LCOV - code coverage report
Current view: top level - src/bin/pg_resetwal - pg_resetwal.c (source / functions) Hit Total Coverage
Test: PostgreSQL 17devel Lines: 469 522 89.8 %
Date: 2024-04-25 06:13:26 Functions: 13 13 100.0 %
Legend: Lines: hit not hit

          Line data    Source code
       1             : /*-------------------------------------------------------------------------
       2             :  *
       3             :  * pg_resetwal.c
       4             :  *    A utility to "zero out" the xlog when it's corrupt beyond recovery.
       5             :  *    Can also rebuild pg_control if needed.
       6             :  *
       7             :  * The theory of operation is fairly simple:
       8             :  *    1. Read the existing pg_control (which will include the last
       9             :  *       checkpoint record).
      10             :  *    2. If pg_control is corrupt, attempt to intuit reasonable values,
      11             :  *       by scanning the old xlog if necessary.
      12             :  *    3. Modify pg_control to reflect a "shutdown" state with a checkpoint
      13             :  *       record at the start of xlog.
      14             :  *    4. Flush the existing xlog files and write a new segment with
      15             :  *       just a checkpoint record in it.  The new segment is positioned
      16             :  *       just past the end of the old xlog, so that existing LSNs in
      17             :  *       data pages will appear to be "in the past".
      18             :  * This is all pretty straightforward except for the intuition part of
      19             :  * step 2 ...
      20             :  *
      21             :  *
      22             :  * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
      23             :  * Portions Copyright (c) 1994, Regents of the University of California
      24             :  *
      25             :  * src/bin/pg_resetwal/pg_resetwal.c
      26             :  *
      27             :  *-------------------------------------------------------------------------
      28             :  */
      29             : 
      30             : /*
      31             :  * We have to use postgres.h not postgres_fe.h here, because there's so much
      32             :  * backend-only stuff in the XLOG include files we need.  But we need a
      33             :  * frontend-ish environment otherwise.  Hence this ugly hack.
      34             :  */
      35             : #define FRONTEND 1
      36             : 
      37             : #include "postgres.h"
      38             : 
      39             : #include <dirent.h>
      40             : #include <fcntl.h>
      41             : #include <sys/stat.h>
      42             : #include <sys/time.h>
      43             : #include <time.h>
      44             : #include <unistd.h>
      45             : 
      46             : #include "access/heaptoast.h"
      47             : #include "access/multixact.h"
      48             : #include "access/transam.h"
      49             : #include "access/xlog.h"
      50             : #include "access/xlog_internal.h"
      51             : #include "common/controldata_utils.h"
      52             : #include "common/fe_memutils.h"
      53             : #include "common/file_perm.h"
      54             : #include "common/logging.h"
      55             : #include "common/restricted_token.h"
      56             : #include "common/string.h"
      57             : #include "fe_utils/option_utils.h"
      58             : #include "getopt_long.h"
      59             : #include "pg_getopt.h"
      60             : #include "storage/large_object.h"
      61             : 
      62             : static ControlFileData ControlFile; /* pg_control values */
      63             : static XLogSegNo newXlogSegNo;  /* new XLOG segment # */
      64             : static bool guessed = false;    /* T if we had to guess at any values */
      65             : static const char *progname;
      66             : static uint32 set_xid_epoch = (uint32) -1;
      67             : static TransactionId set_oldest_xid = 0;
      68             : static TransactionId set_xid = 0;
      69             : static TransactionId set_oldest_commit_ts_xid = 0;
      70             : static TransactionId set_newest_commit_ts_xid = 0;
      71             : static Oid  set_oid = 0;
      72             : static MultiXactId set_mxid = 0;
      73             : static MultiXactOffset set_mxoff = (MultiXactOffset) -1;
      74             : static TimeLineID minXlogTli = 0;
      75             : static XLogSegNo minXlogSegNo = 0;
      76             : static int  WalSegSz;
      77             : static int  set_wal_segsize;
      78             : 
      79             : static void CheckDataVersion(void);
      80             : static bool read_controlfile(void);
      81             : static void GuessControlValues(void);
      82             : static void PrintControlValues(bool guessed);
      83             : static void PrintNewControlValues(void);
      84             : static void RewriteControlFile(void);
      85             : static void FindEndOfXLOG(void);
      86             : static void KillExistingXLOG(void);
      87             : static void KillExistingArchiveStatus(void);
      88             : static void KillExistingWALSummaries(void);
      89             : static void WriteEmptyXLOG(void);
      90             : static void usage(void);
      91             : 
      92             : 
      93             : int
      94         216 : main(int argc, char *argv[])
      95             : {
      96             :     static struct option long_options[] = {
      97             :         {"commit-timestamp-ids", required_argument, NULL, 'c'},
      98             :         {"pgdata", required_argument, NULL, 'D'},
      99             :         {"epoch", required_argument, NULL, 'e'},
     100             :         {"force", no_argument, NULL, 'f'},
     101             :         {"next-wal-file", required_argument, NULL, 'l'},
     102             :         {"multixact-ids", required_argument, NULL, 'm'},
     103             :         {"dry-run", no_argument, NULL, 'n'},
     104             :         {"next-oid", required_argument, NULL, 'o'},
     105             :         {"multixact-offset", required_argument, NULL, 'O'},
     106             :         {"oldest-transaction-id", required_argument, NULL, 'u'},
     107             :         {"next-transaction-id", required_argument, NULL, 'x'},
     108             :         {"wal-segsize", required_argument, NULL, 1},
     109             :         {NULL, 0, NULL, 0}
     110             :     };
     111             : 
     112             :     int         c;
     113         216 :     bool        force = false;
