks as
1618 : : * "unused" that have since become used. This is fine because
1619 : : * they only can be used for later insertions that we would not
1620 : : * want to wait on anyway. Not taking a lock to acquire the
1621 : : * current insertingAt value means that we might see older
1622 : : * insertingAt values. This is also fine, because if we read a
1623 : : * value too old, we will add ourselves to the wait queue, which
1624 : : * contains atomic operations.
1625 : : */
1626 [ + + ]: 4459731 : if (LWLockWaitForVar(&WALInsertLocks[i].l.lock,
1627 : 4459731 : &WALInsertLocks[i].l.insertingAt,
1628 : : insertingat, &insertingat))
1629 : : {
1630 : : /* the lock was free, so no insertion in progress */
1631 : 3036314 : insertingat = InvalidXLogRecPtr;
1632 : 3036314 : break;
1633 : : }
1634 : :
1635 : : /*
1636 : : * This insertion is still in progress. Have to wait, unless the
1637 : : * inserter has proceeded past 'upto'.
1638 : : */
1639 [ + + ]: 1423417 : } while (insertingat < upto);
1640 : :
1641 [ + + + + ]: 4325384 : if (XLogRecPtrIsValid(insertingat) && insertingat < finishedUpto)
1642 : 454408 : finishedUpto = insertingat;
1643 : : }
1644 : :
1645 : : /*
1646 : : * Advance the limit we know to have been inserted and return the freshest
1647 : : * value we know of, which might be beyond what we requested if somebody
1648 : : * is concurrently doing this with an 'upto' pointer ahead of us.
1649 : : */
1650 : 540673 : finishedUpto = pg_atomic_monotonic_advance_u64(&XLogCtl->logInsertResult,
1651 : : finishedUpto);
1652 : :
1653 : 540673 : return finishedUpto;
1654 : : }
1655 : :
1656 : : /*
1657 : : * Get a pointer to the right location in the WAL buffer containing the
1658 : : * given XLogRecPtr.
1659 : : *
1660 : : * If the page is not initialized yet, it is initialized. That might require
1661 : : * evicting an old dirty buffer from the buffer cache, which means I/O.
1662 : : *
1663 : : * The caller must ensure that the page containing the requested location
1664 : : * isn't evicted yet, and won't be evicted. The way to ensure that is to
1665 : : * hold onto a WAL insertion lock with the insertingAt position set to
1666 : : * something <= ptr. GetXLogBuffer() will update insertingAt if it needs
1667 : : * to evict an old page from the buffer. (This means that once you call
1668 : : * GetXLogBuffer() with a given 'ptr', you must not access anything before
1669 : : * that point anymore, and must not call GetXLogBuffer() with an older 'ptr'
1670 : : * later, because older buffers might be recycled already)
1671 : : */
1672 : : static char *
1673 : 27552245 : GetXLogBuffer(XLogRecPtr ptr, TimeLineID tli)
1674 : : {
1675 : : int idx;
1676 : : XLogRecPtr endptr;
1677 : : static uint64 cachedPage = 0;
1678 : : static char *cachedPos = NULL;
1679 : : XLogRecPtr expectedEndPtr;
1680 : :
1681 : : /*
1682 : : * Fast path for the common case that we need to access again the same
1683 : : * page as last time.
1684 : : */
1685 [ + + ]: 27552245 : if (ptr / XLOG_BLCKSZ == cachedPage)
1686 : : {
1687 : : Assert(((XLogPageHeader) cachedPos)->xlp_magic == XLOG_PAGE_MAGIC);
1688 : : Assert(((XLogPageHeader) cachedPos)->xlp_pageaddr == ptr - (ptr % XLOG_BLCKSZ));
1689 : 24443113 : return cachedPos + ptr % XLOG_BLCKSZ;
1690 : : }
1691 : :
1692 : : /*
1693 : : * The XLog buffer cache is organized so that a page is always loaded to a
1694 : : * particular buffer. That way we can easily calculate the buffer a given
1695 : : * page must be loaded into, from the XLogRecPtr alone.
1696 : : */
1697 : 3109132 : idx = XLogRecPtrToBufIdx(ptr);
1698 : :
1699 : : /*
1700 : : * See what page is loaded in the buffer at the moment. It could be the
1701 : : * page we're looking for, or something older. It can't be anything newer
1702 : : * - that would imply the page we're looking for has already been written
1703 : : * out to disk and evicted, and the caller is responsible for making sure
1704 : : * that doesn't happen.
1705 : : *
1706 : : * We don't hold a lock while we read the value. If someone is just about
1707 : : * to initialize or has just initialized the page, it's possible that we
1708 : : * get InvalidXLogRecPtr. That's ok, we'll grab the mapping lock (in
1709 : : * AdvanceXLInsertBuffer) and retry if we see anything other than the page
1710 : : * we're looking for.
1711 : : */
1712 : 3109132 : expectedEndPtr = ptr;
1713 : 3109132 : expectedEndPtr += XLOG_BLCKSZ - ptr % XLOG_BLCKSZ;
1714 : :
1715 : 3109132 : endptr = pg_atomic_read_u64(&XLogCtl->xlblocks[idx]);
1716 [ + + ]: 3109132 : if (expectedEndPtr != endptr)
1717 : : {
1718 : : XLogRecPtr initializedUpto;
1719 : :
1720 : : /*
1721 : : * Before calling AdvanceXLInsertBuffer(), which can block, let others
1722 : : * know how far we're finished with inserting the record.
1723 : : *
1724 : : * NB: If 'ptr' points to just after the page header, advertise a
1725 : : * position at the beginning of the page rather than 'ptr' itself. If
1726 : : * there are no other insertions running, someone might try to flush
1727 : : * up to our advertised location. If we advertised a position after
1728 : : * the page header, someone might try to flush the page header, even
1729 : : * though page might actually not be initialized yet. As the first
1730 : : * inserter on the page, we are effectively responsible for making
1731 : : * sure that it's initialized, before we let insertingAt to move past
1732 : : * the page header.
1733 : : */
1734 [ + + ]: 2629755 : if (ptr % XLOG_BLCKSZ == SizeOfXLogShortPHD &&
1735 [ + - ]: 11860 : XLogSegmentOffset(ptr, wal_segment_size) > XLOG_BLCKSZ)
1736 : 11860 : initializedUpto = ptr - SizeOfXLogShortPHD;
1737 [ + + ]: 2617895 : else if (ptr % XLOG_BLCKSZ == SizeOfXLogLongPHD &&
1738 [ + + ]: 896 : XLogSegmentOffset(ptr, wal_segment_size) < XLOG_BLCKSZ)
1739 : 633 : initializedUpto = ptr - SizeOfXLogLongPHD;
1740 : : else
1741 : 2617262 : initializedUpto = ptr;
1742 : :
1743 : 2629755 : WALInsertLockUpdateInsertingAt(initializedUpto);
1744 : :
1745 : 2629755 : AdvanceXLInsertBuffer(ptr, tli, false);
1746 : 2629755 : endptr = pg_atomic_read_u64(&XLogCtl->xlblocks[idx]);
1747 : :
1748 [ - + ]: 2629755 : if (expectedEndPtr != endptr)
1749 [ # # ]: 0 : elog(PANIC, "could not find WAL buffer for %X/%08X",
1750 : : LSN_FORMAT_ARGS(ptr));
1751 : : }
1752 : : else
1753 : : {
1754 : : /*
1755 : : * Make sure the initialization of the page is visible to us, and
1756 : : * won't arrive later to overwrite the WAL data we write on the page.
1757 : : */
1758 : 479377 : pg_memory_barrier();
1759 : : }
1760 : :
1761 : : /*
1762 : : * Found the buffer holding this page. Return a pointer to the right
1763 : : * offset within the page.
1764 : : */
1765 : 3109132 : cachedPage = ptr / XLOG_BLCKSZ;
1766 : 3109132 : cachedPos = XLogCtl->pages + idx * (Size) XLOG_BLCKSZ;
1767 : :
1768 : : Assert(((XLogPageHeader) cachedPos)->xlp_magic == XLOG_PAGE_MAGIC);
1769 : : Assert(((XLogPageHeader) cachedPos)->xlp_pageaddr == ptr - (ptr % XLOG_BLCKSZ));
1770 : :
1771 : 3109132 : return cachedPos + ptr % XLOG_BLCKSZ;
1772 : : }
1773 : :
1774 : : /*
1775 : : * Read WAL data directly from WAL buffers, if available. Returns the number
1776 : : * of bytes read successfully.
1777 : : *
1778 : : * Fewer than 'count' bytes may be read if some of the requested WAL data has
1779 : : * already been evicted.
1780 : : *
1781 : : * No locks are taken.
1782 : : *
1783 : : * Caller should ensure that it reads no further than LogwrtResult.Write
1784 : : * (which should have been updated by the caller when determining how far to
1785 : : * read). The 'tli' argument is only used as a convenient safety check so that
1786 : : * callers do not read from WAL buffers on a historical timeline.
1787 : : */
1788 : : Size
1789 : 106980 : WALReadFromBuffers(char *dstbuf, XLogRecPtr startptr, Size count,
1790 : : TimeLineID tli)
1791 : : {
1792 : 106980 : char *pdst = dstbuf;
1793 : 106980 : XLogRecPtr recptr = startptr;
1794 : : XLogRecPtr inserted;
1795 : 106980 : Size nbytes = count;
1796 : :
1797 [ + + + + ]: 106980 : if (RecoveryInProgress() || tli != GetWALInsertionTimeLine())
1798 : 1085 : return 0;
1799 : :
1800 : : Assert(XLogRecPtrIsValid(startptr));
1801 : :
1802 : : /*
1803 : : * Caller should ensure that the requested data has been inserted into WAL
1804 : : * buffers before we try to read it.
1805 : : */
1806 : 105895 : inserted = pg_atomic_read_u64(&XLogCtl->logInsertResult);
1807 [ - + ]: 105895 : if (startptr + count > inserted)
1808 [ # # ]: 0 : ereport(ERROR,
1809 : : errmsg("cannot read past end of generated WAL: requested %X/%08X, current position %X/%08X",
1810 : : LSN_FORMAT_ARGS(startptr + count),
1811 : : LSN_FORMAT_ARGS(inserted)));
1812 : :
1813 : : /*
1814 : : * Loop through the buffers without a lock. For each buffer, atomically
1815 : : * read and verify the end pointer, then copy the data out, and finally
1816 : : * re-read and re-verify the end pointer.
1817 : : *
1818 : : * Once a page is evicted, it never returns to the WAL buffers, so if the
1819 : : * end pointer matches the expected end pointer before and after we copy
1820 : : * the data, then the right page must have been present during the data
1821 : : * copy. Read barriers are necessary to ensure that the data copy actually
1822 : : * happens between the two verification steps.
1823 : : *
1824 : : * If either verification fails, we simply terminate the loop and return
1825 : : * with the data that had been already copied out successfully.
1826 : : */
1827 [ + + ]: 130430 : while (nbytes > 0)
1828 : : {
1829 : 123259 : uint32 offset = recptr % XLOG_BLCKSZ;
1830 : 123259 : int idx = XLogRecPtrToBufIdx(recptr);
1831 : : XLogRecPtr expectedEndPtr;
1832 : : XLogRecPtr endptr;
1833 : : const char *page;
1834 : : const char *psrc;
1835 : : Size npagebytes;
1836 : :
1837 : : /*
1838 : : * Calculate the end pointer we expect in the xlblocks array if the
1839 : : * correct page is present.
1840 : : */
1841 : 123259 : expectedEndPtr = recptr + (XLOG_BLCKSZ - offset);
1842 : :
1843 : : /*
1844 : : * First verification step: check that the correct page is present in
1845 : : * the WAL buffers.
1846 : : */
1847 : 123259 : endptr = pg_atomic_read_u64(&XLogCtl->xlblocks[idx]);
1848 [ + + ]: 123259 : if (expectedEndPtr != endptr)
1849 : 98723 : break;
1850 : :
1851 : : /*
1852 : : * The correct page is present (or was at the time the endptr was
1853 : : * read; must re-verify later). Calculate pointer to source data and
1854 : : * determine how much data to read from this page.
1855 : : */
1856 : 24536 : page = XLogCtl->pages + idx * (Size) XLOG_BLCKSZ;
1857 : 24536 : psrc = page + offset;
1858 : 24536 : npagebytes = Min(nbytes, XLOG_BLCKSZ - offset);
1859 : :
1860 : : /*
1861 : : * Ensure that the data copy and the first verification step are not
1862 : : * reordered.
1863 : : */
1864 : 24536 : pg_read_barrier();
1865 : :
1866 : : /* data copy */
1867 : 24536 : memcpy(pdst, psrc, npagebytes);
1868 : :
1869 : : /*
1870 : : * Ensure that the data copy and the second verification step are not
1871 : : * reordered.
1872 : : */
1873 : 24536 : pg_read_barrier();
1874 : :
1875 : : /*
1876 : : * Second verification step: check that the page we read from wasn't
1877 : : * evicted while we were copying the data.
1878 : : */
1879 : 24536 : endptr = pg_atomic_read_u64(&XLogCtl->xlblocks[idx]);
1880 [ + + ]: 24536 : if (expectedEndPtr != endptr)
1881 : 1 : break;
1882 : :
1883 : 24535 : pdst += npagebytes;
1884 : 24535 : recptr += npagebytes;
1885 : 24535 : nbytes -= npagebytes;
1886 : : }
1887 : :
1888 : : Assert(pdst - dstbuf <= count);
1889 : :
1890 : 105895 : return pdst - dstbuf;
1891 : : }
1892 : :
1893 : : /*
1894 : : * Converts a "usable byte position" to XLogRecPtr. A usable byte position
1895 : : * is the position starting from the beginning of WAL, excluding all WAL
1896 : : * page headers.
1897 : : */
1898 : : static XLogRecPtr
1899 : 49571213 : XLogBytePosToRecPtr(uint64 bytepos)
1900 : : {
1901 : : uint64 fullsegs;
1902 : : uint64 fullpages;
1903 : : uint64 bytesleft;
1904 : : uint32 seg_offset;
1905 : : XLogRecPtr result;
1906 : :
1907 : 49571213 : fullsegs = bytepos / UsableBytesInSegment;
1908 : 49571213 : bytesleft = bytepos % UsableBytesInSegment;
1909 : :
1910 [ + + ]: 49571213 : if (bytesleft < XLOG_BLCKSZ - SizeOfXLogLongPHD)
1911 : : {
1912 : : /* fits on first page of segment */
1913 : 72018 : seg_offset = bytesleft + SizeOfXLogLongPHD;
1914 : : }
1915 : : else
1916 : : {
1917 : : /* account for the first page on segment with long header */
1918 : 49499195 : seg_offset = XLOG_BLCKSZ;
1919 : 49499195 : bytesleft -= XLOG_BLCKSZ - SizeOfXLogLongPHD;
1920 : :
1921 : 49499195 : fullpages = bytesleft / UsableBytesInPage;
1922 : 49499195 : bytesleft = bytesleft % UsableBytesInPage;
1923 : :
1924 : 49499195 : seg_offset += fullpages * XLOG_BLCKSZ + bytesleft + SizeOfXLogShortPHD;
1925 : : }
1926 : :
1927 : 49571213 : XLogSegNoOffsetToRecPtr(fullsegs, seg_offset, wal_segment_size, result);
1928 : :
1929 : 49571213 : return result;
1930 : : }
1931 : :
1932 : : /*
1933 : : * Like XLogBytePosToRecPtr, but if the position is at a page boundary,
1934 : : * returns a pointer to the beginning of the page (ie. before page header),
1935 : : * not to where the first xlog record on that page would go to. This is used
1936 : : * when converting a pointer to the end of a record.
1937 : : */
1938 : : static XLogRecPtr
1939 : 25327337 : XLogBytePosToEndRecPtr(uint64 bytepos)
1940 : : {
1941 : : uint64 fullsegs;
1942 : : uint64 fullpages;
1943 : : uint64 bytesleft;
1944 : : uint32 seg_offset;
1945 : : XLogRecPtr result;
1946 : :
1947 : 25327337 : fullsegs = bytepos / UsableBytesInSegment;
1948 : 25327337 : bytesleft = bytepos % UsableBytesInSegment;
1949 : :
1950 [ + + ]: 25327337 : if (bytesleft < XLOG_BLCKSZ - SizeOfXLogLongPHD)
1951 : : {
1952 : : /* fits on first page of segment */
1953 [ + + ]: 110470 : if (bytesleft == 0)
1954 : 73028 : seg_offset = 0;
1955 : : else
1956 : 37442 : seg_offset = bytesleft + SizeOfXLogLongPHD;
1957 : : }
1958 : : else
1959 : : {
1960 : : /* account for the first page on segment with long header */
1961 : 25216867 : seg_offset = XLOG_BLCKSZ;
1962 : 25216867 : bytesleft -= XLOG_BLCKSZ - SizeOfXLogLongPHD;
1963 : :
1964 : 25216867 : fullpages = bytesleft / UsableBytesInPage;
1965 : 25216867 : bytesleft = bytesleft % UsableBytesInPage;
1966 : :
1967 [ + + ]: 25216867 : if (bytesleft == 0)
1968 : 24381 : seg_offset += fullpages * XLOG_BLCKSZ + bytesleft;
1969 : : else
1970 : 25192486 : seg_offset += fullpages * XLOG_BLCKSZ + bytesleft + SizeOfXLogShortPHD;
1971 : : }
1972 : :
1973 : 25327337 : XLogSegNoOffsetToRecPtr(fullsegs, seg_offset, wal_segment_size, result);
1974 : :
1975 : 25327337 : return result;
1976 : : }
1977 : :
1978 : : /*
1979 : : * Convert an XLogRecPtr to a "usable byte position".
1980 : : */
1981 : : static uint64
1982 : 2795 : XLogRecPtrToBytePos(XLogRecPtr ptr)
1983 : : {
1984 : : uint64 fullsegs;
1985 : : uint32 fullpages;
1986 : : uint32 offset;
1987 : : uint64 result;
1988 : :
1989 : 2795 : XLByteToSeg(ptr, fullsegs, wal_segment_size);
1990 : :
1991 : 2795 : fullpages = (XLogSegmentOffset(ptr, wal_segment_size)) / XLOG_BLCKSZ;
1992 : 2795 : offset = ptr % XLOG_BLCKSZ;
1993 : :
1994 [ + + ]: 2795 : if (fullpages == 0)
1995 : : {
1996 : 1071 : result = fullsegs * UsableBytesInSegment;
1997 [ + + ]: 1071 : if (offset > 0)
1998 : : {
1999 : : Assert(offset >= SizeOfXLogLongPHD);
2000 : 289 : result += offset - SizeOfXLogLongPHD;
2001 : : }
2002 : : }
2003 : : else
2004 : : {
2005 : 1724 : result = fullsegs * UsableBytesInSegment +
2006 : 1724 : (XLOG_BLCKSZ - SizeOfXLogLongPHD) + /* account for first page */
2007 : 1724 : (fullpages - 1) * UsableBytesInPage; /* full pages */
2008 [ + + ]: 1724 : if (offset > 0)
2009 : : {
2010 : : Assert(offset >= SizeOfXLogShortPHD);
2011 : 1714 : result += offset - SizeOfXLogShortPHD;
2012 : : }
2013 : : }
2014 : :
2015 : 2795 : return result;
2016 : : }
2017 : :
2018 : : /*
2019 : : * Initialize XLOG buffers, writing out old buffers if they still contain
2020 : : * unwritten data, upto the page containing 'upto'. Or if 'opportunistic' is
2021 : : * true, initialize as many pages as we can without having to write out
2022 : : * unwritten data. Any new pages are initialized to zeros, with pages headers
2023 : : * initialized properly.
2024 : : */
2025 : : static void
2026 : 2635218 : AdvanceXLInsertBuffer(XLogRecPtr upto, TimeLineID tli, bool opportunistic)
2027 : : {
2028 : : int nextidx;
2029 : : XLogRecPtr OldPageRqstPtr;
2030 : : XLogwrtRqst WriteRqst;
2031 : 2635218 : XLogRecPtr NewPageEndPtr = InvalidXLogRecPtr;
2032 : : XLogRecPtr NewPageBeginPtr;
2033 : : XLogPageHeader NewPage;
2034 : 2635218 : int npages pg_attribute_unused() = 0;
2035 : :
2036 : 2635218 : LWLockAcquire(WALBufMappingLock, LW_EXCLUSIVE);
2037 : :
2038 : : /*
2039 : : * Now that we have the lock, check if someone initialized the page
2040 : : * already.
2041 : : */
2042 [ + + + + ]: 7778362 : while (upto >= XLogCtl->InitializedUpTo || opportunistic)
2043 : : {
2044 : 5148607 : nextidx = XLogRecPtrToBufIdx(XLogCtl->InitializedUpTo);
2045 : :
2046 : : /*
2047 : : * Get ending-offset of the buffer page we need to replace (this may
2048 : : * be zero if the buffer hasn't been used yet). Fall through if it's
2049 : : * already written out.
2050 : : */
2051 : 5148607 : OldPageRqstPtr = pg_atomic_read_u64(&XLogCtl->xlblocks[nextidx]);
2052 [ + + ]: 5148607 : if (LogwrtResult.Write < OldPageRqstPtr)
2053 : : {
2054 : : /*
2055 : : * Nope, got work to do. If we just want to pre-initialize as much
2056 : : * as we can without flushing, give up now.
2057 : : */
2058 [ + + ]: 2341752 : if (opportunistic)
2059 : 5463 : break;
2060 : :
2061 : : /* Advance shared memory write request position */
2062 : 2336289 : SpinLockAcquire(&XLogCtl->info_lck);
2063 [ + + ]: 2336289 : if (XLogCtl->LogwrtRqst.Write < OldPageRqstPtr)
2064 : 711015 : XLogCtl->LogwrtRqst.Write = OldPageRqstPtr;
2065 : 2336289 : SpinLockRelease(&XLogCtl->info_lck);
2066 : :
2067 : : /*
2068 : : * Acquire an up-to-date LogwrtResult value and see if we still
2069 : : * need to write it or if someone else already did.
2070 : : */
2071 : 2336289 : RefreshXLogWriteResult(LogwrtResult);
2072 [ + + ]: 2336289 : if (LogwrtResult.Write < OldPageRqstPtr)
2073 : : {
2074 : : /*
2075 : : * Must acquire write lock. Release WALBufMappingLock first,
2076 : : * to make sure that all insertions that we need to wait for
2077 : : * can finish (up to this same position). Otherwise we risk
2078 : : * deadlock.
2079 : : */
2080 : 2324823 : LWLockRelease(WALBufMappingLock);
2081 : :
2082 : 2324823 : WaitXLogInsertionsToFinish(OldPageRqstPtr);
2083 : :
2084 : 2324823 : LWLockAcquire(WALWriteLock, LW_EXCLUSIVE);
2085 : :
2086 : 2324823 : RefreshXLogWriteResult(LogwrtResult);
2087 [ + + ]: 2324823 : if (LogwrtResult.Write >= OldPageRqstPtr)
2088 : : {
2089 : : /* OK, someone wrote it already */
2090 : 122918 : LWLockRelease(WALWriteLock);
2091 : : }
2092 : : else
2093 : : {
2094 : : /* Have to write it ourselves */
2095 : : TRACE_POSTGRESQL_WAL_BUFFER_WRITE_DIRTY_START();
2096 : 2201905 : WriteRqst.Write = OldPageRqstPtr;
2097 : 2201905 : WriteRqst.Flush = InvalidXLogRecPtr;
2098 : 2201905 : XLogWrite(WriteRqst, tli, false);
2099 : 2201905 : LWLockRelease(WALWriteLock);
2100 : 2201905 : pgWalUsage.wal_buffers_full++;
2101 : : TRACE_POSTGRESQL_WAL_BUFFER_WRITE_DIRTY_DONE();
2102 : :
2103 : : /*
2104 : : * Required for the flush of pending stats WAL data, per
2105 : : * update of pgWalUsage.
2106 : : */
2107 : 2201905 : pgstat_report_fixed = true;
2108 : : }
2109 : : /* Re-acquire WALBufMappingLock and retry */
2110 : 2324823 : LWLockAcquire(WALBufMappingLock, LW_EXCLUSIVE);
2111 : 2324823 : continue;
2112 : : }
2113 : : }
2114 : :
2115 : : /*
2116 : : * Now the next buffer slot is free and we can set it up to be the
2117 : : * next output page.
2118 : : */
2119 : 2818321 : NewPageBeginPtr = XLogCtl->InitializedUpTo;
2120 : 2818321 : NewPageEndPtr = NewPageBeginPtr + XLOG_BLCKSZ;
2121 : :
2122 : : Assert(XLogRecPtrToBufIdx(NewPageBeginPtr) == nextidx);
2123 : :
2124 : 2818321 : NewPage = (XLogPageHeader) (XLogCtl->pages + nextidx * (Size) XLOG_BLCKSZ);
2125 : :
2126 : : /*
2127 : : * Mark the xlblock with InvalidXLogRecPtr and issue a write barrier
2128 : : * before initializing. Otherwise, the old page may be partially
2129 : : * zeroed but look valid.
2130 : : */
2131 : 2818321 : pg_atomic_write_u64(&XLogCtl->xlblocks[nextidx], InvalidXLogRecPtr);
2132 : 2818321 : pg_write_barrier();
2133 : :
2134 : : /*
2135 : : * Be sure to re-zero the buffer so that bytes beyond what we've
2136 : : * written will look like zeroes and not valid XLOG records...
2137 : : */
2138 [ + - + - : 2818321 : MemSet(NewPage, 0, XLOG_BLCKSZ);
+ - - + -
- ]
2139 : :
2140 : : /*
2141 : : * Fill the new page's header
2142 : : */
2143 : 2818321 : NewPage->xlp_magic = XLOG_PAGE_MAGIC;
2144 : :
2145 : : /* NewPage->xlp_info = 0; */ /* done by memset */
2146 : 2818321 : NewPage->xlp_tli = tli;
2147 : 2818321 : NewPage->xlp_pageaddr = NewPageBeginPtr;
2148 : :
2149 : : /* NewPage->xlp_rem_len = 0; */ /* done by memset */
2150 : :
2151 : : /*
2152 : : * If first page of an XLOG segment file, make it a long header.
2153 : : */
2154 [ + + ]: 2818321 : if ((XLogSegmentOffset(NewPage->xlp_pageaddr, wal_segment_size)) == 0)
2155 : : {
2156 : 1935 : XLogLongPageHeader NewLongPage = (XLogLongPageHeader) NewPage;
2157 : :
2158 : 1935 : NewLongPage->xlp_sysid = ControlFile->system_identifier;
2159 : 1935 : NewLongPage->xlp_seg_size = wal_segment_size;
2160 : 1935 : NewLongPage->xlp_xlog_blcksz = XLOG_BLCKSZ;
2161 : 1935 : NewPage->xlp_info |= XLP_LONG_HEADER;
2162 : : }
2163 : :
2164 : : /*
2165 : : * Make sure the initialization of the page becomes visible to others
2166 : : * before the xlblocks update. GetXLogBuffer() reads xlblocks without
2167 : : * holding a lock.
2168 : : */
2169 : 2818321 : pg_write_barrier();
2170 : :
2171 : 2818321 : pg_atomic_write_u64(&XLogCtl->xlblocks[nextidx], NewPageEndPtr);
2172 : 2818321 : XLogCtl->InitializedUpTo = NewPageEndPtr;
2173 : :
2174 : 2818321 : npages++;
2175 : : }
2176 : 2635218 : LWLockRelease(WALBufMappingLock);
2177 : :
2178 : : #ifdef WAL_DEBUG
2179 : : if (XLOG_DEBUG && npages > 0)
2180 : : {
2181 : : elog(DEBUG1, "initialized %d pages, up to %X/%08X",
2182 : : npages, LSN_FORMAT_ARGS(NewPageEndPtr));
2183 : : }
2184 : : #endif
2185 : 2635218 : }
2186 : :
2187 : : /*
2188 : : * Calculate CheckPointSegments based on max_wal_size_mb and
2189 : : * checkpoint_completion_target.
2190 : : */
2191 : : static void
2192 : 9727 : CalculateCheckpointSegments(void)
2193 : : {
2194 : : double target;
2195 : :
2196 : : /*-------
2197 : : * Calculate the distance at which to trigger a checkpoint, to avoid
2198 : : * exceeding max_wal_size_mb. This is based on two assumptions:
2199 : : *
2200 : : * a) we keep WAL for only one checkpoint cycle (prior to PG11 we kept
2201 : : * WAL for two checkpoint cycles to allow us to recover from the
2202 : : * secondary checkpoint if the first checkpoint failed, though we
2203 : : * only did this on the primary anyway, not on standby. Keeping just
2204 : : * one checkpoint simplifies processing and reduces disk space in
2205 : : * many smaller databases.)
2206 : : * b) during checkpoint, we consume checkpoint_completion_target *
2207 : : * number of segments consumed between checkpoints.
2208 : : *-------
2209 : : */
2210 : 9727 : target = (double) ConvertToXSegs(max_wal_size_mb, wal_segment_size) /
2211 : 9727 : (1.0 + CheckPointCompletionTarget);
2212 : :
2213 : : /* round down */
2214 : 9727 : CheckPointSegments = (int) target;
2215 : :
2216 [ + + ]: 9727 : if (CheckPointSegments < 1)
2217 : 10 : CheckPointSegments = 1;
2218 : 9727 : }
2219 : :
2220 : : void
2221 : 7288 : assign_max_wal_size(int newval, void *extra)
2222 : : {
2223 : 7288 : max_wal_size_mb = newval;
2224 : 7288 : CalculateCheckpointSegments();
2225 : 7288 : }
2226 : :
2227 : : void
2228 : 1291 : assign_checkpoint_completion_target(double newval, void *extra)
2229 : : {
2230 : 1291 : CheckPointCompletionTarget = newval;
2231 : 1291 : CalculateCheckpointSegments();
2232 : 1291 : }
2233 : :
2234 : : bool
2235 : 2497 : check_wal_segment_size(int *newval, void **extra, GucSource source)
2236 : : {
2237 [ + - + - : 2497 : if (!IsValidWalSegSize(*newval))
+ - - + ]
2238 : : {
2239 : 0 : GUC_check_errdetail("The WAL segment size must be a power of two between 1 MB and 1 GB.");
2240 : 0 : return false;
2241 : : }
2242 : :
2243 : 2497 : return true;
2244 : : }
2245 : :
2246 : : /*
2247 : : * At a checkpoint, how many WAL segments to recycle as preallocated future
2248 : : * XLOG segments? Returns the highest segment that should be preallocated.
2249 : : */
2250 : : static XLogSegNo
2251 : 1944 : XLOGfileslop(XLogRecPtr lastredoptr)
2252 : : {
2253 : : XLogSegNo minSegNo;
2254 : : XLogSegNo maxSegNo;
2255 : : double distance;
2256 : : XLogSegNo recycleSegNo;
2257 : :
2258 : : /*
2259 : : * Calculate the segment numbers that min_wal_size_mb and max_wal_size_mb
2260 : : * correspond to. Always recycle enough segments to meet the minimum, and
2261 : : * remove enough segments to stay below the maximum.
2262 : : */
2263 : 1944 : minSegNo = lastredoptr / wal_segment_size +
2264 : 1944 : ConvertToXSegs(min_wal_size_mb, wal_segment_size) - 1;
2265 : 1944 : maxSegNo = lastredoptr / wal_segment_size +
2266 : 1944 : ConvertToXSegs(max_wal_size_mb, wal_segment_size) - 1;
2267 : :
2268 : : /*
2269 : : * Between those limits, recycle enough segments to get us through to the
2270 : : * estimated end of next checkpoint.
2271 : : *
2272 : : * To estimate where the next checkpoint will finish, assume that the
2273 : : * system runs steadily consuming CheckPointDistanceEstimate bytes between
2274 : : * every checkpoint.
2275 : : */
2276 : 1944 : distance = (1.0 + CheckPointCompletionTarget) * CheckPointDistanceEstimate;
2277 : : /* add 10% for good measure. */
2278 : 1944 : distance *= 1.10;
2279 : :
2280 : 1944 : recycleSegNo = (XLogSegNo) ceil(((double) lastredoptr + distance) /
2281 : : wal_segment_size);
2282 : :
2283 [ + + ]: 1944 : if (recycleSegNo < minSegNo)
2284 : 1367 : recycleSegNo = minSegNo;
2285 [ + + ]: 1944 : if (recycleSegNo > maxSegNo)
2286 : 425 : recycleSegNo = maxSegNo;
2287 : :
2288 : 1944 : return recycleSegNo;
2289 : : }
2290 : :
2291 : : /*
2292 : : * Check whether we've consumed enough xlog space that a checkpoint is needed.
2293 : : *
2294 : : * new_segno indicates a log file that has just been filled up (or read
2295 : : * during recovery). We measure the distance from RedoRecPtr to new_segno
2296 : : * and see if that exceeds CheckPointSegments.
2297 : : *
2298 : : * Note: it is caller's responsibility that RedoRecPtr is up-to-date.
2299 : : */
2300 : : bool
2301 : 5017 : XLogCheckpointNeeded(XLogSegNo new_segno)
2302 : : {
2303 : : XLogSegNo old_segno;
2304 : :
2305 : 5017 : XLByteToSeg(RedoRecPtr, old_segno, wal_segment_size);
2306 : :
2307 [ + + ]: 5017 : if (new_segno >= old_segno + (uint64) (CheckPointSegments - 1))
2308 : 3066 : return true;
2309 : 1951 : return false;
2310 : : }
2311 : :
2312 : : /*
2313 : : * Write and/or fsync the log at least as far as WriteRqst indicates.
2314 : : *
2315 : : * If flexible == true, we don't have to write as far as WriteRqst, but
2316 : : * may stop at any convenient boundary (such as a cache or logfile boundary).
2317 : : * This option allows us to avoid uselessly issuing multiple writes when a
2318 : : * single one would do.
2319 : : *
2320 : : * Must be called with WALWriteLock held. WaitXLogInsertionsToFinish(WriteRqst)
2321 : : * must be called before grabbing the lock, to make sure the data is ready to
2322 : : * write.
2323 : : */
2324 : : static void
2325 : 2370756 : XLogWrite(XLogwrtRqst WriteRqst, TimeLineID tli, bool flexible)
2326 : : {
2327 : : bool ispartialpage;
2328 : : bool last_iteration;
2329 : : bool finishing_seg;
2330 : : int curridx;
2331 : : int npages;
2332 : : int startidx;
2333 : : uint32 startoffset;
2334 : :
2335 : : /* We should always be inside a critical section here */
2336 : : Assert(CritSectionCount > 0);
2337 : :
2338 : : /*
2339 : : * Update local LogwrtResult (caller probably did this already, but...)
2340 : : */
2341 : 2370756 : RefreshXLogWriteResult(LogwrtResult);
2342 : :
2343 : : /*
2344 : : * Since successive pages in the xlog cache are consecutively allocated,
2345 : : * we can usually gather multiple pages together and issue just one
2346 : : * write() call. npages is the number of pages we have determined can be
2347 : : * written together; startidx is the cache block index of the first one,
2348 : : * and startoffset is the file offset at which it should go. The latter
2349 : : * two variables are only valid when npages > 0, but we must initialize
2350 : : * all of them to keep the compiler quiet.
2351 : : */
2352 : 2370756 : npages = 0;
2353 : 2370756 : startidx = 0;
2354 : 2370756 : startoffset = 0;
2355 : :
2356 : : /*
2357 : : * Within the loop, curridx is the cache block index of the page to
2358 : : * consider writing. Begin at the buffer containing the next unwritten
2359 : : * page, or last partially written page.
2360 : : */
2361 : 2370756 : curridx = XLogRecPtrToBufIdx(LogwrtResult.Write);
2362 : :
2363 [ + + ]: 5144770 : while (LogwrtResult.Write < WriteRqst.Write)
2364 : : {
2365 : : /*
2366 : : * Make sure we're not ahead of the insert process. This could happen
2367 : : * if we're passed a bogus WriteRqst.Write that is past the end of the
2368 : : * last page that's been initialized by AdvanceXLInsertBuffer.
2369 : : */
2370 : 2937078 : XLogRecPtr EndPtr = pg_atomic_read_u64(&XLogCtl->xlblocks[curridx]);
2371 : :
2372 [ - + ]: 2937078 : if (LogwrtResult.Write >= EndPtr)
2373 [ # # ]: 0 : elog(PANIC, "xlog write request %X/%08X is past end of log %X/%08X",
2374 : : LSN_FORMAT_ARGS(LogwrtResult.Write),
2375 : : LSN_FORMAT_ARGS(EndPtr));
2376 : :
2377 : : /* Advance LogwrtResult.Write to end of current buffer page */
2378 : 2937078 : LogwrtResult.Write = EndPtr;
2379 : 2937078 : ispartialpage = WriteRqst.Write < LogwrtResult.Write;
2380 : :
2381 [ + + ]: 2937078 : if (!XLByteInPrevSeg(LogwrtResult.Write, openLogSegNo,
2382 : : wal_segment_size))
2383 : : {
2384 : : /*
2385 : : * Switch to new logfile segment. We cannot have any pending
2386 : : * pages here (since we dump what we have at segment end).
2387 : : */
2388 : : Assert(npages == 0);
2389 [ + + ]: 15067 : if (openLogFile >= 0)
2390 : 6701 : XLogFileClose();
2391 : 15067 : XLByteToPrevSeg(LogwrtResult.Write, openLogSegNo,
2392 : : wal_segment_size);
2393 : 15067 : openLogTLI = tli;
2394 : :
2395 : : /* create/use new log file */
2396 : 15067 : openLogFile = XLogFileInit(openLogSegNo, tli);
2397 : 15067 : ReserveExternalFD();
2398 : : }
2399 : :
2400 : : /* Make sure we have the current logfile open */
2401 [ - + ]: 2937078 : if (openLogFile < 0)
2402 : : {
2403 : 0 : XLByteToPrevSeg(LogwrtResult.Write, openLogSegNo,
2404 : : wal_segment_size);
2405 : 0 : openLogTLI = tli;
2406 : 0 : openLogFile = XLogFileOpen(openLogSegNo, tli);
2407 : 0 : ReserveExternalFD();
2408 : : }
2409 : :
2410 : : /* Add current page to the set of pending pages-to-dump */
2411 [ + + ]: 2937078 : if (npages == 0)
2412 : : {
2413 : : /* first of group */
2414 : 2386219 : startidx = curridx;
2415 : 2386219 : startoffset = XLogSegmentOffset(LogwrtResult.Write - XLOG_BLCKSZ,
2416 : : wal_segment_size);
2417 : : }
2418 : 2937078 : npages++;
2419 : :
2420 : : /*
2421 : : * Dump the set if this will be the last loop iteration, or if we are
2422 : : * at the last page of the cache area (since the next page won't be
2423 : : * contiguous in memory), or if we are at the end of the logfile
2424 : : * segment.
2425 : : */
2426 : 2937078 : last_iteration = WriteRqst.Write <= LogwrtResult.Write;
2427 : :
2428 [ + + ]: 5715540 : finishing_seg = !ispartialpage &&
2429 [ + + ]: 2778462 : (startoffset + npages * XLOG_BLCKSZ) >= wal_segment_size;
2430 : :
2431 [ + + ]: 2937078 : if (last_iteration ||
2432 [ + + - + ]: 569236 : curridx == XLogCtl->XLogCacheBlck ||
2433 : : finishing_seg)
2434 : : {
2435 : : char *from;
2436 : : Size nbytes;
2437 : : Size nleft;
2438 : : ssize_t written;
2439 : : instr_time start;
2440 : :
2441 : : /* OK to write the page(s) */
2442 : 2386219 : from = XLogCtl->pages + startidx * (Size) XLOG_BLCKSZ;
2443 : 2386219 : nbytes = npages * (Size) XLOG_BLCKSZ;
2444 : 2386219 : nleft = nbytes;
2445 : : do
2446 : : {
2447 : 2386219 : errno = 0;
2448 : :
2449 : : /*
2450 : : * Measure I/O timing to write WAL data, for pg_stat_io.
2451 : : */
2452 : 2386219 : start = pgstat_prepare_io_time(track_wal_io_timing);
2453 : :
2454 : 2386219 : pgstat_report_wait_start(WAIT_EVENT_WAL_WRITE);
2455 : 2386219 : written = pg_pwrite(openLogFile, from, nleft, startoffset);
2456 : 2386219 : pgstat_report_wait_end();
2457 : :
2458 [ - + ]: 2386219 : if (written <= 0)
2459 : : {
2460 : : char xlogfname[MAXFNAMELEN];
2461 : : int save_errno;
2462 : :
2463 [ # # ]: 0 : if (errno == EINTR)
2464 : 0 : continue;
2465 : :
2466 : 0 : save_errno = errno;
2467 : 0 : XLogFileName(xlogfname, tli, openLogSegNo,
2468 : : wal_segment_size);
2469 : 0 : errno = save_errno;
2470 [ # # ]: 0 : ereport(PANIC,
2471 : : (errcode_for_file_access(),
2472 : : errmsg("could not write to log file \"%s\" at offset %u, length %zu: %m",
2473 : : xlogfname, startoffset, nleft)));
2474 : : }
2475 : :
2476 : 2386219 : pgstat_count_io_op_time(IOOBJECT_WAL, IOCONTEXT_NORMAL,
2477 : : IOOP_WRITE, start, 1, written);
2478 : 2386219 : nleft -= written;
2479 : 2386219 : from += written;
2480 : 2386219 : startoffset += written;
2481 [ - + ]: 2386219 : } while (nleft > 0);
2482 : :
2483 : 2386219 : npages = 0;
2484 : :
2485 : : /*
2486 : : * If we just wrote the whole last page of a logfile segment,
2487 : : * fsync the segment immediately. This avoids having to go back
2488 : : * and re-open prior segments when an fsync request comes along
2489 : : * later. Doing it here ensures that one and only one backend will
2490 : : * perform this fsync.
2491 : : *
2492 : : * This is also the right place to notify the Archiver that the
2493 : : * segment is ready to copy to archival storage, and to update the
2494 : : * timer for archive_timeout, and to signal for a checkpoint if
2495 : : * too many logfile segments have been used since the last
2496 : : * checkpoint.
2497 : : */
2498 [ + + ]: 2386219 : if (finishing_seg)
2499 : : {
2500 : 2063 : issue_xlog_fsync(openLogFile, openLogSegNo, tli);
2501 : :
2502 : : /* signal that we need to wakeup walsenders later */
2503 : 2063 : WalSndWakeupRequest();
2504 : :
2505 : 2063 : LogwrtResult.Flush = LogwrtResult.Write; /* end of page */
2506 : :
2507 [ + + ]: 2063 : if (XLogArchivingActive())
2508 : 416 : XLogArchiveNotifySeg(openLogSegNo, tli);
2509 : :
2510 : 2063 : XLogCtl->lastSegSwitchTime = (pg_time_t) time(NULL);
2511 : 2063 : XLogCtl->lastSegSwitchLSN = LogwrtResult.Flush;
2512 : :
2513 : : /*
2514 : : * Request a checkpoint if we've consumed too much xlog since
2515 : : * the last one. For speed, we first check using the local
2516 : : * copy of RedoRecPtr, which might be out of date; if it looks
2517 : : * like a checkpoint is needed, forcibly update RedoRecPtr and
2518 : : * recheck.
2519 : : */
2520 [ + + + + ]: 2063 : if (IsUnderPostmaster && XLogCheckpointNeeded(openLogSegNo))
2521 : : {
2522 : 279 : (void) GetRedoRecPtr();
2523 [ + + ]: 279 : if (XLogCheckpointNeeded(openLogSegNo))
2524 : 221 : RequestCheckpoint(CHECKPOINT_CAUSE_XLOG);
2525 : : }
2526 : : }
2527 : : }
2528 : :
2529 [ + + ]: 2937078 : if (ispartialpage)
2530 : : {
2531 : : /* Only asked to write a partial page */
2532 : 158616 : LogwrtResult.Write = WriteRqst.Write;
2533 : 158616 : break;
2534 : : }
2535 [ + + ]: 2778462 : curridx = NextBufIdx(curridx);
2536 : :
2537 : : /* If flexible, break out of loop as soon as we wrote something */
2538 [ + + + + ]: 2778462 : if (flexible && npages == 0)
2539 : 4448 : break;
2540 : : }
2541 : :
2542 : : Assert(npages == 0);
2543 : :
2544 : : /*
2545 : : * If asked to flush, do so
2546 : : */
2547 [ + + ]: 2370756 : if (LogwrtResult.Flush < WriteRqst.Flush &&
2548 [ + + ]: 168066 : LogwrtResult.Flush < LogwrtResult.Write)
2549 : : {
2550 : : /*
2551 : : * Could get here without iterating above loop, in which case we might
2552 : : * have no open file or the wrong one. However, we do not need to
2553 : : * fsync more than one file.
2554 : : */
2555 [ + - ]: 167982 : if (wal_sync_method != WAL_SYNC_METHOD_OPEN &&
2556 [ + - ]: 167982 : wal_sync_method != WAL_SYNC_METHOD_OPEN_DSYNC)
2557 : : {
2558 [ + + ]: 167982 : if (openLogFile >= 0 &&
2559 [ + + ]: 167955 : !XLByteInPrevSeg(LogwrtResult.Write, openLogSegNo,
2560 : : wal_segment_size))
2561 : 180 : XLogFileClose();
2562 [ + + ]: 167982 : if (openLogFile < 0)
2563 : : {
2564 : 207 : XLByteToPrevSeg(LogwrtResult.Write, openLogSegNo,
2565 : : wal_segment_size);
2566 : 207 : openLogTLI = tli;
2567 : 207 : openLogFile = XLogFileOpen(openLogSegNo, tli);
2568 : 207 : ReserveExternalFD();
2569 : : }
2570 : :
2571 : 167982 : issue_xlog_fsync(openLogFile, openLogSegNo, tli);
2572 : : }
2573 : :
2574 : : /* signal that we need to wakeup walsenders later */
2575 : 167982 : WalSndWakeupRequest();
2576 : :
2577 : 167982 : LogwrtResult.Flush = LogwrtResult.Write;
2578 : : }
2579 : :
2580 : : /*
2581 : : * Update shared-memory status
2582 : : *
2583 : : * We make sure that the shared 'request' values do not fall behind the
2584 : : * 'result' values. This is not absolutely essential, but it saves some
2585 : : * code in a couple of places.
2586 : : */
2587 : 2370756 : SpinLockAcquire(&XLogCtl->info_lck);
2588 [ + + ]: 2370756 : if (XLogCtl->LogwrtRqst.Write < LogwrtResult.Write)
2589 : 145674 : XLogCtl->LogwrtRqst.Write = LogwrtResult.Write;
2590 [ + + ]: 2370756 : if (XLogCtl->LogwrtRqst.Flush < LogwrtResult.Flush)
2591 : 169625 : XLogCtl->LogwrtRqst.Flush = LogwrtResult.Flush;
2592 : 2370756 : SpinLockRelease(&XLogCtl->info_lck);
2593 : :
2594 : : /*
2595 : : * We write Write first, bar, then Flush. When reading, the opposite must
2596 : : * be done (with a matching barrier in between), so that we always see a
2597 : : * Flush value that trails behind the Write value seen.
2598 : : */
2599 : 2370756 : pg_atomic_write_u64(&XLogCtl->logWriteResult, LogwrtResult.Write);
2600 : 2370756 : pg_write_barrier();
2601 : 2370756 : pg_atomic_write_u64(&XLogCtl->logFlushResult, LogwrtResult.Flush);
2602 : :
2603 : : #ifdef USE_ASSERT_CHECKING
2604 : : {
2605 : : XLogRecPtr Flush;
2606 : : XLogRecPtr Write;
2607 : : XLogRecPtr Insert;
2608 : :
2609 : : Flush = pg_atomic_read_u64(&XLogCtl->logFlushResult);
2610 : : pg_read_barrier();
2611 : : Write = pg_atomic_read_u64(&XLogCtl->logWriteResult);
2612 : : pg_read_barrier();
2613 : : Insert = pg_atomic_read_u64(&XLogCtl->logInsertResult);
2614 : :
2615 : : /* WAL written to disk is always ahead of WAL flushed */
2616 : : Assert(Write >= Flush);
2617 : :
2618 : : /* WAL inserted to buffers is always ahead of WAL written */
2619 : : Assert(Insert >= Write);
2620 : : }
2621 : : #endif
2622 : 2370756 : }
2623 : :
2624 : : /*
2625 : : * Record the LSN for an asynchronous transaction commit/abort
2626 : : * and nudge the WALWriter if there is work for it to do.
2627 : : * (This should not be called for synchronous commits.)
2628 : : */
2629 : : void
2630 : 62264 : XLogSetAsyncXactLSN(XLogRecPtr asyncXactLSN)
2631 : : {
2632 : 62264 : XLogRecPtr WriteRqstPtr = asyncXactLSN;
2633 : : bool sleeping;
2634 : 62264 : bool wakeup = false;
2635 : : XLogRecPtr prevAsyncXactLSN;
2636 : :
2637 : 62264 : SpinLockAcquire(&XLogCtl->info_lck);
2638 : 62264 : sleeping = XLogCtl->WalWriterSleeping;
2639 : 62264 : prevAsyncXactLSN = XLogCtl->asyncXactLSN;
2640 [ + + ]: 62264 : if (XLogCtl->asyncXactLSN < asyncXactLSN)
2641 : 61668 : XLogCtl->asyncXactLSN = asyncXactLSN;
2642 : 62264 : SpinLockRelease(&XLogCtl->info_lck);
2643 : :
2644 : : /*
2645 : : * If somebody else already called this function with a more aggressive
2646 : : * LSN, they will have done what we needed (and perhaps more).
2647 : : */
2648 [ + + ]: 62264 : if (asyncXactLSN <= prevAsyncXactLSN)
2649 : 596 : return;
2650 : :
2651 : : /*
2652 : : * If the WALWriter is sleeping, kick it to make it come out of low-power
2653 : : * mode, so that this async commit will reach disk within the expected
2654 : : * amount of time. Otherwise, determine whether it has enough WAL
2655 : : * available to flush, the same way that XLogBackgroundFlush() does.
2656 : : */
2657 [ + + ]: 61668 : if (sleeping)
2658 : 29 : wakeup = true;
2659 : : else
2660 : : {
2661 : : int flushblocks;
2662 : :
2663 : 61639 : RefreshXLogWriteResult(LogwrtResult);
2664 : :
2665 : 61639 : flushblocks =
2666 : 61639 : WriteRqstPtr / XLOG_BLCKSZ - LogwrtResult.Flush / XLOG_BLCKSZ;
2667 : :
2668 [ + - + + ]: 61639 : if (WalWriterFlushAfter == 0 || flushblocks >= WalWriterFlushAfter)
2669 : 5132 : wakeup = true;
2670 : : }
2671 : :
2672 [ + + ]: 61668 : if (wakeup)
2673 : : {
2674 : 5161 : volatile PROC_HDR *procglobal = ProcGlobal;
2675 : 5161 : ProcNumber walwriterProc = procglobal->walwriterProc;
2676 : :
2677 [ + + ]: 5161 : if (walwriterProc != INVALID_PROC_NUMBER)
2678 : 861 : SetLatch(&GetPGProcByNumber(walwriterProc)->procLatch);
2679 : : }
2680 : : }
2681 : :
2682 : : /*
2683 : : * Record the LSN up to which we can remove WAL because it's not required by
2684 : : * any replication slot.
2685 : : */
2686 : : void
2687 : 48810 : XLogSetReplicationSlotMinimumLSN(XLogRecPtr lsn)
2688 : : {
2689 : 48810 : SpinLockAcquire(&XLogCtl->info_lck);
2690 : 48810 : XLogCtl->replicationSlotMinLSN = lsn;
2691 : 48810 : SpinLockRelease(&XLogCtl->info_lck);
2692 : 48810 : }
2693 : :
2694 : :
2695 : : /*
2696 : : * Return the oldest LSN we must retain to satisfy the needs of some
2697 : : * replication slot.
2698 : : */
2699 : : XLogRecPtr
2700 : 2563 : XLogGetReplicationSlotMinimumLSN(void)
2701 : : {
2702 : : XLogRecPtr retval;
2703 : :
2704 : 2563 : SpinLockAcquire(&XLogCtl->info_lck);
2705 : 2563 : retval = XLogCtl->replicationSlotMinLSN;
2706 : 2563 : SpinLockRelease(&XLogCtl->info_lck);
2707 : :
2708 : 2563 : return retval;
2709 : : }
2710 : :
2711 : : /*
2712 : : * Advance minRecoveryPoint in control file.
