Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * xlogarchive.c
4 : * Functions for archiving WAL files and restoring from the archive.
5 : *
6 : *
7 : * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
8 : * Portions Copyright (c) 1994, Regents of the University of California
9 : *
10 : * src/backend/access/transam/xlogarchive.c
11 : *
12 : *-------------------------------------------------------------------------
13 : */
14 :
15 : #include "postgres.h"
16 :
17 : #include <sys/stat.h>
18 : #include <sys/wait.h>
19 : #include <signal.h>
20 : #include <unistd.h>
21 :
22 : #include "access/xlog.h"
23 : #include "access/xlog_internal.h"
24 : #include "access/xlogarchive.h"
25 : #include "common/archive.h"
26 : #include "common/percentrepl.h"
27 : #include "miscadmin.h"
28 : #include "pgstat.h"
29 : #include "postmaster/pgarch.h"
30 : #include "postmaster/startup.h"
31 : #include "replication/walsender.h"
32 : #include "storage/fd.h"
33 : #include "storage/ipc.h"
34 :
35 : /*
36 : * Attempt to retrieve the specified file from off-line archival storage.
37 : * If successful, fill "path" with its complete path (note that this will be
38 : * a temp file name that doesn't follow the normal naming convention), and
39 : * return true.
40 : *
41 : * If not successful, fill "path" with the name of the normal on-line file
42 : * (which may or may not actually exist, but we'll try to use it), and return
43 : * false.
44 : *
45 : * For fixed-size files, the caller may pass the expected size as an
46 : * additional crosscheck on successful recovery. If the file size is not
47 : * known, set expectedSize = 0.
48 : *
49 : * When 'cleanupEnabled' is false, refrain from deleting any old WAL segments
50 : * in the archive. This is used when fetching the initial checkpoint record,
51 : * when we are not yet sure how far back we need the WAL.
52 : */
53 : bool
54 1620 : RestoreArchivedFile(char *path, const char *xlogfname,
55 : const char *recovername, off_t expectedSize,
56 : bool cleanupEnabled)
57 : {
58 : char xlogpath[MAXPGPATH];
59 : char *xlogRestoreCmd;
60 : char lastRestartPointFname[MAXPGPATH];
61 : int rc;
62 : struct stat stat_buf;
63 : XLogSegNo restartSegNo;
64 : XLogRecPtr restartRedoPtr;
65 : TimeLineID restartTli;
66 :
67 : /*
68 : * Ignore restore_command when not in archive recovery (meaning we are in
69 : * crash recovery).
70 : */
71 1620 : if (!ArchiveRecoveryRequested)
72 46 : goto not_available;
73 :
74 : /* In standby mode, restore_command might not be supplied */
75 1574 : if (recoveryRestoreCommand == NULL || strcmp(recoveryRestoreCommand, "") == 0)
76 1206 : goto not_available;
77 :
78 : /*
79 : * When doing archive recovery, we always prefer an archived log file even
80 : * if a file of the same name exists in XLOGDIR. The reason is that the
81 : * file in XLOGDIR could be an old, un-filled or partly-filled version
82 : * that was copied and restored as part of backing up $PGDATA.
83 : *
84 : * We could try to optimize this slightly by checking the local copy
85 : * lastchange timestamp against the archived copy, but we have no API to
86 : * do this, nor can we guarantee that the lastchange timestamp was
87 : * preserved correctly when we copied to archive. Our aim is robustness,
88 : * so we elect not to do this.
89 : *
90 : * If we cannot obtain the log file from the archive, however, we will try
91 : * to use the XLOGDIR file if it exists. This is so that we can make use
92 : * of log segments that weren't yet transferred to the archive.
93 : *
94 : * Notice that we don't actually overwrite any files when we copy back
95 : * from archive because the restore_command may inadvertently restore
96 : * inappropriate xlogs, or they may be corrupt, so we may wish to fallback
97 : * to the segments remaining in current XLOGDIR later. The
98 : * copy-from-archive filename is always the same, ensuring that we don't
99 : * run out of disk space on long recoveries.
100 : */
101 368 : snprintf(xlogpath, MAXPGPATH, XLOGDIR "/%s", recovername);
102 :
103 : /*
104 : * Make sure there is no existing file named recovername.