     114         216 :     bool        noupdate = false;
     115         216 :     MultiXactId set_oldestmxid = 0;
     116             :     char       *endptr;
     117             :     char       *endptr2;
     118         216 :     char       *DataDir = NULL;
     119         216 :     char       *log_fname = NULL;
     120             :     int         fd;
     121             : 
     122         216 :     pg_logging_init(argv[0]);
     123         216 :     set_pglocale_pgservice(argv[0], PG_TEXTDOMAIN("pg_resetwal"));
     124         216 :     progname = get_progname(argv[0]);
     125             : 
     126         216 :     if (argc > 1)
     127             :     {
     128         214 :         if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
     129             :         {
     130           2 :             usage();
     131           2 :             exit(0);
     132             :         }
     133         212 :         if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
     134             :         {
     135          56 :             puts("pg_resetwal (PostgreSQL) " PG_VERSION);
     136          56 :             exit(0);
     137             :         }
     138             :     }
     139             : 
     140             : 
     141         328 :     while ((c = getopt_long(argc, argv, "c:D:e:fl:m:no:O:u:x:", long_options, NULL)) != -1)
     142             :     {
     143         214 :         switch (c)
     144             :         {
     145           8 :             case 'D':
     146           8 :                 DataDir = optarg;
     147           8 :                 break;
     148             : 
     149          28 :             case 'f':
     150          28 :                 force = true;
     151          28 :                 break;
     152             : 
     153          48 :             case 'n':
     154          48 :                 noupdate = true;
     155          48 :                 break;
     156             : 
     157          16 :             case 'e':
     158          16 :                 errno = 0;
     159          16 :                 set_xid_epoch = strtoul(optarg, &endptr, 0);
     160          16 :                 if (endptr == optarg || *endptr != '\0' || errno != 0)
     161             :                 {
     162             :                     /*------
     163             :                       translator: the second %s is a command line argument (-e, etc) */
     164           2 :                     pg_log_error("invalid argument for option %s", "-e");
     165           2 :                     pg_log_error_hint("Try \"%s --help\" for more information.", progname);
     166           2 :                     exit(1);
     167             :                 }
     168          14 :                 if (set_xid_epoch == -1)
     169           2 :                     pg_fatal("transaction ID epoch (-e) must not be -1");
     170          12 :                 break;
     171             : 
     172          14 :             case 'u':
     173          14 :                 errno = 0;
     174          14 :                 set_oldest_xid = strtoul(optarg, &endptr, 0);
     175          14 :                 if (endptr == optarg || *endptr != '\0' || errno != 0)
     176             :                 {
     177           2 :                     pg_log_error("invalid argument for option %s", "-u");
     178           2 :                     pg_log_error_hint("Try \"%s --help\" for more information.", progname);
     179           2 :                     exit(1);
     180             :                 }
     181          12 :                 if (!TransactionIdIsNormal(set_oldest_xid))
     182           2 :                     pg_fatal("oldest transaction ID (-u) must be greater than or equal to %u", FirstNormalTransactionId);
     183          10 :                 break;
     184             : 
     185          14 :             case 'x':
     186          14 :                 errno = 0;
     187          14 :                 set_xid = strtoul(optarg, &endptr, 0);
     188          14 :                 if (endptr == optarg || *endptr != '\0' || errno != 0)
     189             :                 {
     190           2 :                     pg_log_error("invalid argument for option %s", "-x");
     191           2 :                     pg_log_error_hint("Try \"%s --help\" for more information.", progname);
     192           2 :                     exit(1);
     193             :                 }
     194          12 :                 if (!TransactionIdIsNormal(set_xid))
     195           2 :                     pg_fatal("transaction ID (-x) must be greater than or equal to %u", FirstNormalTransactionId);
     196          10 :                 break;
     197             : 
     198          18 :             case 'c':
     199          18 :                 errno = 0;
     200          18 :                 set_oldest_commit_ts_xid = strtoul(optarg, &endptr, 0);
     201          18 :                 if (endptr == optarg || *endptr != ',' || errno != 0)
     202             :                 {
     203           2 :                     pg_log_error("invalid argument for option %s", "-c");
     204           2 :                     pg_log_error_hint("Try \"%s --help\" for more information.", progname);
     205           2 :                     exit(1);
     206             :                 }
     207          16 :                 set_newest_commit_ts_xid = strtoul(endptr + 1, &endptr2, 0);
     208          16 :                 if (endptr2 == endptr + 1 || *endptr2 != '\0' || errno != 0)
     209             :                 {
     210           2 :                     pg_log_error("invalid argument for option %s", "-c");
     211           2 :                     pg_log_error_hint("Try \"%s --help\" for more information.", progname);
     212           2 :                     exit(1);
     213             :                 }
     214             : 
     215          14 :                 if (set_oldest_commit_ts_xid < FirstNormalTransactionId &&
     216           2 :                     set_oldest_commit_ts_xid != InvalidTransactionId)
     217           2 :                     pg_fatal("transaction ID (-c) must be either %u or greater than or equal to %u", InvalidTransactionId, FirstNormalTransactionId);
     218             : 
     219          12 :                 if (set_newest_commit_ts_xid < FirstNormalTransactionId &&
     220           6 :                     set_newest_commit_ts_xid != InvalidTransactionId)
     221           2 :                     pg_fatal("transaction ID (-c) must be either %u or greater than or equal to %u", InvalidTransactionId, FirstNormalTransactionId);
     222          10 :                 break;
     223             : 
     224          14 :             case 'o':