2713 : : *
2714 : : * If we crash during recovery, we must reach this point again before the
2715 : : * database is consistent.
2716 : : *
2717 : : * If 'force' is true, 'lsn' argument is ignored. Otherwise, minRecoveryPoint
2718 : : * is only updated if it's not already greater than or equal to 'lsn'.
2719 : : */
2720 : : static void
2721 : 127586 : UpdateMinRecoveryPoint(XLogRecPtr lsn, bool force)
2722 : : {
2723 : : /* Quick check using our local copy of the variable */
2724 [ + + + + : 127586 : if (!updateMinRecoveryPoint || (!force && lsn <= LocalMinRecoveryPoint))
+ + ]
2725 : 119808 : return;
2726 : :
2727 : : /*
2728 : : * An invalid minRecoveryPoint means that we need to recover all the WAL,
2729 : : * i.e., we're doing crash recovery. We never modify the control file's
2730 : : * value in that case, so we can short-circuit future checks here too. The
2731 : : * local values of minRecoveryPoint and minRecoveryPointTLI should not be
2732 : : * updated until crash recovery finishes. We only do this for the startup
2733 : : * process as it should not update its own reference of minRecoveryPoint
2734 : : * until it has finished crash recovery to make sure that all WAL
2735 : : * available is replayed in this case. This also saves from extra locks
2736 : : * taken on the control file from the startup process.
2737 : : */
2738 [ + + + + ]: 7778 : if (!XLogRecPtrIsValid(LocalMinRecoveryPoint) && InRecovery)
2739 : : {
2740 : 32 : updateMinRecoveryPoint = false;
2741 : 32 : return;
2742 : : }
2743 : :
2744 : 7746 : LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
2745 : :
2746 : : /* update local copy */
2747 : 7746 : LocalMinRecoveryPoint = ControlFile->minRecoveryPoint;
2748 : 7746 : LocalMinRecoveryPointTLI = ControlFile->minRecoveryPointTLI;
2749 : :
2750 [ + + ]: 7746 : if (!XLogRecPtrIsValid(LocalMinRecoveryPoint))
2751 : 1 : updateMinRecoveryPoint = false;
2752 [ + + + + ]: 7745 : else if (force || LocalMinRecoveryPoint < lsn)
2753 : : {
2754 : : XLogRecPtr newMinRecoveryPoint;
2755 : : TimeLineID newMinRecoveryPointTLI;
2756 : :
2757 : : /*
2758 : : * To avoid having to update the control file too often, we update it
2759 : : * all the way to the last record being replayed, even though 'lsn'
2760 : : * would suffice for correctness. This also allows the 'force' case
2761 : : * to not need a valid 'lsn' value.
2762 : : *
2763 : : * Another important reason for doing it this way is that the passed
2764 : : * 'lsn' value could be bogus, i.e., past the end of available WAL, if
2765 : : * the caller got it from a corrupted heap page. Accepting such a
2766 : : * value as the min recovery point would prevent us from coming up at
2767 : : * all. Instead, we just log a warning and continue with recovery.
2768 : : * (See also the comments about corrupt LSNs in XLogFlush.)
2769 : : */
2770 : 6085 : newMinRecoveryPoint = GetCurrentReplayRecPtr(&newMinRecoveryPointTLI);
2771 [ + + - + ]: 6085 : if (!force && newMinRecoveryPoint < lsn)
2772 [ # # ]: 0 : elog(WARNING,
2773 : : "xlog min recovery request %X/%08X is past current point %X/%08X",
2774 : : LSN_FORMAT_ARGS(lsn), LSN_FORMAT_ARGS(newMinRecoveryPoint));
2775 : :
2776 : : /* update control file */
2777 [ + + ]: 6085 : if (ControlFile->minRecoveryPoint < newMinRecoveryPoint)
2778 : : {
2779 : 5730 : ControlFile->minRecoveryPoint = newMinRecoveryPoint;
2780 : 5730 : ControlFile->minRecoveryPointTLI = newMinRecoveryPointTLI;
2781 : 5730 : UpdateControlFile();
2782 : 5730 : LocalMinRecoveryPoint = newMinRecoveryPoint;
2783 : 5730 : LocalMinRecoveryPointTLI = newMinRecoveryPointTLI;
2784 : :
2785 [ + + ]: 5730 : ereport(DEBUG2,
2786 : : errmsg_internal("updated min recovery point to %X/%08X on timeline %u",
2787 : : LSN_FORMAT_ARGS(newMinRecoveryPoint),
2788 : : newMinRecoveryPointTLI));
2789 : : }
2790 : : }
2791 : 7746 : LWLockRelease(ControlFileLock);
2792 : : }
2793 : :
2794 : : /*
2795 : : * Ensure that all XLOG data through the given position is flushed to disk.
2796 : : *
2797 : : * NOTE: this differs from XLogWrite mainly in that the WALWriteLock is not
2798 : : * already held, and we try to avoid acquiring it if possible.
2799 : : */
2800 : : void
2801 : 885914 : XLogFlush(XLogRecPtr record)
2802 : : {
2803 : : XLogRecPtr WriteRqstPtr;
2804 : : XLogwrtRqst WriteRqst;
2805 : 885914 : TimeLineID insertTLI = XLogCtl->InsertTimeLineID;
2806 : :
2807 : : /*
2808 : : * During REDO, we are reading not writing WAL. Therefore, instead of
2809 : : * trying to flush the WAL, we should update minRecoveryPoint instead. We
2810 : : * test XLogInsertAllowed(), not InRecovery, because we need checkpointer
2811 : : * to act this way too, and because when it tries to write the
2812 : : * end-of-recovery checkpoint, it should indeed flush.
2813 : : */
2814 [ + + ]: 885914 : if (!XLogInsertAllowed())
2815 : : {
2816 : 127110 : UpdateMinRecoveryPoint(record, false);
2817 : 705649 : return;
2818 : : }
2819 : :
2820 : : /* Quick exit if already known flushed */
2821 [ + + ]: 758804 : if (record <= LogwrtResult.Flush)
2822 : 578539 : return;
2823 : :
2824 : : #ifdef WAL_DEBUG
2825 : : if (XLOG_DEBUG)
2826 : : elog(LOG, "xlog flush request %X/%08X; write %X/%08X; flush %X/%08X",
2827 : : LSN_FORMAT_ARGS(record),
2828 : : LSN_FORMAT_ARGS(LogwrtResult.Write),
2829 : : LSN_FORMAT_ARGS(LogwrtResult.Flush));
2830 : : #endif
2831 : :
2832 : 180265 : START_CRIT_SECTION();
2833 : :
2834 : : /*
2835 : : * Since fsync is usually a horribly expensive operation, we try to
2836 : : * piggyback as much data as we can on each fsync: if we see any more data
2837 : : * entered into the xlog buffer, we'll write and fsync that too, so that
2838 : : * the final value of LogwrtResult.Flush is as large as possible. This
2839 : : * gives us some chance of avoiding another fsync immediately after.
2840 : : */
2841 : :
2842 : : /* initialize to given target; may increase below */
2843 : 180265 : WriteRqstPtr = record;
2844 : :
2845 : : /*
2846 : : * Now wait until we get the write lock, or someone else does the flush
2847 : : * for us.
2848 : : */
2849 : : for (;;)
2850 : 2418 : {
2851 : : XLogRecPtr insertpos;
2852 : :
2853 : : /* done already? */
2854 : 182683 : RefreshXLogWriteResult(LogwrtResult);
2855 [ + + ]: 182683 : if (record <= LogwrtResult.Flush)
2856 : 12632 : break;
2857 : :
2858 : : /*
2859 : : * Before actually performing the write, wait for all in-flight
2860 : : * insertions to the pages we're about to write to finish.
2861 : : */
2862 : 170051 : SpinLockAcquire(&XLogCtl->info_lck);
2863 [ + + ]: 170051 : if (WriteRqstPtr < XLogCtl->LogwrtRqst.Write)
2864 : 12700 : WriteRqstPtr = XLogCtl->LogwrtRqst.Write;
2865 : 170051 : SpinLockRelease(&XLogCtl->info_lck);
2866 : 170051 : insertpos = WaitXLogInsertionsToFinish(WriteRqstPtr);
2867 : :
2868 : : /*
2869 : : * Try to get the write lock. If we can't get it immediately, wait
2870 : : * until it's released, and recheck if we still need to do the flush
2871 : : * or if the backend that held the lock did it for us already. This
2872 : : * helps to maintain a good rate of group committing when the system
2873 : : * is bottlenecked by the speed of fsyncing.
2874 : : */
2875 [ + + ]: 170051 : if (!LWLockAcquireOrWait(WALWriteLock, LW_EXCLUSIVE))
2876 : : {
2877 : : /*
2878 : : * The lock is now free, but we didn't acquire it yet. Before we
2879 : : * do, loop back to check if someone else flushed the record for
2880 : : * us already.
2881 : : */
2882 : 2418 : continue;
2883 : : }
2884 : :
2885 : : /* Got the lock; recheck whether request is satisfied */
2886 : 167633 : RefreshXLogWriteResult(LogwrtResult);
2887 [ + + ]: 167633 : if (record <= LogwrtResult.Flush)
2888 : : {
2889 : 4143 : LWLockRelease(WALWriteLock);
2890 : 4143 : break;
2891 : : }
2892 : :
2893 : : /*
2894 : : * Sleep before flush! By adding a delay here, we may give further
2895 : : * backends the opportunity to join the backlog of group commit
2896 : : * followers; this can significantly improve transaction throughput,
2897 : : * at the risk of increasing transaction latency.
2898 : : *
2899 : : * We do not sleep if enableFsync is not turned on, nor if there are
2900 : : * fewer than CommitSiblings other backends with active transactions.
2901 : : */
2902 [ - + - - : 163490 : if (CommitDelay > 0 && enableFsync &&
- - ]
2903 : 0 : MinimumActiveBackends(CommitSiblings))
2904 : : {
2905 : 0 : pgstat_report_wait_start(WAIT_EVENT_COMMIT_DELAY);
2906 : 0 : pg_usleep(CommitDelay);
2907 : 0 : pgstat_report_wait_end();
2908 : :
2909 : : /*
2910 : : * Re-check how far we can now flush the WAL. It's generally not
2911 : : * safe to call WaitXLogInsertionsToFinish while holding
2912 : : * WALWriteLock, because an in-progress insertion might need to
2913 : : * also grab WALWriteLock to make progress. But we know that all
2914 : : * the insertions up to insertpos have already finished, because
2915 : : * that's what the earlier WaitXLogInsertionsToFinish() returned.
2916 : : * We're only calling it again to allow insertpos to be moved
2917 : : * further forward, not to actually wait for anyone.
2918 : : */
2919 : 0 : insertpos = WaitXLogInsertionsToFinish(insertpos);
2920 : : }
2921 : :
2922 : : /* try to write/flush later additions to XLOG as well */
2923 : 163490 : WriteRqst.Write = insertpos;
2924 : 163490 : WriteRqst.Flush = insertpos;
2925 : :
2926 : 163490 : XLogWrite(WriteRqst, insertTLI, false);
2927 : :
2928 : 163490 : LWLockRelease(WALWriteLock);
2929 : : /* done */
2930 : 163490 : break;
2931 : : }
2932 : :
2933 : 180265 : END_CRIT_SECTION();
2934 : :
2935 : : /* wake up walsenders now that we've released heavily contended locks */
2936 : 180265 : WalSndWakeupProcessRequests(true, !RecoveryInProgress());
2937 : :
2938 : : /*
2939 : : * Wake up processes waiting for primary flush LSN to reach current flush
2940 : : * position.
2941 : : */
2942 : 180265 : WaitLSNWakeup(WAIT_LSN_TYPE_PRIMARY_FLUSH, LogwrtResult.Flush);
2943 : :
2944 : : /*
2945 : : * If we still haven't flushed to the request point then we have a
2946 : : * problem; most likely, the requested flush point is past end of XLOG.
2947 : : * This has been seen to occur when a disk page has a corrupted LSN.
2948 : : *
2949 : : * Formerly we treated this as a PANIC condition, but that hurts the
2950 : : * system's robustness rather than helping it: we do not want to take down
2951 : : * the whole system due to corruption on one data page. In particular, if
2952 : : * the bad page is encountered again during recovery then we would be
2953 : : * unable to restart the database at all! (This scenario actually
2954 : : * happened in the field several times with 7.1 releases.) As of 8.4, bad
2955 : : * LSNs encountered during recovery are UpdateMinRecoveryPoint's problem;
2956 : : * the only time we can reach here during recovery is while flushing the
2957 : : * end-of-recovery checkpoint record, and we don't expect that to have a
2958 : : * bad LSN.
2959 : : *
2960 : : * Note that for calls from xact.c, the ERROR will be promoted to PANIC
2961 : : * since xact.c calls this routine inside a critical section. However,
2962 : : * calls from bufmgr.c are not within critical sections and so we will not
2963 : : * force a restart for a bad LSN on a data page.
2964 : : */
2965 [ - + ]: 180265 : if (LogwrtResult.Flush < record)
2966 [ # # ]: 0 : elog(ERROR,
2967 : : "xlog flush request %X/%08X is not satisfied --- flushed only to %X/%08X",
2968 : : LSN_FORMAT_ARGS(record),
2969 : : LSN_FORMAT_ARGS(LogwrtResult.Flush));
2970 : :
2971 : : /*
2972 : : * Cross-check XLogNeedsFlush(). Some of the checks of XLogFlush() and
2973 : : * XLogNeedsFlush() are duplicated, and this assertion ensures that these
2974 : : * remain consistent.
2975 : : */
2976 : : Assert(!XLogNeedsFlush(record));
2977 : : }
2978 : :
2979 : : /*
2980 : : * Write & flush xlog, but without specifying exactly where to.
2981 : : *
2982 : : * We normally write only completed blocks; but if there is nothing to do on
2983 : : * that basis, we check for unwritten async commits in the current incomplete
2984 : : * block, and write through the latest one of those. Thus, if async commits
2985 : : * are not being used, we will write complete blocks only.
2986 : : *
2987 : : * If, based on the above, there's anything to write we do so immediately. But
2988 : : * to avoid calling fsync, fdatasync et. al. at a rate that'd impact
2989 : : * concurrent IO, we only flush WAL every wal_writer_delay ms, or if there's
2990 : : * more than wal_writer_flush_after unflushed blocks.
2991 : : *
2992 : : * We can guarantee that async commits reach disk after at most three
2993 : : * wal_writer_delay cycles. (When flushing complete blocks, we allow XLogWrite
2994 : : * to write "flexibly", meaning it can stop at the end of the buffer ring;
2995 : : * this makes a difference only with very high load or long wal_writer_delay,
2996 : : * but imposes one extra cycle for the worst case for async commits.)
2997 : : *
2998 : : * This routine is invoked periodically by the background walwriter process.
2999 : : *
3000 : : * Returns true if there was any work to do, even if we skipped flushing due
3001 : : * to wal_writer_delay/wal_writer_flush_after.
3002 : : */
3003 : : bool
3004 : 15706 : XLogBackgroundFlush(void)
3005 : : {
3006 : : XLogwrtRqst WriteRqst;
3007 : 15706 : bool flexible = true;
3008 : : static TimestampTz lastflush;
3009 : : TimestampTz now;
3010 : : int flushblocks;
3011 : : TimeLineID insertTLI;
3012 : :
3013 : : /* XLOG doesn't need flushing during recovery */
3014 [ - + ]: 15706 : if (RecoveryInProgress())
3015 : 0 : return false;
3016 : :
3017 : : /*
3018 : : * Since we're not in recovery, InsertTimeLineID is set and can't change,
3019 : : * so we can read it without a lock.
3020 : : */
3021 : 15706 : insertTLI = XLogCtl->InsertTimeLineID;
3022 : :
3023 : : /* read updated LogwrtRqst */
3024 : 15706 : SpinLockAcquire(&XLogCtl->info_lck);
3025 : 15706 : WriteRqst = XLogCtl->LogwrtRqst;
3026 : 15706 : SpinLockRelease(&XLogCtl->info_lck);
3027 : :
3028 : : /* back off to last completed page boundary */
3029 : 15706 : WriteRqst.Write -= WriteRqst.Write % XLOG_BLCKSZ;
3030 : :
3031 : : /* if we have already flushed that far, consider async commit records */
3032 : 15706 : RefreshXLogWriteResult(LogwrtResult);
3033 [ + + ]: 15706 : if (WriteRqst.Write <= LogwrtResult.Flush)
3034 : : {
3035 : 11052 : SpinLockAcquire(&XLogCtl->info_lck);
3036 : 11052 : WriteRqst.Write = XLogCtl->asyncXactLSN;
3037 : 11052 : SpinLockRelease(&XLogCtl->info_lck);
3038 : 11052 : flexible = false; /* ensure it all gets written */
3039 : : }
3040 : :
3041 : : /*
3042 : : * If already known flushed, we're done. Just need to check if we are
3043 : : * holding an open file handle to a logfile that's no longer in use,
3044 : : * preventing the file from being deleted.
3045 : : */
3046 [ + + ]: 15706 : if (WriteRqst.Write <= LogwrtResult.Flush)
3047 : : {
3048 [ + + ]: 10243 : if (openLogFile >= 0)
3049 : : {
3050 [ + + ]: 6791 : if (!XLByteInPrevSeg(LogwrtResult.Write, openLogSegNo,
3051 : : wal_segment_size))
3052 : : {
3053 : 201 : XLogFileClose();
3054 : : }
3055 : : }
3056 : 10243 : return false;
3057 : : }
3058 : :
3059 : : /*
3060 : : * Determine how far to flush WAL, based on the wal_writer_delay and
3061 : : * wal_writer_flush_after GUCs.
3062 : : *
3063 : : * Note that XLogSetAsyncXactLSN() performs similar calculation based on
3064 : : * wal_writer_flush_after, to decide when to wake us up. Make sure the
3065 : : * logic is the same in both places if you change this.
3066 : : */
3067 : 5463 : now = GetCurrentTimestamp();
3068 : 5463 : flushblocks =
3069 : 5463 : WriteRqst.Write / XLOG_BLCKSZ - LogwrtResult.Flush / XLOG_BLCKSZ;
3070 : :
3071 [ + - + + ]: 5463 : if (WalWriterFlushAfter == 0 || lastflush == 0)
3072 : : {
3073 : : /* first call, or block based limits disabled */
3074 : 310 : WriteRqst.Flush = WriteRqst.Write;
3075 : 310 : lastflush = now;
3076 : : }
3077 [ + + ]: 5153 : else if (TimestampDifferenceExceeds(lastflush, now, WalWriterDelay))
3078 : : {
3079 : : /*
3080 : : * Flush the writes at least every WalWriterDelay ms. This is
3081 : : * important to bound the amount of time it takes for an asynchronous
3082 : : * commit to hit disk.
3083 : : */
3084 : 4907 : WriteRqst.Flush = WriteRqst.Write;
3085 : 4907 : lastflush = now;
3086 : : }
3087 [ + + ]: 246 : else if (flushblocks >= WalWriterFlushAfter)
3088 : : {
3089 : : /* exceeded wal_writer_flush_after blocks, flush */
3090 : 223 : WriteRqst.Flush = WriteRqst.Write;
3091 : 223 : lastflush = now;
3092 : : }
3093 : : else
3094 : : {
3095 : : /* no flushing, this time round */
3096 : 23 : WriteRqst.Flush = InvalidXLogRecPtr;
3097 : : }
3098 : :
3099 : : #ifdef WAL_DEBUG
3100 : : if (XLOG_DEBUG)
3101 : : elog(LOG, "xlog bg flush request write %X/%08X; flush: %X/%08X, current is write %X/%08X; flush %X/%08X",
3102 : : LSN_FORMAT_ARGS(WriteRqst.Write),
3103 : : LSN_FORMAT_ARGS(WriteRqst.Flush),
3104 : : LSN_FORMAT_ARGS(LogwrtResult.Write),
3105 : : LSN_FORMAT_ARGS(LogwrtResult.Flush));
3106 : : #endif
3107 : :
3108 : 5463 : START_CRIT_SECTION();
3109 : :
3110 : : /* now wait for any in-progress insertions to finish and get write lock */
3111 : 5463 : WaitXLogInsertionsToFinish(WriteRqst.Write);
3112 : 5463 : LWLockAcquire(WALWriteLock, LW_EXCLUSIVE);
3113 : 5463 : RefreshXLogWriteResult(LogwrtResult);
3114 [ + + ]: 5463 : if (WriteRqst.Write > LogwrtResult.Write ||
3115 [ + + ]: 218 : WriteRqst.Flush > LogwrtResult.Flush)
3116 : : {
3117 : 5361 : XLogWrite(WriteRqst, insertTLI, flexible);
3118 : : }
3119 : 5463 : LWLockRelease(WALWriteLock);
3120 : :
3121 : 5463 : END_CRIT_SECTION();
3122 : :
3123 : : /* wake up walsenders now that we've released heavily contended locks */
3124 : 5463 : WalSndWakeupProcessRequests(true, !RecoveryInProgress());
3125 : :
3126 : : /*
3127 : : * Wake up processes waiting for primary flush LSN to reach current flush
3128 : : * position.
3129 : : */
3130 : 5463 : WaitLSNWakeup(WAIT_LSN_TYPE_PRIMARY_FLUSH, LogwrtResult.Flush);
3131 : :
3132 : : /*
3133 : : * Great, done. To take some work off the critical path, try to initialize
3134 : : * as many of the no-longer-needed WAL buffers for future use as we can.
3135 : : */
3136 : 5463 : AdvanceXLInsertBuffer(InvalidXLogRecPtr, insertTLI, true);
3137 : :
3138 : : /*
3139 : : * If we determined that we need to write data, but somebody else
3140 : : * wrote/flushed already, it should be considered as being active, to
3141 : : * avoid hibernating too early.
3142 : : */
3143 : 5463 : return true;
3144 : : }
3145 : :
3146 : : /*
3147 : : * Test whether XLOG data has been flushed up to (at least) the given
3148 : : * position, or whether the minimum recovery point has been updated past
3149 : : * the given position.
3150 : : *
3151 : : * Returns true if a flush is still needed, or if the minimum recovery point
3152 : : * must be updated.
3153 : : *
3154 : : * It is possible that someone else is already in the process of flushing
3155 : : * that far, or has updated the minimum recovery point up to the given
3156 : : * position.
3157 : : */
3158 : : bool
3159 : 16312631 : XLogNeedsFlush(XLogRecPtr record)
3160 : : {
3161 : : /*
3162 : : * During recovery, we don't flush WAL but update minRecoveryPoint
3163 : : * instead. So "needs flush" is taken to mean whether minRecoveryPoint
3164 : : * would need to be updated.
3165 : : *
3166 : : * Using XLogInsertAllowed() rather than RecoveryInProgress() matters for
3167 : : * the case of an end-of-recovery checkpoint, where WAL data is flushed.
3168 : : * This check should be consistent with the one in XLogFlush().
3169 : : */
3170 [ + + ]: 16312631 : if (!XLogInsertAllowed())
3171 : : {
3172 : : /* Quick exit if already known to be updated or cannot be updated */
3173 [ + + + + ]: 557764 : if (!updateMinRecoveryPoint || record <= LocalMinRecoveryPoint)
3174 : 551055 : return false;
3175 : :
3176 : : /*
3177 : : * An invalid minRecoveryPoint means that we need to recover all the
3178 : : * WAL, i.e., we're doing crash recovery. We never modify the control
3179 : : * file's value in that case, so we can short-circuit future checks
3180 : : * here too. This triggers a quick exit path for the startup process,
3181 : : * which cannot update its local copy of minRecoveryPoint as long as
3182 : : * it has not replayed all WAL available when doing crash recovery.
3183 : : */
3184 [ + + - + ]: 6709 : if (!XLogRecPtrIsValid(LocalMinRecoveryPoint) && InRecovery)
3185 : : {
3186 : 0 : updateMinRecoveryPoint = false;
3187 : 0 : return false;
3188 : : }
3189 : :
3190 : : /*
3191 : : * Update local copy of minRecoveryPoint. But if the lock is busy,
3192 : : * just return a conservative guess.
3193 : : */
3194 [ - + ]: 6709 : if (!LWLockConditionalAcquire(ControlFileLock, LW_SHARED))
3195 : 0 : return true;
3196 : 6709 : LocalMinRecoveryPoint = ControlFile->minRecoveryPoint;
3197 : 6709 : LocalMinRecoveryPointTLI = ControlFile->minRecoveryPointTLI;
3198 : 6709 : LWLockRelease(ControlFileLock);
3199 : :
3200 : : /*
3201 : : * Check minRecoveryPoint for any other process than the startup
3202 : : * process doing crash recovery, which should not update the control
3203 : : * file value if crash recovery is still running.
3204 : : */
3205 [ + + ]: 6709 : if (!XLogRecPtrIsValid(LocalMinRecoveryPoint))
3206 : 2 : updateMinRecoveryPoint = false;
3207 : :
3208 : : /* check again */
3209 [ + + + + ]: 6709 : if (record <= LocalMinRecoveryPoint || !updateMinRecoveryPoint)
3210 : 97 : return false;
3211 : : else
3212 : 6612 : return true;
3213 : : }
3214 : :
3215 : : /* Quick exit if already known flushed */
3216 [ + + ]: 15754867 : if (record <= LogwrtResult.Flush)
3217 : 15528849 : return false;
3218 : :
3219 : : /* read LogwrtResult and update local state */
3220 : 226018 : RefreshXLogWriteResult(LogwrtResult);
3221 : :
3222 : : /* check again */
3223 [ + + ]: 226018 : if (record <= LogwrtResult.Flush)
3224 : 3356 : return false;
3225 : :
3226 : 222662 : return true;
3227 : : }
3228 : :
3229 : : /*
3230 : : * Try to make a given XLOG file segment exist.
3231 : : *
3232 : : * logsegno: identify segment.
3233 : : *
3234 : : * *added: on return, true if this call raised the number of extant segments.
3235 : : *
3236 : : * path: on return, this char[MAXPGPATH] has the path to the logsegno file.
3237 : : *
3238 : : * Returns -1 or FD of opened file. A -1 here is not an error; a caller
3239 : : * wanting an open segment should attempt to open "path", which usually will
3240 : : * succeed. (This is weird, but it's efficient for the callers.)
3241 : : */
3242 : : static int
3243 : 16247 : XLogFileInitInternal(XLogSegNo logsegno, TimeLineID logtli,
3244 : : bool *added, char *path)
3245 : : {
3246 : : char tmppath[MAXPGPATH];
3247 : : XLogSegNo installed_segno;
3248 : : XLogSegNo max_segno;
3249 : : int fd;
3250 : : int save_errno;
3251 : 16247 : int open_flags = O_RDWR | O_CREAT | O_EXCL | PG_BINARY;
3252 : : instr_time io_start;
3253 : :
3254 : : Assert(logtli != 0);
3255 : :
3256 : 16247 : XLogFilePath(path, logtli, logsegno, wal_segment_size);
3257 : :
3258 : : /*
3259 : : * Try to use existent file (checkpoint maker may have created it already)
3260 : : */
3261 : 16247 : *added = false;
3262 : 16247 : fd = BasicOpenFile(path, O_RDWR | PG_BINARY | O_CLOEXEC |
3263 : 16247 : get_sync_bit(wal_sync_method));
3264 [ + + ]: 16247 : if (fd < 0)
3265 : : {
3266 [ - + ]: 1505 : if (errno != ENOENT)
3267 [ # # ]: 0 : ereport(ERROR,
3268 : : (errcode_for_file_access(),
3269 : : errmsg("could not open file \"%s\": %m", path)));
3270 : : }
3271 : : else
3272 : 14742 : return fd;
3273 : :
3274 : : /*
3275 : : * Initialize an empty (all zeroes) segment. NOTE: it is possible that
3276 : : * another process is doing the same thing. If so, we will end up
3277 : : * pre-creating an extra log segment. That seems OK, and better than
3278 : : * holding the lock throughout this lengthy process.
3279 : : */
3280 [ + + ]: 1505 : elog(DEBUG2, "creating and filling new WAL file");
3281 : :
3282 : 1505 : snprintf(tmppath, MAXPGPATH, XLOGDIR "/xlogtemp.%d", (int) getpid());
3283 : :
3284 : 1505 : unlink(tmppath);
3285 : :
3286 [ - + ]: 1505 : if (io_direct_flags & IO_DIRECT_WAL_INIT)
3287 : 0 : open_flags |= PG_O_DIRECT;
3288 : :
3289 : : /* do not use get_sync_bit() here --- want to fsync only at end of fill */
3290 : 1505 : fd = BasicOpenFile(tmppath, open_flags);
3291 [ - + ]: 1505 : if (fd < 0)
3292 [ # # ]: 0 : ereport(ERROR,
3293 : : (errcode_for_file_access(),
3294 : : errmsg("could not create file \"%s\": %m", tmppath)));
3295 : :
3296 : : /* Measure I/O timing when initializing segment */
3297 : 1505 : io_start = pgstat_prepare_io_time(track_wal_io_timing);
3298 : :
3299 : 1505 : pgstat_report_wait_start(WAIT_EVENT_WAL_INIT_WRITE);
3300 : 1505 : save_errno = 0;
3301 [ + - ]: 1505 : if (wal_init_zero)
3302 : : {
3303 : : ssize_t rc;
3304 : :
3305 : : /*
3306 : : * Zero-fill the file. With this setting, we do this the hard way to
3307 : : * ensure that all the file space has really been allocated. On
3308 : : * platforms that allow "holes" in files, just seeking to the end
3309 : : * doesn't allocate intermediate space. This way, we know that we
3310 : : * have all the space and (after the fsync below) that all the
3311 : : * indirect blocks are down on disk. Therefore, fdatasync(2) or
3312 : : * O_DSYNC will be sufficient to sync future writes to the log file.
3313 : : */
3314 : 1505 : rc = pg_pwrite_zeros(fd, wal_segment_size, 0);
3315 : :
3316 [ - + ]: 1505 : if (rc < 0)
3317 : 0 : save_errno = errno;
3318 : : }
3319 : : else
3320 : : {
3321 : : /*
3322 : : * Otherwise, seeking to the end and writing a solitary byte is
3323 : : * enough.
3324 : : */
3325 : 0 : errno = 0;
3326 [ # # ]: 0 : if (pg_pwrite(fd, "\0", 1, wal_segment_size - 1) != 1)
3327 : : {
3328 : : /* if write didn't set errno, assume no disk space */
3329 [ # # ]: 0 : save_errno = errno ? errno : ENOSPC;
3330 : : }
3331 : : }
3332 : 1505 : pgstat_report_wait_end();
3333 : :
3334 [ - + ]: 1505 : if (save_errno)
3335 : : {
3336 : : /*
3337 : : * If we fail to make the file, delete it to release disk space
3338 : : */
3339 : 0 : unlink(tmppath);
3340 : :
3341 : 0 : close(fd);
3342 : :
3343 : 0 : errno = save_errno;
3344 : :
3345 [ # # ]: 0 : ereport(ERROR,
3346 : : (errcode_for_file_access(),
3347 : : errmsg("could not write to file \"%s\": %m", tmppath)));
3348 : : }
3349 : :
3350 : : /*
3351 : : * A full segment worth of data is written when using wal_init_zero. One
3352 : : * byte is written when not using it.
3353 : : */
3354 : 1505 : pgstat_count_io_op_time(IOOBJECT_WAL, IOCONTEXT_INIT, IOOP_WRITE,
3355 : : io_start, 1,
3356 [ + - ]: 1505 : wal_init_zero ? wal_segment_size : 1);
3357 : :
3358 : : /* Measure I/O timing when flushing segment */
3359 : 1505 : io_start = pgstat_prepare_io_time(track_wal_io_timing);
3360 : :
3361 : 1505 : pgstat_report_wait_start(WAIT_EVENT_WAL_INIT_SYNC);
3362 [ - + ]: 1505 : if (pg_fsync(fd) != 0)
3363 : : {
3364 : 0 : save_errno = errno;
3365 : 0 : close(fd);
3366 : 0 : errno = save_errno;
3367 [ # # ]: 0 : ereport(ERROR,
3368 : : (errcode_for_file_access(),
3369 : : errmsg("could not fsync file \"%s\": %m", tmppath)));
3370 : : }
3371 : 1505 : pgstat_report_wait_end();
3372 : :
3373 : 1505 : pgstat_count_io_op_time(IOOBJECT_WAL, IOCONTEXT_INIT,
3374 : : IOOP_FSYNC, io_start, 1, 0);
3375 : :
3376 [ - + ]: 1505 : if (close(fd) != 0)
3377 [ # # ]: 0 : ereport(ERROR,
3378 : : (errcode_for_file_access(),
3379 : : errmsg("could not close file \"%s\": %m", tmppath)));
3380 : :
3381 : : /*
3382 : : * Now move the segment into place with its final name. Cope with
3383 : : * possibility that someone else has created the file while we were
3384 : : * filling ours: if so, use ours to pre-create a future log segment.
3385 : : */
3386 : 1505 : installed_segno = logsegno;
3387 : :
3388 : : /*
3389 : : * XXX: What should we use as max_segno? We used to use XLOGfileslop when
3390 : : * that was a constant, but that was always a bit dubious: normally, at a
3391 : : * checkpoint, XLOGfileslop was the offset from the checkpoint record, but
3392 : : * here, it was the offset from the insert location. We can't do the
3393 : : * normal XLOGfileslop calculation here because we don't have access to
3394 : : * the prior checkpoint's redo location. So somewhat arbitrarily, just use
3395 : : * CheckPointSegments.
3396 : : */
3397 : 1505 : max_segno = logsegno + CheckPointSegments;
3398 [ + - ]: 1505 : if (InstallXLogFileSegment(&installed_segno, tmppath, true, max_segno,
3399 : : logtli))
3400 : : {
3401 : 1505 : *added = true;
3402 [ + + ]: 1505 : elog(DEBUG2, "done creating and filling new WAL file");
3403 : : }
3404 : : else
3405 : : {
3406 : : /*
3407 : : * No need for any more future segments, or InstallXLogFileSegment()
3408 : : * failed to rename the file into place. If the rename failed, a
3409 : : * caller opening the file may fail.
3410 : : */
3411 : 0 : unlink(tmppath);
3412 [ # # ]: 0 : elog(DEBUG2, "abandoned new WAL file");
3413 : : }
3414 : :
3415 : 1505 : return -1;
3416 : : }
3417 : :
3418 : : /*
3419 : : * Create a new XLOG file segment, or open a pre-existing one.
3420 : : *
3421 : : * logsegno: identify segment to be created/opened.
3422 : : *
3423 : : * Returns FD of opened file.
3424 : : *
3425 : : * Note: errors here are ERROR not PANIC because we might or might not be
3426 : : * inside a critical section (eg, during checkpoint there is no reason to
3427 : : * take down the system on failure). They will promote to PANIC if we are
3428 : : * in a critical section.
3429 : : */
3430 : : int
3431 : 16032 : XLogFileInit(XLogSegNo logsegno, TimeLineID logtli)
3432 : : {
3433 : : bool ignore_added;
3434 : : char path[MAXPGPATH];
3435 : : int fd;
3436 : :
3437 : : Assert(logtli != 0);
3438 : :
3439 : 16032 : fd = XLogFileInitInternal(logsegno, logtli, &ignore_added, path);
3440 [ + + ]: 16032 : if (fd >= 0)
3441 : 14591 : return fd;
3442 : :
3443 : : /* Now open original target segment (might not be file I just made) */
3444 : 1441 : fd = BasicOpenFile(path, O_RDWR | PG_BINARY | O_CLOEXEC |
3445 : 1441 : get_sync_bit(wal_sync_method));
3446 [ - + ]: 1441 : if (fd < 0)
3447 [ # # ]: 0 : ereport(ERROR,
3448 : : (errcode_for_file_access(),
3449 : : errmsg("could not open file \"%s\": %m", path)));
3450 : 1441 : return fd;
3451 : : }
3452 : :
3453 : : /*
3454 : : * Create a new XLOG file segment by copying a pre-existing one.
3455 : : *
3456 : : * destsegno: identify segment to be created.
3457 : : *
3458 : : * srcTLI, srcsegno: identify segment to be copied (could be from
3459 : : * a different timeline)
3460 : : *
3461 : : * upto: how much of the source file to copy (the rest is filled with
3462 : : * zeros)
3463 : : *
3464 : : * Currently this is only used during recovery, and so there are no locking
3465 : : * considerations. But we should be just as tense as XLogFileInit to avoid
3466 : : * emplacing a bogus file.
3467 : : */
3468 : : static void
3469 : 47 : XLogFileCopy(TimeLineID destTLI, XLogSegNo destsegno,
3470 : : TimeLineID srcTLI, XLogSegNo srcsegno,
3471 : : int upto)
3472 : : {
3473 : : char path[MAXPGPATH];
3474 : : char tmppath[MAXPGPATH];
3475 : : PGAlignedXLogBlock buffer;
3476 : : int srcfd;
3477 : : int fd;
3478 : : int nbytes;
3479 : :
3480 : : /*
3481 : : * Open the source file
3482 : : */
3483 : 47 : XLogFilePath(path, srcTLI, srcsegno, wal_segment_size);
3484 : 47 : srcfd = OpenTransientFile(path, O_RDONLY | PG_BINARY);
3485 [ - + ]: 47 : if (srcfd < 0)
3486 [ # # ]: 0 : ereport(ERROR,
3487 : : (errcode_for_file_access(),
3488 : : errmsg("could not open file \"%s\": %m", path)));
3489 : :
3490 : : /*
3491 : : * Copy into a temp file name.
3492 : : */
3493 : 47 : snprintf(tmppath, MAXPGPATH, XLOGDIR "/xlogtemp.%d", (int) getpid());
3494 : :
3495 : 47 : unlink(tmppath);
3496 : :
3497 : : /* do not use get_sync_bit() here --- want to fsync only at end of fill */
3498 : 47 : fd = OpenTransientFile(tmppath, O_RDWR | O_CREAT | O_EXCL | PG_BINARY);
3499 [ - + ]: 47 : if (fd < 0)
3500 [ # # ]: 0 : ereport(ERROR,
3501 : : (errcode_for_file_access(),
3502 : : errmsg("could not create file \"%s\": %m", tmppath)));
3503 : :
3504 : : /*
3505 : : * Do the data copying.
3506 : : */
3507 [ + + ]: 96303 : for (nbytes = 0; nbytes < wal_segment_size; nbytes += sizeof(buffer))
3508 : : {
3509 : : int nread;
3510 : :
3511 : 96256 : nread = upto - nbytes;
3512 : :
3513 : : /*
3514 : : * The part that is not read from the source file is filled with
3515 : : * zeros.
3516 : : */
3517 [ + + ]: 96256 : if (nread < sizeof(buffer))
3518 : 47 : memset(buffer.data, 0, sizeof(buffer));
3519 : :
3520 [ + + ]: 96256 : if (nread > 0)
3521 : : {
3522 : : int r;
3523 : :
3524 [ + + ]: 4425 : if (nread > sizeof(buffer))
3525 : 4378 : nread = sizeof(buffer);
3526 : 4425 : pgstat_report_wait_start(WAIT_EVENT_WAL_COPY_READ);
3527 : 4425 : r = read(srcfd, buffer.data, nread);
3528 [ - + ]: 4425 : if (r != nread)
3529 : : {
3530 [ # # ]: 0 : if (r < 0)
3531 [ # # ]: 0 : ereport(ERROR,
3532 : : (errcode_for_file_access(),
3533 : : errmsg("could not read file \"%s\": %m",
3534 : : path)));
3535 : : else
3536 [ # # ]: 0 : ereport(ERROR,
3537 : : (errcode(ERRCODE_DATA_CORRUPTED),
3538 : : errmsg("could not read file \"%s\": read %d of %zu",
3539 : : path, r, (Size) nread)));
3540 : : }
3541 : 4425 : pgstat_report_wait_end();
3542 : : }
3543 : 96256 : errno = 0;
3544 : 96256 : pgstat_report_wait_start(WAIT_EVENT_WAL_COPY_WRITE);
3545 [ - + ]: 96256 : if ((int) write(fd, buffer.data, sizeof(buffer)) != (int) sizeof(buffer))
3546 : : {
3547 : 0 : int save_errno = errno;
3548 : :
3549 : : /*
3550 : : * If we fail to make the file, delete it to release disk space
3551 : : */
3552 : 0 : unlink(tmppath);
3553 : : /* if write didn't set errno, assume problem is no disk space */
3554 [ # # ]: 0 : errno = save_errno ? save_errno : ENOSPC;
3555 : :
3556 [ # # ]: 0 : ereport(ERROR,
3557 : : (errcode_for_file_access(),
3558 : : errmsg("could not write to file \"%s\": %m", tmppath)));
3559 : : }
3560 : 96256 : pgstat_report_wait_end();
3561 : : }
3562 : :
3563 : 47 : pgstat_report_wait_start(WAIT_EVENT_WAL_COPY_SYNC);
3564 [ - + ]: 47 : if (pg_fsync(fd) != 0)
3565 [ # # ]: 0 : ereport(data_sync_elevel(ERROR),
3566 : : (errcode_for_file_access(),
3567 : : errmsg("could not fsync file \"%s\": %m", tmppath)));
3568 : 47 : pgstat_report_wait_end();
3569 : :
3570 [ - + ]: 47 : if (CloseTransientFile(fd) != 0)
3571 [ # # ]: 0 : ereport(ERROR,
3572 : : (errcode_for_file_access(),
3573 : : errmsg("could not close file \"%s\": %m", tmppath)));
3574 : :
3575 [ - + ]: 47 : if (CloseTransientFile(srcfd) != 0)
3576 [ # # ]: 0 : ereport(ERROR,
3577 : : (errcode_for_file_access(),
3578 : : errmsg("could not close file \"%s\": %m", path)));
3579 : :
3580 : : /*
3581 : : * Now move the segment into place with its final name.
3582 : : */
3583 [ - + ]: 47 : if (!InstallXLogFileSegment(&destsegno, tmppath, false, 0, destTLI))
3584 [ # # ]: 0 : elog(ERROR, "InstallXLogFileSegment should not have failed");
3585 : 47 : }
3586 : :
3587 : : /*
3588 : : * Install a new XLOG segment file as a current or future log segment.
3589 : : *
3590 : : * This is used both to install a newly-created segment (which has a temp
3591 : : * filename while it's being created) and to recycle an old segment.
3592 : : *
3593 : : * *segno: identify segment to install as (or first possible target).
3594 : : * When find_free is true, this is modified on return to indicate the
3595 : : * actual installation location or last segment searched.
3596 : : *
3597 : : * tmppath: initial name of file to install. It will be renamed into place.
3598 : : *
3599 : : * find_free: if true, install the new segment at the first empty segno
3600 : : * number at or after the passed numbers. If false, install the new segment
3601 : : * exactly where specified, deleting any existing segment file there.
3602 : : *
3603 : : * max_segno: maximum segment number to install the new file as. Fail if no
3604 : : * free slot is found between *segno and max_segno. (Ignored when find_free
3605 : : * is false.)
3606 : : *
3607 : : * tli: The timeline on which the new segment should be installed.
3608 : : *
3609 : : * Returns true if the file was installed successfully. false indicates that
3610 : : * max_segno limit was exceeded, the startup process has disabled this
3611 : : * function for now, or an error occurred while renaming the file into place.
3612 : : */
3613 : : static bool
3614 : 3280 : InstallXLogFileSegment(XLogSegNo *segno, char *tmppath,
3615 : : bool find_free, XLogSegNo max_segno, TimeLineID tli)
3616 : : {
3617 : : char path[MAXPGPATH];
3618 : : struct stat stat_buf;
3619 : :
3620 : : Assert(tli != 0);
3621 : :
3622 : 3280 : XLogFilePath(path, tli, *segno, wal_segment_size);
3623 : :
3624 : 3280 : LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
3625 [ - + ]: 3280 : if (!XLogCtl->InstallXLogFileSegmentActive)
3626 : : {
3627 : 0 : LWLockRelease(ControlFileLock);
3628 : 0 : return false;
3629 : : }
3630 : :
3631 [ + + ]: 3280 : if (!find_free)
3632 : : {
3633 : : /* Force installation: get rid of any pre-existing segment file */
3634 : 47 : durable_unlink(path, DEBUG1);
3635 : : }
3636 : : else
3637 : : {
3638 : : /* Find a free slot to put it in */
3639 [ + + ]: 4541 : while (stat(path, &stat_buf) == 0)
3640 : : {
3641 [ + + ]: 1472 : if ((*segno) >= max_segno)
3642 : : {
3643 : : /* Failed to find a free slot within specified range */
3644 : 164 : LWLockRelease(ControlFileLock);
3645 : 164 : return false;
3646 : : }
3647 : 1308 : (*segno)++;
3648 : 1308 : XLogFilePath(path, tli, *segno, wal_segment_size);
3649 : : }
3650 : : }
3651 : :
3652 : : Assert(access(path, F_OK) != 0 && errno == ENOENT);
3653 [ - + ]: 3116 : if (durable_rename(tmppath, path, LOG) != 0)
3654 : : {
3655 : 0 : LWLockRelease(ControlFileLock);
3656 : : /* durable_rename already emitted log message */
3657 : 0 : return false;
3658 : : }
3659 : :
3660 : 3116 : LWLockRelease(ControlFileLock);
3661 : :
3662 : 3116 : return true;
3663 : : }
3664 : :
3665 : : /*
3666 : : * Open a pre-existing logfile segment for writing.
3667 : : */
3668 : : int
3669 : 207 : XLogFileOpen(XLogSegNo segno, TimeLineID tli)
3670 : : {
3671 : : char path[MAXPGPATH];
3672 : : int fd;
3673 : :
3674 : 207 : XLogFilePath(path, tli, segno, wal_segment_size);
3675 : :
3676 : 207 : fd = BasicOpenFile(path, O_RDWR | PG_BINARY | O_CLOEXEC |
3677 : 207 : get_sync_bit(wal_sync_method));
3678 [ - + ]: 207 : if (fd < 0)
3679 [ # # ]: 0 : ereport(PANIC,
3680 : : (errcode_for_file_access(),
3681 : : errmsg("could not open file \"%s\": %m", path)));
3682 : :
3683 : 207 : return fd;
3684 : : }
3685 : :
3686 : : /*
3687 : : * Close the current logfile segment for writing.
3688 : : */
3689 : : static void
3690 : 7082 : XLogFileClose(void)
3691 : : {
3692 : : Assert(openLogFile >= 0);
3693 : :
3694 : : /*
3695 : : * WAL segment files will not be re-read in normal operation, so we advise
3696 : : * the OS to release any cached pages. But do not do so if WAL archiving
3697 : : * or streaming is active, because archiver and walsender process could
3698 : : * use the cache to read the WAL segment.
3699 : : */
3700 : : #if defined(USE_POSIX_FADVISE) && defined(POSIX_FADV_DONTNEED)
3701 [ + + + - ]: 7082 : if (!XLogIsNeeded() && (io_direct_flags & IO_DIRECT_WAL) == 0)
3702 : 139 : (void) posix_fadvise(openLogFile, 0, 0, POSIX_FADV_DONTNEED);
3703 : : #endif
3704 : :
3705 [ - + ]: 7082 : if (close(openLogFile) != 0)
3706 : : {
3707 : : char xlogfname[MAXFNAMELEN];
3708 : 0 : int save_errno = errno;
3709 : :
3710 : 0 : XLogFileName(xlogfname, openLogTLI, openLogSegNo, wal_segment_size);
3711 : 0 : errno = save_errno;
3712 [ # # ]: 0 : ereport(PANIC,
3713 : : (errcode_for_file_access(),
3714 : : errmsg("could not close file \"%s\": %m", xlogfname)));
3715 : : }
3716 : :
3717 : 7082 : openLogFile = -1;
3718 : 7082 : ReleaseExternalFD();
3719 : 7082 : }
3720 : :
3721 : : /*
3722 : : * Preallocate log files beyond the specified log endpoint.
3723 : : *
3724 : : * XXX this is currently extremely conservative, since it forces only one
3725 : : * future log segment to exist, and even that only if we are 75% done with
3726 : : * the current one. This is only appropriate for very low-WAL-volume systems.
3727 : : * High-volume systems will be OK once they've built up a sufficient set of
3728 : : * recycled log segments, but the startup transient is likely to include
3729 : : * a lot of segment creations by foreground processes, which is not so good.
3730 : : *
3731 : : * XLogFileInitInternal() can ereport(ERROR). All known causes indicate big
3732 : : * trouble; for example, a full filesystem is one cause. The checkpoint WAL
3733 : : * and/or ControlFile updates already completed. If a RequestCheckpoint()
3734 : : * initiated the present checkpoint and an ERROR ends this function, the
3735 : : * command that called RequestCheckpoint() fails. That's not ideal, but it's
3736 : : * not worth contorting more functions to use caller-specified elevel values.
3737 : : * (With or without RequestCheckpoint(), an ERROR forestalls some inessential
3738 : : * reporting and resource reclamation.)
3739 : : */
3740 : : static void
3741 : 2226 : PreallocXlogFiles(XLogRecPtr endptr, TimeLineID tli)
3742 : : {
3743 : : XLogSegNo _logSegNo;
3744 : : int lf;
3745 : : bool added;
3746 : : char path[MAXPGPATH];
3747 : : uint64 offset;
3748 : :
3749 [ + + ]: 2226 : if (!XLogCtl->InstallXLogFileSegmentActive)
3750 : 10 : return; /* unlocked check says no */
3751 : :
3752 : 2216 : XLByteToPrevSeg(endptr, _logSegNo, wal_segment_size);
3753 : 2216 : offset = XLogSegmentOffset(endptr - 1, wal_segment_size);
3754 [ + + ]: 2216 : if (offset >= (uint32) (0.75 * wal_segment_size))
3755 : : {
3756 : 215 : _logSegNo++;
3757 : 215 : lf = XLogFileInitInternal(_logSegNo, tli, &added, path);
3758 [ + + ]: 215 : if (lf >= 0)
3759 : 151 : close(lf);
3760 [ + + ]: 215 : if (added)
3761 : 64 : CheckpointStats.ckpt_segs_added++;
3762 : : }
3763 : : }
3764 : :
3765 : : /*
3766 : : * Throws an error if the given log segment has already been removed or
3767 : : * recycled. The caller should only pass a segment that it knows to have
3768 : : * existed while the server has been running, as this function always
3769 : : * succeeds if no WAL segments have been removed since startup.
3770 : : * 'tli' is only used in the error message.
3771 : : *
3772 : : * Note: this function guarantees to keep errno unchanged on return.
3773 : : * This supports callers that use this to possibly deliver a better
3774 : : * error message about a missing file, while still being able to throw
3775 : : * a normal file-access error afterwards, if this does return.
3776 : : */
3777 : : void
3778 : 127759 : CheckXLogRemoved(XLogSegNo segno, TimeLineID tli)
3779 : : {
3780 : 127759 : int save_errno = errno;
3781 : : XLogSegNo lastRemovedSegNo;
3782 : :
3783 : 127759 : SpinLockAcquire(&XLogCtl->info_lck);
3784 : 127759 : lastRemovedSegNo = XLogCtl->lastRemovedSegNo;
3785 : 127759 : SpinLockRelease(&XLogCtl->info_lck);
3786 : :
3787 [ - + ]: 127759 : if (segno <= lastRemovedSegNo)
3788 : : {
3789 : : char filename[MAXFNAMELEN];
3790 : :
3791 : 0 : XLogFileName(filename, tli, segno, wal_segment_size);
3792 : 0 : errno = save_errno;
3793 [ # # ]: 0 : ereport(ERROR,
3794 : : (errcode_for_file_access(),
3795 : : errmsg("requested WAL segment %s has already been removed",
3796 : : filename)));
3797 : : }
3798 : 127759 : errno = save_errno;
3799 : 127759 : }
3800 : :
3801 : : /*
3802 : : * Return the last WAL segment removed, or 0 if no segment has been removed
3803 : : * since startup.
3804 : : *
3805 : : * NB: the result can be out of date arbitrarily fast, the caller has to deal
3806 : : * with that.
3807 : : */
3808 : : XLogSegNo
3809 : 1281 : XLogGetLastRemovedSegno(void)
3810 : : {
3811 : : XLogSegNo lastRemovedSegNo;
3812 : :
3813 : 1281 : SpinLockAcquire(&XLogCtl->info_lck);
3814 : 1281 : lastRemovedSegNo = XLogCtl->lastRemovedSegNo;
3815 : 1281 : SpinLockRelease(&XLogCtl->info_lck);
3816 : :
3817 : 1281 : return lastRemovedSegNo;
3818 : : }
3819 : :
3820 : : /*
3821 : : * Return the oldest WAL segment on the given TLI that still exists in
3822 : : * XLOGDIR, or 0 if none.