105 : */
106 368 : if (stat(xlogpath, &stat_buf) != 0)
107 : {
108 360 : if (errno != ENOENT)
109 0 : ereport(FATAL,
110 : (errcode_for_file_access(),
111 : errmsg("could not stat file \"%s\": %m",
112 : xlogpath)));
113 : }
114 : else
115 : {
116 8 : if (unlink(xlogpath) != 0)
117 0 : ereport(FATAL,
118 : (errcode_for_file_access(),
119 : errmsg("could not remove file \"%s\": %m",
120 : xlogpath)));
121 : }
122 :
123 : /*
124 : * Calculate the archive file cutoff point for use during log shipping
125 : * replication. All files earlier than this point can be deleted from the
126 : * archive, though there is no requirement to do so.
127 : *
128 : * If cleanup is not enabled, initialise this with the filename of
129 : * InvalidXLogRecPtr, which will prevent the deletion of any WAL files
130 : * from the archive because of the alphabetic sorting property of WAL
131 : * filenames.
132 : *
133 : * Once we have successfully located the redo pointer of the checkpoint
134 : * from which we start recovery we never request a file prior to the redo
135 : * pointer of the last restartpoint. When redo begins we know that we have
136 : * successfully located it, so there is no need for additional status
137 : * flags to signify the point when we can begin deleting WAL files from
138 : * the archive.
139 : */
140 368 : if (cleanupEnabled)
141 : {
142 134 : GetOldestRestartPoint(&restartRedoPtr, &restartTli);
143 134 : XLByteToSeg(restartRedoPtr, restartSegNo, wal_segment_size);
144 134 : XLogFileName(lastRestartPointFname, restartTli, restartSegNo,
145 : wal_segment_size);
146 : /* we shouldn't need anything earlier than last restart point */
147 : Assert(strcmp(lastRestartPointFname, xlogfname) <= 0);
148 : }
149 : else
150 234 : XLogFileName(lastRestartPointFname, 0, 0, wal_segment_size);
151 :
152 : /* Build the restore command to execute */
153 368 : xlogRestoreCmd = BuildRestoreCommand(recoveryRestoreCommand,
154 : xlogpath, xlogfname,
155 : lastRestartPointFname);
156 :
157 368 : ereport(DEBUG3,
158 : (errmsg_internal("executing restore command \"%s\"",
159 : xlogRestoreCmd)));
160 :
161 368 : fflush(NULL);
162 368 : pgstat_report_wait_start(WAIT_EVENT_RESTORE_COMMAND);
163 :
164 : /*
165 : * PreRestoreCommand() informs the SIGTERM handler for the startup process
166 : * that it should proc_exit() right away. This is done for the duration
167 : * of the system() call because there isn't a good way to break out while
168 : * it is executing. Since we might call proc_exit() in a signal handler,
169 : * it is best to put any additional logic before or after the
170 : * PreRestoreCommand()/PostRestoreCommand() section.
171 : */
172 368 : PreRestoreCommand();
173 :
174 : /*
175 : * Copy xlog from archival storage to XLOGDIR
176 : */
177 368 : rc = system(xlogRestoreCmd);
178 :
179 368 : PostRestoreCommand();
180 :
181 368 : pgstat_report_wait_end();
182 368 : pfree(xlogRestoreCmd);
183 :
184 368 : if (rc == 0)
185 : {
186 : /*
187 : * command apparently succeeded, but let's make sure the file is
188 : * really there now and has the correct size.
189 : */
190 90 : if (stat(xlogpath, &stat_buf) == 0)
191 : {
192 90 : if (expectedSize > 0 && stat_buf.st_size != expectedSize)
193 : {
194 : int elevel;
195 :
196 : /*
197 : * If we find a partial file in standby mode, we assume it's
198 : * because it's just being copied to the archive, and keep
199 : * trying.
200 : *
201 : * Otherwise treat a wrong-sized file as FATAL to ensure the
202 : * DBA would notice it, but is that too strong? We could try
203 : * to plow ahead with a local copy of the file ... but the
204 : * problem is that there probably isn't one, and we'd
205 : * incorrectly conclude we've reached the end of WAL and we're
206 : * done recovering ...