     225          14 :                 errno = 0;
     226          14 :                 set_oid = strtoul(optarg, &endptr, 0);
     227          14 :                 if (endptr == optarg || *endptr != '\0' || errno != 0)
     228             :                 {
     229           2 :                     pg_log_error("invalid argument for option %s", "-o");
     230           2 :                     pg_log_error_hint("Try \"%s --help\" for more information.", progname);
     231           2 :                     exit(1);
     232             :                 }
     233          12 :                 if (set_oid == 0)
     234           2 :                     pg_fatal("OID (-o) must not be 0");
     235          10 :                 break;
     236             : 
     237          18 :             case 'm':
     238          18 :                 errno = 0;
     239          18 :                 set_mxid = strtoul(optarg, &endptr, 0);
     240          18 :                 if (endptr == optarg || *endptr != ',' || errno != 0)
     241             :                 {
     242           2 :                     pg_log_error("invalid argument for option %s", "-m");
     243           2 :                     pg_log_error_hint("Try \"%s --help\" for more information.", progname);
     244           2 :                     exit(1);
     245             :                 }
     246             : 
     247          16 :                 set_oldestmxid = strtoul(endptr + 1, &endptr2, 0);
     248          16 :                 if (endptr2 == endptr + 1 || *endptr2 != '\0' || errno != 0)
     249             :                 {
     250           2 :                     pg_log_error("invalid argument for option %s", "-m");
     251           2 :                     pg_log_error_hint("Try \"%s --help\" for more information.", progname);
     252           2 :                     exit(1);
     253             :                 }
     254          14 :                 if (set_mxid == 0)
     255           2 :                     pg_fatal("multitransaction ID (-m) must not be 0");
     256             : 
     257             :                 /*
     258             :                  * XXX It'd be nice to have more sanity checks here, e.g. so
     259             :                  * that oldest is not wrapped around w.r.t. nextMulti.
     260             :                  */
     261          12 :                 if (set_oldestmxid == 0)
     262           2 :                     pg_fatal("oldest multitransaction ID (-m) must not be 0");
     263          10 :                 break;
     264             : 
     265          14 :             case 'O':
     266          14 :                 errno = 0;
     267          14 :                 set_mxoff = strtoul(optarg, &endptr, 0);
     268          14 :                 if (endptr == optarg || *endptr != '\0' || errno != 0)
     269             :                 {
     270           2 :                     pg_log_error("invalid argument for option %s", "-O");
     271           2 :                     pg_log_error_hint("Try \"%s --help\" for more information.", progname);
     272           2 :                     exit(1);
     273             :                 }
     274          12 :                 if (set_mxoff == -1)
     275           2 :                     pg_fatal("multitransaction offset (-O) must not be -1");
     276          10 :                 break;
     277             : 
     278          12 :             case 'l':
     279          12 :                 if (strspn(optarg, "01234567890ABCDEFabcdef") != XLOG_FNAME_LEN)
     280             :                 {
     281           2 :                     pg_log_error("invalid argument for option %s", "-l");
     282           2 :                     pg_log_error_hint("Try \"%s --help\" for more information.", progname);
     283           2 :                     exit(1);
     284             :                 }
     285             : 
     286             :                 /*
     287             :                  * XLogFromFileName requires wal segment size which is not yet
     288             :                  * set. Hence wal details are set later on.
     289             :                  */
     290          10 :                 log_fname = pg_strdup(optarg);
     291          10 :                 break;
     292             : 
     293           8 :             case 1:
     294             :                 {
     295             :                     int         wal_segsize_mb;
     296             : 
     297           8 :                     if (!option_parse_int(optarg, "--wal-segsize", 1, 1024, &wal_segsize_mb))
     298           2 :                         exit(1);
     299           6 :                     set_wal_segsize = wal_segsize_mb * 1024 * 1024;
     300           6 :                     if (!IsValidWalSegSize(set_wal_segsize))
     301           2 :                         pg_fatal("argument of %s must be a power of two between 1 and 1024", "--wal-segsize");
     302           4 :                     break;
     303             :                 }
     304             : 
     305           2 :             default:
     306             :                 /* getopt_long already emitted a complaint */
     307           2 :                 pg_log_error_hint("Try \"%s --help\" for more information.", progname);
     308           2 :                 exit(1);
     309             :         }
     310             :     }
     311             : 
     312         114 :     if (DataDir == NULL && optind < argc)
     313         104 :         DataDir = argv[optind++];
     314             : 
     315             :     /* Complain if any arguments remain */
     316         114 :     if (optind < argc)
     317             :     {
     318           2 :         pg_log_error("too many command-line arguments (first is \"%s\")",
     319             :                      argv[optind]);
     320           2 :         pg_log_error_hint("Try \"%s --help\" for more information.", progname);
     321           2 :         exit(1);
     322             :     }
     323             : 
     324         112 :     if (DataDir == NULL)
     325             :     {
     326           2 :         pg_log_error("no data directory specified");
     327           2 :         pg_log_error_hint("Try \"%s --help\" for more information.", progname);
     328           2 :         exit(1);
     329             :     }
     330             : 
     331             :     /*
     332             :      * Don't allow pg_resetwal to be run as root, to avoid overwriting the
     333             :      * ownership of files in the data directory. We need only check for root
     334             :      * -- any other user won't have sufficient permissions to modify files in
     335             :      * the data directory.