3823 : : */
3824 : : XLogSegNo
3825 : 7 : XLogGetOldestSegno(TimeLineID tli)
3826 : : {
3827 : : DIR *xldir;
3828 : : struct dirent *xlde;
3829 : 7 : XLogSegNo oldest_segno = 0;
3830 : :
3831 : 7 : xldir = AllocateDir(XLOGDIR);
3832 [ + + ]: 50 : while ((xlde = ReadDir(xldir, XLOGDIR)) != NULL)
3833 : : {
3834 : : TimeLineID file_tli;
3835 : : XLogSegNo file_segno;
3836 : :
3837 : : /* Ignore files that are not XLOG segments. */
3838 [ + + ]: 43 : if (!IsXLogFileName(xlde->d_name))
3839 : 29 : continue;
3840 : :
3841 : : /* Parse filename to get TLI and segno. */
3842 : 14 : XLogFromFileName(xlde->d_name, &file_tli, &file_segno,
3843 : : wal_segment_size);
3844 : :
3845 : : /* Ignore anything that's not from the TLI of interest. */
3846 [ - + ]: 14 : if (tli != file_tli)
3847 : 0 : continue;
3848 : :
3849 : : /* If it's the oldest so far, update oldest_segno. */
3850 [ + + + + ]: 14 : if (oldest_segno == 0 || file_segno < oldest_segno)
3851 : 9 : oldest_segno = file_segno;
3852 : : }
3853 : :
3854 : 7 : FreeDir(xldir);
3855 : 7 : return oldest_segno;
3856 : : }
3857 : :
3858 : : /*
3859 : : * Update the last removed segno pointer in shared memory, to reflect that the
3860 : : * given XLOG file has been removed.
3861 : : */
3862 : : static void
3863 : 2739 : UpdateLastRemovedPtr(char *filename)
3864 : : {
3865 : : uint32 tli;
3866 : : XLogSegNo segno;
3867 : :
3868 : 2739 : XLogFromFileName(filename, &tli, &segno, wal_segment_size);
3869 : :
3870 : 2739 : SpinLockAcquire(&XLogCtl->info_lck);
3871 [ + + ]: 2739 : if (segno > XLogCtl->lastRemovedSegNo)
3872 : 1243 : XLogCtl->lastRemovedSegNo = segno;
3873 : 2739 : SpinLockRelease(&XLogCtl->info_lck);
3874 : 2739 : }
3875 : :
3876 : : /*
3877 : : * Remove all temporary log files in pg_wal
3878 : : *
3879 : : * This is called at the beginning of recovery after a previous crash,
3880 : : * at a point where no other processes write fresh WAL data.
3881 : : */
3882 : : static void
3883 : 194 : RemoveTempXlogFiles(void)
3884 : : {
3885 : : DIR *xldir;
3886 : : struct dirent *xlde;
3887 : :
3888 [ + + ]: 194 : elog(DEBUG2, "removing all temporary WAL segments");
3889 : :
3890 : 194 : xldir = AllocateDir(XLOGDIR);
3891 [ + + ]: 1307 : while ((xlde = ReadDir(xldir, XLOGDIR)) != NULL)
3892 : : {
3893 : : char path[MAXPGPATH];
3894 : :
3895 [ + - ]: 1113 : if (strncmp(xlde->d_name, "xlogtemp.", 9) != 0)
3896 : 1113 : continue;
3897 : :
3898 : 0 : snprintf(path, MAXPGPATH, XLOGDIR "/%s", xlde->d_name);
3899 : 0 : unlink(path);
3900 [ # # ]: 0 : elog(DEBUG2, "removed temporary WAL segment \"%s\"", path);
3901 : : }
3902 : 194 : FreeDir(xldir);
3903 : 194 : }
3904 : :
3905 : : /*
3906 : : * Recycle or remove all log files older or equal to passed segno.
3907 : : *
3908 : : * endptr is current (or recent) end of xlog, and lastredoptr is the
3909 : : * redo pointer of the last checkpoint. These are used to determine
3910 : : * whether we want to recycle rather than delete no-longer-wanted log files.
3911 : : *
3912 : : * insertTLI is the current timeline for XLOG insertion. Any recycled
3913 : : * segments should be reused for this timeline.
3914 : : */
3915 : : static void
3916 : 1944 : RemoveOldXlogFiles(XLogSegNo segno, XLogRecPtr lastredoptr, XLogRecPtr endptr,
3917 : : TimeLineID insertTLI)
3918 : : {
3919 : : DIR *xldir;
3920 : : struct dirent *xlde;
3921 : : char lastoff[MAXFNAMELEN];
3922 : : XLogSegNo endlogSegNo;
3923 : : XLogSegNo recycleSegNo;
3924 : :
3925 : : /* Initialize info about where to try to recycle to */
3926 : 1944 : XLByteToSeg(endptr, endlogSegNo, wal_segment_size);
3927 : 1944 : recycleSegNo = XLOGfileslop(lastredoptr);
3928 : :
3929 : : /*
3930 : : * Construct a filename of the last segment to be kept. The timeline ID
3931 : : * doesn't matter, we ignore that in the comparison. (During recovery,
3932 : : * InsertTimeLineID isn't set, so we can't use that.)
3933 : : */
3934 : 1944 : XLogFileName(lastoff, 0, segno, wal_segment_size);
3935 : :
3936 [ + + ]: 1944 : elog(DEBUG2, "attempting to remove WAL segments older than log file %s",
3937 : : lastoff);
3938 : :
3939 : 1944 : xldir = AllocateDir(XLOGDIR);
3940 : :
3941 [ + + ]: 46119 : while ((xlde = ReadDir(xldir, XLOGDIR)) != NULL)
3942 : : {
3943 : : /* Ignore files that are not XLOG segments */
3944 [ + + ]: 44175 : if (!IsXLogFileName(xlde->d_name) &&
3945 [ + + ]: 8232 : !IsPartialXLogFileName(xlde->d_name))
3946 : 8230 : continue;
3947 : :
3948 : : /*
3949 : : * We ignore the timeline part of the XLOG segment identifiers in
3950 : : * deciding whether a segment is still needed. This ensures that we
3951 : : * won't prematurely remove a segment from a parent timeline. We could
3952 : : * probably be a little more proactive about removing segments of
3953 : : * non-parent timelines, but that would be a whole lot more
3954 : : * complicated.
3955 : : *
3956 : : * We use the alphanumeric sorting property of the filenames to decide
3957 : : * which ones are earlier than the lastoff segment.
3958 : : */
3959 [ + + ]: 35945 : if (strcmp(xlde->d_name + 8, lastoff + 8) <= 0)
3960 : : {
3961 [ + + ]: 29194 : if (XLogArchiveCheckDone(xlde->d_name))
3962 : : {
3963 : : /* Update the last removed location in shared memory first */
3964 : 2739 : UpdateLastRemovedPtr(xlde->d_name);
3965 : :
3966 : 2739 : RemoveXlogFile(xlde, recycleSegNo, &endlogSegNo, insertTLI);
3967 : : }
3968 : : }
3969 : : }
3970 : :
3971 : 1944 : FreeDir(xldir);
3972 : 1944 : }
3973 : :
3974 : : /*
3975 : : * Recycle or remove WAL files that are not part of the given timeline's
3976 : : * history.
3977 : : *
3978 : : * This is called during recovery, whenever we switch to follow a new
3979 : : * timeline, and at the end of recovery when we create a new timeline. We
3980 : : * wouldn't otherwise care about extra WAL files lying in pg_wal, but they
3981 : : * might be leftover pre-allocated or recycled WAL segments on the old timeline
3982 : : * that we haven't used yet, and contain garbage. If we just leave them in
3983 : : * pg_wal, they will eventually be archived, and we can't let that happen.
3984 : : * Files that belong to our timeline history are valid, because we have
3985 : : * successfully replayed them, but from others we can't be sure.
3986 : : *
3987 : : * 'switchpoint' is the current point in WAL where we switch to new timeline,
3988 : : * and 'newTLI' is the new timeline we switch to.
3989 : : */
3990 : : void
3991 : 73 : RemoveNonParentXlogFiles(XLogRecPtr switchpoint, TimeLineID newTLI)
3992 : : {
3993 : : DIR *xldir;
3994 : : struct dirent *xlde;
3995 : : char switchseg[MAXFNAMELEN];
3996 : : XLogSegNo endLogSegNo;
3997 : : XLogSegNo switchLogSegNo;
3998 : : XLogSegNo recycleSegNo;
3999 : :
4000 : : /*
4001 : : * Initialize info about where to begin the work. This will recycle,
4002 : : * somewhat arbitrarily, 10 future segments.
4003 : : */
4004 : 73 : XLByteToPrevSeg(switchpoint, switchLogSegNo, wal_segment_size);
4005 : 73 : XLByteToSeg(switchpoint, endLogSegNo, wal_segment_size);
4006 : 73 : recycleSegNo = endLogSegNo + 10;
4007 : :
4008 : : /*
4009 : : * Construct a filename of the last segment to be kept.
4010 : : */
4011 : 73 : XLogFileName(switchseg, newTLI, switchLogSegNo, wal_segment_size);
4012 : :
4013 [ + + ]: 73 : elog(DEBUG2, "attempting to remove WAL segments newer than log file %s",
4014 : : switchseg);
4015 : :
4016 : 73 : xldir = AllocateDir(XLOGDIR);
4017 : :
4018 [ + + ]: 691 : while ((xlde = ReadDir(xldir, XLOGDIR)) != NULL)
4019 : : {
4020 : : /* Ignore files that are not XLOG segments */
4021 [ + + ]: 618 : if (!IsXLogFileName(xlde->d_name))
4022 : 384 : continue;
4023 : :
4024 : : /*
4025 : : * Remove files that are on a timeline older than the new one we're
4026 : : * switching to, but with a segment number >= the first segment on the
4027 : : * new timeline.
4028 : : */
4029 [ + + ]: 234 : if (strncmp(xlde->d_name, switchseg, 8) < 0 &&
4030 [ + + ]: 152 : strcmp(xlde->d_name + 8, switchseg + 8) > 0)
4031 : : {
4032 : : /*
4033 : : * If the file has already been marked as .ready, however, don't
4034 : : * remove it yet. It should be OK to remove it - files that are
4035 : : * not part of our timeline history are not required for recovery
4036 : : * - but seems safer to let them be archived and removed later.
4037 : : */
4038 [ + - ]: 16 : if (!XLogArchiveIsReady(xlde->d_name))
4039 : 16 : RemoveXlogFile(xlde, recycleSegNo, &endLogSegNo, newTLI);
4040 : : }
4041 : : }
4042 : :
4043 : 73 : FreeDir(xldir);
4044 : 73 : }
4045 : :
4046 : : /*
4047 : : * Recycle or remove a log file that's no longer needed.
4048 : : *
4049 : : * segment_de is the dirent structure of the segment to recycle or remove.
4050 : : * recycleSegNo is the segment number to recycle up to. endlogSegNo is
4051 : : * the segment number of the current (or recent) end of WAL.
4052 : : *
4053 : : * endlogSegNo gets incremented if the segment is recycled so as it is not
4054 : : * checked again with future callers of this function.
4055 : : *
4056 : : * insertTLI is the current timeline for XLOG insertion. Any recycled segments
4057 : : * should be used for this timeline.
4058 : : */
4059 : : static void
4060 : 2755 : RemoveXlogFile(const struct dirent *segment_de,
4061 : : XLogSegNo recycleSegNo, XLogSegNo *endlogSegNo,
4062 : : TimeLineID insertTLI)
4063 : : {
4064 : : char path[MAXPGPATH];
4065 : : #ifdef WIN32
4066 : : char newpath[MAXPGPATH];
4067 : : #endif
4068 : 2755 : const char *segname = segment_de->d_name;
4069 : :
4070 : 2755 : snprintf(path, MAXPGPATH, XLOGDIR "/%s", segname);
4071 : :
4072 : : /*
4073 : : * Before deleting the file, see if it can be recycled as a future log
4074 : : * segment. Only recycle normal files, because we don't want to recycle
4075 : : * symbolic links pointing to a separate archive directory.
4076 : : */
4077 [ + - ]: 2755 : if (wal_recycle &&
4078 [ + + ]: 2755 : *endlogSegNo <= recycleSegNo &&
4079 [ + + + - ]: 3782 : XLogCtl->InstallXLogFileSegmentActive && /* callee rechecks this */
4080 [ + + ]: 3456 : get_dirent_type(path, segment_de, false, DEBUG2) == PGFILETYPE_REG &&
4081 : 1728 : InstallXLogFileSegment(endlogSegNo, path,
4082 : : true, recycleSegNo, insertTLI))
4083 : : {
4084 [ + + ]: 1564 : ereport(DEBUG2,
4085 : : (errmsg_internal("recycled write-ahead log file \"%s\"",
4086 : : segname)));
4087 : 1564 : CheckpointStats.ckpt_segs_recycled++;
4088 : : /* Needn't recheck that slot on future iterations */
4089 : 1564 : (*endlogSegNo)++;
4090 : : }
4091 : : else
4092 : : {
4093 : : /* No need for any more future segments, or recycling failed ... */
4094 : : int rc;
4095 : :
4096 [ - + ]: 1191 : ereport(DEBUG2,
4097 : : (errmsg_internal("removing write-ahead log file \"%s\"",
4098 : : segname)));
4099 : :
4100 : : #ifdef WIN32
4101 : :
4102 : : /*
4103 : : * On Windows, if another process (e.g another backend) holds the file
4104 : : * open in FILE_SHARE_DELETE mode, unlink will succeed, but the file
4105 : : * will still show up in directory listing until the last handle is
4106 : : * closed. To avoid confusing the lingering deleted file for a live
4107 : : * WAL file that needs to be archived, rename it before deleting it.
4108 : : *
4109 : : * If another process holds the file open without FILE_SHARE_DELETE
4110 : : * flag, rename will fail. We'll try again at the next checkpoint.
4111 : : */
4112 : : snprintf(newpath, MAXPGPATH, "%s.deleted", path);
4113 : : if (rename(path, newpath) != 0)
4114 : : {
4115 : : ereport(LOG,
4116 : : (errcode_for_file_access(),
4117 : : errmsg("could not rename file \"%s\": %m",
4118 : : path)));
4119 : : return;
4120 : : }
4121 : : rc = durable_unlink(newpath, LOG);
4122 : : #else
4123 : 1191 : rc = durable_unlink(path, LOG);
4124 : : #endif
4125 [ - + ]: 1191 : if (rc != 0)
4126 : : {
4127 : : /* Message already logged by durable_unlink() */
4128 : 0 : return;
4129 : : }
4130 : 1191 : CheckpointStats.ckpt_segs_removed++;
4131 : : }
4132 : :
4133 : 2755 : XLogArchiveCleanup(segname);
4134 : : }
4135 : :
4136 : : /*
4137 : : * Verify whether pg_wal, pg_wal/archive_status, and pg_wal/summaries exist.
4138 : : * If the latter do not exist, recreate them.
4139 : : *
4140 : : * It is not the goal of this function to verify the contents of these
4141 : : * directories, but to help in cases where someone has performed a cluster
4142 : : * copy for PITR purposes but omitted pg_wal from the copy.
4143 : : *
4144 : : * We could also recreate pg_wal if it doesn't exist, but a deliberate
4145 : : * policy decision was made not to. It is fairly common for pg_wal to be
4146 : : * a symlink, and if that was the DBA's intent then automatically making a
4147 : : * plain directory would result in degraded performance with no notice.
4148 : : */
4149 : : static void
4150 : 1088 : ValidateXLOGDirectoryStructure(void)
4151 : : {
4152 : : char path[MAXPGPATH];
4153 : : struct stat stat_buf;
4154 : :
4155 : : /* Check for pg_wal; if it doesn't exist, error out */
4156 [ + - ]: 1088 : if (stat(XLOGDIR, &stat_buf) != 0 ||
4157 [ - + ]: 1088 : !S_ISDIR(stat_buf.st_mode))
4158 [ # # ]: 0 : ereport(FATAL,
4159 : : (errcode_for_file_access(),
4160 : : errmsg("required WAL directory \"%s\" does not exist",
4161 : : XLOGDIR)));
4162 : :
4163 : : /* Check for archive_status */
4164 : 1088 : snprintf(path, MAXPGPATH, XLOGDIR "/archive_status");
4165 [ + + ]: 1088 : if (stat(path, &stat_buf) == 0)
4166 : : {
4167 : : /* Check for weird cases where it exists but isn't a directory */
4168 [ - + ]: 1087 : if (!S_ISDIR(stat_buf.st_mode))
4169 [ # # ]: 0 : ereport(FATAL,
4170 : : (errcode_for_file_access(),
4171 : : errmsg("required WAL directory \"%s\" does not exist",
4172 : : path)));
4173 : : }
4174 : : else
4175 : : {
4176 [ + - ]: 1 : ereport(LOG,
4177 : : (errmsg("creating missing WAL directory \"%s\"", path)));
4178 [ - + ]: 1 : if (MakePGDirectory(path) < 0)
4179 [ # # ]: 0 : ereport(FATAL,
4180 : : (errcode_for_file_access(),
4181 : : errmsg("could not create missing directory \"%s\": %m",
4182 : : path)));
4183 : : }
4184 : :
4185 : : /* Check for summaries */
4186 : 1088 : snprintf(path, MAXPGPATH, XLOGDIR "/summaries");
4187 [ + + ]: 1088 : if (stat(path, &stat_buf) == 0)
4188 : : {
4189 : : /* Check for weird cases where it exists but isn't a directory */
4190 [ - + ]: 1087 : if (!S_ISDIR(stat_buf.st_mode))
4191 [ # # ]: 0 : ereport(FATAL,
4192 : : (errmsg("required WAL directory \"%s\" does not exist",
4193 : : path)));
4194 : : }
4195 : : else
4196 : : {
4197 [ + - ]: 1 : ereport(LOG,
4198 : : (errmsg("creating missing WAL directory \"%s\"", path)));
4199 [ - + ]: 1 : if (MakePGDirectory(path) < 0)
4200 [ # # ]: 0 : ereport(FATAL,
4201 : : (errmsg("could not create missing directory \"%s\": %m",
4202 : : path)));
4203 : : }
4204 : 1088 : }
4205 : :
4206 : : /*
4207 : : * Remove previous backup history files. This also retries creation of
4208 : : * .ready files for any backup history files for which XLogArchiveNotify
4209 : : * failed earlier.
4210 : : */
4211 : : static void
4212 : 162 : CleanupBackupHistory(void)
4213 : : {
4214 : : DIR *xldir;
4215 : : struct dirent *xlde;
4216 : : char path[MAXPGPATH + sizeof(XLOGDIR)];
4217 : :
4218 : 162 : xldir = AllocateDir(XLOGDIR);
4219 : :
4220 [ + + ]: 1665 : while ((xlde = ReadDir(xldir, XLOGDIR)) != NULL)
4221 : : {
4222 [ + + ]: 1341 : if (IsBackupHistoryFileName(xlde->d_name))
4223 : : {
4224 [ + + ]: 171 : if (XLogArchiveCheckDone(xlde->d_name))
4225 : : {
4226 [ + + ]: 135 : elog(DEBUG2, "removing WAL backup history file \"%s\"",
4227 : : xlde->d_name);
4228 : 135 : snprintf(path, sizeof(path), XLOGDIR "/%s", xlde->d_name);
4229 : 135 : unlink(path);
4230 : 135 : XLogArchiveCleanup(xlde->d_name);
4231 : : }
4232 : : }
4233 : : }
4234 : :
4235 : 162 : FreeDir(xldir);
4236 : 162 : }
4237 : :
4238 : : /*
4239 : : * I/O routines for pg_control
4240 : : *
4241 : : * *ControlFile is a buffer in shared memory that holds an image of the
4242 : : * contents of pg_control. WriteControlFile() initializes pg_control
4243 : : * given a preloaded buffer, ReadControlFile() loads the buffer from
4244 : : * the pg_control file (during postmaster or standalone-backend startup),
4245 : : * and UpdateControlFile() rewrites pg_control after we modify xlog state.
4246 : : * InitControlFile() fills the buffer with initial values.
4247 : : *
4248 : : * For simplicity, WriteControlFile() initializes the fields of pg_control
4249 : : * that are related to checking backend/database compatibility, and
4250 : : * ReadControlFile() verifies they are correct. We could split out the
4251 : : * I/O and compatibility-check functions, but there seems no need currently.
4252 : : */
4253 : :
4254 : : static void
4255 : 57 : InitControlFile(uint64 sysidentifier, uint32 data_checksum_version)
4256 : : {
4257 : : char mock_auth_nonce[MOCK_AUTH_NONCE_LEN];
4258 : :
4259 : : /*
4260 : : * Generate a random nonce. This is used for authentication requests that
4261 : : * will fail because the user does not exist. The nonce is used to create
4262 : : * a genuine-looking password challenge for the non-existent user, in lieu
4263 : : * of an actual stored password.
4264 : : */
4265 [ - + ]: 57 : if (!pg_strong_random(mock_auth_nonce, MOCK_AUTH_NONCE_LEN))
4266 [ # # ]: 0 : ereport(PANIC,
4267 : : (errcode(ERRCODE_INTERNAL_ERROR),
4268 : : errmsg("could not generate secret authorization token")));
4269 : :
4270 : 57 : memset(ControlFile, 0, sizeof(ControlFileData));
4271 : : /* Initialize pg_control status fields */
4272 : 57 : ControlFile->system_identifier = sysidentifier;
4273 : 57 : memcpy(ControlFile->mock_authentication_nonce, mock_auth_nonce, MOCK_AUTH_NONCE_LEN);
4274 : 57 : ControlFile->state = DB_SHUTDOWNED;
4275 : 57 : ControlFile->unloggedLSN = FirstNormalUnloggedLSN;
4276 : :
4277 : : /* Set important parameter values for use when replaying WAL */
4278 : 57 : ControlFile->MaxConnections = MaxConnections;
4279 : 57 : ControlFile->max_worker_processes = max_worker_processes;
4280 : 57 : ControlFile->max_wal_senders = max_wal_senders;
4281 : 57 : ControlFile->max_prepared_xacts = max_prepared_xacts;
4282 : 57 : ControlFile->max_locks_per_xact = max_locks_per_xact;
4283 : 57 : ControlFile->wal_level = wal_level;
4284 : 57 : ControlFile->wal_log_hints = wal_log_hints;
4285 : 57 : ControlFile->track_commit_timestamp = track_commit_timestamp;
4286 : 57 : ControlFile->data_checksum_version = data_checksum_version;
4287 : :
4288 : : /*
4289 : : * Set the data_checksum_version value into XLogCtl, which is where all
4290 : : * processes get the current value from.
4291 : : */
4292 : 57 : XLogCtl->data_checksum_version = data_checksum_version;
4293 : 57 : }
4294 : :
4295 : : static void
4296 : 57 : WriteControlFile(void)
4297 : : {
4298 : : int fd;
4299 : : char buffer[PG_CONTROL_FILE_SIZE]; /* need not be aligned */
4300 : :
4301 : : /*
4302 : : * Initialize version and compatibility-check fields
4303 : : */
4304 : 57 : ControlFile->pg_control_version = PG_CONTROL_VERSION;
4305 : 57 : ControlFile->catalog_version_no = CATALOG_VERSION_NO;
4306 : :
4307 : 57 : ControlFile->maxAlign = MAXIMUM_ALIGNOF;
4308 : 57 : ControlFile->floatFormat = FLOATFORMAT_VALUE;
4309 : :
4310 : 57 : ControlFile->blcksz = BLCKSZ;
4311 : 57 : ControlFile->relseg_size = RELSEG_SIZE;
4312 : 57 : ControlFile->slru_pages_per_segment = SLRU_PAGES_PER_SEGMENT;
4313 : 57 : ControlFile->xlog_blcksz = XLOG_BLCKSZ;
4314 : 57 : ControlFile->xlog_seg_size = wal_segment_size;
4315 : :
4316 : 57 : ControlFile->nameDataLen = NAMEDATALEN;
4317 : 57 : ControlFile->indexMaxKeys = INDEX_MAX_KEYS;
4318 : :
4319 : 57 : ControlFile->toast_max_chunk_size = TOAST_MAX_CHUNK_SIZE;
4320 : 57 : ControlFile->loblksize = LOBLKSIZE;
4321 : :
4322 : 57 : ControlFile->float8ByVal = true; /* vestigial */
4323 : :
4324 : : /*
4325 : : * Initialize the default 'char' signedness.
4326 : : *
4327 : : * The signedness of the char type is implementation-defined. For instance
4328 : : * on x86 architecture CPUs, the char data type is typically treated as
4329 : : * signed by default, whereas on aarch architecture CPUs, it is typically
4330 : : * treated as unsigned by default. In v17 or earlier, we accidentally let
4331 : : * C implementation signedness affect persistent data. This led to
4332 : : * inconsistent results when comparing char data across different
4333 : : * platforms.
4334 : : *
4335 : : * This flag can be used as a hint to ensure consistent behavior for
4336 : : * pre-v18 data files that store data sorted by the 'char' type on disk,
4337 : : * especially in cross-platform replication scenarios.
4338 : : *
4339 : : * Newly created database clusters unconditionally set the default char
4340 : : * signedness to true. pg_upgrade changes this flag for clusters that were
4341 : : * initialized on signedness=false platforms. As a result,
4342 : : * signedness=false setting will become rare over time. If we had known
4343 : : * about this problem during the last development cycle that forced initdb
4344 : : * (v8.3), we would have made all clusters signed or all clusters
4345 : : * unsigned. Making pg_upgrade the only source of signedness=false will
4346 : : * cause the population of database clusters to converge toward that
4347 : : * retrospective ideal.
4348 : : */
4349 : 57 : ControlFile->default_char_signedness = true;
4350 : :
4351 : : /* Contents are protected with a CRC */
4352 : 57 : INIT_CRC32C(ControlFile->crc);
4353 : 57 : COMP_CRC32C(ControlFile->crc,
4354 : : ControlFile,
4355 : : offsetof(ControlFileData, crc));
4356 : 57 : FIN_CRC32C(ControlFile->crc);
4357 : :
4358 : : /*
4359 : : * We write out PG_CONTROL_FILE_SIZE bytes into pg_control, zero-padding
4360 : : * the excess over sizeof(ControlFileData). This reduces the odds of
4361 : : * premature-EOF errors when reading pg_control. We'll still fail when we
4362 : : * check the contents of the file, but hopefully with a more specific
4363 : : * error than "couldn't read pg_control".
4364 : : */
4365 : 57 : memset(buffer, 0, PG_CONTROL_FILE_SIZE);
4366 : 57 : memcpy(buffer, ControlFile, sizeof(ControlFileData));
4367 : :
4368 : 57 : fd = BasicOpenFile(XLOG_CONTROL_FILE,
4369 : : O_RDWR | O_CREAT | O_EXCL | PG_BINARY);
4370 [ - + ]: 57 : if (fd < 0)
4371 [ # # ]: 0 : ereport(PANIC,
4372 : : (errcode_for_file_access(),
4373 : : errmsg("could not create file \"%s\": %m",
4374 : : XLOG_CONTROL_FILE)));
4375 : :
4376 : 57 : errno = 0;
4377 : 57 : pgstat_report_wait_start(WAIT_EVENT_CONTROL_FILE_WRITE);
4378 [ - + ]: 57 : if (write(fd, buffer, PG_CONTROL_FILE_SIZE) != PG_CONTROL_FILE_SIZE)
4379 : : {
4380 : : /* if write didn't set errno, assume problem is no disk space */
4381 [ # # ]: 0 : if (errno == 0)
4382 : 0 : errno = ENOSPC;
4383 [ # # ]: 0 : ereport(PANIC,
4384 : : (errcode_for_file_access(),
4385 : : errmsg("could not write to file \"%s\": %m",
4386 : : XLOG_CONTROL_FILE)));
4387 : : }
4388 : 57 : pgstat_report_wait_end();
4389 : :
4390 : 57 : pgstat_report_wait_start(WAIT_EVENT_CONTROL_FILE_SYNC);
4391 [ - + ]: 57 : if (pg_fsync(fd) != 0)
4392 [ # # ]: 0 : ereport(PANIC,
4393 : : (errcode_for_file_access(),
4394 : : errmsg("could not fsync file \"%s\": %m",
4395 : : XLOG_CONTROL_FILE)));
4396 : 57 : pgstat_report_wait_end();
4397 : :
4398 [ - + ]: 57 : if (close(fd) != 0)
4399 [ # # ]: 0 : ereport(PANIC,
4400 : : (errcode_for_file_access(),
4401 : : errmsg("could not close file \"%s\": %m",
4402 : : XLOG_CONTROL_FILE)));
4403 : 57 : }
4404 : :
4405 : : static void
4406 : 1148 : ReadControlFile(void)
4407 : : {
4408 : : pg_crc32c crc;
4409 : : int fd;
4410 : : char wal_segsz_str[20];
4411 : : int r;
4412 : :
4413 : : /*
4414 : : * Read data...
4415 : : */
4416 : 1148 : fd = BasicOpenFile(XLOG_CONTROL_FILE,
4417 : : O_RDWR | PG_BINARY);
4418 [ - + ]: 1148 : if (fd < 0)
4419 [ # # ]: 0 : ereport(PANIC,
4420 : : (errcode_for_file_access(),
4421 : : errmsg("could not open file \"%s\": %m",
4422 : : XLOG_CONTROL_FILE)));
4423 : :
4424 : 1148 : pgstat_report_wait_start(WAIT_EVENT_CONTROL_FILE_READ);
4425 : 1148 : r = read(fd, ControlFile, sizeof(ControlFileData));
4426 [ - + ]: 1148 : if (r != sizeof(ControlFileData))
4427 : : {
4428 [ # # ]: 0 : if (r < 0)
4429 [ # # ]: 0 : ereport(PANIC,
4430 : : (errcode_for_file_access(),
4431 : : errmsg("could not read file \"%s\": %m",
4432 : : XLOG_CONTROL_FILE)));
4433 : : else
4434 [ # # ]: 0 : ereport(PANIC,
4435 : : (errcode(ERRCODE_DATA_CORRUPTED),
4436 : : errmsg("could not read file \"%s\": read %d of %zu",
4437 : : XLOG_CONTROL_FILE, r, sizeof(ControlFileData))));
4438 : : }
4439 : 1148 : pgstat_report_wait_end();
4440 : :
4441 : 1148 : close(fd);
4442 : :
4443 : : /*
4444 : : * Check for expected pg_control format version. If this is wrong, the
4445 : : * CRC check will likely fail because we'll be checking the wrong number
4446 : : * of bytes. Complaining about wrong version will probably be more
4447 : : * enlightening than complaining about wrong CRC.
4448 : : */
4449 : :
4450 [ - + - - : 1148 : if (ControlFile->pg_control_version != PG_CONTROL_VERSION && ControlFile->pg_control_version % 65536 == 0 && ControlFile->pg_control_version / 65536 != 0)
- - ]
4451 [ # # ]: 0 : ereport(FATAL,
4452 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4453 : : errmsg("database files are incompatible with server"),
4454 : : errdetail("The database cluster was initialized with PG_CONTROL_VERSION %d (0x%08x),"
4455 : : " but the server was compiled with PG_CONTROL_VERSION %d (0x%08x).",
4456 : : ControlFile->pg_control_version, ControlFile->pg_control_version,
4457 : : PG_CONTROL_VERSION, PG_CONTROL_VERSION),
4458 : : errhint("This could be a problem of mismatched byte ordering. It looks like you need to initdb.")));
4459 : :
4460 [ - + ]: 1148 : if (ControlFile->pg_control_version != PG_CONTROL_VERSION)
4461 [ # # ]: 0 : ereport(FATAL,
4462 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4463 : : errmsg("database files are incompatible with server"),
4464 : : errdetail("The database cluster was initialized with PG_CONTROL_VERSION %d,"
4465 : : " but the server was compiled with PG_CONTROL_VERSION %d.",
4466 : : ControlFile->pg_control_version, PG_CONTROL_VERSION),
4467 : : errhint("It looks like you need to initdb.")));
4468 : :
4469 : : /* Now check the CRC. */
4470 : 1148 : INIT_CRC32C(crc);
4471 : 1148 : COMP_CRC32C(crc,
4472 : : ControlFile,
4473 : : offsetof(ControlFileData, crc));
4474 : 1148 : FIN_CRC32C(crc);
4475 : :
4476 [ - + ]: 1148 : if (!EQ_CRC32C(crc, ControlFile->crc))
4477 [ # # ]: 0 : ereport(FATAL,
4478 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4479 : : errmsg("incorrect checksum in control file")));
4480 : :
4481 : : /*
4482 : : * Do compatibility checking immediately. If the database isn't
4483 : : * compatible with the backend executable, we want to abort before we can
4484 : : * possibly do any damage.
4485 : : */
4486 [ - + ]: 1148 : if (ControlFile->catalog_version_no != CATALOG_VERSION_NO)
4487 [ # # ]: 0 : ereport(FATAL,
4488 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4489 : : errmsg("database files are incompatible with server"),
4490 : : /* translator: %s is a variable name and %d is its value */
4491 : : errdetail("The database cluster was initialized with %s %d,"
4492 : : " but the server was compiled with %s %d.",
4493 : : "CATALOG_VERSION_NO", ControlFile->catalog_version_no,
4494 : : "CATALOG_VERSION_NO", CATALOG_VERSION_NO),
4495 : : errhint("It looks like you need to initdb.")));
4496 [ - + ]: 1148 : if (ControlFile->maxAlign != MAXIMUM_ALIGNOF)
4497 [ # # ]: 0 : ereport(FATAL,
4498 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4499 : : errmsg("database files are incompatible with server"),
4500 : : /* translator: %s is a variable name and %d is its value */
4501 : : errdetail("The database cluster was initialized with %s %d,"
4502 : : " but the server was compiled with %s %d.",
4503 : : "MAXALIGN", ControlFile->maxAlign,
4504 : : "MAXALIGN", MAXIMUM_ALIGNOF),
4505 : : errhint("It looks like you need to initdb.")));
4506 [ - + ]: 1148 : if (ControlFile->floatFormat != FLOATFORMAT_VALUE)
4507 [ # # ]: 0 : ereport(FATAL,
4508 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4509 : : errmsg("database files are incompatible with server"),
4510 : : errdetail("The database cluster appears to use a different floating-point number format than the server executable."),
4511 : : errhint("It looks like you need to initdb.")));
4512 [ - + ]: 1148 : if (ControlFile->blcksz != BLCKSZ)
4513 [ # # ]: 0 : ereport(FATAL,
4514 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4515 : : errmsg("database files are incompatible with server"),
4516 : : /* translator: %s is a variable name and %d is its value */
4517 : : errdetail("The database cluster was initialized with %s %d,"
4518 : : " but the server was compiled with %s %d.",
4519 : : "BLCKSZ", ControlFile->blcksz,
4520 : : "BLCKSZ", BLCKSZ),
4521 : : errhint("It looks like you need to recompile or initdb.")));
4522 [ - + ]: 1148 : if (ControlFile->relseg_size != RELSEG_SIZE)
4523 [ # # ]: 0 : ereport(FATAL,
4524 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4525 : : errmsg("database files are incompatible with server"),
4526 : : /* translator: %s is a variable name and %d is its value */
4527 : : errdetail("The database cluster was initialized with %s %d,"
4528 : : " but the server was compiled with %s %d.",
4529 : : "RELSEG_SIZE", ControlFile->relseg_size,
4530 : : "RELSEG_SIZE", RELSEG_SIZE),
4531 : : errhint("It looks like you need to recompile or initdb.")));
4532 [ - + ]: 1148 : if (ControlFile->slru_pages_per_segment != SLRU_PAGES_PER_SEGMENT)
4533 [ # # ]: 0 : ereport(FATAL,
4534 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4535 : : errmsg("database files are incompatible with server"),
4536 : : /* translator: %s is a variable name and %d is its value */
4537 : : errdetail("The database cluster was initialized with %s %d,"
4538 : : " but the server was compiled with %s %d.",
4539 : : "SLRU_PAGES_PER_SEGMENT", ControlFile->slru_pages_per_segment,
4540 : : "SLRU_PAGES_PER_SEGMENT", SLRU_PAGES_PER_SEGMENT),
4541 : : errhint("It looks like you need to recompile or initdb.")));
4542 [ - + ]: 1148 : if (ControlFile->xlog_blcksz != XLOG_BLCKSZ)
4543 [ # # ]: 0 : ereport(FATAL,
4544 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4545 : : errmsg("database files are incompatible with server"),
4546 : : /* translator: %s is a variable name and %d is its value */
4547 : : errdetail("The database cluster was initialized with %s %d,"
4548 : : " but the server was compiled with %s %d.",
4549 : : "XLOG_BLCKSZ", ControlFile->xlog_blcksz,
4550 : : "XLOG_BLCKSZ", XLOG_BLCKSZ),
4551 : : errhint("It looks like you need to recompile or initdb.")));
4552 [ - + ]: 1148 : if (ControlFile->nameDataLen != NAMEDATALEN)
4553 [ # # ]: 0 : ereport(FATAL,
4554 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4555 : : errmsg("database files are incompatible with server"),
4556 : : /* translator: %s is a variable name and %d is its value */
4557 : : errdetail("The database cluster was initialized with %s %d,"
4558 : : " but the server was compiled with %s %d.",
4559 : : "NAMEDATALEN", ControlFile->nameDataLen,
4560 : : "NAMEDATALEN", NAMEDATALEN),
4561 : : errhint("It looks like you need to recompile or initdb.")));
4562 [ - + ]: 1148 : if (ControlFile->indexMaxKeys != INDEX_MAX_KEYS)
4563 [ # # ]: 0 : ereport(FATAL,
4564 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4565 : : errmsg("database files are incompatible with server"),
4566 : : /* translator: %s is a variable name and %d is its value */
4567 : : errdetail("The database cluster was initialized with %s %d,"
4568 : : " but the server was compiled with %s %d.",
4569 : : "INDEX_MAX_KEYS", ControlFile->indexMaxKeys,
4570 : : "INDEX_MAX_KEYS", INDEX_MAX_KEYS),
4571 : : errhint("It looks like you need to recompile or initdb.")));
4572 [ - + ]: 1148 : if (ControlFile->toast_max_chunk_size != TOAST_MAX_CHUNK_SIZE)
4573 [ # # ]: 0 : ereport(FATAL,
4574 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4575 : : errmsg("database files are incompatible with server"),
4576 : : /* translator: %s is a variable name and %d is its value */
4577 : : errdetail("The database cluster was initialized with %s %d,"
4578 : : " but the server was compiled with %s %d.",
4579 : : "TOAST_MAX_CHUNK_SIZE", ControlFile->toast_max_chunk_size,
4580 : : "TOAST_MAX_CHUNK_SIZE", (int) TOAST_MAX_CHUNK_SIZE),
4581 : : errhint("It looks like you need to recompile or initdb.")));
4582 [ - + ]: 1148 : if (ControlFile->loblksize != LOBLKSIZE)
4583 [ # # ]: 0 : ereport(FATAL,
4584 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
4585 : : errmsg("database files are incompatible with server"),
4586 : : /* translator: %s is a variable name and %d is its value */
4587 : : errdetail("The database cluster was initialized with %s %d,"
4588 : : " but the server was compiled with %s %d.",
4589 : : "LOBLKSIZE", ControlFile->loblksize,
4590 : : "LOBLKSIZE", (int) LOBLKSIZE),
4591 : : errhint("It looks like you need to recompile or initdb.")));
4592 : :
4593 : : Assert(ControlFile->float8ByVal); /* vestigial, not worth an error msg */
4594 : :
4595 : 1148 : wal_segment_size = ControlFile->xlog_seg_size;
4596 : :
4597 [ + - + - : 1148 : if (!IsValidWalSegSize(wal_segment_size))
+ - - + ]
4598 [ # # ]: 0 : ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4599 : : errmsg_plural("invalid WAL segment size in control file (%d byte)",
4600 : : "invalid WAL segment size in control file (%d bytes)",
4601 : : wal_segment_size,
4602 : : wal_segment_size),
4603 : : errdetail("The WAL segment size must be a power of two between 1 MB and 1 GB.")));
4604 : :
4605 : 1148 : snprintf(wal_segsz_str, sizeof(wal_segsz_str), "%d", wal_segment_size);
4606 : 1148 : SetConfigOption("wal_segment_size", wal_segsz_str, PGC_INTERNAL,
4607 : : PGC_S_DYNAMIC_DEFAULT);
4608 : :
4609 : : /* check and update variables dependent on wal_segment_size */
4610 [ - + ]: 1148 : if (ConvertToXSegs(min_wal_size_mb, wal_segment_size) < 2)
4611 [ # # ]: 0 : ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4612 : : /* translator: both %s are GUC names */
4613 : : errmsg("\"%s\" must be at least twice \"%s\"",
4614 : : "min_wal_size", "wal_segment_size")));
4615 : :
4616 [ - + ]: 1148 : if (ConvertToXSegs(max_wal_size_mb, wal_segment_size) < 2)
4617 [ # # ]: 0 : ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4618 : : /* translator: both %s are GUC names */
4619 : : errmsg("\"%s\" must be at least twice \"%s\"",
4620 : : "max_wal_size", "wal_segment_size")));
4621 : :
4622 : 1148 : UsableBytesInSegment =
4623 : 1148 : (wal_segment_size / XLOG_BLCKSZ * UsableBytesInPage) -
4624 : : (SizeOfXLogLongPHD - SizeOfXLogShortPHD);
4625 : :
4626 : 1148 : CalculateCheckpointSegments();
4627 : 1148 : }
4628 : :
4629 : : /*
4630 : : * Utility wrapper to update the control file. Note that the control
4631 : : * file gets flushed.
4632 : : */
4633 : : static void
4634 : 10469 : UpdateControlFile(void)
4635 : : {
4636 : 10469 : update_controlfile(DataDir, ControlFile, true);
4637 : 10469 : }
4638 : :
4639 : : /*
4640 : : * Returns the unique system identifier from control file.
4641 : : */
4642 : : uint64
4643 : 1557 : GetSystemIdentifier(void)
4644 : : {
4645 : : Assert(ControlFile != NULL);
4646 : 1557 : return ControlFile->system_identifier;
4647 : : }
4648 : :
4649 : : /*
4650 : : * Returns the random nonce from control file.
4651 : : */
4652 : : char *
4653 : 2 : GetMockAuthenticationNonce(void)
4654 : : {
4655 : : Assert(ControlFile != NULL);
4656 : 2 : return ControlFile->mock_authentication_nonce;
4657 : : }
4658 : :
4659 : : /*
4660 : : * DataChecksumsNeedWrite
4661 : : * Returns whether data checksums must be written or not
4662 : : *
4663 : : * Returns true if data checksums are enabled, or are in the process of being
4664 : : * enabled. During "inprogress-on" and "inprogress-off" states checksums must
4665 : : * be written even though they are not verified (see datachecksum_state.c for
4666 : : * a longer discussion).
4667 : : *
4668 : : * This function is intended for callsites which are about to write a data page
4669 : : * to storage, and need to know whether to re-calculate the checksum for the
4670 : : * page header. Calling this function must be performed as close to the write
4671 : : * operation as possible to keep the critical section short.
4672 : : */
4673 : : bool
4674 : 860437 : DataChecksumsNeedWrite(void)
4675 : : {
4676 : 965948 : return (LocalDataChecksumState == PG_DATA_CHECKSUM_VERSION ||
4677 [ + + + + ]: 924411 : LocalDataChecksumState == PG_DATA_CHECKSUM_INPROGRESS_ON ||
4678 [ + + ]: 63974 : LocalDataChecksumState == PG_DATA_CHECKSUM_INPROGRESS_OFF);
4679 : : }
4680 : :
4681 : :
4682 : : bool
4683 : 7 : DataChecksumsOff(void)
4684 : : {
4685 : : bool ret;
4686 : :
4687 : 7 : SpinLockAcquire(&XLogCtl->info_lck);
4688 : 7 : ret = (XLogCtl->data_checksum_version == PG_DATA_CHECKSUM_OFF);
4689 : 7 : SpinLockRelease(&XLogCtl->info_lck);
4690 : :
4691 : 7 : return ret;
4692 : : }
4693 : :
4694 : : bool
4695 : 11 : DataChecksumsOn(void)
4696 : : {
4697 : : bool ret;
4698 : :
4699 : 11 : SpinLockAcquire(&XLogCtl->info_lck);
4700 : 11 : ret = (XLogCtl->data_checksum_version == PG_DATA_CHECKSUM_VERSION);
4701 : 11 : SpinLockRelease(&XLogCtl->info_lck);
4702 : :
4703 : 11 : return ret;
4704 : : }
4705 : :
4706 : : bool
4707 : 166 : DataChecksumsInProgressOn(void)
4708 : : {
4709 : : bool ret;
4710 : :
4711 : 166 : SpinLockAcquire(&XLogCtl->info_lck);
4712 : 166 : ret = (XLogCtl->data_checksum_version == PG_DATA_CHECKSUM_INPROGRESS_ON);
4713 : 166 : SpinLockRelease(&XLogCtl->info_lck);
4714 : :
4715 : 166 : return ret;
4716 : : }
4717 : :
4718 : : /*
4719 : : * DataChecksumsNeedVerify
4720 : : * Returns whether data checksums must be verified or not
4721 : : *
4722 : : * Data checksums are only verified if they are fully enabled in the cluster.
4723 : : * During the "inprogress-on" and "inprogress-off" states they are only
4724 : : * updated, not verified (see datachecksum_state.c for a longer discussion).
4725 : : *
4726 : : * This function is intended for callsites which have read data and are about
4727 : : * to perform checksum validation based on the result of this. Calling this
4728 : : * function must be performed as close to the validation call as possible to
4729 : : * keep the critical section short. This is in order to protect against time of
4730 : : * check/time of use situations around data checksum validation.
4731 : : */
4732 : : bool
4733 : 2676020 : DataChecksumsNeedVerify(void)
4734 : : {
4735 : 2676020 : return (LocalDataChecksumState == PG_DATA_CHECKSUM_VERSION);
4736 : : }
4737 : :
4738 : : /*
4739 : : * SetDataChecksumsOnInProgress
4740 : : * Sets the data checksum state to "inprogress-on" to enable checksums
4741 : : *
4742 : : * To start the process of enabling data checksums in a running cluster the
4743 : : * data_checksum_version state must be changed to "inprogress-on". See
4744 : : * SetDataChecksumsOn below for a description on how this state change works.
4745 : : * This function blocks until all backends in the cluster have acknowledged the
4746 : : * state transition.
4747 : : */
4748 : : void
4749 : 9 : SetDataChecksumsOnInProgress(void)
4750 : : {
4751 : : uint64 barrier;
4752 : :
4753 : : /*
4754 : : * The state transition is performed in a critical section with
4755 : : * checkpoints held off to provide crash safety.
4756 : : */
4757 : 9 : START_CRIT_SECTION();
4758 : 9 : MyProc->delayChkptFlags |= DELAY_CHKPT_START;
4759 : :
4760 : 9 : XLogChecksums(PG_DATA_CHECKSUM_INPROGRESS_ON);
4761 : :
4762 : 9 : SpinLockAcquire(&XLogCtl->info_lck);
4763 : 9 : XLogCtl->data_checksum_version = PG_DATA_CHECKSUM_INPROGRESS_ON;
4764 : 9 : SpinLockRelease(&XLogCtl->info_lck);
4765 : :
4766 : 9 : LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
4767 : 9 : ControlFile->data_checksum_version = PG_DATA_CHECKSUM_INPROGRESS_ON;
4768 : 9 : UpdateControlFile();
4769 : 9 : LWLockRelease(ControlFileLock);
4770 : :
4771 : 9 : barrier = EmitProcSignalBarrier(PROCSIGNAL_BARRIER_CHECKSUM_INPROGRESS_ON);
4772 : :
4773 : 9 : MyProc->delayChkptFlags &= ~DELAY_CHKPT_START;
4774 : 9 : END_CRIT_SECTION();
4775 : :
4776 : 9 : WaitForProcSignalBarrier(barrier);
4777 : 9 : }
4778 : :
4779 : : /*
4780 : : * SetDataChecksumsOn
4781 : : * Set data checksums state to 'on' cluster-wide
4782 : : *
4783 : : * Enabling data checksums is performed using two barriers, the first one to
4784 : : * set the state to "inprogress-on" (done by SetDataChecksumsOnInProgress())
4785 : : * and the second one to set the state to "on" (done here). Below is a short
4786 : : * description of the processing, a more detailed write-up can be found in
4787 : : * datachecksum_state.c.
4788 : : *
4789 : : * To start the process of enabling data checksums in a running cluster the
4790 : : * data_checksum_version state must be changed to "inprogress-on". This state
4791 : : * requires data checksums to be written but not verified. This ensures that
4792 : : * all data pages can be checksummed without the risk of false negatives in
4793 : : * validation during the process. When all existing pages are guaranteed to
4794 : : * have checksums, and all new pages will be initiated with checksums, the
4795 : : * state can be changed to "on". Once the state is "on" checksums will be both
4796 : : * written and verified.
4797 : : *
4798 : : * This function blocks until all backends in the cluster have acknowledged the
4799 : : * state transition.
4800 : : */
4801 : : void
4802 : 7 : SetDataChecksumsOn(void)
4803 : : {
4804 : : uint64 barrier;
4805 : :
4806 : 7 : SpinLockAcquire(&XLogCtl->info_lck);
4807 : :
4808 : : /*
4809 : : * The only allowed state transition to "on" is from "inprogress-on" since
4810 : : * that state ensures that all pages will have data checksums written. Any
4811 : : * other attempted state transition is likely due to a programmer error.
4812 : : */
4813 [ - + ]: 7 : if (XLogCtl->data_checksum_version != PG_DATA_CHECKSUM_INPROGRESS_ON)
4814 : : {
4815 : 0 : SpinLockRelease(&XLogCtl->info_lck);
4816 [ # # ]: 0 : elog(WARNING,
4817 : : "cannot set data checksums to \"on\", current state is not \"inprogress-on\", disabling");
4818 : 0 : SetDataChecksumsOff();
4819 : 0 : return;
4820 : : }
4821 : :
4822 : 7 : SpinLockRelease(&XLogCtl->info_lck);
4823 : :
4824 : 7 : INJECTION_POINT("datachecksums-enable-checksums-delay", NULL);
4825 : 7 : START_CRIT_SECTION();
4826 : 7 : MyProc->delayChkptFlags |= DELAY_CHKPT_START;
4827 : :
4828 : 7 : XLogChecksums(PG_DATA_CHECKSUM_VERSION);
4829 : :
4830 : 7 : SpinLockAcquire(&XLogCtl->info_lck);
4831 : 7 : XLogCtl->data_checksum_version = PG_DATA_CHECKSUM_VERSION;
4832 : 7 : SpinLockRelease(&XLogCtl->info_lck);
4833 : :
4834 : : /*
4835 : : * Update the controlfile before waiting since if we have an immediate
4836 : : * shutdown while waiting we want to come back up with checksums enabled.
4837 : : */
4838 : 7 : LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
4839 : 7 : ControlFile->data_checksum_version = PG_DATA_CHECKSUM_VERSION;
4840 : 7 : UpdateControlFile();
4841 : 7 : LWLockRelease(ControlFileLock);
4842 : :
4843 : 7 : barrier = EmitProcSignalBarrier(PROCSIGNAL_BARRIER_CHECKSUM_ON);
4844 : :
4845 : 7 : MyProc->delayChkptFlags &= ~DELAY_CHKPT_START;
4846 : 7 : END_CRIT_SECTION();
4847 : :
4848 : 7 : RequestCheckpoint(CHECKPOINT_FORCE | CHECKPOINT_WAIT | CHECKPOINT_FAST);
4849 : 7 : WaitForProcSignalBarrier(barrier);
4850 : : }
4851 : :
4852 : : /*
4853 : : * SetDataChecksumsOff
4854 : : * Disables data checksums cluster-wide
4855 : : *
4856 : : * Disabling data checksums must be performed with two sets of barriers, each
4857 : : * carrying a different state. The state is first set to "inprogress-off"
4858 : : * during which checksums are still written but not verified. This ensures that
4859 : : * backends which have yet to observe the state change from "on" won't get
4860 : : * validation errors on concurrently modified pages. Once all backends have
4861 : : * changed to "inprogress-off", the barrier for moving to "off" can be emitted.
4862 : : * This function blocks until all backends in the cluster have acknowledged the
4863 : : * state transition.