207 : */
208 0 : if (StandbyMode && stat_buf.st_size < expectedSize)
209 0 : elevel = DEBUG1;
210 : else
211 0 : elevel = FATAL;
212 0 : ereport(elevel,
213 : (errmsg("archive file \"%s\" has wrong size: %lld instead of %lld",
214 : xlogfname,
215 : (long long int) stat_buf.st_size,
216 : (long long int) expectedSize)));
217 0 : return false;
218 : }
219 : else
220 : {
221 90 : ereport(LOG,
222 : (errmsg("restored log file \"%s\" from archive",
223 : xlogfname)));
224 90 : strcpy(path, xlogpath);
225 90 : return true;
226 : }
227 : }
228 : else
229 : {
230 : /* stat failed */
231 0 : int elevel = (errno == ENOENT) ? LOG : FATAL;
232 :
233 0 : ereport(elevel,
234 : (errcode_for_file_access(),
235 : errmsg("could not stat file \"%s\": %m", xlogpath),
236 : errdetail("\"restore_command\" returned a zero exit status, but stat() failed.")));
237 : }
238 : }
239 :
240 : /*
241 : * Remember, we rollforward UNTIL the restore fails so failure here is
242 : * just part of the process... that makes it difficult to determine
243 : * whether the restore failed because there isn't an archive to restore,
244 : * or because the administrator has specified the restore program
245 : * incorrectly. We have to assume the former.
246 : *
247 : * However, if the failure was due to any sort of signal, it's best to
248 : * punt and abort recovery. (If we "return false" here, upper levels will
249 : * assume that recovery is complete and start up the database!) It's
250 : * essential to abort on child SIGINT and SIGQUIT, because per spec
251 : * system() ignores SIGINT and SIGQUIT while waiting; if we see one of
252 : * those it's a good bet we should have gotten it too.
253 : *
254 : * On SIGTERM, assume we have received a fast shutdown request, and exit
255 : * cleanly. It's pure chance whether we receive the SIGTERM first, or the
256 : * child process. If we receive it first, the signal handler will call
257 : * proc_exit, otherwise we do it here. If we or the child process received
258 : * SIGTERM for any other reason than a fast shutdown request, postmaster
259 : * will perform an immediate shutdown when it sees us exiting
260 : * unexpectedly.
261 : *
262 : * We treat hard shell errors such as "command not found" as fatal, too.
263 : */
264 278 : if (wait_result_is_signal(rc, SIGTERM))
265 0 : proc_exit(1);
266 :
267 278 : ereport(wait_result_is_any_signal(rc, true) ? FATAL : DEBUG2,
268 : (errmsg("could not restore file \"%s\" from archive: %s",
269 : xlogfname, wait_result_to_str(rc))));
270 :
271 278 : not_available:
272 :
273 : /*
274 : * if an archived file is not available, there might still be a version of
275 : * this file in XLOGDIR, so return that as the filename to open.
276 : *
277 : * In many recovery scenarios we expect this to fail also, but if so that
278 : * just means we've reached the end of WAL.
279 : */
280 1530 : snprintf(path, MAXPGPATH, XLOGDIR "/%s", xlogfname);
281 1530 : return false;
282 : }
283 :
284 : /*
285 : * Attempt to execute an external shell command during recovery.
286 : *
287 : * 'command' is the shell command to be executed, 'commandName' is a
288 : * human-readable name describing the command emitted in the logs. If
289 : * 'failOnSignal' is true and the command is killed by a signal, a FATAL
290 : * error is thrown. Otherwise a WARNING is emitted.
291 : *
292 : * This is currently used for recovery_end_command and archive_cleanup_command.
293 : */
294 : void
295 4 : ExecuteRecoveryCommand(const char *command, const char *commandName,
296 : bool failOnSignal, uint32 wait_event_info)
297 : {
298 : char *xlogRecoveryCmd;
299 : char lastRestartPointFname[MAXPGPATH];
300 : int rc;
301 : XLogSegNo restartSegNo;
302 : XLogRecPtr restartRedoPtr;
303 : TimeLineID restartTli;
304 :
305 : Assert(command && commandName);
306 :
307 : /*
308 : * Calculate the archive file cutoff point for use during log shipping
309 : * replication. All files earlier than this point can be deleted from the
310 : * archive, though there is no requirement to do so.