     336             :      */
     337             : #ifndef WIN32
     338         110 :     if (geteuid() == 0)
     339             :     {
     340           0 :         pg_log_error("cannot be executed by \"root\"");
     341           0 :         pg_log_error_hint("You must run %s as the PostgreSQL superuser.",
     342             :                           progname);
     343           0 :         exit(1);
     344             :     }
     345             : #endif
     346             : 
     347         110 :     get_restricted_token();
     348             : 
     349             :     /* Set mask based on PGDATA permissions */
     350         110 :     if (!GetDataDirectoryCreatePerm(DataDir))
     351           2 :         pg_fatal("could not read permissions of directory \"%s\": %m",
     352             :                  DataDir);
     353             : 
     354         108 :     umask(pg_mode_mask);
     355             : 
     356         108 :     if (chdir(DataDir) < 0)
     357           0 :         pg_fatal("could not change directory to \"%s\": %m",
     358             :                  DataDir);
     359             : 
     360             :     /* Check that data directory matches our server version */
     361         108 :     CheckDataVersion();
     362             : 
     363             :     /*
     364             :      * Check for a postmaster lock file --- if there is one, refuse to
     365             :      * proceed, on grounds we might be interfering with a live installation.
     366             :      */
     367         108 :     if ((fd = open("postmaster.pid", O_RDONLY, 0)) < 0)
     368             :     {
     369         106 :         if (errno != ENOENT)
     370           0 :             pg_fatal("could not open file \"%s\" for reading: %m",
     371             :                      "postmaster.pid");
     372             :     }
     373             :     else
     374             :     {
     375           2 :         pg_log_error("lock file \"%s\" exists", "postmaster.pid");
     376           2 :         pg_log_error_hint("Is a server running?  If not, delete the lock file and try again.");
     377           2 :         exit(1);
     378             :     }
     379             : 
     380             :     /*
     381             :      * Attempt to read the existing pg_control file
     382             :      */
     383         106 :     if (!read_controlfile())
     384           8 :         GuessControlValues();
     385             : 
     386             :     /*
     387             :      * If no new WAL segment size was specified, use the control file value.
     388             :      */
     389         106 :     if (set_wal_segsize != 0)
     390           4 :         WalSegSz = set_wal_segsize;
     391             :     else
     392         102 :         WalSegSz = ControlFile.xlog_seg_size;
     393             : 
     394         106 :     if (log_fname != NULL)
     395          10 :         XLogFromFileName(log_fname, &minXlogTli, &minXlogSegNo, WalSegSz);
     396             : 
     397             :     /*
     398             :      * Also look at existing segment files to set up newXlogSegNo
     399             :      */
     400         106 :     FindEndOfXLOG();
     401             : 
     402             :     /*
     403             :      * If we're not going to proceed with the reset, print the current control
     404             :      * file parameters.
     405             :      */
     406         106 :     if ((guessed && !force) || noupdate)
     407          50 :         PrintControlValues(guessed);
     408             : 
     409             :     /*
     410             :      * Adjust fields if required by switches.  (Do this now so that printout,
     411             :      * if any, includes these values.)
     412             :      */
     413         106 :     if (set_xid_epoch != -1)
     414             :         ControlFile.checkPointCopy.nextXid =
     415          12 :             FullTransactionIdFromEpochAndXid(set_xid_epoch,
     416          12 :                                              XidFromFullTransactionId(ControlFile.checkPointCopy.nextXid));
     417             : 
     418         106 :     if (set_oldest_xid != 0)
     419             :     {
     420          10 :         ControlFile.checkPointCopy.oldestXid = set_oldest_xid;
     421          10 :         ControlFile.checkPointCopy.oldestXidDB = InvalidOid;
     422             :     }
     423             : 
     424         106 :     if (set_xid != 0)
     425             :         ControlFile.checkPointCopy.nextXid =
     426          10 :             FullTransactionIdFromEpochAndXid(EpochFromFullTransactionId(ControlFile.checkPointCopy.nextXid),
     427             :                                              set_xid);
     428             : 
     429         106 :     if (set_oldest_commit_ts_xid != 0)
     430          10 :         ControlFile.checkPointCopy.oldestCommitTsXid = set_oldest_commit_ts_xid;
     431         106 :     if (set_newest_commit_ts_xid != 0)
     432           6 :         ControlFile.checkPointCopy.newestCommitTsXid = set_newest_commit_ts_xid;
     433             : 
     434         106 :     if (set_oid != 0)
     435          10 :         ControlFile.checkPointCopy.nextOid = set_oid;
     436             : 
     437         106 :     if (set_mxid != 0)
     438             :     {
     439          10 :         ControlFile.checkPointCopy.nextMulti = set_mxid;
     440             : 
     441          10 :         ControlFile.checkPointCopy.oldestMulti = set_oldestmxid;
     442          10 :         if (ControlFile.checkPointCopy.oldestMulti < FirstMultiXactId)
     443           0 :             ControlFile.checkPointCopy.oldestMulti += FirstMultiXactId;
     444          10 :         ControlFile.checkPointCopy.oldestMultiDB = InvalidOid;
     445             :     }
     446             : 
     447         106 :     if (set_mxoff != -1)
     448          10 :         ControlFile.checkPointCopy.nextMultiOffset = set_mxoff;
     449             : 
     450         106 :     if (minXlogTli > ControlFile.checkPointCopy.ThisTimeLineID)
     451             :     {
     452           0 :         ControlFile.checkPointCopy.ThisTimeLineID = minXlogTli;
     453           0 :         ControlFile.checkPointCopy.PrevTimeLineID = minXlogTli;
     454             :     }
     455             : 
     456         106 :     if (set_wal_segsize != 0)
     457           4 :         ControlFile.xlog_seg_size = WalSegSz;
     458             : 
     459         106 :     if (minXlogSegNo > newXlogSegNo)
     460           6 :         newXlogSegNo = minXlogSegNo;
     461             : 
     462         106 :     if (noupdate)
     463             :     {
     464          48 :         PrintNewControlValues();
     465          48 :         exit(0);
     466             :     }
     467             : 
     468             :     /*
     469             :      * If we had to guess anything, and -f was not given, just print the
     470             :      * guessed values and exit.