4864 : : */
4865 : : void
4866 : 7 : SetDataChecksumsOff(void)
4867 : : {
4868 : : uint64 barrier;
4869 : :
4870 : 7 : SpinLockAcquire(&XLogCtl->info_lck);
4871 : :
4872 : : /* If data checksums are already disabled there is nothing to do */
4873 [ - + ]: 7 : if (XLogCtl->data_checksum_version == PG_DATA_CHECKSUM_OFF)
4874 : : {
4875 : 0 : SpinLockRelease(&XLogCtl->info_lck);
4876 : 0 : return;
4877 : : }
4878 : :
4879 : : /*
4880 : : * If data checksums are currently enabled, or in the process of being
4881 : : * enabled, we first transition to the "inprogress-off" state during which
4882 : : * backends continue to write checksums without verifying them. When all
4883 : : * backends are in "inprogress-off" the next transition to "off" can be
4884 : : * performed, after which all data checksum processing is disabled.
4885 : : */
4886 [ + + ]: 7 : if (XLogCtl->data_checksum_version == PG_DATA_CHECKSUM_VERSION ||
4887 [ + - ]: 2 : XLogCtl->data_checksum_version == PG_DATA_CHECKSUM_INPROGRESS_ON)
4888 : : {
4889 : 7 : SpinLockRelease(&XLogCtl->info_lck);
4890 : :
4891 : 7 : START_CRIT_SECTION();
4892 : 7 : MyProc->delayChkptFlags |= DELAY_CHKPT_START;
4893 : :
4894 : 7 : XLogChecksums(PG_DATA_CHECKSUM_INPROGRESS_OFF);
4895 : :
4896 : 7 : SpinLockAcquire(&XLogCtl->info_lck);
4897 : 7 : XLogCtl->data_checksum_version = PG_DATA_CHECKSUM_INPROGRESS_OFF;
4898 : 7 : SpinLockRelease(&XLogCtl->info_lck);
4899 : :
4900 : 7 : LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
4901 : 7 : ControlFile->data_checksum_version = PG_DATA_CHECKSUM_INPROGRESS_OFF;
4902 : 7 : UpdateControlFile();
4903 : 7 : LWLockRelease(ControlFileLock);
4904 : :
4905 : 7 : barrier = EmitProcSignalBarrier(PROCSIGNAL_BARRIER_CHECKSUM_INPROGRESS_OFF);
4906 : :
4907 : 7 : MyProc->delayChkptFlags &= ~DELAY_CHKPT_START;
4908 : 7 : END_CRIT_SECTION();
4909 : :
4910 : 7 : RequestCheckpoint(CHECKPOINT_FORCE | CHECKPOINT_WAIT | CHECKPOINT_FAST);
4911 : 7 : WaitForProcSignalBarrier(barrier);
4912 : :
4913 : : /*
4914 : : * At this point we know that no backends are verifying data checksums
4915 : : * during reading. Next, we can safely move to state "off" to also
4916 : : * stop writing checksums.
4917 : : */
4918 : : }
4919 : : else
4920 : : {
4921 : : /*
4922 : : * Ending up here implies that the checksums state is "inprogress-off"
4923 : : * and we can transition directly to "off" from there.
4924 : : */
4925 : 0 : SpinLockRelease(&XLogCtl->info_lck);
4926 : : }
4927 : :
4928 : 7 : START_CRIT_SECTION();
4929 : : /* Ensure that we don't incur a checkpoint during disabling checksums */
4930 : 7 : MyProc->delayChkptFlags |= DELAY_CHKPT_START;
4931 : :
4932 : 7 : XLogChecksums(PG_DATA_CHECKSUM_OFF);
4933 : :
4934 : 7 : SpinLockAcquire(&XLogCtl->info_lck);
4935 : 7 : XLogCtl->data_checksum_version = PG_DATA_CHECKSUM_OFF;
4936 : 7 : SpinLockRelease(&XLogCtl->info_lck);
4937 : :
4938 : 7 : LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
4939 : 7 : ControlFile->data_checksum_version = PG_DATA_CHECKSUM_OFF;
4940 : 7 : UpdateControlFile();
4941 : 7 : LWLockRelease(ControlFileLock);
4942 : :
4943 : 7 : barrier = EmitProcSignalBarrier(PROCSIGNAL_BARRIER_CHECKSUM_OFF);
4944 : :
4945 : 7 : MyProc->delayChkptFlags &= ~DELAY_CHKPT_START;
4946 : 7 : END_CRIT_SECTION();
4947 : :
4948 : 7 : RequestCheckpoint(CHECKPOINT_FORCE | CHECKPOINT_WAIT | CHECKPOINT_FAST);
4949 : 7 : WaitForProcSignalBarrier(barrier);
4950 : : }
4951 : :
4952 : : /*
4953 : : * InitLocalDataChecksumState
4954 : : *
4955 : : * Set up backend local caches of controldata variables which may change at
4956 : : * any point during runtime and thus require special cased locking. So far
4957 : : * this only applies to data_checksum_version, but it's intended to be general
4958 : : * purpose enough to handle future cases.
4959 : : */
4960 : : void
4961 : 24490 : InitLocalDataChecksumState(void)
4962 : : {
4963 : : Assert(InterruptHoldoffCount > 0);
4964 : 24490 : SpinLockAcquire(&XLogCtl->info_lck);
4965 : 24490 : SetLocalDataChecksumState(XLogCtl->data_checksum_version);
4966 : 24490 : SpinLockRelease(&XLogCtl->info_lck);
4967 : 24490 : }
4968 : :
4969 : : void
4970 : 27816 : SetLocalDataChecksumState(uint32 data_checksum_version)
4971 : : {
4972 : 27816 : LocalDataChecksumState = data_checksum_version;
4973 : :
4974 : 27816 : data_checksums = data_checksum_version;
4975 : 27816 : }
4976 : :
4977 : : /* guc hook */
4978 : : const char *
4979 : 1930 : show_data_checksums(void)
4980 : : {
4981 : 1930 : return get_checksum_state_string(LocalDataChecksumState);
4982 : : }
4983 : :
4984 : : /*
4985 : : * Return true if the cluster was initialized on a platform where the
4986 : : * default signedness of char is "signed". This function exists for code
4987 : : * that deals with pre-v18 data files that store data sorted by the 'char'
4988 : : * type on disk (e.g., GIN and GiST indexes). See the comments in
4989 : : * WriteControlFile() for details.
4990 : : */
4991 : : bool
4992 : 89903 : GetDefaultCharSignedness(void)
4993 : : {
4994 : 89903 : return ControlFile->default_char_signedness;
4995 : : }
4996 : :
4997 : : /*
4998 : : * Returns a fake LSN for unlogged relations.
4999 : : *
5000 : : * Each call generates an LSN that is greater than any previous value
5001 : : * returned. The current counter value is saved and restored across clean
5002 : : * shutdowns, but like unlogged relations, does not survive a crash. This can
5003 : : * be used in lieu of real LSN values returned by XLogInsert, if you need an
5004 : : * LSN-like increasing sequence of numbers without writing any WAL.
5005 : : */
5006 : : XLogRecPtr
5007 : 202661 : GetFakeLSNForUnloggedRel(void)
5008 : : {
5009 : 202661 : return pg_atomic_fetch_add_u64(&XLogCtl->unloggedLSN, 1);
5010 : : }
5011 : :
5012 : : /*
5013 : : * Auto-tune the number of XLOG buffers.
5014 : : *
5015 : : * The preferred setting for wal_buffers is about 3% of shared_buffers, with
5016 : : * a maximum of one XLOG segment (there is little reason to think that more
5017 : : * is helpful, at least so long as we force an fsync when switching log files)
5018 : : * and a minimum of 8 blocks (which was the default value prior to PostgreSQL
5019 : : * 9.1, when auto-tuning was added).
5020 : : *
5021 : : * This should not be called until NBuffers has received its final value.
5022 : : */
5023 : : static int
5024 : 1244 : XLOGChooseNumBuffers(void)
5025 : : {
5026 : : int xbuffers;
5027 : :
5028 : 1244 : xbuffers = NBuffers / 32;
5029 [ + + ]: 1244 : if (xbuffers > (wal_segment_size / XLOG_BLCKSZ))
5030 : 24 : xbuffers = (wal_segment_size / XLOG_BLCKSZ);
5031 [ + + ]: 1244 : if (xbuffers < 8)
5032 : 474 : xbuffers = 8;
5033 : 1244 : return xbuffers;
5034 : : }
5035 : :
5036 : : /*
5037 : : * GUC check_hook for wal_buffers
5038 : : */
5039 : : bool
5040 : 2535 : check_wal_buffers(int *newval, void **extra, GucSource source)
5041 : : {
5042 : : /*
5043 : : * -1 indicates a request for auto-tune.
5044 : : */
5045 [ + + ]: 2535 : if (*newval == -1)
5046 : : {
5047 : : /*
5048 : : * If we haven't yet changed the boot_val default of -1, just let it
5049 : : * be. We'll fix it when XLOGShmemRequest is called.
5050 : : */
5051 [ + - ]: 1291 : if (XLOGbuffers == -1)
5052 : 1291 : return true;
5053 : :
5054 : : /* Otherwise, substitute the auto-tune value */
5055 : 0 : *newval = XLOGChooseNumBuffers();
5056 : : }
5057 : :
5058 : : /*
5059 : : * We clamp manually-set values to at least 4 blocks. Prior to PostgreSQL
5060 : : * 9.1, a minimum of 4 was enforced by guc.c, but since that is no longer
5061 : : * the case, we just silently treat such values as a request for the
5062 : : * minimum. (We could throw an error instead, but that doesn't seem very
5063 : : * helpful.)
5064 : : */
5065 [ - + ]: 1244 : if (*newval < 4)
5066 : 0 : *newval = 4;
5067 : :
5068 : 1244 : return true;
5069 : : }
5070 : :
5071 : : /*
5072 : : * GUC check_hook for wal_consistency_checking
5073 : : */
5074 : : bool
5075 : 2277 : check_wal_consistency_checking(char **newval, void **extra, GucSource source)
5076 : : {
5077 : : char *rawstring;
5078 : : List *elemlist;
5079 : : ListCell *l;
5080 : : bool newwalconsistency[RM_MAX_ID + 1];
5081 : :
5082 : : /* Initialize the array */
5083 [ + - + - : 75141 : MemSet(newwalconsistency, 0, (RM_MAX_ID + 1) * sizeof(bool));
+ - + - +
+ ]
5084 : :
5085 : : /* Need a modifiable copy of string */
5086 : 2277 : rawstring = pstrdup(*newval);
5087 : :
5088 : : /* Parse string into list of identifiers */
5089 [ - + ]: 2277 : if (!SplitIdentifierString(rawstring, ',', &elemlist))
5090 : : {
5091 : : /* syntax error in list */
5092 : 0 : GUC_check_errdetail("List syntax is invalid.");
5093 : 0 : pfree(rawstring);
5094 : 0 : list_free(elemlist);
5095 : 0 : return false;
5096 : : }
5097 : :
5098 [ + + + + : 2773 : foreach(l, elemlist)
+ + ]
5099 : : {
5100 : 496 : char *tok = (char *) lfirst(l);
5101 : : int rmid;
5102 : :
5103 : : /* Check for 'all'. */
5104 [ + + ]: 496 : if (pg_strcasecmp(tok, "all") == 0)
5105 : : {
5106 [ + + ]: 126958 : for (rmid = 0; rmid <= RM_MAX_ID; rmid++)
5107 [ + + + + ]: 126464 : if (RmgrIdExists(rmid) && GetRmgr(rmid).rm_mask != NULL)
5108 : 4940 : newwalconsistency[rmid] = true;
5109 : : }
5110 : : else
5111 : : {
5112 : : /* Check if the token matches any known resource manager. */
5113 : 2 : bool found = false;
5114 : :
5115 [ + - ]: 36 : for (rmid = 0; rmid <= RM_MAX_ID; rmid++)
5116 : : {
5117 [ + - + + : 54 : if (RmgrIdExists(rmid) && GetRmgr(rmid).rm_mask != NULL &&
+ + ]
5118 : 18 : pg_strcasecmp(tok, GetRmgr(rmid).rm_name) == 0)
5119 : : {
5120 : 2 : newwalconsistency[rmid] = true;
5121 : 2 : found = true;
5122 : 2 : break;
5123 : : }
5124 : : }
5125 [ - + ]: 2 : if (!found)
5126 : : {
5127 : : /*
5128 : : * During startup, it might be a not-yet-loaded custom
5129 : : * resource manager. Defer checking until
5130 : : * InitializeWalConsistencyChecking().
5131 : : */
5132 [ # # ]: 0 : if (!process_shared_preload_libraries_done)
5133 : : {
5134 : 0 : check_wal_consistency_checking_deferred = true;
5135 : : }
5136 : : else
5137 : : {
5138 : 0 : GUC_check_errdetail("Unrecognized key word: \"%s\".", tok);
5139 : 0 : pfree(rawstring);
5140 : 0 : list_free(elemlist);
5141 : 0 : return false;
5142 : : }
5143 : : }
5144 : : }
5145 : : }
5146 : :
5147 : 2277 : pfree(rawstring);
5148 : 2277 : list_free(elemlist);
5149 : :
5150 : : /* assign new value */
5151 : 2277 : *extra = guc_malloc(LOG, (RM_MAX_ID + 1) * sizeof(bool));
5152 [ - + ]: 2277 : if (!*extra)
5153 : 0 : return false;
5154 : 2277 : memcpy(*extra, newwalconsistency, (RM_MAX_ID + 1) * sizeof(bool));
5155 : 2277 : return true;
5156 : : }
5157 : :
5158 : : /*
5159 : : * GUC assign_hook for wal_consistency_checking
5160 : : */
5161 : : void
5162 : 2276 : assign_wal_consistency_checking(const char *newval, void *extra)
5163 : : {
5164 : : /*
5165 : : * If some checks were deferred, it's possible that the checks will fail
5166 : : * later during InitializeWalConsistencyChecking(). But in that case, the
5167 : : * postmaster will exit anyway, so it's safe to proceed with the
5168 : : * assignment.
5169 : : *
5170 : : * Any built-in resource managers specified are assigned immediately,
5171 : : * which affects WAL created before shared_preload_libraries are
5172 : : * processed. Any custom resource managers specified won't be assigned
5173 : : * until after shared_preload_libraries are processed, but that's OK
5174 : : * because WAL for a custom resource manager can't be written before the
5175 : : * module is loaded anyway.
5176 : : */
5177 : 2276 : wal_consistency_checking = extra;
5178 : 2276 : }
5179 : :
5180 : : /*
5181 : : * InitializeWalConsistencyChecking: run after loading custom resource managers
5182 : : *
5183 : : * If any unknown resource managers were specified in the
5184 : : * wal_consistency_checking GUC, processing was deferred. Now that
5185 : : * shared_preload_libraries have been loaded, process wal_consistency_checking
5186 : : * again.
5187 : : */
5188 : : void
5189 : 1073 : InitializeWalConsistencyChecking(void)
5190 : : {
5191 : : Assert(process_shared_preload_libraries_done);
5192 : :
5193 [ - + ]: 1073 : if (check_wal_consistency_checking_deferred)
5194 : : {
5195 : : struct config_generic *guc;
5196 : :
5197 : 0 : guc = find_option("wal_consistency_checking", false, false, ERROR);
5198 : :
5199 : 0 : check_wal_consistency_checking_deferred = false;
5200 : :
5201 : 0 : set_config_option_ext("wal_consistency_checking",
5202 : : wal_consistency_checking_string,
5203 : : guc->scontext, guc->source, guc->srole,
5204 : : GUC_ACTION_SET, true, ERROR, false);
5205 : :
5206 : : /* checking should not be deferred again */
5207 : : Assert(!check_wal_consistency_checking_deferred);
5208 : : }
5209 : 1073 : }
5210 : :
5211 : : /*
5212 : : * GUC show_hook for archive_command
5213 : : */
5214 : : const char *
5215 : 1926 : show_archive_command(void)
5216 : : {
5217 [ + + ]: 1926 : if (XLogArchivingActive())
5218 : 109 : return XLogArchiveCommand;
5219 : : else
5220 : 1817 : return "(disabled)";
5221 : : }
5222 : :
5223 : : /*
5224 : : * GUC show_hook for in_hot_standby
5225 : : */
5226 : : const char *
5227 : 17535 : show_in_hot_standby(void)
5228 : : {
5229 : : /*
5230 : : * We display the actual state based on shared memory, so that this GUC
5231 : : * reports up-to-date state if examined intra-query. The underlying
5232 : : * variable (in_hot_standby_guc) changes only when we transmit a new value
5233 : : * to the client.
5234 : : */
5235 [ + + ]: 17535 : return RecoveryInProgress() ? "on" : "off";
5236 : : }
5237 : :
5238 : : /*
5239 : : * GUC show_hook for effective_wal_level
5240 : : */
5241 : : const char *
5242 : 1965 : show_effective_wal_level(void)
5243 : : {
5244 [ + + ]: 1965 : if (wal_level == WAL_LEVEL_MINIMAL)
5245 : 239 : return "minimal";
5246 : :
5247 : : /*
5248 : : * During recovery, effective_wal_level reflects the primary's
5249 : : * configuration rather than the local wal_level value.
5250 : : */
5251 [ + + ]: 1726 : if (RecoveryInProgress())
5252 [ + + ]: 31 : return IsXLogLogicalInfoEnabled() ? "logical" : "replica";
5253 : :
5254 [ + + + + ]: 1695 : return XLogLogicalInfoActive() ? "logical" : "replica";
5255 : : }
5256 : :
5257 : : /*
5258 : : * Read the control file, set respective GUCs.
5259 : : *
5260 : : * This is to be called during startup, including a crash recovery cycle,
5261 : : * unless in bootstrap mode, where no control file yet exists. As there's no
5262 : : * usable shared memory yet (its sizing can depend on the contents of the
5263 : : * control file!), first store the contents in local memory. XLOGShmemInit()
5264 : : * will then copy it to shared memory later.
5265 : : *
5266 : : * reset just controls whether previous contents are to be expected (in the
5267 : : * reset case, there's a dangling pointer into old shared memory), or not.
5268 : : */
5269 : : void
5270 : 1091 : LocalProcessControlFile(bool reset)
5271 : : {
5272 : : Assert(reset || ControlFile == NULL);
5273 : 1091 : LocalControlFile = palloc_object(ControlFileData);
5274 : 1091 : ControlFile = LocalControlFile;
5275 : 1091 : ReadControlFile();
5276 : 1091 : SetLocalDataChecksumState(ControlFile->data_checksum_version);
5277 : 1091 : }
5278 : :
5279 : : /*
5280 : : * Get the wal_level from the control file. For a standby, this value should be
5281 : : * considered as its active wal_level, because it may be different from what
5282 : : * was originally configured on standby.
5283 : : */
5284 : : WalLevel
5285 : 0 : GetActiveWalLevelOnStandby(void)
5286 : : {
5287 : 0 : return ControlFile->wal_level;
5288 : : }
5289 : :
5290 : : /*
5291 : : * Register shared memory for XLOG.
5292 : : */
5293 : : static void
5294 : 1249 : XLOGShmemRequest(void *arg)
5295 : : {
5296 : : Size size;
5297 : :
5298 : : /*
5299 : : * If the value of wal_buffers is -1, use the preferred auto-tune value.
5300 : : * This isn't an amazingly clean place to do this, but we must wait till
5301 : : * NBuffers has received its final value, and must do it before using the
5302 : : * value of XLOGbuffers to do anything important.
5303 : : *
5304 : : * We prefer to report this value's source as PGC_S_DYNAMIC_DEFAULT.
5305 : : * However, if the DBA explicitly set wal_buffers = -1 in the config file,
5306 : : * then PGC_S_DYNAMIC_DEFAULT will fail to override that and we must force
5307 : : * the matter with PGC_S_OVERRIDE.
5308 : : */
5309 [ + + ]: 1249 : if (XLOGbuffers == -1)
5310 : : {
5311 : : char buf[32];
5312 : :
5313 : 1244 : snprintf(buf, sizeof(buf), "%d", XLOGChooseNumBuffers());
5314 : 1244 : SetConfigOption("wal_buffers", buf, PGC_POSTMASTER,
5315 : : PGC_S_DYNAMIC_DEFAULT);
5316 [ - + ]: 1244 : if (XLOGbuffers == -1) /* failed to apply it? */
5317 : 0 : SetConfigOption("wal_buffers", buf, PGC_POSTMASTER,
5318 : : PGC_S_OVERRIDE);
5319 : : }
5320 : : Assert(XLOGbuffers > 0);
5321 : :
5322 : : /* XLogCtl */
5323 : 1249 : size = sizeof(XLogCtlData);
5324 : :
5325 : : /* WAL insertion locks, plus alignment */
5326 : 1249 : size = add_size(size, mul_size(sizeof(WALInsertLockPadded), NUM_XLOGINSERT_LOCKS + 1));
5327 : : /* xlblocks array */
5328 : 1249 : size = add_size(size, mul_size(sizeof(pg_atomic_uint64), XLOGbuffers));
5329 : : /* extra alignment padding for XLOG I/O buffers */
5330 : 1249 : size = add_size(size, Max(XLOG_BLCKSZ, PG_IO_ALIGN_SIZE));
5331 : : /* and the buffers themselves */
5332 : 1249 : size = add_size(size, mul_size(XLOG_BLCKSZ, XLOGbuffers));
5333 : :
5334 : 1249 : ShmemRequestStruct(.name = "XLOG Ctl",
5335 : : .size = size,
5336 : : .ptr = (void **) &XLogCtl,
5337 : : );
5338 : 1249 : ShmemRequestStruct(.name = "Control File",
5339 : : .size = sizeof(ControlFileData),
5340 : : .ptr = (void **) &ControlFile,
5341 : : );
5342 : 1249 : }
5343 : :
5344 : : /*
5345 : : * XLOGShmemInit - initialize the XLogCtl shared memory area.
5346 : : */
5347 : : static void
5348 : 1246 : XLOGShmemInit(void *arg)
5349 : : {
5350 : : char *allocptr;
5351 : : int i;
5352 : :
5353 : : #ifdef WAL_DEBUG
5354 : :
5355 : : /*
5356 : : * Create a memory context for WAL debugging that's exempt from the normal
5357 : : * "no pallocs in critical section" rule. Yes, that can lead to a PANIC if
5358 : : * an allocation fails, but wal_debug is not for production use anyway.
5359 : : */
5360 : : if (walDebugCxt == NULL)
5361 : : {
5362 : : walDebugCxt = AllocSetContextCreate(TopMemoryContext,
5363 : : "WAL Debug",
5364 : : ALLOCSET_DEFAULT_SIZES);
5365 : : MemoryContextAllowInCriticalSection(walDebugCxt, true);
5366 : : }
5367 : : #endif
5368 : :
5369 : 1246 : memset(XLogCtl, 0, sizeof(XLogCtlData));
5370 : :
5371 : : /*
5372 : : * Already have read control file locally, unless in bootstrap mode. Move
5373 : : * contents into shared memory.
5374 : : */
5375 [ + + ]: 1246 : if (LocalControlFile)
5376 : : {
5377 : 1075 : memcpy(ControlFile, LocalControlFile, sizeof(ControlFileData));
5378 : 1075 : pfree(LocalControlFile);
5379 : 1075 : LocalControlFile = NULL;
5380 : : }
5381 : :
5382 : : /*
5383 : : * Since XLogCtlData contains XLogRecPtr fields, its sizeof should be a
5384 : : * multiple of the alignment for same, so no extra alignment padding is
5385 : : * needed here.
5386 : : */
5387 : 1246 : allocptr = ((char *) XLogCtl) + sizeof(XLogCtlData);
5388 : 1246 : XLogCtl->xlblocks = (pg_atomic_uint64 *) allocptr;
5389 : 1246 : allocptr += sizeof(pg_atomic_uint64) * XLOGbuffers;
5390 : :
5391 [ + + ]: 362157 : for (i = 0; i < XLOGbuffers; i++)
5392 : : {
5393 : 360911 : pg_atomic_init_u64(&XLogCtl->xlblocks[i], InvalidXLogRecPtr);
5394 : : }
5395 : :
5396 : : /* WAL insertion locks. Ensure they're aligned to the full padded size */
5397 : 1246 : allocptr += sizeof(WALInsertLockPadded) -
5398 : 1246 : ((uintptr_t) allocptr) % sizeof(WALInsertLockPadded);
5399 : 1246 : WALInsertLocks = XLogCtl->Insert.WALInsertLocks =
5400 : : (WALInsertLockPadded *) allocptr;
5401 : 1246 : allocptr += sizeof(WALInsertLockPadded) * NUM_XLOGINSERT_LOCKS;
5402 : :
5403 [ + + ]: 11214 : for (i = 0; i < NUM_XLOGINSERT_LOCKS; i++)
5404 : : {
5405 : 9968 : LWLockInitialize(&WALInsertLocks[i].l.lock, LWTRANCHE_WAL_INSERT);
5406 : 9968 : pg_atomic_init_u64(&WALInsertLocks[i].l.insertingAt, InvalidXLogRecPtr);
5407 : 9968 : WALInsertLocks[i].l.lastImportantAt = InvalidXLogRecPtr;
5408 : : }
5409 : :
5410 : : /*
5411 : : * Align the start of the page buffers to a full xlog block size boundary.
5412 : : * This simplifies some calculations in XLOG insertion. It is also
5413 : : * required for O_DIRECT.
5414 : : */
5415 : 1246 : allocptr = (char *) TYPEALIGN(XLOG_BLCKSZ, allocptr);
5416 : 1246 : XLogCtl->pages = allocptr;
5417 : 1246 : memset(XLogCtl->pages, 0, (Size) XLOG_BLCKSZ * XLOGbuffers);
5418 : :
5419 : : /*
5420 : : * Do basic initialization of XLogCtl shared data. (StartupXLOG will fill
5421 : : * in additional info.)
5422 : : */
5423 : 1246 : XLogCtl->XLogCacheBlck = XLOGbuffers - 1;
5424 : 1246 : XLogCtl->SharedRecoveryState = RECOVERY_STATE_CRASH;
5425 : 1246 : XLogCtl->InstallXLogFileSegmentActive = false;
5426 : 1246 : XLogCtl->WalWriterSleeping = false;
5427 : :
5428 : : /* Use the checksum info from control file */
5429 : 1246 : XLogCtl->data_checksum_version = ControlFile->data_checksum_version;
5430 : 1246 : SetLocalDataChecksumState(XLogCtl->data_checksum_version);
5431 : :
5432 : 1246 : SpinLockInit(&XLogCtl->Insert.insertpos_lck);
5433 : 1246 : SpinLockInit(&XLogCtl->info_lck);
5434 : 1246 : pg_atomic_init_u64(&XLogCtl->logInsertResult, InvalidXLogRecPtr);
5435 : 1246 : pg_atomic_init_u64(&XLogCtl->logWriteResult, InvalidXLogRecPtr);
5436 : 1246 : pg_atomic_init_u64(&XLogCtl->logFlushResult, InvalidXLogRecPtr);
5437 : 1246 : pg_atomic_init_u64(&XLogCtl->unloggedLSN, InvalidXLogRecPtr);
5438 : 1246 : }
5439 : :
5440 : : /*
5441 : : * XLOGShmemAttach - re-establish WALInsertLocks pointer after attaching.
5442 : : */
5443 : : static void
5444 : 0 : XLOGShmemAttach(void *arg)
5445 : : {
5446 : 0 : WALInsertLocks = XLogCtl->Insert.WALInsertLocks;
5447 : 0 : }
5448 : :
5449 : : /*
5450 : : * This func must be called ONCE on system install. It creates pg_control
5451 : : * and the initial XLOG segment.
5452 : : */
5453 : : void
5454 : 57 : BootStrapXLOG(uint32 data_checksum_version)
5455 : : {
5456 : : CheckPoint checkPoint;
5457 : : PGAlignedXLogBlock buffer;
5458 : : XLogPageHeader page;
5459 : : XLogLongPageHeader longpage;
5460 : : XLogRecord *record;
5461 : : char *recptr;
5462 : : uint64 sysidentifier;
5463 : : struct timeval tv;
5464 : : pg_crc32c crc;
5465 : :
5466 : : /* allow ordinary WAL segment creation, like StartupXLOG() would */
5467 : 57 : SetInstallXLogFileSegmentActive();
5468 : :
5469 : : /*
5470 : : * Select a hopefully-unique system identifier code for this installation.
5471 : : * We use the result of gettimeofday(), including the fractional seconds
5472 : : * field, as being about as unique as we can easily get. (Think not to
5473 : : * use random(), since it hasn't been seeded and there's no portable way
5474 : : * to seed it other than the system clock value...) The upper half of the
5475 : : * uint64 value is just the tv_sec part, while the lower half contains the
5476 : : * tv_usec part (which must fit in 20 bits), plus 12 bits from our current
5477 : : * PID for a little extra uniqueness. A person knowing this encoding can
5478 : : * determine the initialization time of the installation, which could
5479 : : * perhaps be useful sometimes.
5480 : : */
5481 : 57 : gettimeofday(&tv, NULL);
5482 : 57 : sysidentifier = ((uint64) tv.tv_sec) << 32;
5483 : 57 : sysidentifier |= ((uint64) tv.tv_usec) << 12;
5484 : 57 : sysidentifier |= getpid() & 0xFFF;
5485 : :
5486 : 57 : memset(&buffer, 0, sizeof buffer);
5487 : 57 : page = (XLogPageHeader) &buffer;
5488 : :
5489 : : /*
5490 : : * Set up information for the initial checkpoint record
5491 : : *
5492 : : * The initial checkpoint record is written to the beginning of the WAL
5493 : : * segment with logid=0 logseg=1. The very first WAL segment, 0/0, is not
5494 : : * used, so that we can use 0/0 to mean "before any valid WAL segment".
5495 : : */
5496 : 57 : checkPoint.redo = wal_segment_size + SizeOfXLogLongPHD;
5497 : 57 : checkPoint.ThisTimeLineID = BootstrapTimeLineID;
5498 : 57 : checkPoint.PrevTimeLineID = BootstrapTimeLineID;
5499 : 57 : checkPoint.fullPageWrites = fullPageWrites;
5500 : 57 : checkPoint.logicalDecodingEnabled = (wal_level == WAL_LEVEL_LOGICAL);
5501 : 57 : checkPoint.wal_level = wal_level;
5502 : : checkPoint.nextXid =
5503 : 57 : FullTransactionIdFromEpochAndXid(0, FirstNormalTransactionId);
5504 : 57 : checkPoint.nextOid = FirstGenbkiObjectId;
5505 : 57 : checkPoint.nextMulti = FirstMultiXactId;
5506 : 57 : checkPoint.nextMultiOffset = 1;
5507 : 57 : checkPoint.oldestXid = FirstNormalTransactionId;
5508 : 57 : checkPoint.oldestXidDB = Template1DbOid;
5509 : 57 : checkPoint.oldestMulti = FirstMultiXactId;
5510 : 57 : checkPoint.oldestMultiDB = Template1DbOid;
5511 : 57 : checkPoint.oldestCommitTsXid = InvalidTransactionId;
5512 : 57 : checkPoint.newestCommitTsXid = InvalidTransactionId;
5513 : 57 : checkPoint.time = (pg_time_t) time(NULL);
5514 : 57 : checkPoint.oldestActiveXid = InvalidTransactionId;
5515 : 57 : checkPoint.dataChecksumState = data_checksum_version;
5516 : :
5517 : 57 : TransamVariables->nextXid = checkPoint.nextXid;
5518 : 57 : TransamVariables->nextOid = checkPoint.nextOid;
5519 : 57 : TransamVariables->oidCount = 0;
5520 : 57 : MultiXactSetNextMXact(checkPoint.nextMulti, checkPoint.nextMultiOffset);
5521 : 57 : AdvanceOldestClogXid(checkPoint.oldestXid);
5522 : 57 : SetTransactionIdLimit(checkPoint.oldestXid, checkPoint.oldestXidDB);
5523 : 57 : SetMultiXactIdLimit(checkPoint.oldestMulti, checkPoint.oldestMultiDB);
5524 : 57 : SetCommitTsLimit(InvalidTransactionId, InvalidTransactionId);
5525 : :
5526 : : /* Set up the XLOG page header */
5527 : 57 : page->xlp_magic = XLOG_PAGE_MAGIC;
5528 : 57 : page->xlp_info = XLP_LONG_HEADER;
5529 : 57 : page->xlp_tli = BootstrapTimeLineID;
5530 : 57 : page->xlp_pageaddr = wal_segment_size;
5531 : 57 : longpage = (XLogLongPageHeader) page;
5532 : 57 : longpage->xlp_sysid = sysidentifier;
5533 : 57 : longpage->xlp_seg_size = wal_segment_size;
5534 : 57 : longpage->xlp_xlog_blcksz = XLOG_BLCKSZ;
5535 : :
5536 : : /* Insert the initial checkpoint record */
5537 : 57 : recptr = ((char *) page + SizeOfXLogLongPHD);
5538 : 57 : record = (XLogRecord *) recptr;
5539 : 57 : record->xl_prev = InvalidXLogRecPtr;
5540 : 57 : record->xl_xid = InvalidTransactionId;
5541 : 57 : record->xl_tot_len = SizeOfXLogRecord + SizeOfXLogRecordDataHeaderShort + sizeof(checkPoint);
5542 : 57 : record->xl_info = XLOG_CHECKPOINT_SHUTDOWN;
5543 : 57 : record->xl_rmid = RM_XLOG_ID;
5544 : 57 : recptr += SizeOfXLogRecord;
5545 : : /* fill the XLogRecordDataHeaderShort struct */
5546 : 57 : *(recptr++) = (char) XLR_BLOCK_ID_DATA_SHORT;
5547 : 57 : *(recptr++) = sizeof(checkPoint);
5548 : 57 : memcpy(recptr, &checkPoint, sizeof(checkPoint));
5549 : 57 : recptr += sizeof(checkPoint);
5550 : : Assert(recptr - (char *) record == record->xl_tot_len);
5551 : :
5552 : 57 : INIT_CRC32C(crc);
5553 : 57 : COMP_CRC32C(crc, ((char *) record) + SizeOfXLogRecord, record->xl_tot_len - SizeOfXLogRecord);
5554 : 57 : COMP_CRC32C(crc, (char *) record, offsetof(XLogRecord, xl_crc));
5555 : 57 : FIN_CRC32C(crc);
5556 : 57 : record->xl_crc = crc;
5557 : :
5558 : : /* Create first XLOG segment file */
5559 : 57 : openLogTLI = BootstrapTimeLineID;
5560 : 57 : openLogFile = XLogFileInit(1, BootstrapTimeLineID);
5561 : :
5562 : : /*
5563 : : * We needn't bother with Reserve/ReleaseExternalFD here, since we'll
5564 : : * close the file again in a moment.
5565 : : */
5566 : :
5567 : : /* Write the first page with the initial record */
5568 : 57 : errno = 0;
5569 : 57 : pgstat_report_wait_start(WAIT_EVENT_WAL_BOOTSTRAP_WRITE);
5570 [ - + ]: 57 : if (write(openLogFile, &buffer, XLOG_BLCKSZ) != XLOG_BLCKSZ)
5571 : : {
5572 : : /* if write didn't set errno, assume problem is no disk space */
5573 [ # # ]: 0 : if (errno == 0)
5574 : 0 : errno = ENOSPC;
5575 [ # # ]: 0 : ereport(PANIC,
5576 : : (errcode_for_file_access(),
5577 : : errmsg("could not write bootstrap write-ahead log file: %m")));
5578 : : }
5579 : 57 : pgstat_report_wait_end();
5580 : :
5581 : 57 : pgstat_report_wait_start(WAIT_EVENT_WAL_BOOTSTRAP_SYNC);
5582 [ - + ]: 57 : if (pg_fsync(openLogFile) != 0)
5583 [ # # ]: 0 : ereport(PANIC,
5584 : : (errcode_for_file_access(),
5585 : : errmsg("could not fsync bootstrap write-ahead log file: %m")));
5586 : 57 : pgstat_report_wait_end();
5587 : :
5588 [ - + ]: 57 : if (close(openLogFile) != 0)
5589 [ # # ]: 0 : ereport(PANIC,
5590 : : (errcode_for_file_access(),
5591 : : errmsg("could not close bootstrap write-ahead log file: %m")));
5592 : :
5593 : 57 : openLogFile = -1;
5594 : :
5595 : : /* Now create pg_control */
5596 : 57 : InitControlFile(sysidentifier, data_checksum_version);
5597 : 57 : ControlFile->time = checkPoint.time;
5598 : 57 : ControlFile->checkPoint = checkPoint.redo;
5599 : 57 : ControlFile->checkPointCopy = checkPoint;
5600 : :
5601 : : /* some additional ControlFile fields are set in WriteControlFile() */
5602 : 57 : WriteControlFile();
5603 : :
5604 : : /* Bootstrap the commit log, too */
5605 : 57 : BootStrapCLOG();
5606 : 57 : BootStrapCommitTs();
5607 : 57 : BootStrapSUBTRANS();
5608 : 57 : BootStrapMultiXact();
5609 : :
5610 : : /*
5611 : : * Force control file to be read - in contrast to normal processing we'd
5612 : : * otherwise never run the checks and GUC related initializations therein.
5613 : : */
5614 : 57 : ReadControlFile();
5615 : 57 : }
5616 : :
5617 : : static char *
5618 : 964 : str_time(pg_time_t tnow, char *buf, size_t bufsize)
5619 : : {
5620 : 964 : pg_strftime(buf, bufsize,
5621 : : "%Y-%m-%d %H:%M:%S %Z",
5622 : 964 : pg_localtime(&tnow, log_timezone));
5623 : :
5624 : 964 : return buf;
5625 : : }
5626 : :
5627 : : /*
5628 : : * Initialize the first WAL segment on new timeline.
5629 : : */
5630 : : static void
5631 : 59 : XLogInitNewTimeline(TimeLineID endTLI, XLogRecPtr endOfLog, TimeLineID newTLI)
5632 : : {
5633 : : char xlogfname[MAXFNAMELEN];
5634 : : XLogSegNo endLogSegNo;
5635 : : XLogSegNo startLogSegNo;
5636 : :
5637 : : /* we always switch to a new timeline after archive recovery */
5638 : : Assert(endTLI != newTLI);
5639 : :
5640 : : /*
5641 : : * Update min recovery point one last time.
5642 : : */
5643 : 59 : UpdateMinRecoveryPoint(InvalidXLogRecPtr, true);
5644 : :
5645 : : /*
5646 : : * Calculate the last segment on the old timeline, and the first segment
5647 : : * on the new timeline. If the switch happens in the middle of a segment,
5648 : : * they are the same, but if the switch happens exactly at a segment
5649 : : * boundary, startLogSegNo will be endLogSegNo + 1.
5650 : : */
5651 : 59 : XLByteToPrevSeg(endOfLog, endLogSegNo, wal_segment_size);
5652 : 59 : XLByteToSeg(endOfLog, startLogSegNo, wal_segment_size);
5653 : :
5654 : : /*
5655 : : * Initialize the starting WAL segment for the new timeline. If the switch
5656 : : * happens in the middle of a segment, copy data from the last WAL segment
5657 : : * of the old timeline up to the switch point, to the starting WAL segment
5658 : : * on the new timeline.
5659 : : */
5660 [ + + ]: 59 : if (endLogSegNo == startLogSegNo)
5661 : : {
5662 : : /*
5663 : : * Make a copy of the file on the new timeline.
5664 : : *
5665 : : * Writing WAL isn't allowed yet, so there are no locking
5666 : : * considerations. But we should be just as tense as XLogFileInit to
5667 : : * avoid emplacing a bogus file.
5668 : : */
5669 : 47 : XLogFileCopy(newTLI, endLogSegNo, endTLI, endLogSegNo,
5670 : 47 : XLogSegmentOffset(endOfLog, wal_segment_size));
5671 : : }
5672 : : else
5673 : : {
5674 : : /*
5675 : : * The switch happened at a segment boundary, so just create the next
5676 : : * segment on the new timeline.
5677 : : */
5678 : : int fd;
5679 : :
5680 : 12 : fd = XLogFileInit(startLogSegNo, newTLI);
5681 : :
5682 [ - + ]: 12 : if (close(fd) != 0)
5683 : : {
5684 : 0 : int save_errno = errno;
5685 : :
5686 : 0 : XLogFileName(xlogfname, newTLI, startLogSegNo, wal_segment_size);
5687 : 0 : errno = save_errno;
5688 [ # # ]: 0 : ereport(ERROR,
5689 : : (errcode_for_file_access(),
5690 : : errmsg("could not close file \"%s\": %m", xlogfname)));
5691 : : }
5692 : : }
5693 : :
5694 : : /*
5695 : : * Let's just make real sure there are not .ready or .done flags posted
5696 : : * for the new segment.
5697 : : */
5698 : 59 : XLogFileName(xlogfname, newTLI, startLogSegNo, wal_segment_size);
5699 : 59 : XLogArchiveCleanup(xlogfname);
5700 : 59 : }
5701 : :
5702 : : /*
5703 : : * Perform cleanup actions at the conclusion of archive recovery.
5704 : : */
5705 : : static void
5706 : 59 : CleanupAfterArchiveRecovery(TimeLineID EndOfLogTLI, XLogRecPtr EndOfLog,
5707 : : TimeLineID newTLI)
5708 : : {
5709 : : /*
5710 : : * Execute the recovery_end_command, if any.
5711 : : */
5712 [ + - + + ]: 59 : if (recoveryEndCommand && strcmp(recoveryEndCommand, "") != 0)
5713 : 2 : ExecuteRecoveryCommand(recoveryEndCommand,
5714 : : "recovery_end_command",
5715 : : true,
5716 : : WAIT_EVENT_RECOVERY_END_COMMAND);
5717 : :
5718 : : /*
5719 : : * We switched to a new timeline. Clean up segments on the old timeline.
5720 : : *
5721 : : * If there are any higher-numbered segments on the old timeline, remove
5722 : : * them. They might contain valid WAL, but they might also be
5723 : : * pre-allocated files containing garbage. In any case, they are not part
5724 : : * of the new timeline's history so we don't need them.
5725 : : */
5726 : 59 : RemoveNonParentXlogFiles(EndOfLog, newTLI);
5727 : :
5728 : : /*
5729 : : * If the switch happened in the middle of a segment, what to do with the
5730 : : * last, partial segment on the old timeline? If we don't archive it, and
5731 : : * the server that created the WAL never archives it either (e.g. because
5732 : : * it was hit by a meteor), it will never make it to the archive. That's
5733 : : * OK from our point of view, because the new segment that we created with
5734 : : * the new TLI contains all the WAL from the old timeline up to the switch
5735 : : * point. But if you later try to do PITR to the "missing" WAL on the old
5736 : : * timeline, recovery won't find it in the archive. It's physically
5737 : : * present in the new file with new TLI, but recovery won't look there
5738 : : * when it's recovering to the older timeline. On the other hand, if we
5739 : : * archive the partial segment, and the original server on that timeline
5740 : : * is still running and archives the completed version of the same segment
5741 : : * later, it will fail. (We used to do that in 9.4 and below, and it
5742 : : * caused such problems).
5743 : : *
5744 : : * As a compromise, we rename the last segment with the .partial suffix,
5745 : : * and archive it. Archive recovery will never try to read .partial
5746 : : * segments, so they will normally go unused. But in the odd PITR case,
5747 : : * the administrator can copy them manually to the pg_wal directory
5748 : : * (removing the suffix). They can be useful in debugging, too.
5749 : : *
5750 : : * If a .done or .ready file already exists for the old timeline, however,
5751 : : * we had already determined that the segment is complete, so we can let
5752 : : * it be archived normally. (In particular, if it was restored from the
5753 : : * archive to begin with, it's expected to have a .done file).
5754 : : */
5755 [ + + + + ]: 59 : if (XLogSegmentOffset(EndOfLog, wal_segment_size) != 0 &&
5756 : : XLogArchivingActive())
5757 : : {
5758 : : char origfname[MAXFNAMELEN];
5759 : : XLogSegNo endLogSegNo;
5760 : :
5761 : 10 : XLByteToPrevSeg(EndOfLog, endLogSegNo, wal_segment_size);
5762 : 10 : XLogFileName(origfname, EndOfLogTLI, endLogSegNo, wal_segment_size);
5763 : :
5764 [ + + ]: 10 : if (!XLogArchiveIsReadyOrDone(origfname))
5765 : : {
5766 : : char origpath[MAXPGPATH];
5767 : : char partialfname[MAXFNAMELEN];
5768 : : char partialpath[MAXPGPATH];
5769 : :
5770 : : /*
5771 : : * If we're summarizing WAL, we can't rename the partial file
5772 : : * until the summarizer finishes with it, else it will fail.
5773 : : */
5774 [ + + ]: 6 : if (summarize_wal)
5775 : 1 : WaitForWalSummarization(EndOfLog);
5776 : :
5777 : 6 : XLogFilePath(origpath, EndOfLogTLI, endLogSegNo, wal_segment_size);
5778 : 6 : snprintf(partialfname, MAXFNAMELEN, "%s.partial", origfname);
5779 : 6 : snprintf(partialpath, MAXPGPATH, "%s.partial", origpath);
5780 : :
5781 : : /*
5782 : : * Make sure there's no .done or .ready file for the .partial
5783 : : * file.
5784 : : */
5785 : 6 : XLogArchiveCleanup(partialfname);
5786 : :
5787 : 6 : durable_rename(origpath, partialpath, ERROR);
5788 : 6 : XLogArchiveNotify(partialfname);
5789 : : }
5790 : : }
5791 : 59 : }
5792 : :
5793 : : /*
5794 : : * Check to see if required parameters are set high enough on this server
5795 : : * for various aspects of recovery operation.
5796 : : *
5797 : : * Note that all the parameters which this function tests need to be
5798 : : * listed in Administrator's Overview section in high-availability.sgml.
5799 : : * If you change them, don't forget to update the list.
5800 : : */
5801 : : static void
5802 : 271 : CheckRequiredParameterValues(void)
5803 : : {
5804 : : /*
5805 : : * For archive recovery, the WAL must be generated with at least 'replica'
5806 : : * wal_level.
5807 : : */
5808 [ + + + + ]: 271 : if (ArchiveRecoveryRequested && ControlFile->wal_level == WAL_LEVEL_MINIMAL)
5809 : : {
5810 [ + - ]: 2 : ereport(FATAL,
5811 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
5812 : : errmsg("WAL was generated with \"wal_level=minimal\", cannot continue recovering"),
5813 : : errdetail("This happens if you temporarily set \"wal_level=minimal\" on the server."),
5814 : : errhint("Use a backup taken after setting \"wal_level\" to higher than \"minimal\".")));
5815 : : }
5816 : :
5817 : : /*
5818 : : * For Hot Standby, the WAL must be generated with 'replica' mode, and we
5819 : : * must have at least as many backend slots as the primary.
5820 : : */
5821 [ + + + + ]: 269 : if (ArchiveRecoveryRequested && EnableHotStandby)
5822 : : {
5823 : : /* We ignore autovacuum_worker_slots when we make this test. */
5824 : 145 : RecoveryRequiresIntParameter("max_connections",
5825 : : MaxConnections,
5826 : 145 : ControlFile->MaxConnections);
5827 : 145 : RecoveryRequiresIntParameter("max_worker_processes",
5828 : : max_worker_processes,
5829 : 145 : ControlFile->max_worker_processes);
5830 : 145 : RecoveryRequiresIntParameter("max_wal_senders",
5831 : : max_wal_senders,
5832 : 145 : ControlFile->max_wal_senders);
5833 : 145 : RecoveryRequiresIntParameter("max_prepared_transactions",
5834 : : max_prepared_xacts,
5835 : 145 : ControlFile->max_prepared_xacts);
5836 : 145 : RecoveryRequiresIntParameter("max_locks_per_transaction",
5837 : : max_locks_per_xact,
5838 : 145 : ControlFile->max_locks_per_xact);
5839 : : }
5840 : 269 : }
5841 : :
5842 : : /*
5843 : : * This must be called ONCE during postmaster or standalone-backend startup
5844 : : */
5845 : : void
5846 : 1088 : StartupXLOG(void)
5847 : : {
5848 : : XLogCtlInsert *Insert;
5849 : : CheckPoint checkPoint;
5850 : : bool wasShutdown;
5851 : : bool didCrash;
5852 : : bool haveTblspcMap;
5853 : : bool haveBackupLabel;
5854 : : XLogRecPtr EndOfLog;
5855 : : TimeLineID EndOfLogTLI;
5856 : : TimeLineID newTLI;
5857 : : bool performedWalRecovery;
5858 : : EndOfWalRecoveryInfo *endOfRecoveryInfo;
5859 : : XLogRecPtr abortedRecPtr;
5860 : : XLogRecPtr missingContrecPtr;
5861 : : TransactionId oldestActiveXID;
5862 : 1088 : bool promoted = false;
5863 : : char timebuf[128];
5864 : :
5865 : : /*
5866 : : * We should have an aux process resource owner to use, and we should not
5867 : : * be in a transaction that's installed some other resowner.
5868 : : */
5869 : : Assert(AuxProcessResourceOwner != NULL);
5870 : : Assert(CurrentResourceOwner == NULL ||
5871 : : CurrentResourceOwner == AuxProcessResourceOwner);
5872 : 1088 : CurrentResourceOwner = AuxProcessResourceOwner;
5873 : :
5874 : : /*
5875 : : * Check that contents look valid.
5876 : : */
5877 [ - + ]: 1088 : if (!XRecOffIsValid(ControlFile->checkPoint))
5878 [ # # ]: 0 : ereport(FATAL,
5879 : : (errcode(ERRCODE_DATA_CORRUPTED),
5880 : : errmsg("control file contains invalid checkpoint location")));
5881 : :
5882 [ + + - - : 1088 : switch (ControlFile->state)
+ + - ]
5883 : : {
5884 : 860 : case DB_SHUTDOWNED:
5885 : :
5886 : : /*
5887 : : * This is the expected case, so don't be chatty in standalone
5888 : : * mode
5889 : : */
5890 [ + + + + ]: 860 : ereport(IsPostmasterEnvironment ? LOG : NOTICE,
5891 : : (errmsg("database system was shut down at %s",
5892 : : str_time(ControlFile->time,
5893 : : timebuf, sizeof(timebuf)))));
5894 : 860 : break;
5895 : :
5896 : 34 : case DB_SHUTDOWNED_IN_RECOVERY:
5897 [ + - ]: 34 : ereport(LOG,
5898 : : (errmsg("database system was shut down in recovery at %s",
5899 : : str_time(ControlFile->time,
5900 : : timebuf, sizeof(timebuf)))));
5901 : 34 : break;
5902 : :
5903 : 0 : case DB_SHUTDOWNING:
5904 [ # # ]: 0 : ereport(LOG,
5905 : : (errmsg("database system shutdown was interrupted; last known up at %s",
5906 : : str_time(ControlFile->time,
5907 : : timebuf, sizeof(timebuf)))));
5908 : 0 : break;
5909 : :
5910 : 0 : case DB_IN_CRASH_RECOVERY:
5911 [ # # ]: 0 : ereport(LOG,
5912 : : (errmsg("database system was interrupted while in recovery at %s",
5913 : : str_time(ControlFile->time,
5914 : : timebuf, sizeof(timebuf))),
5915 : : errhint("This probably means that some data is corrupted and"
5916 : : " you will have to use the last backup for recovery.")));
5917 : 0 : break;
5918 : :
5919 : 9 : case DB_IN_ARCHIVE_RECOVERY:
5920 [ + - ]: 9 : ereport(LOG,
5921 : : (errmsg("database system was interrupted while in recovery at log time %s",
5922 : : str_time(ControlFile->checkPointCopy.time,
5923 : : timebuf, sizeof(timebuf))),
5924 : : errhint("If this has occurred more than once some data might be corrupted"
5925 : : " and you might need to choose an earlier recovery target.")));
5926 : 9 : break;
5927 : :
5928 : 185 : case DB_IN_PRODUCTION:
5929 [ + - ]: 185 : ereport(LOG,
5930 : : (errmsg("database system was interrupted; last known up at %s",
5931 : : str_time(ControlFile->time,
5932 : : timebuf, sizeof(timebuf)))));
5933 : 185 : break;
5934 : :
5935 : 0 : default:
5936 [ # # ]: 0 : ereport(FATAL,
5937 : : (errcode(ERRCODE_DATA_CORRUPTED),
5938 : : errmsg("control file contains invalid database cluster state")));
5939 : : }
5940 : :
5941 : : /* This is just to allow attaching to startup process with a debugger */
5942 : : #ifdef XLOG_REPLAY_DELAY
5943 : : if (ControlFile->state != DB_SHUTDOWNED)
5944 : : pg_usleep(60000000L);
5945 : : #endif
5946 : :
5947 : : /*
5948 : : * Verify that pg_wal, pg_wal/archive_status, and pg_wal/summaries exist.