311 : */
312 4 : GetOldestRestartPoint(&restartRedoPtr, &restartTli);
313 4 : XLByteToSeg(restartRedoPtr, restartSegNo, wal_segment_size);
314 4 : XLogFileName(lastRestartPointFname, restartTli, restartSegNo,
315 : wal_segment_size);
316 :
317 : /*
318 : * construct the command to be executed
319 : */
320 4 : xlogRecoveryCmd = replace_percent_placeholders(command, commandName, "r", lastRestartPointFname);
321 :
322 4 : ereport(DEBUG3,
323 : (errmsg_internal("executing %s \"%s\"", commandName, command)));
324 :
325 : /*
326 : * execute the constructed command
327 : */
328 4 : fflush(NULL);
329 4 : pgstat_report_wait_start(wait_event_info);
330 4 : rc = system(xlogRecoveryCmd);
331 4 : pgstat_report_wait_end();
332 :
333 4 : pfree(xlogRecoveryCmd);
334 :
335 4 : if (rc != 0)
336 : {
337 : /*
338 : * If the failure was due to any sort of signal, it's best to punt and
339 : * abort recovery. See comments in RestoreArchivedFile().
340 : */
341 2 : ereport((failOnSignal && wait_result_is_any_signal(rc, true)) ? FATAL : WARNING,
342 : /*------
343 : translator: First %s represents a postgresql.conf parameter name like
344 : "recovery_end_command", the 2nd is the value of that parameter, the
345 : third an already translated error message. */
346 : (errmsg("%s \"%s\": %s", commandName,
347 : command, wait_result_to_str(rc))));
348 : }
349 4 : }
350 :
351 :
352 : /*
353 : * A file was restored from the archive under a temporary filename (path),
354 : * and now we want to keep it. Rename it under the permanent filename in
355 : * pg_wal (xlogfname), replacing any existing file with the same name.
356 : */
357 : void
358 76 : KeepFileRestoredFromArchive(const char *path, const char *xlogfname)
359 : {
360 : char xlogfpath[MAXPGPATH];
361 76 : bool reload = false;
362 : struct stat statbuf;
363 :
364 76 : snprintf(xlogfpath, MAXPGPATH, XLOGDIR "/%s", xlogfname);
365 :
366 76 : if (stat(xlogfpath, &statbuf) == 0)
367 : {
368 : char oldpath[MAXPGPATH];
369 :
370 : #ifdef WIN32
371 : static unsigned int deletedcounter = 1;
372 :
373 : /*
374 : * On Windows, if another process (e.g a walsender process) holds the
375 : * file open in FILE_SHARE_DELETE mode, unlink will succeed, but the
376 : * file will still show up in directory listing until the last handle
377 : * is closed, and we cannot rename the new file in its place until
378 : * that. To avoid that problem, rename the old file to a temporary
379 : * name first. Use a counter to create a unique filename, because the
380 : * same file might be restored from the archive multiple times, and a
381 : * walsender could still be holding onto an old deleted version of it.
382 : */
383 : snprintf(oldpath, MAXPGPATH, "%s.deleted%u",
384 : xlogfpath, deletedcounter++);
385 : if (rename(xlogfpath, oldpath) != 0)
386 : {
387 : ereport(ERROR,
388 : (errcode_for_file_access(),
389 : errmsg("could not rename file \"%s\" to \"%s\": %m",
390 : xlogfpath, oldpath)));
391 : }
392 : #else
393 : /* same-size buffers, so this never truncates */
394 42 : strlcpy(oldpath, xlogfpath, MAXPGPATH);
395 : #endif
396 42 : if (unlink(oldpath) != 0)
397 0 : ereport(FATAL,
398 : (errcode_for_file_access(),
399 : errmsg("could not remove file \"%s\": %m",
400 : xlogfpath)));
401 42 : reload = true;
402 : }
403 :
404 76 : durable_rename(path, xlogfpath, ERROR);
405 :
406 : /*
407 : * Create .done file forcibly to prevent the restored segment from being
408 : * archived again later.