     471             :      */
     472          58 :     if (guessed && !force)
     473             :     {
     474           2 :         PrintNewControlValues();
     475           2 :         pg_log_error("not proceeding because control file values were guessed");
     476           2 :         pg_log_error_hint("If these values seem acceptable, use -f to force reset.");
     477           2 :         exit(1);
     478             :     }
     479             : 
     480             :     /*
     481             :      * Don't reset from a dirty pg_control without -f, either.
     482             :      */
     483          56 :     if (ControlFile.state != DB_SHUTDOWNED && !force)
     484             :     {
     485           2 :         pg_log_error("database server was not shut down cleanly");
     486           2 :         pg_log_error_detail("Resetting the write-ahead log might cause data to be lost.");
     487           2 :         pg_log_error_hint("If you want to proceed anyway, use -f to force reset.");
     488           2 :         exit(1);
     489             :     }
     490             : 
     491             :     /*
     492             :      * Else, do the dirty deed.
     493             :      */
     494          54 :     RewriteControlFile();
     495          54 :     KillExistingXLOG();
     496          54 :     KillExistingArchiveStatus();
     497          54 :     KillExistingWALSummaries();
     498          54 :     WriteEmptyXLOG();
     499             : 
     500          54 :     printf(_("Write-ahead log reset\n"));
     501          54 :     return 0;
     502             : }
     503             : 
     504             : 
     505             : /*
     506             :  * Look at the version string stored in PG_VERSION and decide if this utility
     507             :  * can be run safely or not.
     508             :  *
     509             :  * We don't want to inject pg_control and WAL files that are for a different
     510             :  * major version; that can't do anything good.  Note that we don't treat
     511             :  * mismatching version info in pg_control as a reason to bail out, because
     512             :  * recovering from a corrupted pg_control is one of the main reasons for this
     513             :  * program to exist at all.  However, PG_VERSION is unlikely to get corrupted,
     514             :  * and if it were it would be easy to fix by hand.  So let's make this check
     515             :  * to prevent simple user errors.
     516             :  */
     517             : static void
     518         108 : CheckDataVersion(void)
     519             : {
     520         108 :     const char *ver_file = "PG_VERSION";
     521             :     FILE       *ver_fd;
     522             :     char        rawline[64];
     523             : 
     524         108 :     if ((ver_fd = fopen(ver_file, "r")) == NULL)
     525           0 :         pg_fatal("could not open file \"%s\" for reading: %m",
     526             :                  ver_file);
     527             : 
     528             :     /* version number has to be the first line read */
     529         108 :     if (!fgets(rawline, sizeof(rawline), ver_fd))
     530             :     {
     531           0 :         if (!ferror(ver_fd))
     532           0 :             pg_fatal("unexpected empty file \"%s\"", ver_file);
     533             :         else
     534           0 :             pg_fatal("could not read file \"%s\": %m", ver_file);
     535             :     }
     536             : 
     537             :     /* strip trailing newline and carriage return */
     538         108 :     (void) pg_strip_crlf(rawline);
     539             : 
     540         108 :     if (strcmp(rawline, PG_MAJORVERSION) != 0)
     541             :     {
     542           0 :         pg_log_error("data directory is of wrong version");
     543           0 :         pg_log_error_detail("File \"%s\" contains \"%s\", which is not compatible with this program's version \"%s\".",
     544             :                             ver_file, rawline, PG_MAJORVERSION);
     545           0 :         exit(1);
     546             :     }
     547             : 
     548         108 :     fclose(ver_fd);
     549         108 : }
     550             : 
     551             : 
     552             : /*
     553             :  * Try to read the existing pg_control file.
     554             :  *
     555             :  * This routine is also responsible for updating old pg_control versions
     556             :  * to the current format.  (Currently we don't do anything of the sort.)