5949 : : * In cases where someone has performed a copy for PITR, these directories
5950 : : * may have been excluded and need to be re-created.
5951 : : */
5952 : 1088 : ValidateXLOGDirectoryStructure();
5953 : :
5954 : : /* Set up timeout handler needed to report startup progress. */
5955 [ + + ]: 1088 : if (!IsBootstrapProcessingMode())
5956 : 1031 : RegisterTimeout(STARTUP_PROGRESS_TIMEOUT,
5957 : : startup_progress_timeout_handler);
5958 : :
5959 : : /*----------
5960 : : * If we previously crashed, perform a couple of actions:
5961 : : *
5962 : : * - The pg_wal directory may still include some temporary WAL segments
5963 : : * used when creating a new segment, so perform some clean up to not
5964 : : * bloat this path. This is done first as there is no point to sync
5965 : : * this temporary data.
5966 : : *
5967 : : * - There might be data which we had written, intending to fsync it, but
5968 : : * which we had not actually fsync'd yet. Therefore, a power failure in
5969 : : * the near future might cause earlier unflushed writes to be lost, even
5970 : : * though more recent data written to disk from here on would be
5971 : : * persisted. To avoid that, fsync the entire data directory.
5972 : : */
5973 [ + + ]: 1088 : if (ControlFile->state != DB_SHUTDOWNED &&
5974 [ + + ]: 228 : ControlFile->state != DB_SHUTDOWNED_IN_RECOVERY)
5975 : : {
5976 : 194 : RemoveTempXlogFiles();
5977 : 194 : SyncDataDirectory();
5978 : 194 : didCrash = true;
5979 : : }
5980 : : else
5981 : 894 : didCrash = false;
5982 : :
5983 : : /*
5984 : : * Prepare for WAL recovery if needed.
5985 : : *
5986 : : * InitWalRecovery analyzes the control file and the backup label file, if
5987 : : * any. It updates the in-memory ControlFile buffer according to the
5988 : : * starting checkpoint, and sets InRecovery and ArchiveRecoveryRequested.
5989 : : * It also applies the tablespace map file, if any.
5990 : : */
5991 : 1088 : InitWalRecovery(ControlFile, &wasShutdown,
5992 : : &haveBackupLabel, &haveTblspcMap);
5993 : 1086 : checkPoint = ControlFile->checkPointCopy;
5994 : :
5995 : : /* initialize shared memory variables from the checkpoint record */
5996 : 1086 : TransamVariables->nextXid = checkPoint.nextXid;
5997 : 1086 : TransamVariables->nextOid = checkPoint.nextOid;
5998 : 1086 : TransamVariables->oidCount = 0;
5999 : 1086 : MultiXactSetNextMXact(checkPoint.nextMulti, checkPoint.nextMultiOffset);
6000 : 1086 : AdvanceOldestClogXid(checkPoint.oldestXid);
6001 : 1086 : SetTransactionIdLimit(checkPoint.oldestXid, checkPoint.oldestXidDB);
6002 : 1086 : SetMultiXactIdLimit(checkPoint.oldestMulti, checkPoint.oldestMultiDB);
6003 : 1086 : SetCommitTsLimit(checkPoint.oldestCommitTsXid,
6004 : : checkPoint.newestCommitTsXid);
6005 : :
6006 : : /*
6007 : : * Clear out any old relcache cache files. This is *necessary* if we do
6008 : : * any WAL replay, since that would probably result in the cache files
6009 : : * being out of sync with database reality. In theory we could leave them
6010 : : * in place if the database had been cleanly shut down, but it seems
6011 : : * safest to just remove them always and let them be rebuilt during the
6012 : : * first backend startup. These files needs to be removed from all
6013 : : * directories including pg_tblspc, however the symlinks are created only
6014 : : * after reading tablespace_map file in case of archive recovery from
6015 : : * backup, so needs to clear old relcache files here after creating
6016 : : * symlinks.
6017 : : */
6018 : 1086 : RelationCacheInitFileRemove();
6019 : :
6020 : : /*
6021 : : * Initialize replication slots, before there's a chance to remove
6022 : : * required resources.
6023 : : */
6024 : 1086 : StartupReplicationSlots();
6025 : :
6026 : : /*
6027 : : * Startup the logical decoding status with the last status stored in the
6028 : : * checkpoint record.
6029 : : */
6030 : 1084 : StartupLogicalDecodingStatus(checkPoint.logicalDecodingEnabled);
6031 : :
6032 : : /*
6033 : : * Startup logical state, needs to be setup now so we have proper data
6034 : : * during crash recovery.
6035 : : */
6036 : 1084 : StartupReorderBuffer();
6037 : :
6038 : : /*
6039 : : * Startup CLOG. This must be done after TransamVariables->nextXid has
6040 : : * been initialized and before we accept connections or begin WAL replay.
6041 : : */
6042 : 1084 : StartupCLOG();
6043 : :
6044 : : /*
6045 : : * Startup MultiXact. We need to do this early to be able to replay
6046 : : * truncations.
6047 : : */
6048 : 1084 : StartupMultiXact();
6049 : :
6050 : : /*
6051 : : * Ditto for commit timestamps. Activate the facility if the setting is
6052 : : * enabled in the control file, as there should be no tracking of commit
6053 : : * timestamps done when the setting was disabled. This facility can be
6054 : : * started or stopped when replaying a XLOG_PARAMETER_CHANGE record.
6055 : : */
6056 [ + + ]: 1084 : if (ControlFile->track_commit_timestamp)
6057 : 14 : StartupCommitTs();
6058 : :
6059 : : /*
6060 : : * Recover knowledge about replay progress of known replication partners.
6061 : : */
6062 : 1084 : StartupReplicationOrigin();
6063 : :
6064 : : /*
6065 : : * Initialize unlogged LSN. On a clean shutdown, it's restored from the
6066 : : * control file. On recovery, all unlogged relations are blown away, so
6067 : : * the unlogged LSN counter can be reset too.
6068 : : */
6069 [ + + ]: 1084 : if (ControlFile->state == DB_SHUTDOWNED)
6070 : 851 : pg_atomic_write_membarrier_u64(&XLogCtl->unloggedLSN,
6071 : 851 : ControlFile->unloggedLSN);
6072 : : else
6073 : 233 : pg_atomic_write_membarrier_u64(&XLogCtl->unloggedLSN,
6074 : : FirstNormalUnloggedLSN);
6075 : :
6076 : : /*
6077 : : * Copy any missing timeline history files between 'now' and the recovery
6078 : : * target timeline from archive to pg_wal. While we don't need those files
6079 : : * ourselves - the history file of the recovery target timeline covers all
6080 : : * the previous timelines in the history too - a cascading standby server
6081 : : * might be interested in them. Or, if you archive the WAL from this
6082 : : * server to a different archive than the primary, it'd be good for all
6083 : : * the history files to get archived there after failover, so that you can
6084 : : * use one of the old timelines as a PITR target. Timeline history files
6085 : : * are small, so it's better to copy them unnecessarily than not copy them
6086 : : * and regret later.
6087 : : */
6088 : 1084 : restoreTimeLineHistoryFiles(checkPoint.ThisTimeLineID, recoveryTargetTLI);
6089 : :
6090 : : /*
6091 : : * Before running in recovery, scan pg_twophase and fill in its status to
6092 : : * be able to work on entries generated by redo. Doing a scan before
6093 : : * taking any recovery action has the merit to discard any 2PC files that
6094 : : * are newer than the first record to replay, saving from any conflicts at
6095 : : * replay. This avoids as well any subsequent scans when doing recovery
6096 : : * of the on-disk two-phase data.
6097 : : */
6098 : 1084 : restoreTwoPhaseData();
6099 : :
6100 : : /*
6101 : : * When starting with crash recovery, reset pgstat data - it might not be
6102 : : * valid. Otherwise restore pgstat data. It's safe to do this here,
6103 : : * because postmaster will not yet have started any other processes.
6104 : : *
6105 : : * NB: Restoring replication slot stats relies on slot state to have
6106 : : * already been restored from disk.
6107 : : *
6108 : : * TODO: With a bit of extra work we could just start with a pgstat file
6109 : : * associated with the checkpoint redo location we're starting from.
6110 : : */
6111 [ + + ]: 1084 : if (didCrash)
6112 : 192 : pgstat_discard_stats();
6113 : : else
6114 : 892 : pgstat_restore_stats();
6115 : :
6116 : 1084 : lastFullPageWrites = checkPoint.fullPageWrites;
6117 : :
6118 : 1084 : RedoRecPtr = XLogCtl->RedoRecPtr = XLogCtl->Insert.RedoRecPtr = checkPoint.redo;
6119 : 1084 : doPageWrites = lastFullPageWrites;
6120 : :
6121 : : /* REDO */
6122 [ + + ]: 1084 : if (InRecovery)
6123 : : {
6124 : : /* Initialize state for RecoveryInProgress() */
6125 : 233 : SpinLockAcquire(&XLogCtl->info_lck);
6126 [ + + ]: 233 : if (InArchiveRecovery)
6127 : 131 : XLogCtl->SharedRecoveryState = RECOVERY_STATE_ARCHIVE;
6128 : : else
6129 : 102 : XLogCtl->SharedRecoveryState = RECOVERY_STATE_CRASH;
6130 : 233 : SpinLockRelease(&XLogCtl->info_lck);
6131 : :
6132 : : /*
6133 : : * Update pg_control to show that we are recovering and to show the
6134 : : * selected checkpoint as the place we are starting from. We also mark
6135 : : * pg_control with any minimum recovery stop point obtained from a
6136 : : * backup history file.
6137 : : *
6138 : : * No need to hold ControlFileLock yet, we aren't up far enough.
6139 : : */
6140 : 233 : UpdateControlFile();
6141 : :
6142 : : /*
6143 : : * If there was a backup label file, it's done its job and the info
6144 : : * has now been propagated into pg_control. We must get rid of the
6145 : : * label file so that if we crash during recovery, we'll pick up at
6146 : : * the latest recovery restartpoint instead of going all the way back
6147 : : * to the backup start point. It seems prudent though to just rename
6148 : : * the file out of the way rather than delete it completely.
6149 : : */
6150 [ + + ]: 233 : if (haveBackupLabel)
6151 : : {
6152 : 88 : unlink(BACKUP_LABEL_OLD);
6153 : 88 : durable_rename(BACKUP_LABEL_FILE, BACKUP_LABEL_OLD, FATAL);
6154 : : }
6155 : :
6156 : : /*
6157 : : * If there was a tablespace_map file, it's done its job and the
6158 : : * symlinks have been created. We must get rid of the map file so
6159 : : * that if we crash during recovery, we don't create symlinks again.
6160 : : * It seems prudent though to just rename the file out of the way
6161 : : * rather than delete it completely.
6162 : : */
6163 [ + + ]: 233 : if (haveTblspcMap)
6164 : : {
6165 : 2 : unlink(TABLESPACE_MAP_OLD);
6166 : 2 : durable_rename(TABLESPACE_MAP, TABLESPACE_MAP_OLD, FATAL);
6167 : : }
6168 : :
6169 : : /*
6170 : : * Initialize our local copy of minRecoveryPoint. When doing crash
6171 : : * recovery we want to replay up to the end of WAL. Particularly, in
6172 : : * the case of a promoted standby minRecoveryPoint value in the
6173 : : * control file is only updated after the first checkpoint. However,
6174 : : * if the instance crashes before the first post-recovery checkpoint
6175 : : * is completed then recovery will use a stale location causing the
6176 : : * startup process to think that there are still invalid page
6177 : : * references when checking for data consistency.
6178 : : */
6179 [ + + ]: 233 : if (InArchiveRecovery)
6180 : : {
6181 : 131 : LocalMinRecoveryPoint = ControlFile->minRecoveryPoint;
6182 : 131 : LocalMinRecoveryPointTLI = ControlFile->minRecoveryPointTLI;
6183 : : }
6184 : : else
6185 : : {
6186 : 102 : LocalMinRecoveryPoint = InvalidXLogRecPtr;
6187 : 102 : LocalMinRecoveryPointTLI = 0;
6188 : : }
6189 : :
6190 : : /* Check that the GUCs used to generate the WAL allow recovery */
6191 : 233 : CheckRequiredParameterValues();
6192 : :
6193 : : /*
6194 : : * We're in recovery, so unlogged relations may be trashed and must be
6195 : : * reset. This should be done BEFORE allowing Hot Standby
6196 : : * connections, so that read-only backends don't try to read whatever
6197 : : * garbage is left over from before.
6198 : : */
6199 : 233 : ResetUnloggedRelations(UNLOGGED_RELATION_CLEANUP);
6200 : :
6201 : : /*
6202 : : * Likewise, delete any saved transaction snapshot files that got left
6203 : : * behind by crashed backends.
6204 : : */
6205 : 233 : DeleteAllExportedSnapshotFiles();
6206 : :
6207 : : /*
6208 : : * Initialize for Hot Standby, if enabled. We won't let backends in
6209 : : * yet, not until we've reached the min recovery point specified in
6210 : : * control file and we've established a recovery snapshot from a
6211 : : * running-xacts WAL record.
6212 : : */
6213 [ + + + + ]: 233 : if (ArchiveRecoveryRequested && EnableHotStandby)
6214 : : {
6215 : : TransactionId *xids;
6216 : : int nxids;
6217 : :
6218 [ + + ]: 123 : ereport(DEBUG1,
6219 : : (errmsg_internal("initializing for hot standby")));
6220 : :
6221 : 123 : InitRecoveryTransactionEnvironment();
6222 : :
6223 [ + + ]: 123 : if (wasShutdown)
6224 : 26 : oldestActiveXID = PrescanPreparedTransactions(&xids, &nxids);
6225 : : else
6226 : 97 : oldestActiveXID = checkPoint.oldestActiveXid;
6227 : : Assert(TransactionIdIsValid(oldestActiveXID));
6228 : :
6229 : : /* Tell procarray about the range of xids it has to deal with */
6230 : 123 : ProcArrayInitRecovery(XidFromFullTransactionId(TransamVariables->nextXid));
6231 : :
6232 : : /*
6233 : : * Startup subtrans only. CLOG, MultiXact and commit timestamp
6234 : : * have already been started up and other SLRUs are not maintained
6235 : : * during recovery and need not be started yet.
6236 : : */
6237 : 123 : StartupSUBTRANS(oldestActiveXID);
6238 : :
6239 : : /*
6240 : : * If we're beginning at a shutdown checkpoint, we know that
6241 : : * nothing was running on the primary at this point. So fake-up an
6242 : : * empty running-xacts record and use that here and now. Recover
6243 : : * additional standby state for prepared transactions.
6244 : : */
6245 [ + + ]: 123 : if (wasShutdown)
6246 : : {
6247 : : RunningTransactionsData running;
6248 : : TransactionId latestCompletedXid;
6249 : :
6250 : : /* Update pg_subtrans entries for any prepared transactions */
6251 : 26 : StandbyRecoverPreparedTransactions();
6252 : :
6253 : : /*
6254 : : * Construct a RunningTransactions snapshot representing a
6255 : : * shut down server, with only prepared transactions still
6256 : : * alive. We're never overflowed at this point because all
6257 : : * subxids are listed with their parent prepared transactions.
6258 : : */
6259 : 26 : running.xcnt = nxids;
6260 : 26 : running.subxcnt = 0;
6261 : 26 : running.subxid_status = SUBXIDS_IN_SUBTRANS;
6262 : 26 : running.nextXid = XidFromFullTransactionId(checkPoint.nextXid);
6263 : 26 : running.oldestRunningXid = oldestActiveXID;
6264 : 26 : latestCompletedXid = XidFromFullTransactionId(checkPoint.nextXid);
6265 [ - + ]: 26 : TransactionIdRetreat(latestCompletedXid);
6266 : : Assert(TransactionIdIsNormal(latestCompletedXid));
6267 : 26 : running.latestCompletedXid = latestCompletedXid;
6268 : 26 : running.xids = xids;
6269 : :
6270 : 26 : ProcArrayApplyRecoveryInfo(&running);
6271 : : }
6272 : : }
6273 : :
6274 : : /*
6275 : : * We're all set for replaying the WAL now. Do it.
6276 : : */
6277 : 233 : PerformWalRecovery();
6278 : 167 : performedWalRecovery = true;
6279 : : }
6280 : : else
6281 : 851 : performedWalRecovery = false;
6282 : :
6283 : : /*
6284 : : * Finish WAL recovery.
6285 : : */
6286 : 1018 : endOfRecoveryInfo = FinishWalRecovery();
6287 : 1018 : EndOfLog = endOfRecoveryInfo->endOfLog;
6288 : 1018 : EndOfLogTLI = endOfRecoveryInfo->endOfLogTLI;
6289 : 1018 : abortedRecPtr = endOfRecoveryInfo->abortedRecPtr;
6290 : 1018 : missingContrecPtr = endOfRecoveryInfo->missingContrecPtr;
6291 : :
6292 : : /*
6293 : : * Reset ps status display, so as no information related to recovery shows
6294 : : * up.
6295 : : */
6296 : 1018 : set_ps_display("");
6297 : :
6298 : : /*
6299 : : * When recovering from a backup (we are in recovery, and archive recovery
6300 : : * was requested), complain if we did not roll forward far enough to reach
6301 : : * the point where the database is consistent. For regular online
6302 : : * backup-from-primary, that means reaching the end-of-backup WAL record
6303 : : * (at which point we reset backupStartPoint to be Invalid), for
6304 : : * backup-from-replica (which can't inject records into the WAL stream),
6305 : : * that point is when we reach the minRecoveryPoint in pg_control (which
6306 : : * we purposefully copy last when backing up from a replica). For
6307 : : * pg_rewind (which creates a backup_label with a method of "pg_rewind")
6308 : : * or snapshot-style backups (which don't), backupEndRequired will be set
6309 : : * to false.
6310 : : *
6311 : : * Note: it is indeed okay to look at the local variable
6312 : : * LocalMinRecoveryPoint here, even though ControlFile->minRecoveryPoint
6313 : : * might be further ahead --- ControlFile->minRecoveryPoint cannot have
6314 : : * been advanced beyond the WAL we processed.
6315 : : */
6316 [ + + ]: 1018 : if (InRecovery &&
6317 [ + - ]: 167 : (EndOfLog < LocalMinRecoveryPoint ||
6318 [ - + ]: 167 : XLogRecPtrIsValid(ControlFile->backupStartPoint)))
6319 : : {
6320 : : /*
6321 : : * Ran off end of WAL before reaching end-of-backup WAL record, or
6322 : : * minRecoveryPoint. That's a bad sign, indicating that you tried to
6323 : : * recover from an online backup but never called pg_backup_stop(), or
6324 : : * you didn't archive all the WAL needed.
6325 : : */
6326 [ # # # # ]: 0 : if (ArchiveRecoveryRequested || ControlFile->backupEndRequired)
6327 : : {
6328 [ # # # # ]: 0 : if (XLogRecPtrIsValid(ControlFile->backupStartPoint) || ControlFile->backupEndRequired)
6329 [ # # ]: 0 : ereport(FATAL,
6330 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
6331 : : errmsg("WAL ends before end of online backup"),
6332 : : errhint("All WAL generated while online backup was taken must be available at recovery.")));
6333 : : else
6334 [ # # ]: 0 : ereport(FATAL,
6335 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
6336 : : errmsg("WAL ends before consistent recovery point")));
6337 : : }
6338 : : }
6339 : :
6340 : : /*
6341 : : * Reset unlogged relations to the contents of their INIT fork. This is
6342 : : * done AFTER recovery is complete so as to include any unlogged relations
6343 : : * created during recovery, but BEFORE recovery is marked as having
6344 : : * completed successfully. Otherwise we'd not retry if any of the post
6345 : : * end-of-recovery steps fail.
6346 : : */
6347 [ + + ]: 1018 : if (InRecovery)
6348 : 167 : ResetUnloggedRelations(UNLOGGED_RELATION_INIT);
6349 : :
6350 : : /*
6351 : : * Pre-scan prepared transactions to find out the range of XIDs present.
6352 : : * This information is not quite needed yet, but it is positioned here so
6353 : : * as potential problems are detected before any on-disk change is done.
6354 : : */
6355 : 1018 : oldestActiveXID = PrescanPreparedTransactions(NULL, NULL);
6356 : :
6357 : : /*
6358 : : * Allow ordinary WAL segment creation before possibly switching to a new
6359 : : * timeline, which creates a new segment, and after the last ReadRecord().
6360 : : */
6361 : 1018 : SetInstallXLogFileSegmentActive();
6362 : :
6363 : : /*
6364 : : * Consider whether we need to assign a new timeline ID.
6365 : : *
6366 : : * If we did archive recovery, we always assign a new ID. This handles a
6367 : : * couple of issues. If we stopped short of the end of WAL during
6368 : : * recovery, then we are clearly generating a new timeline and must assign
6369 : : * it a unique new ID. Even if we ran to the end, modifying the current
6370 : : * last segment is problematic because it may result in trying to
6371 : : * overwrite an already-archived copy of that segment, and we encourage
6372 : : * DBAs to make their archive_commands reject that. We can dodge the
6373 : : * problem by making the new active segment have a new timeline ID.
6374 : : *
6375 : : * In a normal crash recovery, we can just extend the timeline we were in.
6376 : : */
6377 : 1018 : newTLI = endOfRecoveryInfo->lastRecTLI;
6378 [ + + ]: 1018 : if (ArchiveRecoveryRequested)
6379 : : {
6380 : 59 : newTLI = findNewestTimeLine(recoveryTargetTLI) + 1;
6381 [ + - ]: 59 : ereport(LOG,
6382 : : (errmsg("selected new timeline ID: %u", newTLI)));
6383 : :
6384 : : /*
6385 : : * Make a writable copy of the last WAL segment. (Note that we also
6386 : : * have a copy of the last block of the old WAL in
6387 : : * endOfRecovery->lastPage; we will use that below.)
6388 : : */
6389 : 59 : XLogInitNewTimeline(EndOfLogTLI, EndOfLog, newTLI);
6390 : :
6391 : : /*
6392 : : * Remove the signal files out of the way, so that we don't
6393 : : * accidentally re-enter archive recovery mode in a subsequent crash.
6394 : : */
6395 [ + + ]: 59 : if (endOfRecoveryInfo->standby_signal_file_found)
6396 : 56 : durable_unlink(STANDBY_SIGNAL_FILE, FATAL);
6397 : :
6398 [ + + ]: 59 : if (endOfRecoveryInfo->recovery_signal_file_found)
6399 : 4 : durable_unlink(RECOVERY_SIGNAL_FILE, FATAL);
6400 : :
6401 : : /*
6402 : : * Write the timeline history file, and have it archived. After this
6403 : : * point (or rather, as soon as the file is archived), the timeline
6404 : : * will appear as "taken" in the WAL archive and to any standby
6405 : : * servers. If we crash before actually switching to the new
6406 : : * timeline, standby servers will nevertheless think that we switched
6407 : : * to the new timeline, and will try to connect to the new timeline.
6408 : : * To minimize the window for that, try to do as little as possible
6409 : : * between here and writing the end-of-recovery record.
6410 : : */
6411 : 59 : writeTimeLineHistory(newTLI, recoveryTargetTLI,
6412 : : EndOfLog, endOfRecoveryInfo->recoveryStopReason);
6413 : :
6414 [ + - ]: 59 : ereport(LOG,
6415 : : (errmsg("archive recovery complete")));
6416 : : }
6417 : :
6418 : : /* Save the selected TimeLineID in shared memory, too */
6419 : 1018 : SpinLockAcquire(&XLogCtl->info_lck);
6420 : 1018 : XLogCtl->InsertTimeLineID = newTLI;
6421 : 1018 : XLogCtl->PrevTimeLineID = endOfRecoveryInfo->lastRecTLI;
6422 : 1018 : SpinLockRelease(&XLogCtl->info_lck);
6423 : :
6424 : : /*
6425 : : * Actually, if WAL ended in an incomplete record, skip the parts that
6426 : : * made it through and start writing after the portion that persisted.
6427 : : * (It's critical to first write an OVERWRITE_CONTRECORD message, which
6428 : : * we'll do as soon as we're open for writing new WAL.)
6429 : : */
6430 [ + + ]: 1018 : if (XLogRecPtrIsValid(missingContrecPtr))
6431 : : {
6432 : : /*
6433 : : * We should only have a missingContrecPtr if we're not switching to a
6434 : : * new timeline. When a timeline switch occurs, WAL is copied from the
6435 : : * old timeline to the new only up to the end of the last complete
6436 : : * record, so there can't be an incomplete WAL record that we need to
6437 : : * disregard.
6438 : : */
6439 : : Assert(newTLI == endOfRecoveryInfo->lastRecTLI);
6440 : : Assert(XLogRecPtrIsValid(abortedRecPtr));
6441 : 11 : EndOfLog = missingContrecPtr;
6442 : : }
6443 : :
6444 : : /*
6445 : : * Prepare to write WAL starting at EndOfLog location, and init xlog
6446 : : * buffer cache using the block containing the last record from the
6447 : : * previous incarnation.
6448 : : */
6449 : 1018 : Insert = &XLogCtl->Insert;
6450 : 1018 : Insert->PrevBytePos = XLogRecPtrToBytePos(endOfRecoveryInfo->lastRec);
6451 : 1018 : Insert->CurrBytePos = XLogRecPtrToBytePos(EndOfLog);
6452 : :
6453 : : /*
6454 : : * Tricky point here: lastPage contains the *last* block that the LastRec
6455 : : * record spans, not the one it starts in. The last block is indeed the
6456 : : * one we want to use.
6457 : : */
6458 [ + + ]: 1018 : if (EndOfLog % XLOG_BLCKSZ != 0)
6459 : : {
6460 : : char *page;
6461 : : int len;
6462 : : int firstIdx;
6463 : :
6464 : 985 : firstIdx = XLogRecPtrToBufIdx(EndOfLog);
6465 : 985 : len = EndOfLog - endOfRecoveryInfo->lastPageBeginPtr;
6466 : : Assert(len < XLOG_BLCKSZ);
6467 : :
6468 : : /* Copy the valid part of the last block, and zero the rest */
6469 : 985 : page = &XLogCtl->pages[firstIdx * XLOG_BLCKSZ];
6470 : 985 : memcpy(page, endOfRecoveryInfo->lastPage, len);
6471 : 985 : memset(page + len, 0, XLOG_BLCKSZ - len);
6472 : :
6473 : 985 : pg_atomic_write_u64(&XLogCtl->xlblocks[firstIdx], endOfRecoveryInfo->lastPageBeginPtr + XLOG_BLCKSZ);
6474 : 985 : XLogCtl->InitializedUpTo = endOfRecoveryInfo->lastPageBeginPtr + XLOG_BLCKSZ;
6475 : : }
6476 : : else
6477 : : {
6478 : : /*
6479 : : * There is no partial block to copy. Just set InitializedUpTo, and
6480 : : * let the first attempt to insert a log record to initialize the next
6481 : : * buffer.
6482 : : */
6483 : 33 : XLogCtl->InitializedUpTo = EndOfLog;
6484 : : }
6485 : :
6486 : : /*
6487 : : * Update local and shared status. This is OK to do without any locks
6488 : : * because no other process can be reading or writing WAL yet.
6489 : : */
6490 : 1018 : LogwrtResult.Write = LogwrtResult.Flush = EndOfLog;
6491 : 1018 : pg_atomic_write_u64(&XLogCtl->logInsertResult, EndOfLog);
6492 : 1018 : pg_atomic_write_u64(&XLogCtl->logWriteResult, EndOfLog);
6493 : 1018 : pg_atomic_write_u64(&XLogCtl->logFlushResult, EndOfLog);
6494 : 1018 : XLogCtl->LogwrtRqst.Write = EndOfLog;
6495 : 1018 : XLogCtl->LogwrtRqst.Flush = EndOfLog;
6496 : :
6497 : : /*
6498 : : * Preallocate additional log files, if wanted.
6499 : : */
6500 : 1018 : PreallocXlogFiles(EndOfLog, newTLI);
6501 : :
6502 : : /*
6503 : : * Okay, we're officially UP.
6504 : : */
6505 : 1018 : InRecovery = false;
6506 : :
6507 : : /* start the archive_timeout timer and LSN running */
6508 : 1018 : XLogCtl->lastSegSwitchTime = (pg_time_t) time(NULL);
6509 : 1018 : XLogCtl->lastSegSwitchLSN = EndOfLog;
6510 : :
6511 : : /* also initialize latestCompletedXid, to nextXid - 1 */
6512 : 1018 : LWLockAcquire(ProcArrayLock, LW_EXCLUSIVE);
6513 : 1018 : TransamVariables->latestCompletedXid = TransamVariables->nextXid;
6514 : 1018 : FullTransactionIdRetreat(&TransamVariables->latestCompletedXid);
6515 : 1018 : LWLockRelease(ProcArrayLock);
6516 : :
6517 : : /*
6518 : : * Start up subtrans, if not already done for hot standby. (commit
6519 : : * timestamps are started below, if necessary.)
6520 : : */
6521 [ + + ]: 1018 : if (standbyState == STANDBY_DISABLED)
6522 : 959 : StartupSUBTRANS(oldestActiveXID);
6523 : :
6524 : : /*
6525 : : * Perform end of recovery actions for any SLRUs that need it.
6526 : : */
6527 : 1018 : TrimCLOG();
6528 : 1018 : TrimMultiXact();
6529 : :
6530 : : /*
6531 : : * Reload shared-memory state for prepared transactions. This needs to
6532 : : * happen before renaming the last partial segment of the old timeline as
6533 : : * it may be possible that we have to recover some transactions from it.
6534 : : */
6535 : 1018 : RecoverPreparedTransactions();
6536 : :
6537 : : /* Shut down xlogreader */
6538 : 1018 : ShutdownWalRecovery();
6539 : :
6540 : : /* Enable WAL writes for this backend only. */
6541 : 1018 : LocalSetXLogInsertAllowed();
6542 : :
6543 : : /* If necessary, write overwrite-contrecord before doing anything else */
6544 [ + + ]: 1018 : if (XLogRecPtrIsValid(abortedRecPtr))
6545 : : {
6546 : : Assert(XLogRecPtrIsValid(missingContrecPtr));
6547 : 11 : CreateOverwriteContrecordRecord(abortedRecPtr, missingContrecPtr, newTLI);
6548 : : }
6549 : :
6550 : : /*
6551 : : * Update full_page_writes in shared memory and write an XLOG_FPW_CHANGE
6552 : : * record before resource manager writes cleanup WAL records or checkpoint
6553 : : * record is written.
6554 : : */
6555 : 1018 : Insert->fullPageWrites = lastFullPageWrites;
6556 : 1018 : UpdateFullPageWrites();
6557 : :
6558 : : /*
6559 : : * Emit checkpoint or end-of-recovery record in XLOG, if required.
6560 : : */
6561 [ + + ]: 1018 : if (performedWalRecovery)
6562 : 167 : promoted = PerformRecoveryXLogAction();
6563 : :
6564 : : /*
6565 : : * If any of the critical GUCs have changed, log them before we allow
6566 : : * backends to write WAL.
6567 : : */
6568 : 1018 : XLogReportParameters();
6569 : :
6570 : : /* If this is archive recovery, perform post-recovery cleanup actions. */
6571 [ + + ]: 1018 : if (ArchiveRecoveryRequested)
6572 : 59 : CleanupAfterArchiveRecovery(EndOfLogTLI, EndOfLog, newTLI);
6573 : :
6574 : 1018 : INJECTION_POINT("promotion-after-wal-segment-cleanup", NULL);
6575 : :
6576 : : /*
6577 : : * Local WAL inserts enabled, so it's time to finish initialization of
6578 : : * commit timestamp.
6579 : : */
6580 : 1018 : CompleteCommitTsInitialization();
6581 : :
6582 : : /*
6583 : : * Update logical decoding status in shared memory and write an
6584 : : * XLOG_LOGICAL_DECODING_STATUS_CHANGE, if necessary.
6585 : : */
6586 : 1018 : UpdateLogicalDecodingStatusEndOfRecovery();
6587 : :
6588 : : /* Clean up EndOfWalRecoveryInfo data to appease Valgrind leak checking */
6589 [ + + ]: 1018 : if (endOfRecoveryInfo->lastPage)
6590 : 996 : pfree(endOfRecoveryInfo->lastPage);
6591 : 1018 : pfree(endOfRecoveryInfo->recoveryStopReason);
6592 : 1018 : pfree(endOfRecoveryInfo);
6593 : :
6594 : : /*
6595 : : * If we reach this point with checksums in the state inprogress-on, it
6596 : : * means that data checksums were in the process of being enabled when the
6597 : : * cluster shut down. Since processing didn't finish, the operation will
6598 : : * have to be restarted from scratch since there is no capability to
6599 : : * continue where it was when the cluster shut down. Thus, revert the
6600 : : * state back to off, and inform the user with a warning message. Being
6601 : : * able to restart processing is a TODO, but it wouldn't be possible to
6602 : : * restart here since we cannot launch a dynamic background worker
6603 : : * directly from here (it has to be from a regular backend).
6604 : : */
6605 [ + + ]: 1018 : if (XLogCtl->data_checksum_version == PG_DATA_CHECKSUM_INPROGRESS_ON)
6606 : : {
6607 : 1 : XLogChecksums(PG_DATA_CHECKSUM_OFF);
6608 : :
6609 : 1 : SpinLockAcquire(&XLogCtl->info_lck);
6610 : 1 : XLogCtl->data_checksum_version = PG_DATA_CHECKSUM_OFF;
6611 : 1 : SetLocalDataChecksumState(XLogCtl->data_checksum_version);
6612 : 1 : SpinLockRelease(&XLogCtl->info_lck);
6613 : :
6614 : 1 : EmitAndWaitDataChecksumsBarrier(PG_DATA_CHECKSUM_OFF);
6615 [ + - ]: 1 : ereport(WARNING,
6616 : : errmsg("enabling data checksums was interrupted"),
6617 : : errhint("Data checksum processing must be manually restarted for checksums to be enabled."));
6618 : : }
6619 : :
6620 : : /*
6621 : : * If data checksums were being disabled when the cluster was shut down,
6622 : : * we know that we have a state where all backends have stopped validating
6623 : : * checksums and we can move to off instead of prompting the user to
6624 : : * perform any action.
6625 : : */
6626 [ - + ]: 1017 : else if (XLogCtl->data_checksum_version == PG_DATA_CHECKSUM_INPROGRESS_OFF)
6627 : : {
6628 : 0 : XLogChecksums(PG_DATA_CHECKSUM_OFF);
6629 : :
6630 : 0 : SpinLockAcquire(&XLogCtl->info_lck);
6631 : 0 : XLogCtl->data_checksum_version = PG_DATA_CHECKSUM_OFF;
6632 : 0 : SetLocalDataChecksumState(XLogCtl->data_checksum_version);
6633 : 0 : SpinLockRelease(&XLogCtl->info_lck);
6634 : :
6635 : 0 : EmitAndWaitDataChecksumsBarrier(PG_DATA_CHECKSUM_OFF);
6636 : : }
6637 : :
6638 : : /*
6639 : : * All done with end-of-recovery actions.
6640 : : *
6641 : : * Now allow backends to write WAL and update the control file status in
6642 : : * consequence. SharedRecoveryState, that controls if backends can write
6643 : : * WAL, is updated while holding ControlFileLock to prevent other backends
6644 : : * to look at an inconsistent state of the control file in shared memory.
6645 : : * There is still a small window during which backends can write WAL and
6646 : : * the control file is still referring to a system not in DB_IN_PRODUCTION
6647 : : * state while looking at the on-disk control file.
6648 : : *
6649 : : * Also, we use info_lck to update SharedRecoveryState to ensure that
6650 : : * there are no race conditions concerning visibility of other recent
6651 : : * updates to shared memory.
6652 : : */
6653 : 1018 : LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
6654 : 1018 : ControlFile->state = DB_IN_PRODUCTION;
6655 : :
6656 : 1018 : SpinLockAcquire(&XLogCtl->info_lck);
6657 : 1018 : ControlFile->data_checksum_version = XLogCtl->data_checksum_version;
6658 : 1018 : XLogCtl->SharedRecoveryState = RECOVERY_STATE_DONE;
6659 : 1018 : SpinLockRelease(&XLogCtl->info_lck);
6660 : :
6661 : 1018 : UpdateControlFile();
6662 : 1018 : LWLockRelease(ControlFileLock);
6663 : :
6664 : : /*
6665 : : * Wake up the checkpointer process as there might be a request to disable
6666 : : * logical decoding by concurrent slot drop.
6667 : : */
6668 : 1018 : WakeupCheckpointer();
6669 : :
6670 : : /*
6671 : : * Wake up all waiters. They need to report an error that recovery was
6672 : : * ended before reaching the target LSN.
6673 : : */
6674 : 1018 : WaitLSNWakeup(WAIT_LSN_TYPE_STANDBY_REPLAY, InvalidXLogRecPtr);
6675 : 1018 : WaitLSNWakeup(WAIT_LSN_TYPE_STANDBY_WRITE, InvalidXLogRecPtr);
6676 : 1018 : WaitLSNWakeup(WAIT_LSN_TYPE_STANDBY_FLUSH, InvalidXLogRecPtr);
6677 : :
6678 : : /*
6679 : : * Shutdown the recovery environment. This must occur after
6680 : : * RecoverPreparedTransactions() (see notes in lock_twophase_recover())
6681 : : * and after switching SharedRecoveryState to RECOVERY_STATE_DONE so as
6682 : : * any session building a snapshot will not rely on KnownAssignedXids as
6683 : : * RecoveryInProgress() would return false at this stage. This is
6684 : : * particularly critical for prepared 2PC transactions, that would still
6685 : : * need to be included in snapshots once recovery has ended.
6686 : : */
6687 [ + + ]: 1018 : if (standbyState != STANDBY_DISABLED)
6688 : 59 : ShutdownRecoveryTransactionEnvironment();
6689 : :
6690 : : /*
6691 : : * If there were cascading standby servers connected to us, nudge any wal
6692 : : * sender processes to notice that we've been promoted.
6693 : : */
6694 : 1018 : WalSndWakeup(true, true);
6695 : :
6696 : : /*
6697 : : * If this was a promotion, request an (online) checkpoint now. This isn't
6698 : : * required for consistency, but the last restartpoint might be far back,
6699 : : * and in case of a crash, recovering from it might take a longer than is
6700 : : * appropriate now that we're not in standby mode anymore.
6701 : : */
6702 [ + + ]: 1018 : if (promoted)
6703 : 52 : RequestCheckpoint(CHECKPOINT_FORCE);
6704 : 1018 : }
6705 : :
6706 : : /*
6707 : : * Callback from PerformWalRecovery(), called when we switch from crash
6708 : : * recovery to archive recovery mode. Updates the control file accordingly.
6709 : : */
6710 : : void
6711 : 1 : SwitchIntoArchiveRecovery(XLogRecPtr EndRecPtr, TimeLineID replayTLI)
6712 : : {
6713 : : /* initialize minRecoveryPoint to this record */
6714 : 1 : LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
6715 : 1 : ControlFile->state = DB_IN_ARCHIVE_RECOVERY;
6716 [ + - ]: 1 : if (ControlFile->minRecoveryPoint < EndRecPtr)
6717 : : {
6718 : 1 : ControlFile->minRecoveryPoint = EndRecPtr;
6719 : 1 : ControlFile->minRecoveryPointTLI = replayTLI;
6720 : : }
6721 : : /* update local copy */
6722 : 1 : LocalMinRecoveryPoint = ControlFile->minRecoveryPoint;
6723 : 1 : LocalMinRecoveryPointTLI = ControlFile->minRecoveryPointTLI;
6724 : :
6725 : : /*
6726 : : * The startup process can update its local copy of minRecoveryPoint from
6727 : : * this point.
6728 : : */
6729 : 1 : updateMinRecoveryPoint = true;
6730 : :
6731 : 1 : UpdateControlFile();
6732 : :
6733 : : /*
6734 : : * We update SharedRecoveryState while holding the lock on ControlFileLock
6735 : : * so both states are consistent in shared memory.
6736 : : */
6737 : 1 : SpinLockAcquire(&XLogCtl->info_lck);
6738 : 1 : XLogCtl->SharedRecoveryState = RECOVERY_STATE_ARCHIVE;
6739 : 1 : SpinLockRelease(&XLogCtl->info_lck);
6740 : :
6741 : 1 : LWLockRelease(ControlFileLock);
6742 : 1 : }
6743 : :
6744 : : /*
6745 : : * Callback from PerformWalRecovery(), called when we reach the end of backup.
6746 : : * Updates the control file accordingly.
6747 : : */
6748 : : void
6749 : 88 : ReachedEndOfBackup(XLogRecPtr EndRecPtr, TimeLineID tli)
6750 : : {
6751 : : /*
6752 : : * We have reached the end of base backup, as indicated by pg_control. The
6753 : : * data on disk is now consistent (unless minRecoveryPoint is further
6754 : : * ahead, which can happen if we crashed during previous recovery). Reset
6755 : : * backupStartPoint and backupEndPoint, and update minRecoveryPoint to
6756 : : * make sure we don't allow starting up at an earlier point even if
6757 : : * recovery is stopped and restarted soon after this.
6758 : : */
6759 : 88 : LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
6760 : :
6761 [ + + ]: 88 : if (ControlFile->minRecoveryPoint < EndRecPtr)
6762 : : {
6763 : 81 : ControlFile->minRecoveryPoint = EndRecPtr;
6764 : 81 : ControlFile->minRecoveryPointTLI = tli;
6765 : : }
6766 : :
6767 : 88 : ControlFile->backupStartPoint = InvalidXLogRecPtr;
6768 : 88 : ControlFile->backupEndPoint = InvalidXLogRecPtr;
6769 : 88 : ControlFile->backupEndRequired = false;
6770 : 88 : UpdateControlFile();
6771 : :
6772 : 88 : LWLockRelease(ControlFileLock);
6773 : 88 : }
6774 : :
6775 : : /*
6776 : : * Perform whatever XLOG actions are necessary at end of REDO.
6777 : : *
6778 : : * The goal here is to make sure that we'll be able to recover properly if
6779 : : * we crash again. If we choose to write a checkpoint, we'll write a shutdown
6780 : : * checkpoint rather than an on-line one. This is not particularly critical,
6781 : : * but since we may be assigning a new TLI, using a shutdown checkpoint allows
6782 : : * us to have the rule that TLI only changes in shutdown checkpoints, which
6783 : : * allows some extra error checking in xlog_redo.
6784 : : */
6785 : : static bool
6786 : 167 : PerformRecoveryXLogAction(void)
6787 : : {
6788 : 167 : bool promoted = false;
6789 : :
6790 : : /*
6791 : : * Perform a checkpoint to update all our recovery activity to disk.
6792 : : *
6793 : : * Note that we write a shutdown checkpoint rather than an on-line one.
6794 : : * This is not particularly critical, but since we may be assigning a new
6795 : : * TLI, using a shutdown checkpoint allows us to have the rule that TLI
6796 : : * only changes in shutdown checkpoints, which allows some extra error
6797 : : * checking in xlog_redo.
6798 : : *
6799 : : * In promotion, only create a lightweight end-of-recovery record instead
6800 : : * of a full checkpoint. A checkpoint is requested later, after we're
6801 : : * fully out of recovery mode and already accepting queries.
6802 : : */
6803 [ + + + - : 226 : if (ArchiveRecoveryRequested && IsUnderPostmaster &&
+ + ]
6804 : 59 : PromoteIsTriggered())
6805 : : {
6806 : 52 : promoted = true;
6807 : :
6808 : : /*
6809 : : * Insert a special WAL record to mark the end of recovery, since we
6810 : : * aren't doing a checkpoint. That means that the checkpointer process
6811 : : * may likely be in the middle of a time-smoothed restartpoint and
6812 : : * could continue to be for minutes after this. That sounds strange,
6813 : : * but the effect is roughly the same and it would be stranger to try
6814 : : * to come out of the restartpoint and then checkpoint. We request a
6815 : : * checkpoint later anyway, just for safety.
6816 : : */
6817 : 52 : CreateEndOfRecoveryRecord();
6818 : : }
6819 : : else
6820 : : {
6821 : 115 : RequestCheckpoint(CHECKPOINT_END_OF_RECOVERY |
6822 : : CHECKPOINT_FAST |
6823 : : CHECKPOINT_WAIT);
6824 : : }
6825 : :
6826 : 167 : return promoted;
6827 : : }
6828 : :
6829 : : /*
6830 : : * Is the system still in recovery?
6831 : : *
6832 : : * Unlike testing InRecovery, this works in any process that's connected to
6833 : : * shared memory.
6834 : : */
6835 : : bool
6836 : 98017585 : RecoveryInProgress(void)
6837 : : {
6838 : : /*
6839 : : * We check shared state each time only until we leave recovery mode. We
6840 : : * can't re-enter recovery, so there's no need to keep checking after the
6841 : : * shared variable has once been seen false.
6842 : : */
6843 [ + + ]: 98017585 : if (!LocalRecoveryInProgress)
6844 : 96166979 : return false;
6845 : : else
6846 : : {
6847 : : /*
6848 : : * use volatile pointer to make sure we make a fresh read of the
6849 : : * shared variable.
6850 : : */
6851 : 1850606 : volatile XLogCtlData *xlogctl = XLogCtl;
6852 : :
6853 : 1850606 : LocalRecoveryInProgress = (xlogctl->SharedRecoveryState != RECOVERY_STATE_DONE);
6854 : :
6855 : : /*
6856 : : * Note: We don't need a memory barrier when we're still in recovery.
6857 : : * We might exit recovery immediately after return, so the caller
6858 : : * can't rely on 'true' meaning that we're still in recovery anyway.
6859 : : */
6860 : :
6861 : 1850606 : return LocalRecoveryInProgress;
6862 : : }
6863 : : }
6864 : :
6865 : : /*
6866 : : * Returns current recovery state from shared memory.
6867 : : *
6868 : : * This returned state is kept consistent with the contents of the control
6869 : : * file. See details about the possible values of RecoveryState in xlog.h.
6870 : : */
6871 : : RecoveryState
6872 : 27091 : GetRecoveryState(void)
6873 : : {
6874 : : RecoveryState retval;
6875 : :
6876 : 27091 : SpinLockAcquire(&XLogCtl->info_lck);
6877 : 27091 : retval = XLogCtl->SharedRecoveryState;
6878 : 27091 : SpinLockRelease(&XLogCtl->info_lck);
6879 : :
6880 : 27091 : return retval;
6881 : : }
6882 : :
6883 : : /*
6884 : : * Is this process allowed to insert new WAL records?
6885 : : *
6886 : : * Ordinarily this is essentially equivalent to !RecoveryInProgress().
6887 : : * But we also have provisions for forcing the result "true" or "false"
6888 : : * within specific processes regardless of the global state.
6889 : : */
6890 : : bool
6891 : 67498962 : XLogInsertAllowed(void)
6892 : : {
6893 : : /*
6894 : : * If value is "unconditionally true" or "unconditionally false", just
6895 : : * return it. This provides the normal fast path once recovery is known
6896 : : * done.
6897 : : */
6898 [ + + ]: 67498962 : if (LocalXLogInsertAllowed >= 0)
6899 : 66803462 : return (bool) LocalXLogInsertAllowed;
6900 : :
6901 : : /*
6902 : : * Else, must check to see if we're still in recovery.
6903 : : */
6904 [ + + ]: 695500 : if (RecoveryInProgress())
6905 : 684874 : return false;
6906 : :
6907 : : /*
6908 : : * On exit from recovery, reset to "unconditionally true", since there is
6909 : : * no need to keep checking.
6910 : : */
6911 : 10626 : LocalXLogInsertAllowed = 1;
6912 : 10626 : return true;
6913 : : }
6914 : :
6915 : : /*
6916 : : * Make XLogInsertAllowed() return true in the current process only.
6917 : : *
6918 : : * Note: it is allowed to switch LocalXLogInsertAllowed back to -1 later,
6919 : : * and even call LocalSetXLogInsertAllowed() again after that.
6920 : : *
6921 : : * Returns the previous value of LocalXLogInsertAllowed.
6922 : : */
6923 : : static int
6924 : 1048 : LocalSetXLogInsertAllowed(void)
6925 : : {
6926 : 1048 : int oldXLogAllowed = LocalXLogInsertAllowed;
6927 : :
6928 : 1048 : LocalXLogInsertAllowed = 1;
6929 : :
6930 : 1048 : return oldXLogAllowed;
6931 : : }
6932 : :
6933 : : /*
6934 : : * Return the current Redo pointer from shared memory.
6935 : : *
6936 : : * As a side-effect, the local RedoRecPtr copy is updated.
6937 : : */
6938 : : XLogRecPtr
6939 : 367757 : GetRedoRecPtr(void)
6940 : : {
6941 : : XLogRecPtr ptr;
6942 : :
6943 : : /*
6944 : : * The possibly not up-to-date copy in XLogCtl is enough. Even if we
6945 : : * grabbed a WAL insertion lock to read the authoritative value in
6946 : : * Insert->RedoRecPtr, someone might update it just after we've released
6947 : : * the lock.
6948 : : */
6949 : 367757 : SpinLockAcquire(&XLogCtl->info_lck);
6950 : 367757 : ptr = XLogCtl->RedoRecPtr;
6951 : 367757 : SpinLockRelease(&XLogCtl->info_lck);
6952 : :
6953 [ + + ]: 367757 : if (RedoRecPtr < ptr)
6954 : 1703 : RedoRecPtr = ptr;
6955 : :
6956 : 367757 : return RedoRecPtr;
6957 : : }
6958 : :
6959 : : /*
6960 : : * Return information needed to decide whether a modified block needs a
6961 : : * full-page image to be included in the WAL record.
6962 : : *
6963 : : * The returned values are cached copies from backend-private memory, and
6964 : : * possibly out-of-date or, indeed, uninitialized, in which case they will
6965 : : * be InvalidXLogRecPtr and false, respectively. XLogInsertRecord will
6966 : : * re-check them against up-to-date values, while holding the WAL insert lock.
6967 : : */
6968 : : void
6969 : 25005323 : GetFullPageWriteInfo(XLogRecPtr *RedoRecPtr_p, bool *doPageWrites_p)
6970 : : {
6971 : 25005323 : *RedoRecPtr_p = RedoRecPtr;
6972 : 25005323 : *doPageWrites_p = doPageWrites;
6973 : 25005323 : }
6974 : :
6975 : : /*
6976 : : * GetInsertRecPtr -- Returns the current insert position.
6977 : : *
6978 : : * NOTE: The value *actually* returned is the position of the last full
6979 : : * xlog page. It lags behind the real insert position by at most 1 page.
6980 : : * For that, we don't need to scan through WAL insertion locks, and an
6981 : : * approximation is enough for the current usage of this function.
6982 : : */
6983 : : XLogRecPtr
6984 : 7734 : GetInsertRecPtr(void)
6985 : : {
6986 : : XLogRecPtr recptr;
6987 : :
6988 : 7734 : SpinLockAcquire(&XLogCtl->info_lck);
6989 : 7734 : recptr = XLogCtl->LogwrtRqst.Write;
6990 : 7734 : SpinLockRelease(&XLogCtl->info_lck);
6991 : :
6992 : 7734 : return recptr;
6993 : : }
6994 : :
6995 : : /*
6996 : : * GetFlushRecPtr -- Returns the current flush position, ie, the last WAL
6997 : : * position known to be fsync'd to disk. This should only be used on a
6998 : : * system that is known not to be in recovery.
6999 : : */
7000 : : XLogRecPtr
7001 : 224215 : GetFlushRecPtr(TimeLineID *insertTLI)
7002 : : {
7003 : : Assert(XLogCtl->SharedRecoveryState == RECOVERY_STATE_DONE);
7004 : :
7005 : 224215 : RefreshXLogWriteResult(LogwrtResult);
7006 : :
7007 : : /*
7008 : : * If we're writing and flushing WAL, the time line can't be changing, so
7009 : : * no lock is required.
7010 : : */
7011 [ + + ]: 224215 : if (insertTLI)
7012 : 50103 : *insertTLI = XLogCtl->InsertTimeLineID;
7013 : :
7014 : 224215 : return LogwrtResult.Flush;
7015 : : }
7016 : :
7017 : : /*
7018 : : * GetWALInsertionTimeLine -- Returns the current timeline of a system that
7019 : : * is not in recovery.