409 : */
410 76 : if (XLogArchiveMode != ARCHIVE_MODE_ALWAYS)
411 74 : XLogArchiveForceDone(xlogfname);
412 : else
413 2 : XLogArchiveNotify(xlogfname);
414 :
415 : /*
416 : * If the existing file was replaced, since walsenders might have it open,
417 : * request them to reload a currently-open segment. This is only required
418 : * for WAL segments, walsenders don't hold other files open, but there's
419 : * no harm in doing this too often, and we don't know what kind of a file
420 : * we're dealing with here.
421 : */
422 76 : if (reload)
423 42 : WalSndRqstFileReload();
424 :
425 : /*
426 : * Signal walsender that new WAL has arrived. Again, this isn't necessary
427 : * if we restored something other than a WAL segment, but it does no harm
428 : * either.
429 : */
430 76 : WalSndWakeup(true, false);
431 76 : }
432 :
433 : /*
434 : * XLogArchiveNotify
435 : *
436 : * Create an archive notification file
437 : *
438 : * The name of the notification file is the message that will be picked up
439 : * by the archiver, e.g. we write 0000000100000001000000C6.ready
440 : * and the archiver then knows to archive XLOGDIR/0000000100000001000000C6,
441 : * then when complete, rename it to 0000000100000001000000C6.done
442 : */
443 : void
444 256 : XLogArchiveNotify(const char *xlog)
445 : {
446 : char archiveStatusPath[MAXPGPATH];
447 : FILE *fd;
448 :
449 : /* insert an otherwise empty file called <XLOG>.ready */
450 256 : StatusFilePath(archiveStatusPath, xlog, ".ready");
451 256 : fd = AllocateFile(archiveStatusPath, "w");
452 256 : if (fd == NULL)
453 : {
454 0 : ereport(LOG,
455 : (errcode_for_file_access(),
456 : errmsg("could not create archive status file \"%s\": %m",
457 : archiveStatusPath)));
458 0 : return;
459 : }
460 256 : if (FreeFile(fd))
461 : {
462 0 : ereport(LOG,
463 : (errcode_for_file_access(),
464 : errmsg("could not write archive status file \"%s\": %m",
465 : archiveStatusPath)));
466 0 : return;
467 : }
468 :
469 : /*
470 : * Timeline history files are given the highest archival priority to lower
471 : * the chance that a promoted standby will choose a timeline that is
472 : * already in use. However, the archiver ordinarily tries to gather
473 : * multiple files to archive from each scan of the archive_status
474 : * directory, which means that newly created timeline history files could
475 : * be left unarchived for a while. To ensure that the archiver picks up
476 : * timeline history files as soon as possible, we force the archiver to
477 : * scan the archive_status directory the next time it looks for a file to
478 : * archive.
479 : */
480 256 : if (IsTLHistoryFileName(xlog))
481 26 : PgArchForceDirScan();
482 :
483 : /* Notify archiver that it's got something to do */
484 256 : if (IsUnderPostmaster)
485 256 : PgArchWakeup();
486 : }
487 :
488 : /*
489 : * Convenience routine to notify using segment number representation of filename
490 : */
491 : void
492 156 : XLogArchiveNotifySeg(XLogSegNo segno, TimeLineID tli)
493 : {
494 : char xlog[MAXFNAMELEN];
495 :
496 : Assert(tli != 0);
497 :
498 156 : XLogFileName(xlog, tli, segno, wal_segment_size);
499 156 : XLogArchiveNotify(xlog);
500 156 : }
501 :
502 : /*
503 : * XLogArchiveForceDone
504 : *
505 : * Emit notification forcibly that an XLOG segment file has been successfully
506 : * archived, by creating <XLOG>.done regardless of whether <XLOG>.ready
507 : * exists or not.