     557             :  */
     558             : static bool
     559         106 : read_controlfile(void)
     560             : {
     561             :     int         fd;
     562             :     int         len;
     563             :     char       *buffer;
     564             :     pg_crc32c   crc;
     565             : 
     566         106 :     if ((fd = open(XLOG_CONTROL_FILE, O_RDONLY | PG_BINARY, 0)) < 0)
     567             :     {
     568             :         /*
     569             :          * If pg_control is not there at all, or we can't read it, the odds
     570             :          * are we've been handed a bad DataDir path, so give up. User can do
     571             :          * "touch pg_control" to force us to proceed.
     572             :          */
     573           0 :         pg_log_error("could not open file \"%s\" for reading: %m",
     574             :                      XLOG_CONTROL_FILE);
     575           0 :         if (errno == ENOENT)
     576           0 :             pg_log_error_hint("If you are sure the data directory path is correct, execute\n"
     577             :                               "  touch %s\n"
     578             :                               "and try again.",
     579             :                               XLOG_CONTROL_FILE);
     580           0 :         exit(1);
     581             :     }
     582             : 
     583             :     /* Use malloc to ensure we have a maxaligned buffer */
     584         106 :     buffer = (char *) pg_malloc(PG_CONTROL_FILE_SIZE);
     585             : 
     586         106 :     len = read(fd, buffer, PG_CONTROL_FILE_SIZE);
     587         106 :     if (len < 0)
     588           0 :         pg_fatal("could not read file \"%s\": %m", XLOG_CONTROL_FILE);
     589         106 :     close(fd);
     590             : 
     591         106 :     if (len >= sizeof(ControlFileData) &&
     592         106 :         ((ControlFileData *) buffer)->pg_control_version == PG_CONTROL_VERSION)
     593             :     {
     594             :         /* Check the CRC. */
     595         104 :         INIT_CRC32C(crc);
     596         104 :         COMP_CRC32C(crc,
     597             :                     buffer,
     598             :                     offsetof(ControlFileData, crc));
     599         104 :         FIN_CRC32C(crc);
     600             : 
     601         104 :         if (!EQ_CRC32C(crc, ((ControlFileData *) buffer)->crc))
     602             :         {
     603             :             /* We will use the data but treat it as guessed. */
     604           6 :             pg_log_warning("pg_control exists but has invalid CRC; proceed with caution");
     605           6 :             guessed = true;
     606             :         }
     607             : 
     608         104 :         memcpy(&ControlFile, buffer, sizeof(ControlFile));
     609             : 
     610             :         /* return false if WAL segment size is not valid */
     611         104 :         if (!IsValidWalSegSize(ControlFile.xlog_seg_size))
     612             :         {
     613           6 :             pg_log_warning(ngettext("pg_control specifies invalid WAL segment size (%d byte); proceed with caution",
     614             :                                     "pg_control specifies invalid WAL segment size (%d bytes); proceed with caution",
     615             :                                     ControlFile.xlog_seg_size),
     616             :                            ControlFile.xlog_seg_size);
     617           6 :             return false;
     618             :         }
     619             : 
     620          98 :         return true;
     621             :     }
     622             : 
     623             :     /* Looks like it's a mess. */
     624           2 :     pg_log_warning("pg_control exists but is broken or wrong version; ignoring it");
     625           2 :     return false;
     626             : }
     627             : 
     628             : 
     629             : /*
     630             :  * Guess at pg_control values when we can't read the old ones.
     631             :  */
     632             : static void
     633           8 : GuessControlValues(void)
     634             : {
     635             :     uint64      sysidentifier;
     636             :     struct timeval tv;
     637             : 
     638             :     /*
     639             :      * Set up a completely default set of pg_control values.
     640             :      */
     641           8 :     guessed = true;
     642           8 :     memset(&ControlFile, 0, sizeof(ControlFile));
     643             : 
     644           8 :     ControlFile.pg_control_version = PG_CONTROL_VERSION;
     645           8 :     ControlFile.catalog_version_no = CATALOG_VERSION_NO;
     646             : 
     647             :     /*
     648             :      * Create a new unique installation identifier, since we can no longer use
     649             :      * any old XLOG records.  See notes in xlog.c about the algorithm.