7020 : : */
7021 : : TimeLineID
7022 : 120192 : GetWALInsertionTimeLine(void)
7023 : : {
7024 : : Assert(XLogCtl->SharedRecoveryState == RECOVERY_STATE_DONE);
7025 : :
7026 : : /* Since the value can't be changing, no lock is required. */
7027 : 120192 : return XLogCtl->InsertTimeLineID;
7028 : : }
7029 : :
7030 : : /*
7031 : : * GetWALInsertionTimeLineIfSet -- If the system is not in recovery, returns
7032 : : * the WAL insertion timeline; else, returns 0. Wherever possible, use
7033 : : * GetWALInsertionTimeLine() instead, since it's cheaper. Note that this
7034 : : * function decides recovery has ended as soon as the insert TLI is set, which
7035 : : * happens before we set XLogCtl->SharedRecoveryState to RECOVERY_STATE_DONE.
7036 : : */
7037 : : TimeLineID
7038 : 939 : GetWALInsertionTimeLineIfSet(void)
7039 : : {
7040 : : TimeLineID insertTLI;
7041 : :
7042 : 939 : SpinLockAcquire(&XLogCtl->info_lck);
7043 : 939 : insertTLI = XLogCtl->InsertTimeLineID;
7044 : 939 : SpinLockRelease(&XLogCtl->info_lck);
7045 : :
7046 : 939 : return insertTLI;
7047 : : }
7048 : :
7049 : : /*
7050 : : * GetLastImportantRecPtr -- Returns the LSN of the last important record
7051 : : * inserted. All records not explicitly marked as unimportant are considered
7052 : : * important.
7053 : : *
7054 : : * The LSN is determined by computing the maximum of
7055 : : * WALInsertLocks[i].lastImportantAt.
7056 : : */
7057 : : XLogRecPtr
7058 : 1790 : GetLastImportantRecPtr(void)
7059 : : {
7060 : 1790 : XLogRecPtr res = InvalidXLogRecPtr;
7061 : : int i;
7062 : :
7063 [ + + ]: 16110 : for (i = 0; i < NUM_XLOGINSERT_LOCKS; i++)
7064 : : {
7065 : : XLogRecPtr last_important;
7066 : :
7067 : : /*
7068 : : * Need to take a lock to prevent torn reads of the LSN, which are
7069 : : * possible on some of the supported platforms. WAL insert locks only
7070 : : * support exclusive mode, so we have to use that.
7071 : : */
7072 : 14320 : LWLockAcquire(&WALInsertLocks[i].l.lock, LW_EXCLUSIVE);
7073 : 14320 : last_important = WALInsertLocks[i].l.lastImportantAt;
7074 : 14320 : LWLockRelease(&WALInsertLocks[i].l.lock);
7075 : :
7076 [ + + ]: 14320 : if (res < last_important)
7077 : 3020 : res = last_important;
7078 : : }
7079 : :
7080 : 1790 : return res;
7081 : : }
7082 : :
7083 : : /*
7084 : : * Get the time and LSN of the last xlog segment switch
7085 : : */
7086 : : pg_time_t
7087 : 0 : GetLastSegSwitchData(XLogRecPtr *lastSwitchLSN)
7088 : : {
7089 : : pg_time_t result;
7090 : :
7091 : : /* Need WALWriteLock, but shared lock is sufficient */
7092 : 0 : LWLockAcquire(WALWriteLock, LW_SHARED);
7093 : 0 : result = XLogCtl->lastSegSwitchTime;
7094 : 0 : *lastSwitchLSN = XLogCtl->lastSegSwitchLSN;
7095 : 0 : LWLockRelease(WALWriteLock);
7096 : :
7097 : 0 : return result;
7098 : : }
7099 : :
7100 : : /*
7101 : : * This must be called ONCE during postmaster or standalone-backend shutdown
7102 : : */
7103 : : void
7104 : 769 : ShutdownXLOG(int code, Datum arg)
7105 : : {
7106 : : /*
7107 : : * We should have an aux process resource owner to use, and we should not
7108 : : * be in a transaction that's installed some other resowner.
7109 : : */
7110 : : Assert(AuxProcessResourceOwner != NULL);
7111 : : Assert(CurrentResourceOwner == NULL ||
7112 : : CurrentResourceOwner == AuxProcessResourceOwner);
7113 : 769 : CurrentResourceOwner = AuxProcessResourceOwner;
7114 : :
7115 : : /* Don't be chatty in standalone mode */
7116 [ + + + + ]: 769 : ereport(IsPostmasterEnvironment ? LOG : NOTICE,
7117 : : (errmsg("shutting down")));
7118 : :
7119 : : /*
7120 : : * Signal walsenders to move to stopping state.
7121 : : */
7122 : 769 : WalSndInitStopping();
7123 : :
7124 : : /*
7125 : : * Wait for WAL senders to be in stopping state. This prevents commands
7126 : : * from writing new WAL.
7127 : : */
7128 : 769 : WalSndWaitStopping();
7129 : :
7130 [ + + ]: 769 : if (RecoveryInProgress())
7131 : 63 : CreateRestartPoint(CHECKPOINT_IS_SHUTDOWN | CHECKPOINT_FAST);
7132 : : else
7133 : : {
7134 : : /*
7135 : : * If archiving is enabled, rotate the last XLOG file so that all the
7136 : : * remaining records are archived (postmaster wakes up the archiver
7137 : : * process one more time at the end of shutdown). The checkpoint
7138 : : * record will go to the next XLOG file and won't be archived (yet).
7139 : : */
7140 [ + + ]: 706 : if (XLogArchivingActive())
7141 : 18 : RequestXLogSwitch(false);
7142 : :
7143 : 706 : CreateCheckPoint(CHECKPOINT_IS_SHUTDOWN | CHECKPOINT_FAST);
7144 : : }
7145 : 769 : }
7146 : :
7147 : : /*
7148 : : * Format checkpoint request flags as a space-separated string for
7149 : : * log messages.
7150 : : */
7151 : : static const char *
7152 : 3220 : CheckpointFlagsString(int flags)
7153 : : {
7154 : : static char buf[128];
7155 : :
7156 : 25760 : snprintf(buf, sizeof(buf), "%s%s%s%s%s%s%s%s",
7157 [ + + ]: 3220 : (flags & CHECKPOINT_IS_SHUTDOWN) ? " shutdown" : "",
7158 [ + + ]: 3220 : (flags & CHECKPOINT_END_OF_RECOVERY) ? " end-of-recovery" : "",
7159 [ + + ]: 3220 : (flags & CHECKPOINT_FAST) ? " fast" : "",
7160 [ + + ]: 3220 : (flags & CHECKPOINT_FORCE) ? " force" : "",
7161 [ + + ]: 3220 : (flags & CHECKPOINT_WAIT) ? " wait" : "",
7162 [ + + ]: 3220 : (flags & CHECKPOINT_CAUSE_XLOG) ? " wal" : "",
7163 [ + + ]: 3220 : (flags & CHECKPOINT_CAUSE_TIME) ? " time" : "",
7164 [ + + ]: 3220 : (flags & CHECKPOINT_FLUSH_UNLOGGED) ? " flush-unlogged" : "");
7165 : :
7166 : 3220 : return buf;
7167 : : }
7168 : :
7169 : : /*
7170 : : * Log start of a checkpoint.
7171 : : */
7172 : : static void
7173 : 1610 : LogCheckpointStart(int flags, bool restartpoint)
7174 : : {
7175 [ + + ]: 1610 : if (restartpoint)
7176 [ + - ]: 209 : ereport(LOG,
7177 : : /* translator: the placeholder shows checkpoint options */
7178 : : (errmsg("restartpoint starting:%s",
7179 : : CheckpointFlagsString(flags))));
7180 : : else
7181 [ + - ]: 1401 : ereport(LOG,
7182 : : /* translator: the placeholder shows checkpoint options */
7183 : : (errmsg("checkpoint starting:%s",
7184 : : CheckpointFlagsString(flags))));
7185 : 1610 : }
7186 : :
7187 : : /*
7188 : : * Log end of a checkpoint.
7189 : : */
7190 : : static void
7191 : 1944 : LogCheckpointEnd(bool restartpoint, int flags)
7192 : : {
7193 : : long write_msecs,
7194 : : sync_msecs,
7195 : : total_msecs,
7196 : : longest_msecs,
7197 : : average_msecs;
7198 : : uint64 average_sync_time;
7199 : :
7200 : 1944 : CheckpointStats.ckpt_end_t = GetCurrentTimestamp();
7201 : :
7202 : 1944 : write_msecs = TimestampDifferenceMilliseconds(CheckpointStats.ckpt_write_t,
7203 : : CheckpointStats.ckpt_sync_t);
7204 : :
7205 : 1944 : sync_msecs = TimestampDifferenceMilliseconds(CheckpointStats.ckpt_sync_t,
7206 : : CheckpointStats.ckpt_sync_end_t);
7207 : :
7208 : : /* Accumulate checkpoint timing summary data, in milliseconds. */
7209 : 1944 : PendingCheckpointerStats.write_time += write_msecs;
7210 : 1944 : PendingCheckpointerStats.sync_time += sync_msecs;
7211 : :
7212 : : /*
7213 : : * All of the published timing statistics are accounted for. Only
7214 : : * continue if a log message is to be written.
7215 : : */
7216 [ + + ]: 1944 : if (!log_checkpoints)
7217 : 334 : return;
7218 : :
7219 : 1610 : total_msecs = TimestampDifferenceMilliseconds(CheckpointStats.ckpt_start_t,
7220 : : CheckpointStats.ckpt_end_t);
7221 : :
7222 : : /*
7223 : : * Timing values returned from CheckpointStats are in microseconds.
7224 : : * Convert to milliseconds for consistent printing.
7225 : : */
7226 : 1610 : longest_msecs = (long) ((CheckpointStats.ckpt_longest_sync + 999) / 1000);
7227 : :
7228 : 1610 : average_sync_time = 0;
7229 [ - + ]: 1610 : if (CheckpointStats.ckpt_sync_rels > 0)
7230 : 0 : average_sync_time = CheckpointStats.ckpt_agg_sync_time /
7231 : 0 : CheckpointStats.ckpt_sync_rels;
7232 : 1610 : average_msecs = (long) ((average_sync_time + 999) / 1000);
7233 : :
7234 : : /*
7235 : : * ControlFileLock is not required to see ControlFile->checkPoint and
7236 : : * ->checkPointCopy here as we are the only updator of those variables at
7237 : : * this moment.
7238 : : */
7239 [ + + ]: 1610 : if (restartpoint)
7240 [ + - ]: 209 : ereport(LOG,
7241 : : (errmsg("restartpoint complete:%s: wrote %d buffers (%.1f%%), "
7242 : : "wrote %d SLRU buffers; %d WAL file(s) added, "
7243 : : "%d removed, %d recycled; write=%ld.%03d s, "
7244 : : "sync=%ld.%03d s, total=%ld.%03d s; sync files=%d, "
7245 : : "longest=%ld.%03d s, average=%ld.%03d s; distance=%d kB, "
7246 : : "estimate=%d kB; lsn=%X/%08X, redo lsn=%X/%08X",
7247 : : CheckpointFlagsString(flags),
7248 : : CheckpointStats.ckpt_bufs_written,
7249 : : (double) CheckpointStats.ckpt_bufs_written * 100 / NBuffers,
7250 : : CheckpointStats.ckpt_slru_written,
7251 : : CheckpointStats.ckpt_segs_added,
7252 : : CheckpointStats.ckpt_segs_removed,
7253 : : CheckpointStats.ckpt_segs_recycled,
7254 : : write_msecs / 1000, (int) (write_msecs % 1000),
7255 : : sync_msecs / 1000, (int) (sync_msecs % 1000),
7256 : : total_msecs / 1000, (int) (total_msecs % 1000),
7257 : : CheckpointStats.ckpt_sync_rels,
7258 : : longest_msecs / 1000, (int) (longest_msecs % 1000),
7259 : : average_msecs / 1000, (int) (average_msecs % 1000),
7260 : : (int) (PrevCheckPointDistance / 1024.0),
7261 : : (int) (CheckPointDistanceEstimate / 1024.0),
7262 : : LSN_FORMAT_ARGS(ControlFile->checkPoint),
7263 : : LSN_FORMAT_ARGS(ControlFile->checkPointCopy.redo))));
7264 : : else
7265 [ + - ]: 1401 : ereport(LOG,
7266 : : (errmsg("checkpoint complete:%s: wrote %d buffers (%.1f%%), "
7267 : : "wrote %d SLRU buffers; %d WAL file(s) added, "
7268 : : "%d removed, %d recycled; write=%ld.%03d s, "
7269 : : "sync=%ld.%03d s, total=%ld.%03d s; sync files=%d, "
7270 : : "longest=%ld.%03d s, average=%ld.%03d s; distance=%d kB, "
7271 : : "estimate=%d kB; lsn=%X/%08X, redo lsn=%X/%08X",
7272 : : CheckpointFlagsString(flags),
7273 : : CheckpointStats.ckpt_bufs_written,
7274 : : (double) CheckpointStats.ckpt_bufs_written * 100 / NBuffers,
7275 : : CheckpointStats.ckpt_slru_written,
7276 : : CheckpointStats.ckpt_segs_added,
7277 : : CheckpointStats.ckpt_segs_removed,
7278 : : CheckpointStats.ckpt_segs_recycled,
7279 : : write_msecs / 1000, (int) (write_msecs % 1000),
7280 : : sync_msecs / 1000, (int) (sync_msecs % 1000),
7281 : : total_msecs / 1000, (int) (total_msecs % 1000),
7282 : : CheckpointStats.ckpt_sync_rels,
7283 : : longest_msecs / 1000, (int) (longest_msecs % 1000),
7284 : : average_msecs / 1000, (int) (average_msecs % 1000),
7285 : : (int) (PrevCheckPointDistance / 1024.0),
7286 : : (int) (CheckPointDistanceEstimate / 1024.0),
7287 : : LSN_FORMAT_ARGS(ControlFile->checkPoint),
7288 : : LSN_FORMAT_ARGS(ControlFile->checkPointCopy.redo))));
7289 : : }
7290 : :
7291 : : /*
7292 : : * Update the estimate of distance between checkpoints.
7293 : : *
7294 : : * The estimate is used to calculate the number of WAL segments to keep
7295 : : * preallocated, see XLOGfileslop().
7296 : : */
7297 : : static void
7298 : 1944 : UpdateCheckPointDistanceEstimate(uint64 nbytes)
7299 : : {
7300 : : /*
7301 : : * To estimate the number of segments consumed between checkpoints, keep a
7302 : : * moving average of the amount of WAL generated in previous checkpoint
7303 : : * cycles. However, if the load is bursty, with quiet periods and busy
7304 : : * periods, we want to cater for the peak load. So instead of a plain
7305 : : * moving average, let the average decline slowly if the previous cycle
7306 : : * used less WAL than estimated, but bump it up immediately if it used
7307 : : * more.
7308 : : *
7309 : : * When checkpoints are triggered by max_wal_size, this should converge to
7310 : : * CheckpointSegments * wal_segment_size,
7311 : : *
7312 : : * Note: This doesn't pay any attention to what caused the checkpoint.
7313 : : * Checkpoints triggered manually with CHECKPOINT command, or by e.g.
7314 : : * starting a base backup, are counted the same as those created
7315 : : * automatically. The slow-decline will largely mask them out, if they are
7316 : : * not frequent. If they are frequent, it seems reasonable to count them
7317 : : * in as any others; if you issue a manual checkpoint every 5 minutes and
7318 : : * never let a timed checkpoint happen, it makes sense to base the
7319 : : * preallocation on that 5 minute interval rather than whatever
7320 : : * checkpoint_timeout is set to.
7321 : : */
7322 : 1944 : PrevCheckPointDistance = nbytes;
7323 [ + + ]: 1944 : if (CheckPointDistanceEstimate < nbytes)
7324 : 866 : CheckPointDistanceEstimate = nbytes;
7325 : : else
7326 : 1078 : CheckPointDistanceEstimate =
7327 : 1078 : (0.90 * CheckPointDistanceEstimate + 0.10 * (double) nbytes);
7328 : 1944 : }
7329 : :
7330 : : /*
7331 : : * Update the ps display for a process running a checkpoint. Note that
7332 : : * this routine should not do any allocations so as it can be called
7333 : : * from a critical section.
7334 : : */
7335 : : static void
7336 : 3888 : update_checkpoint_display(int flags, bool restartpoint, bool reset)
7337 : : {
7338 : : /*
7339 : : * The status is reported only for end-of-recovery and shutdown
7340 : : * checkpoints or shutdown restartpoints. Updating the ps display is
7341 : : * useful in those situations as it may not be possible to rely on
7342 : : * pg_stat_activity to see the status of the checkpointer or the startup
7343 : : * process.
7344 : : */
7345 [ + + ]: 3888 : if ((flags & (CHECKPOINT_END_OF_RECOVERY | CHECKPOINT_IS_SHUTDOWN)) == 0)
7346 : 2368 : return;
7347 : :
7348 [ + + ]: 1520 : if (reset)
7349 : 760 : set_ps_display("");
7350 : : else
7351 : : {
7352 : : char activitymsg[128];
7353 : :
7354 [ + + ]: 2280 : snprintf(activitymsg, sizeof(activitymsg), "performing %s%s%s",
7355 [ + + ]: 760 : (flags & CHECKPOINT_END_OF_RECOVERY) ? "end-of-recovery " : "",
7356 [ + + ]: 760 : (flags & CHECKPOINT_IS_SHUTDOWN) ? "shutdown " : "",
7357 : : restartpoint ? "restartpoint" : "checkpoint");
7358 : 760 : set_ps_display(activitymsg);
7359 : : }
7360 : : }
7361 : :
7362 : :
7363 : : /*
7364 : : * Perform a checkpoint --- either during shutdown, or on-the-fly
7365 : : *
7366 : : * flags is a bitwise OR of the following:
7367 : : * CHECKPOINT_IS_SHUTDOWN: checkpoint is for database shutdown.
7368 : : * CHECKPOINT_END_OF_RECOVERY: checkpoint is for end of WAL recovery.
7369 : : * CHECKPOINT_FAST: finish the checkpoint ASAP, ignoring
7370 : : * checkpoint_completion_target parameter.
7371 : : * CHECKPOINT_FORCE: force a checkpoint even if no XLOG activity has occurred
7372 : : * since the last one (implied by CHECKPOINT_IS_SHUTDOWN or
7373 : : * CHECKPOINT_END_OF_RECOVERY).
7374 : : * CHECKPOINT_FLUSH_UNLOGGED: also flush buffers of unlogged tables.
7375 : : *
7376 : : * Note: flags contains other bits, of interest here only for logging purposes.
7377 : : * In particular note that this routine is synchronous and does not pay
7378 : : * attention to CHECKPOINT_WAIT.
7379 : : *
7380 : : * If !shutdown then we are writing an online checkpoint. An XLOG_CHECKPOINT_REDO
7381 : : * record is inserted into WAL at the logical location of the checkpoint, before
7382 : : * flushing anything to disk, and when the checkpoint is eventually completed,
7383 : : * and it is from this point that WAL replay will begin in the case of a recovery
7384 : : * from this checkpoint. Once everything is written to disk, an
7385 : : * XLOG_CHECKPOINT_ONLINE record is written to complete the checkpoint, and
7386 : : * points back to the earlier XLOG_CHECKPOINT_REDO record. This mechanism allows
7387 : : * other write-ahead log records to be written while the checkpoint is in
7388 : : * progress, but we must be very careful about order of operations. This function
7389 : : * may take many minutes to execute on a busy system.
7390 : : *
7391 : : * On the other hand, when shutdown is true, concurrent insertion into the
7392 : : * write-ahead log is impossible, so there is no need for two separate records.
7393 : : * In this case, we only insert an XLOG_CHECKPOINT_SHUTDOWN record, and it's
7394 : : * both the record marking the completion of the checkpoint and the location
7395 : : * from which WAL replay would begin if needed.
7396 : : *
7397 : : * Returns true if a new checkpoint was performed, or false if it was skipped
7398 : : * because the system was idle.
7399 : : */
7400 : : bool
7401 : 1735 : CreateCheckPoint(int flags)
7402 : : {
7403 : : bool shutdown;
7404 : : CheckPoint checkPoint;
7405 : : XLogRecPtr recptr;
7406 : : XLogSegNo _logSegNo;
7407 : 1735 : XLogCtlInsert *Insert = &XLogCtl->Insert;
7408 : : uint32 freespace;
7409 : : XLogRecPtr PriorRedoPtr;
7410 : : XLogRecPtr last_important_lsn;
7411 : : VirtualTransactionId *vxids;
7412 : : int nvxids;
7413 : 1735 : int oldXLogAllowed = 0;
7414 : :
7415 : : /*
7416 : : * An end-of-recovery checkpoint is really a shutdown checkpoint, just
7417 : : * issued at a different time.
7418 : : */
7419 [ + + ]: 1735 : if (flags & (CHECKPOINT_IS_SHUTDOWN | CHECKPOINT_END_OF_RECOVERY))
7420 : 736 : shutdown = true;
7421 : : else
7422 : 999 : shutdown = false;
7423 : :
7424 : : /* sanity check */
7425 [ + + - + ]: 1735 : if (RecoveryInProgress() && (flags & CHECKPOINT_END_OF_RECOVERY) == 0)
7426 [ # # ]: 0 : elog(ERROR, "can't create a checkpoint during recovery");
7427 : :
7428 : : /*
7429 : : * Prepare to accumulate statistics.
7430 : : *
7431 : : * Note: because it is possible for log_checkpoints to change while a
7432 : : * checkpoint proceeds, we always accumulate stats, even if
7433 : : * log_checkpoints is currently off.
7434 : : */
7435 [ + - + - : 19085 : MemSet(&CheckpointStats, 0, sizeof(CheckpointStats));
+ - + - +
+ ]
7436 : 1735 : CheckpointStats.ckpt_start_t = GetCurrentTimestamp();
7437 : :
7438 : : /*
7439 : : * Let smgr prepare for checkpoint; this has to happen outside the
7440 : : * critical section and before we determine the REDO pointer. Note that
7441 : : * smgr must not do anything that'd have to be undone if we decide no
7442 : : * checkpoint is needed.
7443 : : */
7444 : 1735 : SyncPreCheckpoint();
7445 : :
7446 : : /* Run these points outside the critical section. */
7447 : 1735 : INJECTION_POINT("create-checkpoint-initial", NULL);
7448 : 1735 : INJECTION_POINT_LOAD("create-checkpoint-run");
7449 : :
7450 : : /*
7451 : : * Use a critical section to force system panic if we have trouble.
7452 : : */
7453 : 1735 : START_CRIT_SECTION();
7454 : :
7455 [ + + ]: 1735 : if (shutdown)
7456 : : {
7457 : 736 : LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
7458 : 736 : ControlFile->state = DB_SHUTDOWNING;
7459 : 736 : UpdateControlFile();
7460 : 736 : LWLockRelease(ControlFileLock);
7461 : : }
7462 : :
7463 : : /* Begin filling in the checkpoint WAL record */
7464 [ + - + - : 22555 : MemSet(&checkPoint, 0, sizeof(checkPoint));
+ - + - +
+ ]
7465 : 1735 : checkPoint.time = (pg_time_t) time(NULL);
7466 : :
7467 : : /*
7468 : : * For Hot Standby, derive the oldestActiveXid before we fix the redo
7469 : : * pointer. This allows us to begin accumulating changes to assemble our
7470 : : * starting snapshot of locks and transactions.
7471 : : */
7472 [ + + + + ]: 1735 : if (!shutdown && XLogStandbyInfoActive())
7473 : 957 : checkPoint.oldestActiveXid = GetOldestActiveTransactionId(false, true);
7474 : : else
7475 : 778 : checkPoint.oldestActiveXid = InvalidTransactionId;
7476 : :
7477 : : /*
7478 : : * Get location of last important record before acquiring insert locks (as
7479 : : * GetLastImportantRecPtr() also locks WAL locks).
7480 : : */
7481 : 1735 : last_important_lsn = GetLastImportantRecPtr();
7482 : :
7483 : : /*
7484 : : * If this isn't a shutdown or forced checkpoint, and if there has been no
7485 : : * WAL activity requiring a checkpoint, skip it. The idea here is to
7486 : : * avoid inserting duplicate checkpoints when the system is idle.
7487 : : */
7488 [ + + ]: 1735 : if ((flags & (CHECKPOINT_IS_SHUTDOWN | CHECKPOINT_END_OF_RECOVERY |
7489 : : CHECKPOINT_FORCE)) == 0)
7490 : : {
7491 [ - + ]: 208 : if (last_important_lsn == ControlFile->checkPoint)
7492 : : {
7493 : 0 : END_CRIT_SECTION();
7494 [ # # ]: 0 : ereport(DEBUG1,
7495 : : (errmsg_internal("checkpoint skipped because system is idle")));
7496 : 0 : return false;
7497 : : }
7498 : : }
7499 : :
7500 : : /*
7501 : : * An end-of-recovery checkpoint is created before anyone is allowed to
7502 : : * write WAL. To allow us to write the checkpoint record, temporarily
7503 : : * enable XLogInsertAllowed.
7504 : : */
7505 [ + + ]: 1735 : if (flags & CHECKPOINT_END_OF_RECOVERY)
7506 : 30 : oldXLogAllowed = LocalSetXLogInsertAllowed();
7507 : :
7508 : 1735 : checkPoint.ThisTimeLineID = XLogCtl->InsertTimeLineID;
7509 [ + + ]: 1735 : if (flags & CHECKPOINT_END_OF_RECOVERY)
7510 : 30 : checkPoint.PrevTimeLineID = XLogCtl->PrevTimeLineID;
7511 : : else
7512 : 1705 : checkPoint.PrevTimeLineID = checkPoint.ThisTimeLineID;
7513 : :
7514 : : /*
7515 : : * We must block concurrent insertions while examining insert state.
7516 : : */
7517 : 1735 : WALInsertLockAcquireExclusive();
7518 : :
7519 : 1735 : checkPoint.fullPageWrites = Insert->fullPageWrites;
7520 : 1735 : checkPoint.wal_level = wal_level;
7521 : :
7522 : : /*
7523 : : * Get the current data_checksum_version value from xlogctl, valid at the
7524 : : * time of the checkpoint.
7525 : : */
7526 : 1735 : SpinLockAcquire(&XLogCtl->info_lck);
7527 : 1735 : checkPoint.dataChecksumState = XLogCtl->data_checksum_version;
7528 : 1735 : SpinLockRelease(&XLogCtl->info_lck);
7529 : :
7530 [ + + ]: 1735 : if (shutdown)
7531 : : {
7532 : 736 : XLogRecPtr curInsert = XLogBytePosToRecPtr(Insert->CurrBytePos);
7533 : :
7534 : : /*
7535 : : * Compute new REDO record ptr = location of next XLOG record.
7536 : : *
7537 : : * Since this is a shutdown checkpoint, there can't be any concurrent
7538 : : * WAL insertion.
7539 : : */
7540 [ + - ]: 736 : freespace = INSERT_FREESPACE(curInsert);
7541 [ - + ]: 736 : if (freespace == 0)
7542 : : {
7543 [ # # ]: 0 : if (XLogSegmentOffset(curInsert, wal_segment_size) == 0)
7544 : 0 : curInsert += SizeOfXLogLongPHD;
7545 : : else
7546 : 0 : curInsert += SizeOfXLogShortPHD;
7547 : : }
7548 : 736 : checkPoint.redo = curInsert;
7549 : :
7550 : : /*
7551 : : * Here we update the shared RedoRecPtr for future XLogInsert calls;
7552 : : * this must be done while holding all the insertion locks.
7553 : : *
7554 : : * Note: if we fail to complete the checkpoint, RedoRecPtr will be
7555 : : * left pointing past where it really needs to point. This is okay;
7556 : : * the only consequence is that XLogInsert might back up whole buffers
7557 : : * that it didn't really need to. We can't postpone advancing
7558 : : * RedoRecPtr because XLogInserts that happen while we are dumping
7559 : : * buffers must assume that their buffer changes are not included in
7560 : : * the checkpoint.
7561 : : */
7562 : 736 : RedoRecPtr = XLogCtl->Insert.RedoRecPtr = checkPoint.redo;
7563 : : }
7564 : :
7565 : : /*
7566 : : * Now we can release the WAL insertion locks, allowing other xacts to
7567 : : * proceed while we are flushing disk buffers.
7568 : : */
7569 : 1735 : WALInsertLockRelease();
7570 : :
7571 : : /*
7572 : : * If this is an online checkpoint, we have not yet determined the redo
7573 : : * point. We do so now by inserting the special XLOG_CHECKPOINT_REDO
7574 : : * record; the LSN at which it starts becomes the new redo pointer. We
7575 : : * don't do this for a shutdown checkpoint, because in that case no WAL
7576 : : * can be written between the redo point and the insertion of the
7577 : : * checkpoint record itself, so the checkpoint record itself serves to
7578 : : * mark the redo point.
7579 : : */
7580 [ + + ]: 1735 : if (!shutdown)
7581 : : {
7582 : : xl_checkpoint_redo redo_rec;
7583 : :
7584 : 999 : WALInsertLockAcquire();
7585 : 999 : redo_rec.wal_level = wal_level;
7586 : 999 : SpinLockAcquire(&XLogCtl->info_lck);
7587 : 999 : redo_rec.data_checksum_version = XLogCtl->data_checksum_version;
7588 : 999 : SpinLockRelease(&XLogCtl->info_lck);
7589 : 999 : WALInsertLockRelease();
7590 : :
7591 : : /* Include WAL level in record for WAL summarizer's benefit. */
7592 : 999 : XLogBeginInsert();
7593 : 999 : XLogRegisterData(&redo_rec, sizeof(xl_checkpoint_redo));
7594 : 999 : (void) XLogInsert(RM_XLOG_ID, XLOG_CHECKPOINT_REDO);
7595 : :
7596 : : /*
7597 : : * XLogInsertRecord will have updated XLogCtl->Insert.RedoRecPtr in
7598 : : * shared memory and RedoRecPtr in backend-local memory, but we need
7599 : : * to copy that into the record that will be inserted when the
7600 : : * checkpoint is complete.
7601 : : */
7602 : 999 : checkPoint.redo = RedoRecPtr;
7603 : : }
7604 : :
7605 : : /* Update the info_lck-protected copy of RedoRecPtr as well */
7606 : 1735 : SpinLockAcquire(&XLogCtl->info_lck);
7607 : 1735 : XLogCtl->RedoRecPtr = checkPoint.redo;
7608 : 1735 : SpinLockRelease(&XLogCtl->info_lck);
7609 : :
7610 : : /*
7611 : : * If enabled, log checkpoint start. We postpone this until now so as not
7612 : : * to log anything if we decided to skip the checkpoint.
7613 : : */
7614 [ + + ]: 1735 : if (log_checkpoints)
7615 : 1401 : LogCheckpointStart(flags, false);
7616 : :
7617 : 1735 : INJECTION_POINT_CACHED("create-checkpoint-run", NULL);
7618 : :
7619 : : /* Update the process title */
7620 : 1735 : update_checkpoint_display(flags, false, false);
7621 : :
7622 : : TRACE_POSTGRESQL_CHECKPOINT_START(flags);
7623 : :
7624 : : /*
7625 : : * Get the other info we need for the checkpoint record.
7626 : : *
7627 : : * We don't need to save oldestClogXid in the checkpoint, it only matters
7628 : : * for the short period in which clog is being truncated, and if we crash
7629 : : * during that we'll redo the clog truncation and fix up oldestClogXid
7630 : : * there.
7631 : : */
7632 : 1735 : LWLockAcquire(XidGenLock, LW_SHARED);
7633 : 1735 : checkPoint.nextXid = TransamVariables->nextXid;
7634 : 1735 : checkPoint.oldestXid = TransamVariables->oldestXid;
7635 : 1735 : checkPoint.oldestXidDB = TransamVariables->oldestXidDB;
7636 : 1735 : LWLockRelease(XidGenLock);
7637 : :
7638 : 1735 : LWLockAcquire(CommitTsLock, LW_SHARED);
7639 : 1735 : checkPoint.oldestCommitTsXid = TransamVariables->oldestCommitTsXid;
7640 : 1735 : checkPoint.newestCommitTsXid = TransamVariables->newestCommitTsXid;
7641 : 1735 : LWLockRelease(CommitTsLock);
7642 : :
7643 : 1735 : LWLockAcquire(OidGenLock, LW_SHARED);
7644 : 1735 : checkPoint.nextOid = TransamVariables->nextOid;
7645 [ + + ]: 1735 : if (!shutdown)
7646 : 999 : checkPoint.nextOid += TransamVariables->oidCount;
7647 : 1735 : LWLockRelease(OidGenLock);
7648 : :
7649 : 1735 : checkPoint.logicalDecodingEnabled = IsLogicalDecodingEnabled();
7650 : :
7651 : 1735 : MultiXactGetCheckptMulti(shutdown,
7652 : : &checkPoint.nextMulti,
7653 : : &checkPoint.nextMultiOffset,
7654 : : &checkPoint.oldestMulti,
7655 : : &checkPoint.oldestMultiDB);
7656 : :
7657 : : /*
7658 : : * Having constructed the checkpoint record, ensure all shmem disk buffers
7659 : : * and commit-log buffers are flushed to disk.
7660 : : *
7661 : : * This I/O could fail for various reasons. If so, we will fail to
7662 : : * complete the checkpoint, but there is no reason to force a system
7663 : : * panic. Accordingly, exit critical section while doing it.
7664 : : */
7665 : 1735 : END_CRIT_SECTION();
7666 : :
7667 : : /*
7668 : : * In some cases there are groups of actions that must all occur on one
7669 : : * side or the other of a checkpoint record. Before flushing the
7670 : : * checkpoint record we must explicitly wait for any backend currently
7671 : : * performing those groups of actions.
7672 : : *
7673 : : * One example is end of transaction, so we must wait for any transactions
7674 : : * that are currently in commit critical sections. If an xact inserted
7675 : : * its commit record into XLOG just before the REDO point, then a crash
7676 : : * restart from the REDO point would not replay that record, which means
7677 : : * that our flushing had better include the xact's update of pg_xact. So
7678 : : * we wait till he's out of his commit critical section before proceeding.
7679 : : * See notes in RecordTransactionCommit().
7680 : : *
7681 : : * Because we've already released the insertion locks, this test is a bit
7682 : : * fuzzy: it is possible that we will wait for xacts we didn't really need
7683 : : * to wait for. But the delay should be short and it seems better to make
7684 : : * checkpoint take a bit longer than to hold off insertions longer than
7685 : : * necessary. (In fact, the whole reason we have this issue is that xact.c
7686 : : * does commit record XLOG insertion and clog update as two separate steps
7687 : : * protected by different locks, but again that seems best on grounds of
7688 : : * minimizing lock contention.)
7689 : : *
7690 : : * A transaction that has not yet set delayChkptFlags when we look cannot
7691 : : * be at risk, since it has not inserted its commit record yet; and one
7692 : : * that's already cleared it is not at risk either, since it's done fixing
7693 : : * clog and we will correctly flush the update below. So we cannot miss
7694 : : * any xacts we need to wait for.
7695 : : */
7696 : 1735 : vxids = GetVirtualXIDsDelayingChkpt(&nvxids, DELAY_CHKPT_START);
7697 [ + + ]: 1735 : if (nvxids > 0)
7698 : : {
7699 : : do
7700 : : {
7701 : : /*
7702 : : * Keep absorbing fsync requests while we wait. There could even
7703 : : * be a deadlock if we don't, if the process that prevents the
7704 : : * checkpoint is trying to add a request to the queue.
7705 : : */
7706 : 41 : AbsorbSyncRequests();
7707 : :
7708 : 41 : pgstat_report_wait_start(WAIT_EVENT_CHECKPOINT_DELAY_START);
7709 : 41 : pg_usleep(10000L); /* wait for 10 msec */
7710 : 41 : pgstat_report_wait_end();
7711 [ + + ]: 41 : } while (HaveVirtualXIDsDelayingChkpt(vxids, nvxids,
7712 : : DELAY_CHKPT_START));
7713 : : }
7714 : 1735 : pfree(vxids);
7715 : :
7716 : 1735 : CheckPointGuts(checkPoint.redo, flags);
7717 : :
7718 : 1735 : vxids = GetVirtualXIDsDelayingChkpt(&nvxids, DELAY_CHKPT_COMPLETE);
7719 [ - + ]: 1735 : if (nvxids > 0)
7720 : : {
7721 : : do
7722 : : {
7723 : 0 : AbsorbSyncRequests();
7724 : :
7725 : 0 : pgstat_report_wait_start(WAIT_EVENT_CHECKPOINT_DELAY_COMPLETE);
7726 : 0 : pg_usleep(10000L); /* wait for 10 msec */
7727 : 0 : pgstat_report_wait_end();
7728 [ # # ]: 0 : } while (HaveVirtualXIDsDelayingChkpt(vxids, nvxids,
7729 : : DELAY_CHKPT_COMPLETE));
7730 : : }
7731 : 1735 : pfree(vxids);
7732 : :
7733 : : /*
7734 : : * Take a snapshot of running transactions and write this to WAL. This
7735 : : * allows us to reconstruct the state of running transactions during
7736 : : * archive recovery, if required. Skip, if this info disabled.
7737 : : *
7738 : : * If we are shutting down, or Startup process is completing crash
7739 : : * recovery we don't need to write running xact data.
7740 : : */
7741 [ + + + + ]: 1735 : if (!shutdown && XLogStandbyInfoActive())
7742 : 957 : LogStandbySnapshot();
7743 : :
7744 : 1735 : START_CRIT_SECTION();
7745 : :
7746 : : /*
7747 : : * Now insert the checkpoint record into XLOG.
7748 : : */
7749 : 1735 : XLogBeginInsert();
7750 : 1735 : XLogRegisterData(&checkPoint, sizeof(checkPoint));
7751 [ + + ]: 1735 : recptr = XLogInsert(RM_XLOG_ID,
7752 : : shutdown ? XLOG_CHECKPOINT_SHUTDOWN :
7753 : : XLOG_CHECKPOINT_ONLINE);
7754 : :
7755 : 1735 : XLogFlush(recptr);
7756 : :
7757 : : /*
7758 : : * We mustn't write any new WAL after a shutdown checkpoint, or it will be
7759 : : * overwritten at next startup. No-one should even try, this just allows
7760 : : * sanity-checking. In the case of an end-of-recovery checkpoint, we want
7761 : : * to just temporarily disable writing until the system has exited
7762 : : * recovery.
7763 : : */
7764 [ + + ]: 1735 : if (shutdown)
7765 : : {
7766 [ + + ]: 736 : if (flags & CHECKPOINT_END_OF_RECOVERY)
7767 : 30 : LocalXLogInsertAllowed = oldXLogAllowed;
7768 : : else
7769 : 706 : LocalXLogInsertAllowed = 0; /* never again write WAL */
7770 : : }
7771 : :
7772 : : /*
7773 : : * We now have ProcLastRecPtr = start of actual checkpoint record, recptr
7774 : : * = end of actual checkpoint record.
7775 : : */
7776 [ + + - + ]: 1735 : if (shutdown && checkPoint.redo != ProcLastRecPtr)
7777 [ # # ]: 0 : ereport(PANIC,
7778 : : (errmsg("concurrent write-ahead log activity while database system is shutting down")));
7779 : :
7780 : : /*
7781 : : * Remember the prior checkpoint's redo ptr for
7782 : : * UpdateCheckPointDistanceEstimate()
7783 : : */
7784 : 1735 : PriorRedoPtr = ControlFile->checkPointCopy.redo;
7785 : :
7786 : : /*
7787 : : * Update the control file.
7788 : : */
7789 : 1735 : LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
7790 [ + + ]: 1735 : if (shutdown)
7791 : 736 : ControlFile->state = DB_SHUTDOWNED;
7792 : 1735 : ControlFile->checkPoint = ProcLastRecPtr;
7793 : 1735 : ControlFile->checkPointCopy = checkPoint;
7794 : : /* crash recovery should always recover to the end of WAL */
7795 : 1735 : ControlFile->minRecoveryPoint = InvalidXLogRecPtr;
7796 : 1735 : ControlFile->minRecoveryPointTLI = 0;
7797 : :
7798 : : /*
7799 : : * Persist unloggedLSN value. It's reset on crash recovery, so this goes
7800 : : * unused on non-shutdown checkpoints, but seems useful to store it always
7801 : : * for debugging purposes.
7802 : : */
7803 : 1735 : ControlFile->unloggedLSN = pg_atomic_read_membarrier_u64(&XLogCtl->unloggedLSN);
7804 : :
7805 : 1735 : UpdateControlFile();
7806 : 1735 : LWLockRelease(ControlFileLock);
7807 : :
7808 : : /*
7809 : : * We are now done with critical updates; no need for system panic if we
7810 : : * have trouble while fooling with old log segments.
7811 : : */
7812 : 1735 : END_CRIT_SECTION();
7813 : :
7814 : : /*
7815 : : * WAL summaries end when the next XLOG_CHECKPOINT_REDO or
7816 : : * XLOG_CHECKPOINT_SHUTDOWN record is reached. This is the first point
7817 : : * where (a) we're not inside of a critical section and (b) we can be
7818 : : * certain that the relevant record has been flushed to disk, which must
7819 : : * happen before it can be summarized.
7820 : : *
7821 : : * If this is a shutdown checkpoint, then this happens reasonably
7822 : : * promptly: we've only just inserted and flushed the
7823 : : * XLOG_CHECKPOINT_SHUTDOWN record. If this is not a shutdown checkpoint,
7824 : : * then this might not be very prompt at all: the XLOG_CHECKPOINT_REDO
7825 : : * record was written before we began flushing data to disk, and that
7826 : : * could be many minutes ago at this point. However, we don't XLogFlush()
7827 : : * after inserting that record, so we're not guaranteed that it's on disk
7828 : : * until after the above call that flushes the XLOG_CHECKPOINT_ONLINE
7829 : : * record.
7830 : : */
7831 : 1735 : WakeupWalSummarizer();
7832 : :
7833 : : /*
7834 : : * Let smgr do post-checkpoint cleanup (eg, deleting old files).
7835 : : */
7836 : 1735 : SyncPostCheckpoint();
7837 : :
7838 : : /*
7839 : : * Update the average distance between checkpoints if the prior checkpoint
7840 : : * exists.
7841 : : */
7842 [ + - ]: 1735 : if (XLogRecPtrIsValid(PriorRedoPtr))
7843 : 1735 : UpdateCheckPointDistanceEstimate(RedoRecPtr - PriorRedoPtr);
7844 : :
7845 : 1735 : INJECTION_POINT("checkpoint-before-old-wal-removal", NULL);
7846 : :
7847 : : /*
7848 : : * Delete old log files, those no longer needed for last checkpoint to
7849 : : * prevent the disk holding the xlog from growing full.
7850 : : */
7851 : 1735 : XLByteToSeg(RedoRecPtr, _logSegNo, wal_segment_size);
7852 : 1735 : KeepLogSeg(recptr, &_logSegNo);
7853 [ + + ]: 1735 : if (InvalidateObsoleteReplicationSlots(RS_INVAL_WAL_REMOVED | RS_INVAL_IDLE_TIMEOUT,
7854 : : _logSegNo, InvalidOid,
7855 : : InvalidTransactionId))
7856 : : {
7857 : : /*
7858 : : * Some slots have been invalidated; recalculate the old-segment
7859 : : * horizon, starting again from RedoRecPtr.
7860 : : */
7861 : 4 : XLByteToSeg(RedoRecPtr, _logSegNo, wal_segment_size);
7862 : 4 : KeepLogSeg(recptr, &_logSegNo);
7863 : : }
7864 : 1735 : _logSegNo--;
7865 : 1735 : RemoveOldXlogFiles(_logSegNo, RedoRecPtr, recptr,
7866 : : checkPoint.ThisTimeLineID);
7867 : :
7868 : : /*
7869 : : * Make more log segments if needed. (Do this after recycling old log
7870 : : * segments, since that may supply some of the needed files.)
7871 : : */
7872 [ + + ]: 1735 : if (!shutdown)
7873 : 999 : PreallocXlogFiles(recptr, checkPoint.ThisTimeLineID);
7874 : :
7875 : : /*
7876 : : * Truncate pg_subtrans if possible. We can throw away all data before
7877 : : * the oldest XMIN of any running transaction. No future transaction will
7878 : : * attempt to reference any pg_subtrans entry older than that (see Asserts
7879 : : * in subtrans.c). During recovery, though, we mustn't do this because
7880 : : * StartupSUBTRANS hasn't been called yet.
7881 : : */
7882 [ + + ]: 1735 : if (!RecoveryInProgress())
7883 : 1705 : TruncateSUBTRANS(GetOldestTransactionIdConsideredRunning());
7884 : :
7885 : : /* Real work is done; log and update stats. */
7886 : 1735 : LogCheckpointEnd(false, flags);
7887 : :
7888 : : /* Reset the process title */
7889 : 1735 : update_checkpoint_display(flags, false, true);
7890 : :
7891 : : TRACE_POSTGRESQL_CHECKPOINT_DONE(CheckpointStats.ckpt_bufs_written,
7892 : : NBuffers,
7893 : : CheckpointStats.ckpt_segs_added,
7894 : : CheckpointStats.ckpt_segs_removed,
7895 : : CheckpointStats.ckpt_segs_recycled);
7896 : :
7897 : 1735 : return true;
7898 : : }
7899 : :
7900 : : /*
7901 : : * Mark the end of recovery in WAL though without running a full checkpoint.
7902 : : * We can expect that a restartpoint is likely to be in progress as we
7903 : : * do this, though we are unwilling to wait for it to complete.
7904 : : *
7905 : : * CreateRestartPoint() allows for the case where recovery may end before
7906 : : * the restartpoint completes so there is no concern of concurrent behaviour.
7907 : : */
7908 : : static void
7909 : 52 : CreateEndOfRecoveryRecord(void)
7910 : : {
7911 : : xl_end_of_recovery xlrec;
7912 : : XLogRecPtr recptr;
7913 : :
7914 : : /* sanity check */
7915 [ - + ]: 52 : if (!RecoveryInProgress())
7916 [ # # ]: 0 : elog(ERROR, "can only be used to end recovery");
7917 : :
7918 : 52 : xlrec.end_time = GetCurrentTimestamp();
7919 : 52 : xlrec.wal_level = wal_level;
7920 : :
7921 : 52 : WALInsertLockAcquireExclusive();
7922 : 52 : xlrec.ThisTimeLineID = XLogCtl->InsertTimeLineID;
7923 : 52 : xlrec.PrevTimeLineID = XLogCtl->PrevTimeLineID;
7924 : 52 : WALInsertLockRelease();
7925 : :
7926 : 52 : START_CRIT_SECTION();
7927 : :
7928 : 52 : XLogBeginInsert();
7929 : 52 : XLogRegisterData(&xlrec, sizeof(xl_end_of_recovery));
7930 : 52 : recptr = XLogInsert(RM_XLOG_ID, XLOG_END_OF_RECOVERY);
7931 : :
7932 : 52 : XLogFlush(recptr);
7933 : :
7934 : : /*
7935 : : * Update the control file so that crash recovery can follow the timeline
7936 : : * changes to this point.
7937 : : */
7938 : 52 : LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
7939 : 52 : ControlFile->minRecoveryPoint = recptr;
7940 : 52 : ControlFile->minRecoveryPointTLI = xlrec.ThisTimeLineID;
7941 : :
7942 : : /* start with the latest checksum version (as of the end of recovery) */
7943 : 52 : SpinLockAcquire(&XLogCtl->info_lck);
7944 : 52 : ControlFile->data_checksum_version = XLogCtl->data_checksum_version;
7945 : 52 : SpinLockRelease(&XLogCtl->info_lck);
7946 : :
7947 : 52 : UpdateControlFile();
7948 : 52 : LWLockRelease(ControlFileLock);
7949 : :
7950 : 52 : END_CRIT_SECTION();
7951 : 52 : }
7952 : :
7953 : : /*
7954 : : * Write an OVERWRITE_CONTRECORD message.
7955 : : *
7956 : : * When on WAL replay we expect a continuation record at the start of a page
7957 : : * that is not there, recovery ends and WAL writing resumes at that point.
7958 : : * But it's wrong to resume writing new WAL back at the start of the record
7959 : : * that was broken, because downstream consumers of that WAL (physical
7960 : : * replicas) are not prepared to "rewind". So the first action after
7961 : : * finishing replay of all valid WAL must be to write a record of this type
7962 : : * at the point where the contrecord was missing; to support xlogreader
7963 : : * detecting the special case, XLP_FIRST_IS_OVERWRITE_CONTRECORD is also added
7964 : : * to the page header where the record occurs. xlogreader has an ad-hoc
7965 : : * mechanism to report metadata about the broken record, which is what we
7966 : : * use here.
7967 : : *
7968 : : * At replay time, XLP_FIRST_IS_OVERWRITE_CONTRECORD instructs xlogreader to
7969 : : * skip the record it was reading, and pass back the LSN of the skipped
7970 : : * record, so that its caller can verify (on "replay" of that record) that the
7971 : : * XLOG_OVERWRITE_CONTRECORD matches what was effectively overwritten.
7972 : : *
7973 : : * 'aborted_lsn' is the beginning position of the record that was incomplete.
7974 : : * It is included in the WAL record. 'pagePtr' and 'newTLI' point to the
7975 : : * beginning of the XLOG page where the record is to be inserted. They must
7976 : : * match the current WAL insert position, they're passed here just so that we
7977 : : * can verify that.
7978 : : */
7979 : : static XLogRecPtr
7980 : 11 : CreateOverwriteContrecordRecord(XLogRecPtr aborted_lsn, XLogRecPtr pagePtr,
7981 : : TimeLineID newTLI)
7982 : : {
7983 : : xl_overwrite_contrecord xlrec;
7984 : : XLogRecPtr recptr;
7985 : : XLogPageHeader pagehdr;
7986 : : XLogRecPtr startPos;
7987 : :
7988 : : /* sanity checks */
7989 [ - + ]: 11 : if (!RecoveryInProgress())
7990 [ # # ]: 0 : elog(ERROR, "can only be used at end of recovery");
7991 [ - + ]: 11 : if (pagePtr % XLOG_BLCKSZ != 0)
7992 [ # # ]: 0 : elog(ERROR, "invalid position for missing continuation record %X/%08X",
7993 : : LSN_FORMAT_ARGS(pagePtr));
7994 : :
7995 : : /* The current WAL insert position should be right after the page header */
7996 : 11 : startPos = pagePtr;
7997 [ + + ]: 11 : if (XLogSegmentOffset(startPos, wal_segment_size) == 0)
7998 : 1 : startPos += SizeOfXLogLongPHD;
7999 : : else
8000 : 10 : startPos += SizeOfXLogShortPHD;
8001 : 11 : recptr = GetXLogInsertRecPtr();
8002 [ - + ]: 11 : if (recptr != startPos)
8003 [ # # ]: 0 : elog(ERROR, "invalid WAL insert position %X/%08X for OVERWRITE_CONTRECORD",
8004 : : LSN_FORMAT_ARGS(recptr));
8005 : :
8006 : 11 : START_CRIT_SECTION();
8007 : :
8008 : : /*
8009 : : * Initialize the XLOG page header (by GetXLogBuffer), and set the
8010 : : * XLP_FIRST_IS_OVERWRITE_CONTRECORD flag.
8011 : : *
8012 : : * No other backend is allowed to write WAL yet, so acquiring the WAL
8013 : : * insertion lock is just pro forma.
8014 : : */
8015 : 11 : WALInsertLockAcquire();
8016 : 11 : pagehdr = (XLogPageHeader) GetXLogBuffer(pagePtr, newTLI);
8017 : 11 : pagehdr->xlp_info |= XLP_FIRST_IS_OVERWRITE_CONTRECORD;
8018 : 11 : WALInsertLockRelease();
8019 : :
8020 : : /*
8021 : : * Insert the XLOG_OVERWRITE_CONTRECORD record as the first record on the
8022 : : * page. We know it becomes the first record, because no other backend is
8023 : : * allowed to write WAL yet.