508 : */
509 : void
510 1482 : XLogArchiveForceDone(const char *xlog)
511 : {
512 : char archiveReady[MAXPGPATH];
513 : char archiveDone[MAXPGPATH];
514 : struct stat stat_buf;
515 : FILE *fd;
516 :
517 : /* Exit if already known done */
518 1482 : StatusFilePath(archiveDone, xlog, ".done");
519 1482 : if (stat(archiveDone, &stat_buf) == 0)
520 22 : return;
521 :
522 : /* If .ready exists, rename it to .done */
523 1460 : StatusFilePath(archiveReady, xlog, ".ready");
524 1460 : if (stat(archiveReady, &stat_buf) == 0)
525 : {
526 0 : (void) durable_rename(archiveReady, archiveDone, WARNING);
527 0 : return;
528 : }
529 :
530 : /* insert an otherwise empty file called <XLOG>.done */
531 1460 : fd = AllocateFile(archiveDone, "w");
532 1460 : if (fd == NULL)
533 : {
534 0 : ereport(LOG,
535 : (errcode_for_file_access(),
536 : errmsg("could not create archive status file \"%s\": %m",
537 : archiveDone)));
538 0 : return;
539 : }
540 1460 : if (FreeFile(fd))
541 : {
542 0 : ereport(LOG,
543 : (errcode_for_file_access(),
544 : errmsg("could not write archive status file \"%s\": %m",
545 : archiveDone)));
546 0 : return;
547 : }
548 : }
549 :
550 : /*
551 : * XLogArchiveCheckDone
552 : *
553 : * This is called when we are ready to delete or recycle an old XLOG segment
554 : * file or backup history file. If it is okay to delete it then return true.
555 : * If it is not time to delete it, make sure a .ready file exists, and return
556 : * false.
557 : *
558 : * If <XLOG>.done exists, then return true; else if <XLOG>.ready exists,
559 : * then return false; else create <XLOG>.ready and return false.
560 : *
561 : * The reason we do things this way is so that if the original attempt to
562 : * create <XLOG>.ready fails, we'll retry during subsequent checkpoints.
563 : */
564 : bool
565 4098 : XLogArchiveCheckDone(const char *xlog)
566 : {
567 : char archiveStatusPath[MAXPGPATH];
568 : struct stat stat_buf;
569 :
570 : /* The file is always deletable if archive_mode is "off". */
571 4098 : if (!XLogArchivingActive())
572 3974 : return true;
573 :
574 : /*
575 : * During archive recovery, the file is deletable if archive_mode is not
576 : * "always".
577 : */
578 238 : if (!XLogArchivingAlways() &&
579 114 : GetRecoveryState() == RECOVERY_STATE_ARCHIVE)
580 6 : return true;
581 :
582 : /*
583 : * At this point of the logic, note that we are either a primary with
584 : * archive_mode set to "on" or "always", or a standby with archive_mode
585 : * set to "always".
586 : */
587 :
588 : /* First check for .done --- this means archiver is done with it */
589 118 : StatusFilePath(archiveStatusPath, xlog, ".done");
590 118 : if (stat(archiveStatusPath, &stat_buf) == 0)
591 40 : return true;
592 :
593 : /* check for .ready --- this means archiver is still busy with it */
594 78 : StatusFilePath(archiveStatusPath, xlog, ".ready");
595 78 : if (stat(archiveStatusPath, &stat_buf) == 0)
596 16 : return false;
597 :
598 : /* Race condition --- maybe archiver just finished, so recheck */
599 62 : StatusFilePath(archiveStatusPath, xlog, ".done");
600 62 : if (stat(archiveStatusPath, &stat_buf) == 0)
601 0 : return true;
602 :
603 : /* Retry creation of the .ready file */
604 62 : XLogArchiveNotify(xlog);
605 62 : return false;
606 : }
607 :
608 : /*
609 : * XLogArchiveIsBusy
610 : *
611 : * Check to see if an XLOG segment file is still unarchived.
612 : * This is almost but not quite the inverse of XLogArchiveCheckDone: in
613 : * the first place we aren't chartered to recreate the .ready file, and
614 : * in the second place we should consider that if the file is already gone
615 : * then it's not busy. (This check is needed to handle the race condition
616 : * that a checkpoint already deleted the no-longer-needed file.)