     650             :      */
     651           8 :     gettimeofday(&tv, NULL);
     652           8 :     sysidentifier = ((uint64) tv.tv_sec) << 32;
     653           8 :     sysidentifier |= ((uint64) tv.tv_usec) << 12;
     654           8 :     sysidentifier |= getpid() & 0xFFF;
     655             : 
     656           8 :     ControlFile.system_identifier = sysidentifier;
     657             : 
     658           8 :     ControlFile.checkPointCopy.redo = SizeOfXLogLongPHD;
     659           8 :     ControlFile.checkPointCopy.ThisTimeLineID = 1;
     660           8 :     ControlFile.checkPointCopy.PrevTimeLineID = 1;
     661           8 :     ControlFile.checkPointCopy.fullPageWrites = false;
     662             :     ControlFile.checkPointCopy.nextXid =
     663           8 :         FullTransactionIdFromEpochAndXid(0, FirstNormalTransactionId);
     664           8 :     ControlFile.checkPointCopy.nextOid = FirstGenbkiObjectId;
     665           8 :     ControlFile.checkPointCopy.nextMulti = FirstMultiXactId;
     666           8 :     ControlFile.checkPointCopy.nextMultiOffset = 0;
     667           8 :     ControlFile.checkPointCopy.oldestXid = FirstNormalTransactionId;
     668           8 :     ControlFile.checkPointCopy.oldestXidDB = InvalidOid;
     669           8 :     ControlFile.checkPointCopy.oldestMulti = FirstMultiXactId;
     670           8 :     ControlFile.checkPointCopy.oldestMultiDB = InvalidOid;
     671           8 :     ControlFile.checkPointCopy.time = (pg_time_t) time(NULL);
     672           8 :     ControlFile.checkPointCopy.oldestActiveXid = InvalidTransactionId;
     673             : 
     674           8 :     ControlFile.state = DB_SHUTDOWNED;
     675           8 :     ControlFile.time = (pg_time_t) time(NULL);
     676           8 :     ControlFile.checkPoint = ControlFile.checkPointCopy.redo;
     677           8 :     ControlFile.unloggedLSN = FirstNormalUnloggedLSN;
     678             : 
     679             :     /* minRecoveryPoint, backupStartPoint and backupEndPoint can be left zero */
     680             : 
     681           8 :     ControlFile.wal_level = WAL_LEVEL_MINIMAL;
     682           8 :     ControlFile.wal_log_hints = false;
     683           8 :     ControlFile.track_commit_timestamp = false;
     684           8 :     ControlFile.MaxConnections = 100;
     685           8 :     ControlFile.max_wal_senders = 10;
     686           8 :     ControlFile.max_worker_processes = 8;
     687           8 :     ControlFile.max_prepared_xacts = 0;
     688           8 :     ControlFile.max_locks_per_xact = 64;
     689             : 
     690           8 :     ControlFile.maxAlign = MAXIMUM_ALIGNOF;
     691           8 :     ControlFile.floatFormat = FLOATFORMAT_VALUE;
     692           8 :     ControlFile.blcksz = BLCKSZ;
     693           8 :     ControlFile.relseg_size = RELSEG_SIZE;
     694           8 :     ControlFile.xlog_blcksz = XLOG_BLCKSZ;
     695           8 :     ControlFile.xlog_seg_size = DEFAULT_XLOG_SEG_SIZE;
     696           8 :     ControlFile.nameDataLen = NAMEDATALEN;
     697           8 :     ControlFile.indexMaxKeys = INDEX_MAX_KEYS;
     698           8 :     ControlFile.toast_max_chunk_size = TOAST_MAX_CHUNK_SIZE;
     699           8 :     ControlFile.loblksize = LOBLKSIZE;
     700           8 :     ControlFile.float8ByVal = FLOAT8PASSBYVAL;
     701             : 
     702             :     /*
     703             :      * XXX eventually, should try to grovel through old XLOG to develop more
     704             :      * accurate values for TimeLineID, nextXID, etc.
     705             :      */
     706           8 : }
     707             : 
     708             : 
     709             : /*
     710             :  * Print the guessed pg_control values when we had to guess.
     711             :  *
     712             :  * NB: this display should be just those fields that will not be
     713             :  * reset by RewriteControlFile().
     714             :  */
     715             : static void
     716          50 : PrintControlValues(bool guessed)
     717             : {
     718          50 :     if (guessed)
     719           6 :         printf(_("Guessed pg_control values:\n\n"));
     720             :     else
     721          44 :         printf(_("Current pg_control values:\n\n"));
     722             : 
     723          50 :     printf(_("pg_control version number:            %u\n"),
     724             :            ControlFile.pg_control_version);
     725          50 :     printf(_("Catalog version number:               %u\n"),
     726             :            ControlFile.catalog_version_no);
     727          50 :     printf(_("Database system identifier:           %llu\n"),
     728             :            (unsigned long long) ControlFile.system_identifier);
     729          50 :     printf(_("Latest checkpoint's TimeLineID:       %u\n"),
     730             :            ControlFile.checkPointCopy.ThisTimeLineID);
     731          50 :     printf(_("Latest checkpoint's full_page_writes: %s\n"),
     732             :            ControlFile.checkPointCopy.fullPageWrites ? _("on") : _("off"));
     733          50 :     printf(_("Latest checkpoint's NextXID:          %u:%u\n"),
     734             :            EpochFromFullTransactionId(ControlFile.checkPointCopy.nextXid),
     735             :            XidFromFullTransactionId(ControlFile.checkPointCopy.nextXid));
     736          50 :     printf(_("Latest checkpoint's NextOID:          %u\n"),
     737             :            ControlFile.checkPointCopy.nextOid);
     738          50 :     printf(_("Latest checkpoint's NextMultiXactId:  %u\n"),
     739             :            ControlFile.checkPointCopy.nextMulti);
     740          50 :     printf(_("Latest checkpoint's NextMultiOffset:  %u\n"),
     741             :            ControlFile.checkPointCopy.nextMultiOffset);
     742          50 :     printf(_("Latest checkpoint's oldestXID:        %u\n"),
     743             :            ControlFile.checkPointCopy.oldestXid);
     744          50 :     printf(_("Latest checkpoint's oldestXID's DB:   %u\n"),
     745             :            ControlFile.checkPointCopy.oldestXidDB);