8024 : : */
8025 : 11 : XLogBeginInsert();
8026 : 11 : xlrec.overwritten_lsn = aborted_lsn;
8027 : 11 : xlrec.overwrite_time = GetCurrentTimestamp();
8028 : 11 : XLogRegisterData(&xlrec, sizeof(xl_overwrite_contrecord));
8029 : 11 : recptr = XLogInsert(RM_XLOG_ID, XLOG_OVERWRITE_CONTRECORD);
8030 : :
8031 : : /* check that the record was inserted to the right place */
8032 [ - + ]: 11 : if (ProcLastRecPtr != startPos)
8033 [ # # ]: 0 : elog(ERROR, "OVERWRITE_CONTRECORD was inserted to unexpected position %X/%08X",
8034 : : LSN_FORMAT_ARGS(ProcLastRecPtr));
8035 : :
8036 : 11 : XLogFlush(recptr);
8037 : :
8038 : 11 : END_CRIT_SECTION();
8039 : :
8040 : 11 : return recptr;
8041 : : }
8042 : :
8043 : : /*
8044 : : * Flush all data in shared memory to disk, and fsync
8045 : : *
8046 : : * This is the common code shared between regular checkpoints and
8047 : : * recovery restartpoints.
8048 : : */
8049 : : static void
8050 : 1944 : CheckPointGuts(XLogRecPtr checkPointRedo, int flags)
8051 : : {
8052 : 1944 : CheckPointRelationMap();
8053 : 1944 : CheckPointReplicationSlots(flags & CHECKPOINT_IS_SHUTDOWN);
8054 : 1944 : CheckPointSnapBuild();
8055 : 1944 : CheckPointLogicalRewriteHeap();
8056 : 1944 : CheckPointReplicationOrigin();
8057 : :
8058 : : /* Write out all dirty data in SLRUs and the main buffer pool */
8059 : : TRACE_POSTGRESQL_BUFFER_CHECKPOINT_START(flags);
8060 : 1944 : CheckpointStats.ckpt_write_t = GetCurrentTimestamp();
8061 : 1944 : CheckPointCLOG();
8062 : 1944 : CheckPointCommitTs();
8063 : 1944 : CheckPointSUBTRANS();
8064 : 1944 : CheckPointMultiXact();
8065 : 1944 : CheckPointPredicate();
8066 : 1944 : CheckPointBuffers(flags);
8067 : :
8068 : : /* Perform all queued up fsyncs */
8069 : : TRACE_POSTGRESQL_BUFFER_CHECKPOINT_SYNC_START();
8070 : 1944 : CheckpointStats.ckpt_sync_t = GetCurrentTimestamp();
8071 : 1944 : ProcessSyncRequests();
8072 : 1944 : CheckpointStats.ckpt_sync_end_t = GetCurrentTimestamp();
8073 : : TRACE_POSTGRESQL_BUFFER_CHECKPOINT_DONE();
8074 : :
8075 : : /* We deliberately delay 2PC checkpointing as long as possible */
8076 : 1944 : CheckPointTwoPhase(checkPointRedo);
8077 : 1944 : }
8078 : :
8079 : : /*
8080 : : * Save a checkpoint for recovery restart if appropriate
8081 : : *
8082 : : * This function is called each time a checkpoint record is read from XLOG.
8083 : : * It must determine whether the checkpoint represents a safe restartpoint or
8084 : : * not. If so, the checkpoint record is stashed in shared memory so that
8085 : : * CreateRestartPoint can consult it. (Note that the latter function is
8086 : : * executed by the checkpointer, while this one will be executed by the
8087 : : * startup process.)
8088 : : */
8089 : : static void
8090 : 755 : RecoveryRestartPoint(const CheckPoint *checkPoint, XLogReaderState *record)
8091 : : {
8092 : : /*
8093 : : * Also refrain from creating a restartpoint if we have seen any
8094 : : * references to non-existent pages. Restarting recovery from the
8095 : : * restartpoint would not see the references, so we would lose the
8096 : : * cross-check that the pages belonged to a relation that was dropped
8097 : : * later.
8098 : : */
8099 [ - + ]: 755 : if (XLogHaveInvalidPages())
8100 : : {
8101 [ # # ]: 0 : elog(DEBUG2,
8102 : : "could not record restart point at %X/%08X because there are unresolved references to invalid pages",
8103 : : LSN_FORMAT_ARGS(checkPoint->redo));
8104 : 0 : return;
8105 : : }
8106 : :
8107 : : /*
8108 : : * Copy the checkpoint record to shared memory, so that checkpointer can
8109 : : * work out the next time it wants to perform a restartpoint.
8110 : : */
8111 : 755 : SpinLockAcquire(&XLogCtl->info_lck);
8112 : 755 : XLogCtl->lastCheckPointRecPtr = record->ReadRecPtr;
8113 : 755 : XLogCtl->lastCheckPointEndPtr = record->EndRecPtr;
8114 : 755 : XLogCtl->lastCheckPoint = *checkPoint;
8115 : 755 : SpinLockRelease(&XLogCtl->info_lck);
8116 : : }
8117 : :
8118 : : /*
8119 : : * Establish a restartpoint if possible.
8120 : : *
8121 : : * This is similar to CreateCheckPoint, but is used during WAL recovery
8122 : : * to establish a point from which recovery can roll forward without
8123 : : * replaying the entire recovery log.
8124 : : *
8125 : : * Returns true if a new restartpoint was established. We can only establish
8126 : : * a restartpoint if we have replayed a safe checkpoint record since last
8127 : : * restartpoint.
8128 : : */
8129 : : bool
8130 : 626 : CreateRestartPoint(int flags)
8131 : : {
8132 : : XLogRecPtr lastCheckPointRecPtr;
8133 : : XLogRecPtr lastCheckPointEndPtr;
8134 : : CheckPoint lastCheckPoint;
8135 : : XLogRecPtr PriorRedoPtr;
8136 : : XLogRecPtr receivePtr;
8137 : : XLogRecPtr replayPtr;
8138 : : TimeLineID replayTLI;
8139 : : XLogRecPtr endptr;
8140 : : XLogSegNo _logSegNo;
8141 : : TimestampTz xtime;
8142 : :
8143 : : /* Concurrent checkpoint/restartpoint cannot happen */
8144 : : Assert(!IsUnderPostmaster || MyBackendType == B_CHECKPOINTER);
8145 : :
8146 : : /* Get a local copy of the last safe checkpoint record. */
8147 : 626 : SpinLockAcquire(&XLogCtl->info_lck);
8148 : 626 : lastCheckPointRecPtr = XLogCtl->lastCheckPointRecPtr;
8149 : 626 : lastCheckPointEndPtr = XLogCtl->lastCheckPointEndPtr;
8150 : 626 : lastCheckPoint = XLogCtl->lastCheckPoint;
8151 : 626 : SpinLockRelease(&XLogCtl->info_lck);
8152 : :
8153 : : /*
8154 : : * Check that we're still in recovery mode. It's ok if we exit recovery
8155 : : * mode after this check, the restart point is valid anyway.
8156 : : */
8157 [ - + ]: 626 : if (!RecoveryInProgress())
8158 : : {
8159 [ # # ]: 0 : ereport(DEBUG2,
8160 : : (errmsg_internal("skipping restartpoint, recovery has already ended")));
8161 : 0 : return false;
8162 : : }
8163 : :
8164 : : /*
8165 : : * If the last checkpoint record we've replayed is already our last
8166 : : * restartpoint, we can't perform a new restart point. We still update
8167 : : * minRecoveryPoint in that case, so that if this is a shutdown restart
8168 : : * point, we won't start up earlier than before. That's not strictly
8169 : : * necessary, but when hot standby is enabled, it would be rather weird if
8170 : : * the database opened up for read-only connections at a point-in-time
8171 : : * before the last shutdown. Such time travel is still possible in case of
8172 : : * immediate shutdown, though.
8173 : : *
8174 : : * We don't explicitly advance minRecoveryPoint when we do create a
8175 : : * restartpoint. It's assumed that flushing the buffers will do that as a
8176 : : * side-effect.
8177 : : */
8178 [ + + ]: 626 : if (!XLogRecPtrIsValid(lastCheckPointRecPtr) ||
8179 [ + + ]: 295 : lastCheckPoint.redo <= ControlFile->checkPointCopy.redo)
8180 : : {
8181 [ - + ]: 417 : ereport(DEBUG2,
8182 : : errmsg_internal("skipping restartpoint, already performed at %X/%08X",
8183 : : LSN_FORMAT_ARGS(lastCheckPoint.redo)));
8184 : :
8185 : 417 : UpdateMinRecoveryPoint(InvalidXLogRecPtr, true);
8186 [ + + ]: 417 : if (flags & CHECKPOINT_IS_SHUTDOWN)
8187 : : {
8188 : 39 : LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
8189 : 39 : ControlFile->state = DB_SHUTDOWNED_IN_RECOVERY;
8190 : 39 : UpdateControlFile();
8191 : 39 : LWLockRelease(ControlFileLock);
8192 : : }
8193 : 417 : return false;
8194 : : }
8195 : :
8196 : : /*
8197 : : * Update the shared RedoRecPtr so that the startup process can calculate
8198 : : * the number of segments replayed since last restartpoint, and request a
8199 : : * restartpoint if it exceeds CheckPointSegments.
8200 : : *
8201 : : * Like in CreateCheckPoint(), hold off insertions to update it, although
8202 : : * during recovery this is just pro forma, because no WAL insertions are
8203 : : * happening.
8204 : : */
8205 : 209 : WALInsertLockAcquireExclusive();
8206 : 209 : RedoRecPtr = XLogCtl->Insert.RedoRecPtr = lastCheckPoint.redo;
8207 : 209 : WALInsertLockRelease();
8208 : :
8209 : : /* Also update the info_lck-protected copy */
8210 : 209 : SpinLockAcquire(&XLogCtl->info_lck);
8211 : 209 : XLogCtl->RedoRecPtr = lastCheckPoint.redo;
8212 : 209 : SpinLockRelease(&XLogCtl->info_lck);
8213 : :
8214 : : /*
8215 : : * Prepare to accumulate statistics.
8216 : : *
8217 : : * Note: because it is possible for log_checkpoints to change while a
8218 : : * checkpoint proceeds, we always accumulate stats, even if
8219 : : * log_checkpoints is currently off.
8220 : : */
8221 [ + - + - : 2299 : MemSet(&CheckpointStats, 0, sizeof(CheckpointStats));
+ - + - +
+ ]
8222 : 209 : CheckpointStats.ckpt_start_t = GetCurrentTimestamp();
8223 : :
8224 [ + - ]: 209 : if (log_checkpoints)
8225 : 209 : LogCheckpointStart(flags, true);
8226 : :
8227 : : /* Update the process title */
8228 : 209 : update_checkpoint_display(flags, true, false);
8229 : :
8230 : 209 : CheckPointGuts(lastCheckPoint.redo, flags);
8231 : :
8232 : : /*
8233 : : * This location needs to be after CheckPointGuts() to ensure that some
8234 : : * work has already happened during this checkpoint.
8235 : : */
8236 : 209 : INJECTION_POINT("create-restart-point", NULL);
8237 : :
8238 : : /*
8239 : : * Remember the prior checkpoint's redo ptr for
8240 : : * UpdateCheckPointDistanceEstimate()
8241 : : */
8242 : 209 : PriorRedoPtr = ControlFile->checkPointCopy.redo;
8243 : :
8244 : : /*
8245 : : * Update pg_control, using current time. Check that it still shows an
8246 : : * older checkpoint, else do nothing; this is a quick hack to make sure
8247 : : * nothing really bad happens if somehow we get here after the
8248 : : * end-of-recovery checkpoint.
8249 : : */
8250 : 209 : LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
8251 [ + - ]: 209 : if (ControlFile->checkPointCopy.redo < lastCheckPoint.redo)
8252 : : {
8253 : : /*
8254 : : * Update the checkpoint information. We do this even if the cluster
8255 : : * does not show DB_IN_ARCHIVE_RECOVERY to match with the set of WAL
8256 : : * segments recycled below.
8257 : : */
8258 : 209 : ControlFile->checkPoint = lastCheckPointRecPtr;
8259 : 209 : ControlFile->checkPointCopy = lastCheckPoint;
8260 : :
8261 : : /*
8262 : : * Ensure minRecoveryPoint is past the checkpoint record and update it
8263 : : * if the control file still shows DB_IN_ARCHIVE_RECOVERY. Normally,
8264 : : * this will have happened already while writing out dirty buffers,
8265 : : * but not necessarily - e.g. because no buffers were dirtied. We do
8266 : : * this because a backup performed in recovery uses minRecoveryPoint
8267 : : * to determine which WAL files must be included in the backup, and
8268 : : * the file (or files) containing the checkpoint record must be
8269 : : * included, at a minimum. Note that for an ordinary restart of
8270 : : * recovery there's no value in having the minimum recovery point any
8271 : : * earlier than this anyway, because redo will begin just after the
8272 : : * checkpoint record.
8273 : : */
8274 [ + + ]: 209 : if (ControlFile->state == DB_IN_ARCHIVE_RECOVERY)
8275 : : {
8276 [ + + ]: 208 : if (ControlFile->minRecoveryPoint < lastCheckPointEndPtr)
8277 : : {
8278 : 19 : ControlFile->minRecoveryPoint = lastCheckPointEndPtr;
8279 : 19 : ControlFile->minRecoveryPointTLI = lastCheckPoint.ThisTimeLineID;
8280 : :
8281 : : /* update local copy */
8282 : 19 : LocalMinRecoveryPoint = ControlFile->minRecoveryPoint;
8283 : 19 : LocalMinRecoveryPointTLI = ControlFile->minRecoveryPointTLI;
8284 : : }
8285 [ + + ]: 208 : if (flags & CHECKPOINT_IS_SHUTDOWN)
8286 : 24 : ControlFile->state = DB_SHUTDOWNED_IN_RECOVERY;
8287 : : }
8288 : :
8289 : : /* we shall start with the latest checksum version */
8290 : 209 : ControlFile->data_checksum_version = lastCheckPoint.dataChecksumState;
8291 : :
8292 : 209 : UpdateControlFile();
8293 : : }
8294 : 209 : LWLockRelease(ControlFileLock);
8295 : :
8296 : : /*
8297 : : * Update the average distance between checkpoints/restartpoints if the
8298 : : * prior checkpoint exists.
8299 : : */
8300 [ + - ]: 209 : if (XLogRecPtrIsValid(PriorRedoPtr))
8301 : 209 : UpdateCheckPointDistanceEstimate(RedoRecPtr - PriorRedoPtr);
8302 : :
8303 : : /*
8304 : : * Delete old log files, those no longer needed for last restartpoint to
8305 : : * prevent the disk holding the xlog from growing full.
8306 : : */
8307 : 209 : XLByteToSeg(RedoRecPtr, _logSegNo, wal_segment_size);
8308 : :
8309 : : /*
8310 : : * Retreat _logSegNo using the current end of xlog replayed or received,
8311 : : * whichever is later.
8312 : : */
8313 : 209 : receivePtr = GetWalRcvFlushRecPtr(NULL, NULL);
8314 : 209 : replayPtr = GetXLogReplayRecPtr(&replayTLI);
8315 : 209 : endptr = (receivePtr < replayPtr) ? replayPtr : receivePtr;
8316 : 209 : KeepLogSeg(endptr, &_logSegNo);
8317 : :
8318 : 209 : INJECTION_POINT("restartpoint-before-slot-invalidation", NULL);
8319 : :
8320 [ + + ]: 209 : if (InvalidateObsoleteReplicationSlots(RS_INVAL_WAL_REMOVED | RS_INVAL_IDLE_TIMEOUT,
8321 : : _logSegNo, InvalidOid,
8322 : : InvalidTransactionId))
8323 : : {
8324 : : /*
8325 : : * Some slots have been invalidated; recalculate the old-segment
8326 : : * horizon, starting again from RedoRecPtr.
8327 : : */
8328 : 1 : XLByteToSeg(RedoRecPtr, _logSegNo, wal_segment_size);
8329 : 1 : KeepLogSeg(endptr, &_logSegNo);
8330 : : }
8331 : 209 : _logSegNo--;
8332 : :
8333 : : /*
8334 : : * Try to recycle segments on a useful timeline. If we've been promoted
8335 : : * since the beginning of this restartpoint, use the new timeline chosen
8336 : : * at end of recovery. If we're still in recovery, use the timeline we're
8337 : : * currently replaying.
8338 : : *
8339 : : * There is no guarantee that the WAL segments will be useful on the
8340 : : * current timeline; if recovery proceeds to a new timeline right after
8341 : : * this, the pre-allocated WAL segments on this timeline will not be used,
8342 : : * and will go wasted until recycled on the next restartpoint. We'll live
8343 : : * with that.
8344 : : */
8345 [ + + ]: 209 : if (!RecoveryInProgress())
8346 : 1 : replayTLI = XLogCtl->InsertTimeLineID;
8347 : :
8348 : 209 : RemoveOldXlogFiles(_logSegNo, RedoRecPtr, endptr, replayTLI);
8349 : :
8350 : : /*
8351 : : * Make more log segments if needed. (Do this after recycling old log
8352 : : * segments, since that may supply some of the needed files.)
8353 : : */
8354 : 209 : PreallocXlogFiles(endptr, replayTLI);
8355 : :
8356 : : /*
8357 : : * Truncate pg_subtrans if possible. We can throw away all data before
8358 : : * the oldest XMIN of any running transaction. No future transaction will
8359 : : * attempt to reference any pg_subtrans entry older than that (see Asserts
8360 : : * in subtrans.c). When hot standby is disabled, though, we mustn't do
8361 : : * this because StartupSUBTRANS hasn't been called yet.
8362 : : */
8363 [ + - ]: 209 : if (EnableHotStandby)
8364 : 209 : TruncateSUBTRANS(GetOldestTransactionIdConsideredRunning());
8365 : :
8366 : : /* Real work is done; log and update stats. */
8367 : 209 : LogCheckpointEnd(true, flags);
8368 : :
8369 : : /* Reset the process title */
8370 : 209 : update_checkpoint_display(flags, true, true);
8371 : :
8372 : 209 : xtime = GetLatestXTime();
8373 [ + - + - : 209 : ereport((log_checkpoints ? LOG : DEBUG2),
+ + ]
8374 : : errmsg("recovery restart point at %X/%08X",
8375 : : LSN_FORMAT_ARGS(lastCheckPoint.redo)),
8376 : : xtime ? errdetail("Last completed transaction was at log time %s.",
8377 : : timestamptz_to_str(xtime)) : 0);
8378 : :
8379 : : /*
8380 : : * Finally, execute archive_cleanup_command, if any.
8381 : : */
8382 [ + - - + ]: 209 : if (archiveCleanupCommand && strcmp(archiveCleanupCommand, "") != 0)
8383 : 0 : ExecuteRecoveryCommand(archiveCleanupCommand,
8384 : : "archive_cleanup_command",
8385 : : false,
8386 : : WAIT_EVENT_ARCHIVE_CLEANUP_COMMAND);
8387 : :
8388 : 209 : return true;
8389 : : }
8390 : :
8391 : : /*
8392 : : * Report availability of WAL for the given target LSN
8393 : : * (typically a slot's restart_lsn)
8394 : : *
8395 : : * Returns one of the following enum values:
8396 : : *
8397 : : * * WALAVAIL_RESERVED means targetLSN is available and it is in the range of
8398 : : * max_wal_size.
8399 : : *
8400 : : * * WALAVAIL_EXTENDED means it is still available by preserving extra
8401 : : * segments beyond max_wal_size. If max_slot_wal_keep_size is smaller
8402 : : * than max_wal_size, this state is not returned.
8403 : : *
8404 : : * * WALAVAIL_UNRESERVED means it is being lost and the next checkpoint will
8405 : : * remove reserved segments. The walsender using this slot may return to the
8406 : : * above.
8407 : : *
8408 : : * * WALAVAIL_REMOVED means it has been removed. A replication stream on
8409 : : * a slot with this LSN cannot continue. (Any associated walsender
8410 : : * processes should have been terminated already.)
8411 : : *
8412 : : * * WALAVAIL_INVALID_LSN means the slot hasn't been set to reserve WAL.
8413 : : */
8414 : : WALAvailability
8415 : 635 : GetWALAvailability(XLogRecPtr targetLSN)
8416 : : {
8417 : : XLogRecPtr currpos; /* current write LSN */
8418 : : XLogSegNo currSeg; /* segid of currpos */
8419 : : XLogSegNo targetSeg; /* segid of targetLSN */
8420 : : XLogSegNo oldestSeg; /* actual oldest segid */
8421 : : XLogSegNo oldestSegMaxWalSize; /* oldest segid kept by max_wal_size */
8422 : : XLogSegNo oldestSlotSeg; /* oldest segid kept by slot */
8423 : : uint64 keepSegs;
8424 : :
8425 : : /*
8426 : : * slot does not reserve WAL. Either deactivated, or has never been active
8427 : : */
8428 [ + + ]: 635 : if (!XLogRecPtrIsValid(targetLSN))
8429 : 29 : return WALAVAIL_INVALID_LSN;
8430 : :
8431 : : /*
8432 : : * Calculate the oldest segment currently reserved by all slots,
8433 : : * considering wal_keep_size and max_slot_wal_keep_size. Initialize
8434 : : * oldestSlotSeg to the current segment.
8435 : : */
8436 : 606 : currpos = GetXLogWriteRecPtr();
8437 : 606 : XLByteToSeg(currpos, oldestSlotSeg, wal_segment_size);
8438 : 606 : KeepLogSeg(currpos, &oldestSlotSeg);
8439 : :
8440 : : /*
8441 : : * Find the oldest extant segment file. We get 1 until checkpoint removes
8442 : : * the first WAL segment file since startup, which causes the status being
8443 : : * wrong under certain abnormal conditions but that doesn't actually harm.
8444 : : */
8445 : 606 : oldestSeg = XLogGetLastRemovedSegno() + 1;
8446 : :
8447 : : /* calculate oldest segment by max_wal_size */
8448 : 606 : XLByteToSeg(currpos, currSeg, wal_segment_size);
8449 : 606 : keepSegs = ConvertToXSegs(max_wal_size_mb, wal_segment_size) + 1;
8450 : :
8451 [ + + ]: 606 : if (currSeg > keepSegs)
8452 : 13 : oldestSegMaxWalSize = currSeg - keepSegs;
8453 : : else
8454 : 593 : oldestSegMaxWalSize = 1;
8455 : :
8456 : : /* the segment we care about */
8457 : 606 : XLByteToSeg(targetLSN, targetSeg, wal_segment_size);
8458 : :
8459 : : /*
8460 : : * No point in returning reserved or extended status values if the
8461 : : * targetSeg is known to be lost.
8462 : : */
8463 [ + + ]: 606 : if (targetSeg >= oldestSlotSeg)
8464 : : {
8465 : : /* show "reserved" when targetSeg is within max_wal_size */
8466 [ + + ]: 605 : if (targetSeg >= oldestSegMaxWalSize)
8467 : 603 : return WALAVAIL_RESERVED;
8468 : :
8469 : : /* being retained by slots exceeding max_wal_size */
8470 : 2 : return WALAVAIL_EXTENDED;
8471 : : }
8472 : :
8473 : : /* WAL segments are no longer retained but haven't been removed yet */
8474 [ + - ]: 1 : if (targetSeg >= oldestSeg)
8475 : 1 : return WALAVAIL_UNRESERVED;
8476 : :
8477 : : /* Definitely lost */
8478 : 0 : return WALAVAIL_REMOVED;
8479 : : }
8480 : :
8481 : :
8482 : : /*
8483 : : * Retreat *logSegNo to the last segment that we need to retain because of
8484 : : * either wal_keep_size or replication slots.
8485 : : *
8486 : : * This is calculated by subtracting wal_keep_size from the given xlog
8487 : : * location, recptr and by making sure that that result is below the
8488 : : * requirement of replication slots. For the latter criterion we do consider
8489 : : * the effects of max_slot_wal_keep_size: reserve at most that much space back
8490 : : * from recptr.
8491 : : *
8492 : : * Note about replication slots: if this function calculates a value
8493 : : * that's further ahead than what slots need reserved, then affected
8494 : : * slots need to be invalidated and this function invoked again.
8495 : : * XXX it might be a good idea to rewrite this function so that
8496 : : * invalidation is optionally done here, instead.
8497 : : */
8498 : : static void
8499 : 2555 : KeepLogSeg(XLogRecPtr recptr, XLogSegNo *logSegNo)
8500 : : {
8501 : : XLogSegNo currSegNo;
8502 : : XLogSegNo segno;
8503 : : XLogRecPtr keep;
8504 : :
8505 : 2555 : XLByteToSeg(recptr, currSegNo, wal_segment_size);
8506 : 2555 : segno = currSegNo;
8507 : :
8508 : : /* Calculate how many segments are kept by slots. */
8509 : 2555 : keep = XLogGetReplicationSlotMinimumLSN();
8510 [ + + + + ]: 2555 : if (XLogRecPtrIsValid(keep) && keep < recptr)
8511 : : {
8512 : 768 : XLByteToSeg(keep, segno, wal_segment_size);
8513 : :
8514 : : /*
8515 : : * Account for max_slot_wal_keep_size to avoid keeping more than
8516 : : * configured. However, don't do that during a binary upgrade: if
8517 : : * slots were to be invalidated because of this, it would not be
8518 : : * possible to preserve logical ones during the upgrade.
8519 : : */
8520 [ + + + - ]: 768 : if (max_slot_wal_keep_size_mb >= 0 && !IsBinaryUpgrade)
8521 : : {
8522 : : uint64 slot_keep_segs;
8523 : :
8524 : 26 : slot_keep_segs =
8525 : 26 : ConvertToXSegs(max_slot_wal_keep_size_mb, wal_segment_size);
8526 : :
8527 [ + + ]: 26 : if (currSegNo - segno > slot_keep_segs)
8528 : 7 : segno = currSegNo - slot_keep_segs;
8529 : : }
8530 : : }
8531 : :
8532 : : /*
8533 : : * If WAL summarization is in use, don't remove WAL that has yet to be
8534 : : * summarized.
8535 : : */
8536 : 2555 : keep = GetOldestUnsummarizedLSN(NULL, NULL);
8537 [ + + ]: 2555 : if (XLogRecPtrIsValid(keep))
8538 : : {
8539 : : XLogSegNo unsummarized_segno;
8540 : :
8541 : 7 : XLByteToSeg(keep, unsummarized_segno, wal_segment_size);
8542 [ + - ]: 7 : if (unsummarized_segno < segno)
8543 : 7 : segno = unsummarized_segno;
8544 : : }
8545 : :
8546 : : /* but, keep at least wal_keep_size if that's set */
8547 [ + + ]: 2555 : if (wal_keep_size_mb > 0)
8548 : : {
8549 : : uint64 keep_segs;
8550 : :
8551 : 74 : keep_segs = ConvertToXSegs(wal_keep_size_mb, wal_segment_size);
8552 [ + - ]: 74 : if (currSegNo - segno < keep_segs)
8553 : : {
8554 : : /* avoid underflow, don't go below 1 */
8555 [ + + ]: 74 : if (currSegNo <= keep_segs)
8556 : 70 : segno = 1;
8557 : : else
8558 : 4 : segno = currSegNo - keep_segs;
8559 : : }
8560 : : }
8561 : :
8562 : : /* don't delete WAL segments newer than the calculated segment */
8563 [ + + ]: 2555 : if (segno < *logSegNo)
8564 : 362 : *logSegNo = segno;
8565 : 2555 : }
8566 : :
8567 : : /*
8568 : : * Write a NEXTOID log record
8569 : : */
8570 : : void
8571 : 692 : XLogPutNextOid(Oid nextOid)
8572 : : {
8573 : 692 : XLogBeginInsert();
8574 : 692 : XLogRegisterData(&nextOid, sizeof(Oid));
8575 : 692 : (void) XLogInsert(RM_XLOG_ID, XLOG_NEXTOID);
8576 : :
8577 : : /*
8578 : : * We need not flush the NEXTOID record immediately, because any of the
8579 : : * just-allocated OIDs could only reach disk as part of a tuple insert or
8580 : : * update that would have its own XLOG record that must follow the NEXTOID
8581 : : * record. Therefore, the standard buffer LSN interlock applied to those
8582 : : * records will ensure no such OID reaches disk before the NEXTOID record
8583 : : * does.
8584 : : *
8585 : : * Note, however, that the above statement only covers state "within" the
8586 : : * database. When we use a generated OID as a file or directory name, we
8587 : : * are in a sense violating the basic WAL rule, because that filesystem
8588 : : * change may reach disk before the NEXTOID WAL record does. The impact
8589 : : * of this is that if a database crash occurs immediately afterward, we
8590 : : * might after restart re-generate the same OID and find that it conflicts
8591 : : * with the leftover file or directory. But since for safety's sake we
8592 : : * always loop until finding a nonconflicting filename, this poses no real
8593 : : * problem in practice. See pgsql-hackers discussion 27-Sep-2006.
8594 : : */
8595 : 692 : }
8596 : :
8597 : : /*
8598 : : * Write an XLOG SWITCH record.
8599 : : *
8600 : : * Here we just blindly issue an XLogInsert request for the record.
8601 : : * All the magic happens inside XLogInsert.
8602 : : *
8603 : : * The return value is either the end+1 address of the switch record,
8604 : : * or the end+1 address of the prior segment if we did not need to
8605 : : * write a switch record because we are already at segment start.
8606 : : */
8607 : : XLogRecPtr
8608 : 818 : RequestXLogSwitch(bool mark_unimportant)
8609 : : {
8610 : : XLogRecPtr RecPtr;
8611 : :
8612 : : /* XLOG SWITCH has no data */
8613 : 818 : XLogBeginInsert();
8614 : :
8615 [ - + ]: 818 : if (mark_unimportant)
8616 : 0 : XLogSetRecordFlags(XLOG_MARK_UNIMPORTANT);
8617 : 818 : RecPtr = XLogInsert(RM_XLOG_ID, XLOG_SWITCH);
8618 : :
8619 : 818 : return RecPtr;
8620 : : }
8621 : :
8622 : : /*
8623 : : * Write a RESTORE POINT record
8624 : : */
8625 : : XLogRecPtr
8626 : 3 : XLogRestorePoint(const char *rpName)
8627 : : {
8628 : : XLogRecPtr RecPtr;
8629 : : xl_restore_point xlrec;
8630 : :
8631 : 3 : xlrec.rp_time = GetCurrentTimestamp();
8632 : 3 : strlcpy(xlrec.rp_name, rpName, MAXFNAMELEN);
8633 : :
8634 : 3 : XLogBeginInsert();
8635 : 3 : XLogRegisterData(&xlrec, sizeof(xl_restore_point));
8636 : :
8637 : 3 : RecPtr = XLogInsert(RM_XLOG_ID, XLOG_RESTORE_POINT);
8638 : :
8639 [ + - ]: 3 : ereport(LOG,
8640 : : errmsg("restore point \"%s\" created at %X/%08X",
8641 : : rpName, LSN_FORMAT_ARGS(RecPtr)));
8642 : :
8643 : 3 : return RecPtr;
8644 : : }
8645 : :
8646 : : /*
8647 : : * Write an empty XLOG record to assign a distinct LSN.
8648 : : *
8649 : : * This is used by some index AMs when building indexes on permanent relations
8650 : : * with wal_level=minimal. In that scenario, WAL-logging will start after
8651 : : * commit, but the index AM needs distinct LSNs to detect concurrent page
8652 : : * modifications. When the current WAL insert position hasn't advanced since
8653 : : * the last call, we emit a dummy record to ensure we get a new, distinct LSN.
8654 : : */
8655 : : XLogRecPtr
8656 : 442 : XLogAssignLSN(void)
8657 : : {
8658 : 442 : int dummy = 0;
8659 : :
8660 : : /*
8661 : : * Records other than XLOG_SWITCH must have content. We use an integer 0
8662 : : * to satisfy this restriction.
8663 : : */
8664 : 442 : XLogBeginInsert();
8665 : 442 : XLogSetRecordFlags(XLOG_MARK_UNIMPORTANT);
8666 : 442 : XLogRegisterData(&dummy, sizeof(dummy));
8667 : 442 : return XLogInsert(RM_XLOG_ID, XLOG_ASSIGN_LSN);
8668 : : }
8669 : :
8670 : : /*
8671 : : * Check if any of the GUC parameters that are critical for hot standby
8672 : : * have changed, and update the value in pg_control file if necessary.
8673 : : */
8674 : : static void
8675 : 1018 : XLogReportParameters(void)
8676 : : {
8677 [ + + ]: 1018 : if (wal_level != ControlFile->wal_level ||
8678 [ + + ]: 750 : wal_log_hints != ControlFile->wal_log_hints ||
8679 [ + + ]: 656 : MaxConnections != ControlFile->MaxConnections ||
8680 [ + + ]: 655 : max_worker_processes != ControlFile->max_worker_processes ||
8681 [ + + ]: 652 : max_wal_senders != ControlFile->max_wal_senders ||
8682 [ + + ]: 624 : max_prepared_xacts != ControlFile->max_prepared_xacts ||
8683 [ + - ]: 520 : max_locks_per_xact != ControlFile->max_locks_per_xact ||
8684 [ + + ]: 520 : track_commit_timestamp != ControlFile->track_commit_timestamp)
8685 : : {
8686 : : /*
8687 : : * The change in number of backend slots doesn't need to be WAL-logged
8688 : : * if archiving is not enabled, as you can't start archive recovery
8689 : : * with wal_level=minimal anyway. We don't really care about the
8690 : : * values in pg_control either if wal_level=minimal, but seems better
8691 : : * to keep them up-to-date to avoid confusion.
8692 : : */
8693 [ + + + + ]: 510 : if (wal_level != ControlFile->wal_level || XLogIsNeeded())
8694 : : {
8695 : : xl_parameter_change xlrec;
8696 : : XLogRecPtr recptr;
8697 : :
8698 : 483 : xlrec.MaxConnections = MaxConnections;
8699 : 483 : xlrec.max_worker_processes = max_worker_processes;
8700 : 483 : xlrec.max_wal_senders = max_wal_senders;
8701 : 483 : xlrec.max_prepared_xacts = max_prepared_xacts;
8702 : 483 : xlrec.max_locks_per_xact = max_locks_per_xact;
8703 : 483 : xlrec.wal_level = wal_level;
8704 : 483 : xlrec.wal_log_hints = wal_log_hints;
8705 : 483 : xlrec.track_commit_timestamp = track_commit_timestamp;
8706 : :
8707 : 483 : XLogBeginInsert();
8708 : 483 : XLogRegisterData(&xlrec, sizeof(xlrec));
8709 : :
8710 : 483 : recptr = XLogInsert(RM_XLOG_ID, XLOG_PARAMETER_CHANGE);
8711 : 483 : XLogFlush(recptr);
8712 : : }
8713 : :
8714 : 510 : LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
8715 : :
8716 : 510 : ControlFile->MaxConnections = MaxConnections;
8717 : 510 : ControlFile->max_worker_processes = max_worker_processes;
8718 : 510 : ControlFile->max_wal_senders = max_wal_senders;
8719 : 510 : ControlFile->max_prepared_xacts = max_prepared_xacts;
8720 : 510 : ControlFile->max_locks_per_xact = max_locks_per_xact;
8721 : 510 : ControlFile->wal_level = wal_level;
8722 : 510 : ControlFile->wal_log_hints = wal_log_hints;
8723 : 510 : ControlFile->track_commit_timestamp = track_commit_timestamp;
8724 : 510 : UpdateControlFile();
8725 : :
8726 : 510 : LWLockRelease(ControlFileLock);
8727 : : }
8728 : 1018 : }
8729 : :
8730 : : /*
8731 : : * Log the new state of checksums
8732 : : */
8733 : : static void
8734 : 31 : XLogChecksums(uint32 new_type)
8735 : : {
8736 : : xl_checksum_state xlrec;
8737 : : XLogRecPtr recptr;
8738 : :
8739 : 31 : xlrec.new_checksum_state = new_type;
8740 : :
8741 : 31 : XLogBeginInsert();
8742 : 31 : XLogRegisterData((char *) &xlrec, sizeof(xl_checksum_state));
8743 : :
8744 : 31 : recptr = XLogInsert(RM_XLOG2_ID, XLOG2_CHECKSUMS);
8745 : 31 : XLogFlush(recptr);
8746 : 31 : }
8747 : :
8748 : : /*
8749 : : * Update full_page_writes in shared memory, and write an
8750 : : * XLOG_FPW_CHANGE record if necessary.
8751 : : *
8752 : : * Note: this function assumes there is no other process running
8753 : : * concurrently that could update it.
8754 : : */
8755 : : void
8756 : 1739 : UpdateFullPageWrites(void)
8757 : : {
8758 : 1739 : XLogCtlInsert *Insert = &XLogCtl->Insert;
8759 : : bool recoveryInProgress;
8760 : :
8761 : : /*
8762 : : * Do nothing if full_page_writes has not been changed.
8763 : : *
8764 : : * It's safe to check the shared full_page_writes without the lock,
8765 : : * because we assume that there is no concurrently running process which
8766 : : * can update it.
8767 : : */
8768 [ + + ]: 1739 : if (fullPageWrites == Insert->fullPageWrites)
8769 : 1236 : return;
8770 : :
8771 : : /*
8772 : : * Perform this outside critical section so that the WAL insert
8773 : : * initialization done by RecoveryInProgress() doesn't trigger an
8774 : : * assertion failure.
8775 : : */
8776 : 503 : recoveryInProgress = RecoveryInProgress();
8777 : :
8778 : 503 : START_CRIT_SECTION();
8779 : :
8780 : : /*
8781 : : * It's always safe to take full page images, even when not strictly
8782 : : * required, but not the other round. So if we're setting full_page_writes
8783 : : * to true, first set it true and then write the WAL record. If we're
8784 : : * setting it to false, first write the WAL record and then set the global
8785 : : * flag.
8786 : : */
8787 [ + + ]: 503 : if (fullPageWrites)
8788 : : {
8789 : 490 : WALInsertLockAcquireExclusive();
8790 : 490 : Insert->fullPageWrites = true;
8791 : 490 : WALInsertLockRelease();
8792 : : }
8793 : :
8794 : : /*
8795 : : * Write an XLOG_FPW_CHANGE record. This allows us to keep track of
8796 : : * full_page_writes during archive recovery, if required.
8797 : : */
8798 [ + + - + ]: 503 : if (XLogStandbyInfoActive() && !recoveryInProgress)
8799 : : {
8800 : 0 : XLogBeginInsert();
8801 : 0 : XLogRegisterData(&fullPageWrites, sizeof(bool));
8802 : :
8803 : 0 : XLogInsert(RM_XLOG_ID, XLOG_FPW_CHANGE);
8804 : : }
8805 : :
8806 [ + + ]: 503 : if (!fullPageWrites)
8807 : : {
8808 : 13 : WALInsertLockAcquireExclusive();
8809 : 13 : Insert->fullPageWrites = false;
8810 : 13 : WALInsertLockRelease();
8811 : : }
8812 : 503 : END_CRIT_SECTION();
8813 : : }
8814 : :
8815 : : /*
8816 : : * XLOG resource manager's routines
8817 : : *
8818 : : * Definitions of info values are in include/catalog/pg_control.h, though
8819 : : * not all record types are related to control file updates.
8820 : : *
8821 : : * NOTE: Some XLOG record types that are directly related to WAL recovery
8822 : : * are handled in xlogrecovery_redo().
8823 : : */
8824 : : void
8825 : 117443 : xlog_redo(XLogReaderState *record)
8826 : : {
8827 : 117443 : uint8 info = XLogRecGetInfo(record) & ~XLR_INFO_MASK;
8828 : 117443 : XLogRecPtr lsn = record->EndRecPtr;
8829 : :
8830 : : /*
8831 : : * In XLOG rmgr, backup blocks are only used by XLOG_FPI and
8832 : : * XLOG_FPI_FOR_HINT records.
8833 : : */
8834 : : Assert(info == XLOG_FPI || info == XLOG_FPI_FOR_HINT ||
8835 : : !XLogRecHasAnyBlockRefs(record));
8836 : :
8837 [ + + ]: 117443 : if (info == XLOG_NEXTOID)
8838 : : {
8839 : : Oid nextOid;
8840 : :
8841 : : /*
8842 : : * We used to try to take the maximum of TransamVariables->nextOid and
8843 : : * the recorded nextOid, but that fails if the OID counter wraps
8844 : : * around. Since no OID allocation should be happening during replay
8845 : : * anyway, better to just believe the record exactly. We still take
8846 : : * OidGenLock while setting the variable, just in case.
8847 : : */
8848 : 100 : memcpy(&nextOid, XLogRecGetData(record), sizeof(Oid));
8849 : 100 : LWLockAcquire(OidGenLock, LW_EXCLUSIVE);
8850 : 100 : TransamVariables->nextOid = nextOid;
8851 : 100 : TransamVariables->oidCount = 0;
8852 : 100 : LWLockRelease(OidGenLock);
8853 : : }
8854 [ + + ]: 117343 : else if (info == XLOG_CHECKPOINT_SHUTDOWN)
8855 : : {
8856 : : CheckPoint checkPoint;
8857 : : TimeLineID replayTLI;
8858 : :
8859 : 43 : memcpy(&checkPoint, XLogRecGetData(record), sizeof(CheckPoint));
8860 : : /* In a SHUTDOWN checkpoint, believe the counters exactly */
8861 : 43 : LWLockAcquire(XidGenLock, LW_EXCLUSIVE);
8862 : 43 : TransamVariables->nextXid = checkPoint.nextXid;
8863 : 43 : LWLockRelease(XidGenLock);
8864 : 43 : LWLockAcquire(OidGenLock, LW_EXCLUSIVE);
8865 : 43 : TransamVariables->nextOid = checkPoint.nextOid;
8866 : 43 : TransamVariables->oidCount = 0;
8867 : 43 : LWLockRelease(OidGenLock);
8868 : 43 : MultiXactSetNextMXact(checkPoint.nextMulti,
8869 : : checkPoint.nextMultiOffset);
8870 : :
8871 : 43 : MultiXactAdvanceOldest(checkPoint.oldestMulti,
8872 : : checkPoint.oldestMultiDB);
8873 : :
8874 : : /*
8875 : : * No need to set oldestClogXid here as well; it'll be set when we
8876 : : * redo an xl_clog_truncate if it changed since initialization.
8877 : : */
8878 : 43 : SetTransactionIdLimit(checkPoint.oldestXid, checkPoint.oldestXidDB);
8879 : :
8880 : : /*
8881 : : * If we see a shutdown checkpoint while waiting for an end-of-backup
8882 : : * record, the backup was canceled and the end-of-backup record will
8883 : : * never arrive.
8884 : : */
8885 [ + + ]: 43 : if (ArchiveRecoveryRequested &&
8886 [ - + ]: 42 : XLogRecPtrIsValid(ControlFile->backupStartPoint) &&
8887 [ # # ]: 0 : !XLogRecPtrIsValid(ControlFile->backupEndPoint))
8888 [ # # ]: 0 : ereport(PANIC,
8889 : : (errmsg("online backup was canceled, recovery cannot continue")));
8890 : :
8891 : : /*
8892 : : * If we see a shutdown checkpoint, we know that nothing was running
8893 : : * on the primary at this point. So fake-up an empty running-xacts
8894 : : * record and use that here and now. Recover additional standby state
8895 : : * for prepared transactions.
8896 : : */
8897 [ + + ]: 43 : if (standbyState >= STANDBY_INITIALIZED)
8898 : : {
8899 : : TransactionId *xids;
8900 : : int nxids;
8901 : : TransactionId oldestActiveXID;
8902 : : TransactionId latestCompletedXid;
8903 : : RunningTransactionsData running;
8904 : :
8905 : 40 : oldestActiveXID = PrescanPreparedTransactions(&xids, &nxids);
8906 : :
8907 : : /* Update pg_subtrans entries for any prepared transactions */
8908 : 40 : StandbyRecoverPreparedTransactions();
8909 : :
8910 : : /*
8911 : : * Construct a RunningTransactions snapshot representing a shut
8912 : : * down server, with only prepared transactions still alive. We're
8913 : : * never overflowed at this point because all subxids are listed
8914 : : * with their parent prepared transactions.
8915 : : */
8916 : 40 : running.xcnt = nxids;
8917 : 40 : running.subxcnt = 0;
8918 : 40 : running.subxid_status = SUBXIDS_IN_SUBTRANS;
8919 : 40 : running.nextXid = XidFromFullTransactionId(checkPoint.nextXid);
8920 : 40 : running.oldestRunningXid = oldestActiveXID;
8921 : 40 : latestCompletedXid = XidFromFullTransactionId(checkPoint.nextXid);
8922 [ - + ]: 40 : TransactionIdRetreat(latestCompletedXid);
8923 : : Assert(TransactionIdIsNormal(latestCompletedXid));
8924 : 40 : running.latestCompletedXid = latestCompletedXid;
8925 : 40 : running.xids = xids;
8926 : :
8927 : 40 : ProcArrayApplyRecoveryInfo(&running);
8928 : : }
8929 : :
8930 : : /* ControlFile->checkPointCopy always tracks the latest ckpt XID */
8931 : 43 : LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
8932 : 43 : ControlFile->checkPointCopy.nextXid = checkPoint.nextXid;
8933 : 43 : ControlFile->data_checksum_version = checkPoint.dataChecksumState;
8934 : :
8935 : 43 : UpdateControlFile();
8936 : 43 : LWLockRelease(ControlFileLock);
8937 : :
8938 : : /*
8939 : : * We should've already switched to the new TLI before replaying this
8940 : : * record.
8941 : : */
8942 : 43 : (void) GetCurrentReplayRecPtr(&replayTLI);
8943 [ - + ]: 43 : if (checkPoint.ThisTimeLineID != replayTLI)
8944 [ # # ]: 0 : ereport(PANIC,
8945 : : (errmsg("unexpected timeline ID %u (should be %u) in shutdown checkpoint record",
8946 : : checkPoint.ThisTimeLineID, replayTLI)));
8947 : :
8948 : 43 : RecoveryRestartPoint(&checkPoint, record);
8949 : :
8950 : : /*
8951 : : * After replaying a checkpoint record, free all smgr objects.
8952 : : * Otherwise we would never do so for dropped relations, as the
8953 : : * startup does not process shared invalidation messages or call
8954 : : * AtEOXact_SMgr().
8955 : : */
8956 : 43 : smgrdestroyall();
8957 : : }
8958 [ + + ]: 117300 : else if (info == XLOG_CHECKPOINT_ONLINE)
8959 : : {
8960 : : CheckPoint checkPoint;
8961 : : TimeLineID replayTLI;
8962 : :
8963 : 712 : memcpy(&checkPoint, XLogRecGetData(record), sizeof(CheckPoint));
8964 : : /* In an ONLINE checkpoint, treat the XID counter as a minimum */
8965 : 712 : LWLockAcquire(XidGenLock, LW_EXCLUSIVE);
8966 [ - + ]: 712 : if (FullTransactionIdPrecedes(TransamVariables->nextXid,
8967 : : checkPoint.nextXid))
8968 : 0 : TransamVariables->nextXid = checkPoint.nextXid;
8969 : 712 : LWLockRelease(XidGenLock);
8970 : :
8971 : : /*
8972 : : * We ignore the nextOid counter in an ONLINE checkpoint, preferring
8973 : : * to track OID assignment through XLOG_NEXTOID records. The nextOid
8974 : : * counter is from the start of the checkpoint and might well be stale
8975 : : * compared to later XLOG_NEXTOID records. We could try to take the
8976 : : * maximum of the nextOid counter and our latest value, but since
8977 : : * there's no particular guarantee about the speed with which the OID
8978 : : * counter wraps around, that's a risky thing to do. In any case,
8979 : : * users of the nextOid counter are required to avoid assignment of
8980 : : * duplicates, so that a somewhat out-of-date value should be safe.
8981 : : */
8982 : :
8983 : : /* Handle multixact */
8984 : 712 : MultiXactAdvanceNextMXact(checkPoint.nextMulti,
8985 : : checkPoint.nextMultiOffset);
8986 : :
8987 : : /*
8988 : : * NB: This may perform multixact truncation when replaying WAL
8989 : : * generated by an older primary.
8990 : : */
8991 : 712 : MultiXactAdvanceOldest(checkPoint.oldestMulti,
8992 : : checkPoint.oldestMultiDB);
8993 [ - + ]: 712 : if (TransactionIdPrecedes(TransamVariables->oldestXid,
8994 : : checkPoint.oldestXid))
8995 : 0 : SetTransactionIdLimit(checkPoint.oldestXid,
8996 : : checkPoint.oldestXidDB);
8997 : : /* ControlFile->checkPointCopy always tracks the latest ckpt XID */
8998 : 712 : LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
8999 : 712 : ControlFile->checkPointCopy.nextXid = checkPoint.nextXid;
9000 : 712 : LWLockRelease(ControlFileLock);
9001 : :
9002 : : /* TLI should not change in an on-line checkpoint */
9003 : 712 : (void) GetCurrentReplayRecPtr(&replayTLI);
9004 [ - + ]: 712 : if (checkPoint.ThisTimeLineID != replayTLI)
9005 [ # # ]: 0 : ereport(PANIC,
9006 : : (errmsg("unexpected timeline ID %u (should be %u) in online checkpoint record",
9007 : : checkPoint.ThisTimeLineID, replayTLI)));
9008 : :
9009 : 712 : RecoveryRestartPoint(&checkPoint, record);
9010 : :
9011 : : /*
9012 : : * After replaying a checkpoint record, free all smgr objects.
9013 : : * Otherwise we would never do so for dropped relations, as the
9014 : : * startup does not process shared invalidation messages or call
9015 : : * AtEOXact_SMgr().
9016 : : */
9017 : 712 : smgrdestroyall();
9018 : : }
9019 [ + + ]: 116588 : else if (info == XLOG_OVERWRITE_CONTRECORD)
9020 : : {
9021 : : /* nothing to do here, handled in xlogrecovery_redo() */
9022 : : }
9023 [ + + ]: 116587 : else if (info == XLOG_END_OF_RECOVERY)
9024 : : {
9025 : : xl_end_of_recovery xlrec;
9026 : : TimeLineID replayTLI;
9027 : :
9028 : 13 : memcpy(&xlrec, XLogRecGetData(record), sizeof(xl_end_of_recovery));
9029 : :
9030 : : /*
9031 : : * For Hot Standby, we could treat this like a Shutdown Checkpoint,
9032 : : * but this case is rarer and harder to test, so the benefit doesn't
9033 : : * outweigh the potential extra cost of maintenance.
9034 : : */
9035 : :
9036 : : /*
9037 : : * We should've already switched to the new TLI before replaying this
9038 : : * record.
9039 : : */
9040 : 13 : (void) GetCurrentReplayRecPtr(&replayTLI);
9041 [ - + ]: 13 : if (xlrec.ThisTimeLineID != replayTLI)
9042 [ # # ]: 0 : ereport(PANIC,
9043 : : (errmsg("unexpected timeline ID %u (should be %u) in end-of-recovery record",
9044 : : xlrec.ThisTimeLineID, replayTLI)));
9045 : : }
9046 [ + - ]: 116574 : else if (info == XLOG_NOOP)
9047 : : {
9048 : : /* nothing to do here */
9049 : : }
9050 [ + + ]: 116574 : else if (info == XLOG_SWITCH)
9051 : : {
9052 : : /* nothing to do here */
9053 : : }
9054 [ + + ]: 116107 : else if (info == XLOG_RESTORE_POINT)
9055 : : {
9056 : : /* nothing to do here, handled in xlogrecovery.c */
9057 : : }
9058 [ + + ]: 116102 : else if (info == XLOG_ASSIGN_LSN)
9059 : : {
9060 : : /* nothing to do here, see XLogGetFakeLSN() */
9061 : : }
9062 [ + + + + ]: 53775 : else if (info == XLOG_FPI || info == XLOG_FPI_FOR_HINT)
9063 : : {
9064 : : /*
9065 : : * XLOG_FPI records contain nothing else but one or more block
9066 : : * references. Every block reference must include a full-page image
9067 : : * even if full_page_writes was disabled when the record was generated
9068 : : * - otherwise there would be no point in this record.
9069 : : *
9070 : : * XLOG_FPI_FOR_HINT records are generated when a page needs to be
9071 : : * WAL-logged because of a hint bit update. They are only generated
9072 : : * when checksums and/or wal_log_hints are enabled. They may include
9073 : : * no full-page images if full_page_writes was disabled when they were
9074 : : * generated. In this case there is nothing to do here.
9075 : : *
9076 : : * No recovery conflicts are generated by these generic records - if a
9077 : : * resource manager needs to generate conflicts, it has to define a
9078 : : * separate WAL record type and redo routine.