617 : */
618 : bool
619 18 : XLogArchiveIsBusy(const char *xlog)
620 : {
621 : char archiveStatusPath[MAXPGPATH];
622 : struct stat stat_buf;
623 :
624 : /* First check for .done --- this means archiver is done with it */
625 18 : StatusFilePath(archiveStatusPath, xlog, ".done");
626 18 : if (stat(archiveStatusPath, &stat_buf) == 0)
627 12 : return false;
628 :
629 : /* check for .ready --- this means archiver is still busy with it */
630 6 : StatusFilePath(archiveStatusPath, xlog, ".ready");
631 6 : if (stat(archiveStatusPath, &stat_buf) == 0)
632 6 : return true;
633 :
634 : /* Race condition --- maybe archiver just finished, so recheck */
635 0 : StatusFilePath(archiveStatusPath, xlog, ".done");
636 0 : if (stat(archiveStatusPath, &stat_buf) == 0)
637 0 : return false;
638 :
639 : /*
640 : * Check to see if the WAL file has been removed by checkpoint, which
641 : * implies it has already been archived, and explains why we can't see a
642 : * status file for it.
643 : */
644 0 : snprintf(archiveStatusPath, MAXPGPATH, XLOGDIR "/%s", xlog);
645 0 : if (stat(archiveStatusPath, &stat_buf) != 0 &&
646 0 : errno == ENOENT)
647 0 : return false;
648 :
649 0 : return true;
650 : }
651 :
652 : /*
653 : * XLogArchiveIsReadyOrDone
654 : *
655 : * Check to see if an XLOG segment file has a .ready or .done file.
656 : * This is similar to XLogArchiveIsBusy(), but returns true if the file
657 : * is already archived or is about to be archived.
658 : *
659 : * This is currently only used at recovery. During normal operation this
660 : * would be racy: the file might get removed or marked with .ready as we're
661 : * checking it, or immediately after we return.
662 : */
663 : bool
664 16 : XLogArchiveIsReadyOrDone(const char *xlog)
665 : {
666 : char archiveStatusPath[MAXPGPATH];
667 : struct stat stat_buf;
668 :
669 : /* First check for .done --- this means archiver is done with it */
670 16 : StatusFilePath(archiveStatusPath, xlog, ".done");
671 16 : if (stat(archiveStatusPath, &stat_buf) == 0)
672 6 : return true;
673 :
674 : /* check for .ready --- this means archiver is still busy with it */
675 10 : StatusFilePath(archiveStatusPath, xlog, ".ready");
676 10 : if (stat(archiveStatusPath, &stat_buf) == 0)
677 0 : return true;
678 :
679 : /* Race condition --- maybe archiver just finished, so recheck */
680 10 : StatusFilePath(archiveStatusPath, xlog, ".done");
681 10 : if (stat(archiveStatusPath, &stat_buf) == 0)
682 0 : return true;
683 :
684 10 : return false;
685 : }
686 :
687 : /*
688 : * XLogArchiveIsReady
689 : *
690 : * Check to see if an XLOG segment file has an archive notification (.ready)
691 : * file.
692 : */
693 : bool
694 34 : XLogArchiveIsReady(const char *xlog)
695 : {
696 : char archiveStatusPath[MAXPGPATH];
697 : struct stat stat_buf;
698 :
699 34 : StatusFilePath(archiveStatusPath, xlog, ".ready");
700 34 : if (stat(archiveStatusPath, &stat_buf) == 0)
701 0 : return true;
702 :
703 34 : return false;
704 : }
705 :
706 : /*
707 : * XLogArchiveCleanup
708 : *
709 : * Cleanup archive notification file(s) for a particular xlog segment
710 : */
711 : void
712 4160 : XLogArchiveCleanup(const char *xlog)
713 : {
714 : char archiveStatusPath[MAXPGPATH];
715 :
716 : /* Remove the .done file */
717 4160 : StatusFilePath(archiveStatusPath, xlog, ".done");
718 4160 : unlink(archiveStatusPath);
719 : /* should we complain about failure? */
720 :
721 : /* Remove the .ready file if present --- normally it shouldn't be */
722 4160 : StatusFilePath(archiveStatusPath, xlog, ".ready");
723 4160 : unlink(archiveStatusPath);
724 : /* should we complain about failure? */
725 4160 : }
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