9079 : : */
9080 [ + + ]: 110692 : for (uint8 block_id = 0; block_id <= XLogRecMaxBlockId(record); block_id++)
9081 : : {
9082 : : Buffer buffer;
9083 : :
9084 [ + + ]: 57790 : if (!XLogRecHasBlockImage(record, block_id))
9085 : : {
9086 [ - + ]: 66 : if (info == XLOG_FPI)
9087 [ # # ]: 0 : elog(ERROR, "XLOG_FPI record did not contain a full-page image");
9088 : 66 : continue;
9089 : : }
9090 : :
9091 [ - + ]: 57724 : if (XLogReadBufferForRedo(record, block_id, &buffer) != BLK_RESTORED)
9092 [ # # ]: 0 : elog(ERROR, "unexpected XLogReadBufferForRedo result when restoring backup block");
9093 : 57724 : UnlockReleaseBuffer(buffer);
9094 : : }
9095 : : }
9096 [ + + ]: 873 : else if (info == XLOG_BACKUP_END)
9097 : : {
9098 : : /* nothing to do here, handled in xlogrecovery_redo() */
9099 : : }
9100 [ + + ]: 770 : else if (info == XLOG_PARAMETER_CHANGE)
9101 : : {
9102 : : xl_parameter_change xlrec;
9103 : :
9104 : : /* Update our copy of the parameters in pg_control */
9105 : 38 : memcpy(&xlrec, XLogRecGetData(record), sizeof(xl_parameter_change));
9106 : :
9107 : 38 : LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
9108 : 38 : ControlFile->MaxConnections = xlrec.MaxConnections;
9109 : 38 : ControlFile->max_worker_processes = xlrec.max_worker_processes;
9110 : 38 : ControlFile->max_wal_senders = xlrec.max_wal_senders;
9111 : 38 : ControlFile->max_prepared_xacts = xlrec.max_prepared_xacts;
9112 : 38 : ControlFile->max_locks_per_xact = xlrec.max_locks_per_xact;
9113 : 38 : ControlFile->wal_level = xlrec.wal_level;
9114 : 38 : ControlFile->wal_log_hints = xlrec.wal_log_hints;
9115 : :
9116 : : /*
9117 : : * Update minRecoveryPoint to ensure that if recovery is aborted, we
9118 : : * recover back up to this point before allowing hot standby again.
9119 : : * This is important if the max_* settings are decreased, to ensure
9120 : : * you don't run queries against the WAL preceding the change. The
9121 : : * local copies cannot be updated as long as crash recovery is
9122 : : * happening and we expect all the WAL to be replayed.
9123 : : */
9124 [ + + ]: 38 : if (InArchiveRecovery)
9125 : : {
9126 : 23 : LocalMinRecoveryPoint = ControlFile->minRecoveryPoint;
9127 : 23 : LocalMinRecoveryPointTLI = ControlFile->minRecoveryPointTLI;
9128 : : }
9129 [ + + + + ]: 38 : if (XLogRecPtrIsValid(LocalMinRecoveryPoint) && LocalMinRecoveryPoint < lsn)
9130 : : {
9131 : : TimeLineID replayTLI;
9132 : :
9133 : 12 : (void) GetCurrentReplayRecPtr(&replayTLI);
9134 : 12 : ControlFile->minRecoveryPoint = lsn;
9135 : 12 : ControlFile->minRecoveryPointTLI = replayTLI;
9136 : : }
9137 : :
9138 : 38 : CommitTsParameterChange(xlrec.track_commit_timestamp,
9139 : 38 : ControlFile->track_commit_timestamp);
9140 : 38 : ControlFile->track_commit_timestamp = xlrec.track_commit_timestamp;
9141 : :
9142 : 38 : UpdateControlFile();
9143 : 38 : LWLockRelease(ControlFileLock);
9144 : :
9145 : : /* Check to see if any parameter change gives a problem on recovery */
9146 : 38 : CheckRequiredParameterValues();
9147 : : }
9148 [ - + ]: 732 : else if (info == XLOG_FPW_CHANGE)
9149 : : {
9150 : : bool fpw;
9151 : :
9152 : 0 : memcpy(&fpw, XLogRecGetData(record), sizeof(bool));
9153 : :
9154 : : /*
9155 : : * Update the LSN of the last replayed XLOG_FPW_CHANGE record so that
9156 : : * do_pg_backup_start() and do_pg_backup_stop() can check whether
9157 : : * full_page_writes has been disabled during online backup.
9158 : : */
9159 [ # # ]: 0 : if (!fpw)
9160 : : {
9161 : 0 : SpinLockAcquire(&XLogCtl->info_lck);
9162 [ # # ]: 0 : if (XLogCtl->lastFpwDisableRecPtr < record->ReadRecPtr)
9163 : 0 : XLogCtl->lastFpwDisableRecPtr = record->ReadRecPtr;
9164 : 0 : SpinLockRelease(&XLogCtl->info_lck);
9165 : : }
9166 : :
9167 : : /* Keep track of full_page_writes */
9168 : 0 : lastFullPageWrites = fpw;
9169 : : }
9170 [ + + ]: 732 : else if (info == XLOG_CHECKPOINT_REDO)
9171 : : {
9172 : : xl_checkpoint_redo redo_rec;
9173 : 714 : bool new_state = false;
9174 : :
9175 : 714 : memcpy(&redo_rec, XLogRecGetData(record), sizeof(xl_checkpoint_redo));
9176 : :
9177 : 714 : SpinLockAcquire(&XLogCtl->info_lck);
9178 : 714 : XLogCtl->data_checksum_version = redo_rec.data_checksum_version;
9179 : 714 : SetLocalDataChecksumState(redo_rec.data_checksum_version);
9180 [ - + ]: 714 : if (redo_rec.data_checksum_version != ControlFile->data_checksum_version)
9181 : 0 : new_state = true;
9182 : 714 : SpinLockRelease(&XLogCtl->info_lck);
9183 : :
9184 [ - + ]: 714 : if (new_state)
9185 : 0 : EmitAndWaitDataChecksumsBarrier(redo_rec.data_checksum_version);
9186 : : }
9187 [ + - ]: 18 : else if (info == XLOG_LOGICAL_DECODING_STATUS_CHANGE)
9188 : : {
9189 : : bool status;
9190 : :
9191 : 18 : memcpy(&status, XLogRecGetData(record), sizeof(bool));
9192 : :
9193 : : /*
9194 : : * We need to toggle the logical decoding status and update the
9195 : : * XLogLogicalInfo cache of processes synchronously because
9196 : : * XLogLogicalInfoActive() is used even during read-only queries
9197 : : * (e.g., via RelationIsAccessibleInLogicalDecoding()). In the
9198 : : * 'disable' case, it is safe to invalidate existing slots after
9199 : : * disabling logical decoding because logical decoding cannot process
9200 : : * subsequent WAL records, which may not contain logical information.
9201 : : */
9202 [ + + ]: 18 : if (status)
9203 : 9 : EnableLogicalDecoding();
9204 : : else
9205 : 9 : DisableLogicalDecoding();
9206 : :
9207 [ + + ]: 18 : elog(DEBUG1, "update logical decoding status to %d during recovery",
9208 : : status);
9209 : :
9210 [ + - + + ]: 18 : if (InRecovery && InHotStandby)
9211 : : {
9212 [ + + ]: 16 : if (!status)
9213 : : {
9214 : : /*
9215 : : * Invalidate logical slots if we are in hot standby and the
9216 : : * primary disabled logical decoding.
9217 : : */
9218 : 9 : InvalidateObsoleteReplicationSlots(RS_INVAL_WAL_LEVEL,
9219 : : 0, InvalidOid,
9220 : : InvalidTransactionId);
9221 : : }
9222 [ - + ]: 7 : else if (sync_replication_slots)
9223 : : {
9224 : : /*
9225 : : * Signal the postmaster to launch the slotsync worker.
9226 : : *
9227 : : * XXX: For simplicity, we keep the slotsync worker running
9228 : : * even after logical decoding is disabled. A future
9229 : : * improvement can consider starting and stopping the worker
9230 : : * based on logical decoding status change.
9231 : : */
9232 : 0 : kill(PostmasterPid, SIGUSR1);
9233 : : }
9234 : : }
9235 : : }
9236 : 117441 : }
9237 : :
9238 : : void
9239 : 7 : xlog2_redo(XLogReaderState *record)
9240 : : {
9241 : 7 : uint8 info = XLogRecGetInfo(record) & ~XLR_INFO_MASK;
9242 : :
9243 [ + - ]: 7 : if (info == XLOG2_CHECKSUMS)
9244 : : {
9245 : : xl_checksum_state state;
9246 : :
9247 : 7 : memcpy(&state, XLogRecGetData(record), sizeof(xl_checksum_state));
9248 : :
9249 : 7 : SpinLockAcquire(&XLogCtl->info_lck);
9250 : 7 : XLogCtl->data_checksum_version = state.new_checksum_state;
9251 : 7 : SpinLockRelease(&XLogCtl->info_lck);
9252 : :
9253 : 7 : LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
9254 : 7 : ControlFile->data_checksum_version = state.new_checksum_state;
9255 : 7 : UpdateControlFile();
9256 : 7 : LWLockRelease(ControlFileLock);
9257 : :
9258 : : /*
9259 : : * Block on a procsignalbarrier to await all processes having seen the
9260 : : * change to checksum status. Once the barrier has been passed we can
9261 : : * initiate the corresponding processing.
9262 : : */
9263 : 7 : EmitAndWaitDataChecksumsBarrier(state.new_checksum_state);
9264 : : }
9265 : 7 : }
9266 : :
9267 : : /*
9268 : : * Return the extra open flags used for opening a file, depending on the
9269 : : * value of the GUCs wal_sync_method, fsync and debug_io_direct.
9270 : : */
9271 : : static int
9272 : 17895 : get_sync_bit(int method)
9273 : : {
9274 : 17895 : int o_direct_flag = 0;
9275 : :
9276 : : /*
9277 : : * Use O_DIRECT if requested, except in walreceiver process. The WAL
9278 : : * written by walreceiver is normally read by the startup process soon
9279 : : * after it's written. Also, walreceiver performs unaligned writes, which
9280 : : * don't work with O_DIRECT, so it is required for correctness too.
9281 : : */
9282 [ + + + - ]: 17895 : if ((io_direct_flags & IO_DIRECT_WAL) && !AmWalReceiverProcess())
9283 : 7 : o_direct_flag = PG_O_DIRECT;
9284 : :
9285 : : /* If fsync is disabled, never open in sync mode */
9286 [ + - ]: 17895 : if (!enableFsync)
9287 : 17895 : return o_direct_flag;
9288 : :
9289 [ # # # # ]: 0 : switch (method)
9290 : : {
9291 : : /*
9292 : : * enum values for all sync options are defined even if they are
9293 : : * not supported on the current platform. But if not, they are
9294 : : * not included in the enum option array, and therefore will never
9295 : : * be seen here.
9296 : : */
9297 : 0 : case WAL_SYNC_METHOD_FSYNC:
9298 : : case WAL_SYNC_METHOD_FSYNC_WRITETHROUGH:
9299 : : case WAL_SYNC_METHOD_FDATASYNC:
9300 : 0 : return o_direct_flag;
9301 : : #ifdef O_SYNC
9302 : 0 : case WAL_SYNC_METHOD_OPEN:
9303 : 0 : return O_SYNC | o_direct_flag;
9304 : : #endif
9305 : : #ifdef O_DSYNC
9306 : 0 : case WAL_SYNC_METHOD_OPEN_DSYNC:
9307 : 0 : return O_DSYNC | o_direct_flag;
9308 : : #endif
9309 : 0 : default:
9310 : : /* can't happen (unless we are out of sync with option array) */
9311 [ # # ]: 0 : elog(ERROR, "unrecognized \"wal_sync_method\": %d", method);
9312 : : return 0; /* silence warning */
9313 : : }
9314 : : }
9315 : :
9316 : : /*
9317 : : * GUC support
9318 : : */
9319 : : void
9320 : 1291 : assign_wal_sync_method(int new_wal_sync_method, void *extra)
9321 : : {
9322 [ - + ]: 1291 : if (wal_sync_method != new_wal_sync_method)
9323 : : {
9324 : : /*
9325 : : * To ensure that no blocks escape unsynced, force an fsync on the
9326 : : * currently open log segment (if any). Also, if the open flag is
9327 : : * changing, close the log file so it will be reopened (with new flag
9328 : : * bit) at next use.
9329 : : */
9330 [ # # ]: 0 : if (openLogFile >= 0)
9331 : : {
9332 : 0 : pgstat_report_wait_start(WAIT_EVENT_WAL_SYNC_METHOD_ASSIGN);
9333 [ # # ]: 0 : if (pg_fsync(openLogFile) != 0)
9334 : : {
9335 : : char xlogfname[MAXFNAMELEN];
9336 : : int save_errno;
9337 : :
9338 : 0 : save_errno = errno;
9339 : 0 : XLogFileName(xlogfname, openLogTLI, openLogSegNo,
9340 : : wal_segment_size);
9341 : 0 : errno = save_errno;
9342 [ # # ]: 0 : ereport(PANIC,
9343 : : (errcode_for_file_access(),
9344 : : errmsg("could not fsync file \"%s\": %m", xlogfname)));
9345 : : }
9346 : :
9347 : 0 : pgstat_report_wait_end();
9348 [ # # ]: 0 : if (get_sync_bit(wal_sync_method) != get_sync_bit(new_wal_sync_method))
9349 : 0 : XLogFileClose();
9350 : : }
9351 : : }
9352 : 1291 : }
9353 : :
9354 : :
9355 : : /*
9356 : : * Issue appropriate kind of fsync (if any) for an XLOG output file.
9357 : : *
9358 : : * 'fd' is a file descriptor for the XLOG file to be fsync'd.
9359 : : * 'segno' is for error reporting purposes.
9360 : : */
9361 : : void
9362 : 217376 : issue_xlog_fsync(int fd, XLogSegNo segno, TimeLineID tli)
9363 : : {
9364 : 217376 : char *msg = NULL;
9365 : : instr_time start;
9366 : :
9367 : : Assert(tli != 0);
9368 : :
9369 : : /*
9370 : : * Quick exit if fsync is disabled or write() has already synced the WAL
9371 : : * file.
9372 : : */
9373 [ - + ]: 217376 : if (!enableFsync ||
9374 [ # # ]: 0 : wal_sync_method == WAL_SYNC_METHOD_OPEN ||
9375 [ # # ]: 0 : wal_sync_method == WAL_SYNC_METHOD_OPEN_DSYNC)
9376 : 217376 : return;
9377 : :
9378 : : /*
9379 : : * Measure I/O timing to sync the WAL file for pg_stat_io.
9380 : : */
9381 : 0 : start = pgstat_prepare_io_time(track_wal_io_timing);
9382 : :
9383 : 0 : pgstat_report_wait_start(WAIT_EVENT_WAL_SYNC);
9384 [ # # # # ]: 0 : switch (wal_sync_method)
9385 : : {
9386 : 0 : case WAL_SYNC_METHOD_FSYNC:
9387 [ # # ]: 0 : if (pg_fsync_no_writethrough(fd) != 0)
9388 : 0 : msg = _("could not fsync file \"%s\": %m");
9389 : 0 : break;
9390 : : #ifdef HAVE_FSYNC_WRITETHROUGH
9391 : : case WAL_SYNC_METHOD_FSYNC_WRITETHROUGH:
9392 : : if (pg_fsync_writethrough(fd) != 0)
9393 : : msg = _("could not fsync write-through file \"%s\": %m");
9394 : : break;
9395 : : #endif
9396 : 0 : case WAL_SYNC_METHOD_FDATASYNC:
9397 [ # # ]: 0 : if (pg_fdatasync(fd) != 0)
9398 : 0 : msg = _("could not fdatasync file \"%s\": %m");
9399 : 0 : break;
9400 : 0 : case WAL_SYNC_METHOD_OPEN:
9401 : : case WAL_SYNC_METHOD_OPEN_DSYNC:
9402 : : /* not reachable */
9403 : : Assert(false);
9404 : 0 : break;
9405 : 0 : default:
9406 [ # # ]: 0 : ereport(PANIC,
9407 : : errcode(ERRCODE_INVALID_PARAMETER_VALUE),
9408 : : errmsg_internal("unrecognized \"wal_sync_method\": %d", wal_sync_method));
9409 : : break;
9410 : : }
9411 : :
9412 : : /* PANIC if failed to fsync */
9413 [ # # ]: 0 : if (msg)
9414 : : {
9415 : : char xlogfname[MAXFNAMELEN];
9416 : 0 : int save_errno = errno;
9417 : :
9418 : 0 : XLogFileName(xlogfname, tli, segno, wal_segment_size);
9419 : 0 : errno = save_errno;
9420 [ # # ]: 0 : ereport(PANIC,
9421 : : (errcode_for_file_access(),
9422 : : errmsg(msg, xlogfname)));
9423 : : }
9424 : :
9425 : 0 : pgstat_report_wait_end();
9426 : :
9427 : 0 : pgstat_count_io_op_time(IOOBJECT_WAL, IOCONTEXT_NORMAL, IOOP_FSYNC,
9428 : : start, 1, 0);
9429 : : }
9430 : :
9431 : : /*
9432 : : * do_pg_backup_start is the workhorse of the user-visible pg_backup_start()
9433 : : * function. It creates the necessary starting checkpoint and constructs the
9434 : : * backup state and tablespace map.
9435 : : *
9436 : : * Input parameters are "state" (the backup state), "fast" (if true, we do
9437 : : * the checkpoint in fast mode), and "tablespaces" (if non-NULL, indicates a
9438 : : * list of tablespaceinfo structs describing the cluster's tablespaces.).
9439 : : *
9440 : : * The tablespace map contents are appended to passed-in parameter
9441 : : * tablespace_map and the caller is responsible for including it in the backup
9442 : : * archive as 'tablespace_map'. The tablespace_map file is required mainly for
9443 : : * tar format in windows as native windows utilities are not able to create
9444 : : * symlinks while extracting files from tar. However for consistency and
9445 : : * platform-independence, we do it the same way everywhere.
9446 : : *
9447 : : * It fills in "state" with the information required for the backup, such
9448 : : * as the minimum WAL location that must be present to restore from this
9449 : : * backup (starttli) and the corresponding timeline ID (starttli).
9450 : : *
9451 : : * Every successfully started backup must be stopped by calling
9452 : : * do_pg_backup_stop() or do_pg_abort_backup(). There can be many
9453 : : * backups active at the same time.
9454 : : *
9455 : : * It is the responsibility of the caller of this function to verify the
9456 : : * permissions of the calling user!
9457 : : */
9458 : : void
9459 : 178 : do_pg_backup_start(const char *backupidstr, bool fast, List **tablespaces,
9460 : : BackupState *state, StringInfo tblspcmapfile)
9461 : : {
9462 : : bool backup_started_in_recovery;
9463 : :
9464 : : Assert(state != NULL);
9465 : 178 : backup_started_in_recovery = RecoveryInProgress();
9466 : :
9467 : : /*
9468 : : * During recovery, we don't need to check WAL level. Because, if WAL
9469 : : * level is not sufficient, it's impossible to get here during recovery.
9470 : : */
9471 [ + + - + ]: 178 : if (!backup_started_in_recovery && !XLogIsNeeded())
9472 [ # # ]: 0 : ereport(ERROR,
9473 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
9474 : : errmsg("WAL level not sufficient for making an online backup"),
9475 : : errhint("\"wal_level\" must be set to \"replica\" or \"logical\" at server start.")));
9476 : :
9477 [ + + ]: 178 : if (strlen(backupidstr) > MAXPGPATH)
9478 [ + - ]: 1 : ereport(ERROR,
9479 : : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
9480 : : errmsg("backup label too long (max %d bytes)",
9481 : : MAXPGPATH)));
9482 : :
9483 : 177 : strlcpy(state->name, backupidstr, sizeof(state->name));
9484 : :
9485 : : /*
9486 : : * Mark backup active in shared memory. We must do full-page WAL writes
9487 : : * during an on-line backup even if not doing so at other times, because
9488 : : * it's quite possible for the backup dump to obtain a "torn" (partially
9489 : : * written) copy of a database page if it reads the page concurrently with
9490 : : * our write to the same page. This can be fixed as long as the first
9491 : : * write to the page in the WAL sequence is a full-page write. Hence, we
9492 : : * increment runningBackups then force a CHECKPOINT, to ensure there are
9493 : : * no dirty pages in shared memory that might get dumped while the backup
9494 : : * is in progress without having a corresponding WAL record. (Once the
9495 : : * backup is complete, we need not force full-page writes anymore, since
9496 : : * we expect that any pages not modified during the backup interval must
9497 : : * have been correctly captured by the backup.)
9498 : : *
9499 : : * Note that forcing full-page writes has no effect during an online
9500 : : * backup from the standby.
9501 : : *
9502 : : * We must hold all the insertion locks to change the value of
9503 : : * runningBackups, to ensure adequate interlocking against
9504 : : * XLogInsertRecord().
9505 : : */
9506 : 177 : WALInsertLockAcquireExclusive();
9507 : 177 : XLogCtl->Insert.runningBackups++;
9508 : 177 : WALInsertLockRelease();
9509 : :
9510 : : /*
9511 : : * Ensure we decrement runningBackups if we fail below. NB -- for this to
9512 : : * work correctly, it is critical that sessionBackupState is only updated
9513 : : * after this block is over.
9514 : : */
9515 [ + - ]: 177 : PG_ENSURE_ERROR_CLEANUP(do_pg_abort_backup, BoolGetDatum(true));
9516 : : {
9517 : 177 : bool gotUniqueStartpoint = false;
9518 : : DIR *tblspcdir;
9519 : : struct dirent *de;
9520 : : tablespaceinfo *ti;
9521 : : int datadirpathlen;
9522 : :
9523 : : /*
9524 : : * Force an XLOG file switch before the checkpoint, to ensure that the
9525 : : * WAL segment the checkpoint is written to doesn't contain pages with
9526 : : * old timeline IDs. That would otherwise happen if you called
9527 : : * pg_backup_start() right after restoring from a PITR archive: the
9528 : : * first WAL segment containing the startup checkpoint has pages in
9529 : : * the beginning with the old timeline ID. That can cause trouble at
9530 : : * recovery: we won't have a history file covering the old timeline if
9531 : : * pg_wal directory was not included in the base backup and the WAL
9532 : : * archive was cleared too before starting the backup.
9533 : : *
9534 : : * During recovery, we skip forcing XLOG file switch, which means that
9535 : : * the backup taken during recovery is not available for the special
9536 : : * recovery case described above.
9537 : : */
9538 [ + + ]: 177 : if (!backup_started_in_recovery)
9539 : 168 : RequestXLogSwitch(false);
9540 : :
9541 : : do
9542 : : {
9543 : : bool checkpointfpw;
9544 : :
9545 : : /*
9546 : : * Force a CHECKPOINT. Aside from being necessary to prevent torn
9547 : : * page problems, this guarantees that two successive backup runs
9548 : : * will have different checkpoint positions and hence different
9549 : : * history file names, even if nothing happened in between.
9550 : : *
9551 : : * During recovery, establish a restartpoint if possible. We use
9552 : : * the last restartpoint as the backup starting checkpoint. This
9553 : : * means that two successive backup runs can have same checkpoint
9554 : : * positions.
9555 : : *
9556 : : * Since the fact that we are executing do_pg_backup_start()
9557 : : * during recovery means that checkpointer is running, we can use
9558 : : * RequestCheckpoint() to establish a restartpoint.
9559 : : *
9560 : : * We use CHECKPOINT_FAST only if requested by user (via passing
9561 : : * fast = true). Otherwise this can take awhile.
9562 : : */
9563 [ + + ]: 177 : RequestCheckpoint(CHECKPOINT_FORCE | CHECKPOINT_WAIT |
9564 : : (fast ? CHECKPOINT_FAST : 0));
9565 : :
9566 : : /*
9567 : : * Now we need to fetch the checkpoint record location, and also
9568 : : * its REDO pointer. The oldest point in WAL that would be needed
9569 : : * to restore starting from the checkpoint is precisely the REDO
9570 : : * pointer.
9571 : : */
9572 : 177 : LWLockAcquire(ControlFileLock, LW_SHARED);
9573 : 177 : state->checkpointloc = ControlFile->checkPoint;
9574 : 177 : state->startpoint = ControlFile->checkPointCopy.redo;
9575 : 177 : state->starttli = ControlFile->checkPointCopy.ThisTimeLineID;
9576 : 177 : checkpointfpw = ControlFile->checkPointCopy.fullPageWrites;
9577 : 177 : LWLockRelease(ControlFileLock);
9578 : :
9579 [ + + ]: 177 : if (backup_started_in_recovery)
9580 : : {
9581 : : XLogRecPtr recptr;
9582 : :
9583 : : /*
9584 : : * Check to see if all WAL replayed during online backup
9585 : : * (i.e., since last restartpoint used as backup starting
9586 : : * checkpoint) contain full-page writes.
9587 : : */
9588 : 9 : SpinLockAcquire(&XLogCtl->info_lck);
9589 : 9 : recptr = XLogCtl->lastFpwDisableRecPtr;
9590 : 9 : SpinLockRelease(&XLogCtl->info_lck);
9591 : :
9592 [ + - - + ]: 9 : if (!checkpointfpw || state->startpoint <= recptr)
9593 [ # # ]: 0 : ereport(ERROR,
9594 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
9595 : : errmsg("WAL generated with \"full_page_writes=off\" was replayed "
9596 : : "since last restartpoint"),
9597 : : errhint("This means that the backup being taken on the standby "
9598 : : "is corrupt and should not be used. "
9599 : : "Enable \"full_page_writes\" and run CHECKPOINT on the primary, "
9600 : : "and then try an online backup again.")));
9601 : :
9602 : : /*
9603 : : * During recovery, since we don't use the end-of-backup WAL
9604 : : * record and don't write the backup history file, the
9605 : : * starting WAL location doesn't need to be unique. This means
9606 : : * that two base backups started at the same time might use
9607 : : * the same checkpoint as starting locations.
9608 : : */
9609 : 9 : gotUniqueStartpoint = true;
9610 : : }
9611 : :
9612 : : /*
9613 : : * If two base backups are started at the same time (in WAL sender
9614 : : * processes), we need to make sure that they use different
9615 : : * checkpoints as starting locations, because we use the starting
9616 : : * WAL location as a unique identifier for the base backup in the
9617 : : * end-of-backup WAL record and when we write the backup history
9618 : : * file. Perhaps it would be better generate a separate unique ID
9619 : : * for each backup instead of forcing another checkpoint, but
9620 : : * taking a checkpoint right after another is not that expensive
9621 : : * either because only few buffers have been dirtied yet.
9622 : : */
9623 : 177 : WALInsertLockAcquireExclusive();
9624 [ + - ]: 177 : if (XLogCtl->Insert.lastBackupStart < state->startpoint)
9625 : : {
9626 : 177 : XLogCtl->Insert.lastBackupStart = state->startpoint;
9627 : 177 : gotUniqueStartpoint = true;
9628 : : }
9629 : 177 : WALInsertLockRelease();
9630 [ - + ]: 177 : } while (!gotUniqueStartpoint);
9631 : :
9632 : : /*
9633 : : * Construct tablespace_map file.
9634 : : */
9635 : 177 : datadirpathlen = strlen(DataDir);
9636 : :
9637 : : /* Collect information about all tablespaces */
9638 : 177 : tblspcdir = AllocateDir(PG_TBLSPC_DIR);
9639 [ + + ]: 568 : while ((de = ReadDir(tblspcdir, PG_TBLSPC_DIR)) != NULL)
9640 : : {
9641 : : char fullpath[MAXPGPATH + sizeof(PG_TBLSPC_DIR)];
9642 : : char linkpath[MAXPGPATH];
9643 : 391 : char *relpath = NULL;
9644 : : char *s;
9645 : : PGFileType de_type;
9646 : : char *badp;
9647 : : Oid tsoid;
9648 : :
9649 : : /*
9650 : : * Try to parse the directory name as an unsigned integer.
9651 : : *
9652 : : * Tablespace directories should be positive integers that can be
9653 : : * represented in 32 bits, with no leading zeroes or trailing
9654 : : * garbage. If we come across a name that doesn't meet those
9655 : : * criteria, skip it.
9656 : : */
9657 [ + + - + ]: 391 : if (de->d_name[0] < '1' || de->d_name[1] > '9')
9658 : 354 : continue;
9659 : 37 : errno = 0;
9660 : 37 : tsoid = strtoul(de->d_name, &badp, 10);
9661 [ + - + - : 37 : if (*badp != '\0' || errno == EINVAL || errno == ERANGE)
- + ]
9662 : 0 : continue;
9663 : :
9664 : 37 : snprintf(fullpath, sizeof(fullpath), "%s/%s", PG_TBLSPC_DIR, de->d_name);
9665 : :
9666 : 37 : de_type = get_dirent_type(fullpath, de, false, ERROR);
9667 : :
9668 [ + + ]: 37 : if (de_type == PGFILETYPE_LNK)
9669 : : {
9670 : : StringInfoData escapedpath;
9671 : : int rllen;
9672 : :
9673 : 23 : rllen = readlink(fullpath, linkpath, sizeof(linkpath));
9674 [ - + ]: 23 : if (rllen < 0)
9675 : : {
9676 [ # # ]: 0 : ereport(WARNING,
9677 : : (errmsg("could not read symbolic link \"%s\": %m",
9678 : : fullpath)));
9679 : 0 : continue;
9680 : : }
9681 [ - + ]: 23 : else if (rllen >= sizeof(linkpath))
9682 : : {
9683 [ # # ]: 0 : ereport(WARNING,
9684 : : (errmsg("symbolic link \"%s\" target is too long",
9685 : : fullpath)));
9686 : 0 : continue;
9687 : : }
9688 : 23 : linkpath[rllen] = '\0';
9689 : :
9690 : : /*
9691 : : * Relpath holds the relative path of the tablespace directory
9692 : : * when it's located within PGDATA, or NULL if it's located
9693 : : * elsewhere.
9694 : : */
9695 [ + + ]: 23 : if (rllen > datadirpathlen &&
9696 [ - + ]: 1 : strncmp(linkpath, DataDir, datadirpathlen) == 0 &&
9697 [ # # ]: 0 : IS_DIR_SEP(linkpath[datadirpathlen]))
9698 : 0 : relpath = pstrdup(linkpath + datadirpathlen + 1);
9699 : :
9700 : : /*
9701 : : * Add a backslash-escaped version of the link path to the
9702 : : * tablespace map file.
9703 : : */
9704 : 23 : initStringInfo(&escapedpath);
9705 [ + + ]: 562 : for (s = linkpath; *s; s++)
9706 : : {
9707 [ + - + - : 539 : if (*s == '\n' || *s == '\r' || *s == '\\')
- + ]
9708 : 0 : appendStringInfoChar(&escapedpath, '\\');
9709 : 539 : appendStringInfoChar(&escapedpath, *s);
9710 : : }
9711 : 23 : appendStringInfo(tblspcmapfile, "%s %s\n",
9712 : 23 : de->d_name, escapedpath.data);
9713 : 23 : pfree(escapedpath.data);
9714 : : }
9715 [ + - ]: 14 : else if (de_type == PGFILETYPE_DIR)
9716 : : {
9717 : : /*
9718 : : * It's possible to use allow_in_place_tablespaces to create
9719 : : * directories directly under pg_tblspc, for testing purposes
9720 : : * only.
9721 : : *
9722 : : * In this case, we store a relative path rather than an
9723 : : * absolute path into the tablespaceinfo.
9724 : : */
9725 : 14 : snprintf(linkpath, sizeof(linkpath), "%s/%s",
9726 : 14 : PG_TBLSPC_DIR, de->d_name);
9727 : 14 : relpath = pstrdup(linkpath);
9728 : : }
9729 : : else
9730 : : {
9731 : : /* Skip any other file type that appears here. */
9732 : 0 : continue;
9733 : : }
9734 : :
9735 : 37 : ti = palloc_object(tablespaceinfo);
9736 : 37 : ti->oid = tsoid;
9737 : 37 : ti->path = pstrdup(linkpath);
9738 : 37 : ti->rpath = relpath;
9739 : 37 : ti->size = -1;
9740 : :
9741 [ + - ]: 37 : if (tablespaces)
9742 : 37 : *tablespaces = lappend(*tablespaces, ti);
9743 : : }
9744 : 177 : FreeDir(tblspcdir);
9745 : :
9746 : 177 : state->starttime = (pg_time_t) time(NULL);
9747 : : }
9748 [ - + ]: 177 : PG_END_ENSURE_ERROR_CLEANUP(do_pg_abort_backup, BoolGetDatum(true));
9749 : :
9750 : 177 : state->started_in_recovery = backup_started_in_recovery;
9751 : :
9752 : : /*
9753 : : * Mark that the start phase has correctly finished for the backup.
9754 : : */
9755 : 177 : sessionBackupState = SESSION_BACKUP_RUNNING;
9756 : 177 : }
9757 : :
9758 : : /*
9759 : : * Utility routine to fetch the session-level status of a backup running.
9760 : : */
9761 : : SessionBackupState
9762 : 198 : get_backup_status(void)
9763 : : {
9764 : 198 : return sessionBackupState;
9765 : : }
9766 : :
9767 : : /*
9768 : : * do_pg_backup_stop
9769 : : *
9770 : : * Utility function called at the end of an online backup. It creates history
9771 : : * file (if required), resets sessionBackupState and so on. It can optionally
9772 : : * wait for WAL segments to be archived.
9773 : : *
9774 : : * "state" is filled with the information necessary to restore from this
9775 : : * backup with its stop LSN (stoppoint), its timeline ID (stoptli), etc.
9776 : : *
9777 : : * It is the responsibility of the caller of this function to verify the
9778 : : * permissions of the calling user!
9779 : : */
9780 : : void
9781 : 171 : do_pg_backup_stop(BackupState *state, bool waitforarchive)
9782 : : {
9783 : 171 : bool backup_stopped_in_recovery = false;
9784 : : char histfilepath[MAXPGPATH];
9785 : : char lastxlogfilename[MAXFNAMELEN];
9786 : : char histfilename[MAXFNAMELEN];
9787 : : XLogSegNo _logSegNo;
9788 : : FILE *fp;
9789 : : int seconds_before_warning;
9790 : 171 : int waits = 0;
9791 : 171 : bool reported_waiting = false;
9792 : :
9793 : : Assert(state != NULL);
9794 : :
9795 : 171 : backup_stopped_in_recovery = RecoveryInProgress();
9796 : :
9797 : : /*
9798 : : * During recovery, we don't need to check WAL level. Because, if WAL
9799 : : * level is not sufficient, it's impossible to get here during recovery.
9800 : : */
9801 [ + + - + ]: 171 : if (!backup_stopped_in_recovery && !XLogIsNeeded())
9802 [ # # ]: 0 : ereport(ERROR,
9803 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
9804 : : errmsg("WAL level not sufficient for making an online backup"),
9805 : : errhint("\"wal_level\" must be set to \"replica\" or \"logical\" at server start.")));
9806 : :
9807 : : /*
9808 : : * OK to update backup counter and session-level lock.
9809 : : *
9810 : : * Note that CHECK_FOR_INTERRUPTS() must not occur while updating them,
9811 : : * otherwise they can be updated inconsistently, which might cause
9812 : : * do_pg_abort_backup() to fail.
9813 : : */
9814 : 171 : WALInsertLockAcquireExclusive();
9815 : :
9816 : : /*
9817 : : * It is expected that each do_pg_backup_start() call is matched by
9818 : : * exactly one do_pg_backup_stop() call.
9819 : : */
9820 : : Assert(XLogCtl->Insert.runningBackups > 0);
9821 : 171 : XLogCtl->Insert.runningBackups--;
9822 : :
9823 : : /*
9824 : : * Clean up session-level lock.
9825 : : *
9826 : : * You might think that WALInsertLockRelease() can be called before
9827 : : * cleaning up session-level lock because session-level lock doesn't need
9828 : : * to be protected with WAL insertion lock. But since
9829 : : * CHECK_FOR_INTERRUPTS() can occur in it, session-level lock must be
9830 : : * cleaned up before it.
9831 : : */
9832 : 171 : sessionBackupState = SESSION_BACKUP_NONE;
9833 : :
9834 : 171 : WALInsertLockRelease();
9835 : :
9836 : : /*
9837 : : * If we are taking an online backup from the standby, we confirm that the
9838 : : * standby has not been promoted during the backup.
9839 : : */
9840 [ + + - + ]: 171 : if (state->started_in_recovery && !backup_stopped_in_recovery)
9841 [ # # ]: 0 : ereport(ERROR,
9842 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
9843 : : errmsg("the standby was promoted during online backup"),
9844 : : errhint("This means that the backup being taken is corrupt "
9845 : : "and should not be used. "
9846 : : "Try taking another online backup.")));
9847 : :
9848 : : /*
9849 : : * During recovery, we don't write an end-of-backup record. We assume that
9850 : : * pg_control was backed up last and its minimum recovery point can be
9851 : : * available as the backup end location. Since we don't have an
9852 : : * end-of-backup record, we use the pg_control value to check whether
9853 : : * we've reached the end of backup when starting recovery from this
9854 : : * backup. We have no way of checking if pg_control wasn't backed up last
9855 : : * however.
9856 : : *
9857 : : * We don't force a switch to new WAL file but it is still possible to
9858 : : * wait for all the required files to be archived if waitforarchive is
9859 : : * true. This is okay if we use the backup to start a standby and fetch
9860 : : * the missing WAL using streaming replication. But in the case of an
9861 : : * archive recovery, a user should set waitforarchive to true and wait for
9862 : : * them to be archived to ensure that all the required files are
9863 : : * available.
9864 : : *
9865 : : * We return the current minimum recovery point as the backup end
9866 : : * location. Note that it can be greater than the exact backup end
9867 : : * location if the minimum recovery point is updated after the backup of
9868 : : * pg_control. This is harmless for current uses.
9869 : : *
9870 : : * XXX currently a backup history file is for informational and debug
9871 : : * purposes only. It's not essential for an online backup. Furthermore,
9872 : : * even if it's created, it will not be archived during recovery because
9873 : : * an archiver is not invoked. So it doesn't seem worthwhile to write a
9874 : : * backup history file during recovery.
9875 : : */
9876 [ + + ]: 171 : if (backup_stopped_in_recovery)
9877 : : {
9878 : : XLogRecPtr recptr;
9879 : :
9880 : : /*
9881 : : * Check to see if all WAL replayed during online backup contain
9882 : : * full-page writes.
9883 : : */
9884 : 9 : SpinLockAcquire(&XLogCtl->info_lck);
9885 : 9 : recptr = XLogCtl->lastFpwDisableRecPtr;
9886 : 9 : SpinLockRelease(&XLogCtl->info_lck);
9887 : :
9888 [ - + ]: 9 : if (state->startpoint <= recptr)
9889 [ # # ]: 0 : ereport(ERROR,
9890 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
9891 : : errmsg("WAL generated with \"full_page_writes=off\" was replayed "
9892 : : "during online backup"),
9893 : : errhint("This means that the backup being taken on the standby "
9894 : : "is corrupt and should not be used. "
9895 : : "Enable \"full_page_writes\" and run CHECKPOINT on the primary, "
9896 : : "and then try an online backup again.")));
9897 : :
9898 : :
9899 : 9 : LWLockAcquire(ControlFileLock, LW_SHARED);
9900 : 9 : state->stoppoint = ControlFile->minRecoveryPoint;
9901 : 9 : state->stoptli = ControlFile->minRecoveryPointTLI;
9902 : 9 : LWLockRelease(ControlFileLock);
9903 : : }
9904 : : else
9905 : : {
9906 : : char *history_file;
9907 : :
9908 : : /*
9909 : : * Write the backup-end xlog record
9910 : : */
9911 : 162 : XLogBeginInsert();
9912 : 162 : XLogRegisterData(&state->startpoint,
9913 : : sizeof(state->startpoint));
9914 : 162 : state->stoppoint = XLogInsert(RM_XLOG_ID, XLOG_BACKUP_END);
9915 : :
9916 : : /*
9917 : : * Given that we're not in recovery, InsertTimeLineID is set and can't
9918 : : * change, so we can read it without a lock.
9919 : : */
9920 : 162 : state->stoptli = XLogCtl->InsertTimeLineID;
9921 : :
9922 : : /*
9923 : : * Force a switch to a new xlog segment file, so that the backup is
9924 : : * valid as soon as archiver moves out the current segment file.
9925 : : */
9926 : 162 : RequestXLogSwitch(false);
9927 : :
9928 : 162 : state->stoptime = (pg_time_t) time(NULL);
9929 : :
9930 : : /*
9931 : : * Write the backup history file
9932 : : */
9933 : 162 : XLByteToSeg(state->startpoint, _logSegNo, wal_segment_size);
9934 : 162 : BackupHistoryFilePath(histfilepath, state->stoptli, _logSegNo,
9935 : : state->startpoint, wal_segment_size);
9936 : 162 : fp = AllocateFile(histfilepath, "w");
9937 [ - + ]: 162 : if (!fp)
9938 [ # # ]: 0 : ereport(ERROR,
9939 : : (errcode_for_file_access(),
9940 : : errmsg("could not create file \"%s\": %m",
9941 : : histfilepath)));
9942 : :
9943 : : /* Build and save the contents of the backup history file */
9944 : 162 : history_file = build_backup_content(state, true);
9945 : 162 : fprintf(fp, "%s", history_file);
9946 : 162 : pfree(history_file);
9947 : :
9948 [ + - + - : 162 : if (fflush(fp) || ferror(fp) || FreeFile(fp))
- + ]
9949 [ # # ]: 0 : ereport(ERROR,
9950 : : (errcode_for_file_access(),
9951 : : errmsg("could not write file \"%s\": %m",
9952 : : histfilepath)));
9953 : :
9954 : : /*
9955 : : * Clean out any no-longer-needed history files. As a side effect,
9956 : : * this will post a .ready file for the newly created history file,
9957 : : * notifying the archiver that history file may be archived
9958 : : * immediately.
9959 : : */
9960 : 162 : CleanupBackupHistory();
9961 : : }
9962 : :
9963 : : /*
9964 : : * If archiving is enabled, wait for all the required WAL files to be
9965 : : * archived before returning. If archiving isn't enabled, the required WAL
9966 : : * needs to be transported via streaming replication (hopefully with
9967 : : * wal_keep_size set high enough), or some more exotic mechanism like
9968 : : * polling and copying files from pg_wal with script. We have no knowledge
9969 : : * of those mechanisms, so it's up to the user to ensure that he gets all
9970 : : * the required WAL.
9971 : : *
9972 : : * We wait until both the last WAL file filled during backup and the
9973 : : * history file have been archived, and assume that the alphabetic sorting
9974 : : * property of the WAL files ensures any earlier WAL files are safely
9975 : : * archived as well.
9976 : : *
9977 : : * We wait forever, since archive_command is supposed to work and we
9978 : : * assume the admin wanted his backup to work completely. If you don't
9979 : : * wish to wait, then either waitforarchive should be passed in as false,
9980 : : * or you can set statement_timeout. Also, some notices are issued to
9981 : : * clue in anyone who might be doing this interactively.
9982 : : */
9983 : :
9984 [ + + ]: 171 : if (waitforarchive &&
9985 [ + + + + : 10 : ((!backup_stopped_in_recovery && XLogArchivingActive()) ||
+ + ]
9986 [ - + ]: 1 : (backup_stopped_in_recovery && XLogArchivingAlways())))
9987 : : {
9988 : 4 : XLByteToPrevSeg(state->stoppoint, _logSegNo, wal_segment_size);
9989 : 4 : XLogFileName(lastxlogfilename, state->stoptli, _logSegNo,
9990 : : wal_segment_size);
9991 : :
9992 : 4 : XLByteToSeg(state->startpoint, _logSegNo, wal_segment_size);
9993 : 4 : BackupHistoryFileName(histfilename, state->stoptli, _logSegNo,
9994 : : state->startpoint, wal_segment_size);
9995 : :
9996 : 4 : seconds_before_warning = 60;
9997 : 4 : waits = 0;
9998 : :
9999 [ + + - + ]: 12 : while (XLogArchiveIsBusy(lastxlogfilename) ||
10000 : 4 : XLogArchiveIsBusy(histfilename))
10001 : : {
10002 [ - + ]: 4 : CHECK_FOR_INTERRUPTS();
10003 : :
10004 [ + - - + ]: 4 : if (!reported_waiting && waits > 5)
10005 : : {
10006 [ # # ]: 0 : ereport(NOTICE,
10007 : : (errmsg("base backup done, waiting for required WAL segments to be archived")));
10008 : 0 : reported_waiting = true;
10009 : : }
10010 : :
10011 : 4 : (void) WaitLatch(MyLatch,
10012 : : WL_LATCH_SET | WL_TIMEOUT | WL_EXIT_ON_PM_DEATH,
10013 : : 1000L,
10014 : : WAIT_EVENT_BACKUP_WAIT_WAL_ARCHIVE);
10015 : 4 : ResetLatch(MyLatch);
10016 : :
10017 [ - + ]: 4 : if (++waits >= seconds_before_warning)
10018 : : {
10019 : 0 : seconds_before_warning *= 2; /* This wraps in >10 years... */
10020 [ # # ]: 0 : ereport(WARNING,
10021 : : (errmsg("still waiting for all required WAL segments to be archived (%d seconds elapsed)",
10022 : : waits),
10023 : : errhint("Check that your \"archive_command\" is executing properly. "
10024 : : "You can safely cancel this backup, "
10025 : : "but the database backup will not be usable without all the WAL segments.")));
10026 : : }
10027 : : }
10028 : :
10029 [ + + ]: 4 : ereport(NOTICE,
10030 : : (errmsg("all required WAL segments have been archived")));
10031 : : }
10032 [ + + ]: 167 : else if (waitforarchive)
10033 [ + - ]: 6 : ereport(NOTICE,
10034 : : (errmsg("WAL archiving is not enabled; you must ensure that all required WAL segments are copied through other means to complete the backup")));
10035 : 171 : }
10036 : :
10037 : :
10038 : : /*
10039 : : * do_pg_abort_backup: abort a running backup
10040 : : *
10041 : : * This does just the most basic steps of do_pg_backup_stop(), by taking the
10042 : : * system out of backup mode, thus making it a lot more safe to call from
10043 : : * an error handler.
10044 : : *
10045 : : * 'arg' indicates that it's being called during backup setup; so
10046 : : * sessionBackupState has not been modified yet, but runningBackups has
10047 : : * already been incremented. When it's false, then it's invoked as a
10048 : : * before_shmem_exit handler, and therefore we must not change state
10049 : : * unless sessionBackupState indicates that a backup is actually running.
10050 : : *
10051 : : * NB: This gets used as a PG_ENSURE_ERROR_CLEANUP callback and
10052 : : * before_shmem_exit handler, hence the odd-looking signature.
10053 : : */
10054 : : void
10055 : 8 : do_pg_abort_backup(int code, Datum arg)
10056 : : {
10057 : 8 : bool during_backup_start = DatumGetBool(arg);
10058 : :
10059 : : /* If called during backup start, there shouldn't be one already running */
10060 : : Assert(!during_backup_start || sessionBackupState == SESSION_BACKUP_NONE);
10061 : :
10062 [ + - + + ]: 8 : if (during_backup_start || sessionBackupState != SESSION_BACKUP_NONE)
10063 : : {
10064 : 6 : WALInsertLockAcquireExclusive();
10065 : : Assert(XLogCtl->Insert.runningBackups > 0);
10066 : 6 : XLogCtl->Insert.runningBackups--;
10067 : :
10068 : 6 : sessionBackupState = SESSION_BACKUP_NONE;
10069 : 6 : WALInsertLockRelease();
10070 : :
10071 [ + - ]: 6 : if (!during_backup_start)
10072 [ + - ]: 6 : ereport(WARNING,
10073 : : errmsg("aborting backup due to backend exiting before pg_backup_stop was called"));
10074 : : }
10075 : 8 : }
10076 : :
10077 : : /*
10078 : : * Register a handler that will warn about unterminated backups at end of
10079 : : * session, unless this has already been done.
10080 : : */
10081 : : void
10082 : 4 : register_persistent_abort_backup_handler(void)
10083 : : {
10084 : : static bool already_done = false;
10085 : :
10086 [ + + ]: 4 : if (already_done)
10087 : 1 : return;
10088 : 3 : before_shmem_exit(do_pg_abort_backup, BoolGetDatum(false));
10089 : 3 : already_done = true;
10090 : : }
10091 : :
10092 : : /*
10093 : : * Get latest WAL insert pointer
10094 : : */
10095 : : XLogRecPtr
10096 : 2137 : GetXLogInsertRecPtr(void)
10097 : : {
10098 : 2137 : XLogCtlInsert *Insert = &XLogCtl->Insert;
10099 : : uint64 current_bytepos;
10100 : :
10101 : 2137 : SpinLockAcquire(&Insert->insertpos_lck);
10102 : 2137 : current_bytepos = Insert->CurrBytePos;
10103 : 2137 : SpinLockRelease(&Insert->insertpos_lck);
10104 : :
10105 : 2137 : return XLogBytePosToRecPtr(current_bytepos);
10106 : : }
10107 : :
10108 : : /*
10109 : : * Get latest WAL record end pointer
10110 : : */
10111 : : XLogRecPtr
10112 : 1676 : GetXLogInsertEndRecPtr(void)
10113 : : {
10114 : 1676 : XLogCtlInsert *Insert = &XLogCtl->Insert;
10115 : : uint64 current_bytepos;
10116 : :
10117 : 1676 : SpinLockAcquire(&Insert->insertpos_lck);
10118 : 1676 : current_bytepos = Insert->CurrBytePos;
10119 : 1676 : SpinLockRelease(&Insert->insertpos_lck);
10120 : :
10121 : 1676 : return XLogBytePosToEndRecPtr(current_bytepos);
10122 : : }
10123 : :
10124 : : /*
10125 : : * Get latest WAL write pointer
10126 : : */
10127 : : XLogRecPtr
10128 : 3587 : GetXLogWriteRecPtr(void)
10129 : : {
10130 : 3587 : RefreshXLogWriteResult(LogwrtResult);
10131 : :
10132 : 3587 : return LogwrtResult.Write;
10133 : : }
10134 : :
10135 : : /*
10136 : : * Returns the redo pointer of the last checkpoint or restartpoint. This is
10137 : : * the oldest point in WAL that we still need, if we have to restart recovery.
10138 : : */
10139 : : void
10140 : 404 : GetOldestRestartPoint(XLogRecPtr *oldrecptr, TimeLineID *oldtli)
10141 : : {
10142 : 404 : LWLockAcquire(ControlFileLock, LW_SHARED);
10143 : 404 : *oldrecptr = ControlFile->checkPointCopy.redo;
10144 : 404 : *oldtli = ControlFile->checkPointCopy.ThisTimeLineID;
10145 : 404 : LWLockRelease(ControlFileLock);
10146 : 404 : }
10147 : :
10148 : : /* Thin wrapper around ShutdownWalRcv(). */
10149 : : void
10150 : 1085 : XLogShutdownWalRcv(void)
10151 : : {
10152 : : Assert(AmStartupProcess() || !IsUnderPostmaster);
10153 : :
10154 : 1085 : ShutdownWalRcv();
10155 : 1085 : ResetInstallXLogFileSegmentActive();
10156 : 1085 : }
10157 : :
10158 : : /* Enable WAL file recycling and preallocation. */
10159 : : void
10160 : 1302 : SetInstallXLogFileSegmentActive(void)
10161 : : {
10162 : 1302 : LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
10163 : 1302 : XLogCtl->InstallXLogFileSegmentActive = true;
10164 : 1302 : LWLockRelease(ControlFileLock);
10165 : 1302 : }
10166 : :
10167 : : /* Disable WAL file recycling and preallocation. */
10168 : : void
10169 : 1265 : ResetInstallXLogFileSegmentActive(void)
10170 : : {
10171 : 1265 : LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
10172 : 1265 : XLogCtl->InstallXLogFileSegmentActive = false;
10173 : 1265 : LWLockRelease(ControlFileLock);
10174 : 1265 : }
10175 : :
10176 : : bool
10177 : 0 : IsInstallXLogFileSegmentActive(void)
10178 : : {
10179 : : bool result;
10180 : :
10181 : 0 : LWLockAcquire(ControlFileLock, LW_SHARED);
10182 : 0 : result = XLogCtl->InstallXLogFileSegmentActive;
10183 : 0 : LWLockRelease(ControlFileLock);
10184 : :
10185 : 0 : return result;
10186 : : }
10187 : :
10188 : : /*
10189 : : * Update the WalWriterSleeping flag.
10190 : : */
10191 : : void
10192 : 589 : SetWalWriterSleeping(bool sleeping)
10193 : : {
10194 : 589 : SpinLockAcquire(&XLogCtl->info_lck);
10195 : 589 : XLogCtl->WalWriterSleeping = sleeping;
10196 : 589 : SpinLockRelease(&XLogCtl->info_lck);
10197 : 589 : }
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