     746          50 :     printf(_("Latest checkpoint's oldestActiveXID:  %u\n"),
     747             :            ControlFile.checkPointCopy.oldestActiveXid);
     748          50 :     printf(_("Latest checkpoint's oldestMultiXid:   %u\n"),
     749             :            ControlFile.checkPointCopy.oldestMulti);
     750          50 :     printf(_("Latest checkpoint's oldestMulti's DB: %u\n"),
     751             :            ControlFile.checkPointCopy.oldestMultiDB);
     752          50 :     printf(_("Latest checkpoint's oldestCommitTsXid:%u\n"),
     753             :            ControlFile.checkPointCopy.oldestCommitTsXid);
     754          50 :     printf(_("Latest checkpoint's newestCommitTsXid:%u\n"),
     755             :            ControlFile.checkPointCopy.newestCommitTsXid);
     756          50 :     printf(_("Maximum data alignment:               %u\n"),
     757             :            ControlFile.maxAlign);
     758             :     /* we don't print floatFormat since can't say much useful about it */
     759          50 :     printf(_("Database block size:                  %u\n"),
     760             :            ControlFile.blcksz);
     761          50 :     printf(_("Blocks per segment of large relation: %u\n"),
     762             :            ControlFile.relseg_size);
     763          50 :     printf(_("WAL block size:                       %u\n"),
     764             :            ControlFile.xlog_blcksz);
     765          50 :     printf(_("Bytes per WAL segment:                %u\n"),
     766             :            ControlFile.xlog_seg_size);
     767          50 :     printf(_("Maximum length of identifiers:        %u\n"),
     768             :            ControlFile.nameDataLen);
     769          50 :     printf(_("Maximum columns in an index:          %u\n"),
     770             :            ControlFile.indexMaxKeys);
     771          50 :     printf(_("Maximum size of a TOAST chunk:        %u\n"),
     772             :            ControlFile.toast_max_chunk_size);
     773          50 :     printf(_("Size of a large-object chunk:         %u\n"),
     774             :            ControlFile.loblksize);
     775             :     /* This is no longer configurable, but users may still expect to see it: */
     776          50 :     printf(_("Date/time type storage:               %s\n"),
     777             :            _("64-bit integers"));
     778          50 :     printf(_("Float8 argument passing:              %s\n"),
     779             :            (ControlFile.float8ByVal ? _("by value") : _("by reference")));
     780          50 :     printf(_("Data page checksum version:           %u\n"),
     781             :            ControlFile.data_checksum_version);
     782          50 : }
     783             : 
     784             : 
     785             : /*
     786             :  * Print the values to be changed.
     787             :  */
     788             : static void
     789          50 : PrintNewControlValues(void)
     790             : {
     791             :     char        fname[MAXFNAMELEN];
     792             : 
     793             :     /* This will be always printed in order to keep format same. */
     794          50 :     printf(_("\n\nValues to be changed:\n\n"));
     795             : 
     796          50 :     XLogFileName(fname, ControlFile.checkPointCopy.ThisTimeLineID,
     797             :                  newXlogSegNo, WalSegSz);
     798          50 :     printf(_("First log segment after reset:        %s\n"), fname);
     799             : 
     800          50 :     if (set_mxid != 0)
     801             :     {
     802           2 :         printf(_("NextMultiXactId:                      %u\n"),
     803             :                ControlFile.checkPointCopy.nextMulti);
     804           2 :         printf(_("OldestMultiXid:                       %u\n"),
     805             :                ControlFile.checkPointCopy.oldestMulti);
     806           2 :         printf(_("OldestMulti's DB:                     %u\n"),
     807             :                ControlFile.checkPointCopy.oldestMultiDB);
     808             :     }
     809             : 
     810          50 :     if (set_mxoff != -1)
     811             :     {
     812           2 :         printf(_("NextMultiOffset:                      %u\n"),
     813             :                ControlFile.checkPointCopy.nextMultiOffset);
     814             :     }
     815             : 
     816          50 :     if (set_oid != 0)
     817             :     {
     818           2 :         printf(_("NextOID:                              %u\n"),
     819             :                ControlFile.checkPointCopy.nextOid);
     820             :     }
     821             : 
     822          50 :     if (set_xid != 0)
     823             :     {
     824           2 :         printf(_("NextXID:                              %u\n"),
     825             :                XidFromFullTransactionId(ControlFile.checkPointCopy.nextXid));
     826           2 :         printf(_("OldestXID:                            %u\n"),
     827             :                ControlFile.checkPointCopy.oldestXid);
     828           2 :         printf(_("OldestXID's DB:                       %u\n"),
     829             :                ControlFile.checkPointCopy.oldestXidDB);
     830             :     }
     831             : 
     832          50 :     if (set_xid_epoch != -1)
     833             :     {
     834           2 :         printf(_("NextXID epoch:                        %u\n"),
     835             :                EpochFromFullTransactionId(ControlFile.checkPointCopy.nextXid));
     836             :     }
     837             : 
     838          50 :     if (set_oldest_commit_ts_xid != 0)
     839             :     {
     840           2 :         printf(_("oldestCommitTsXid:                    %u\n"),
     841             :                ControlFile.checkPointCopy.oldestCommitTsXid);
     842             :     }
     843          50 :     if (set_newest_commit_ts_xid != 0)
     844             :     {
     845           0 :         printf(_("newestCommitTsXid:                    %u\n"),
     846             :                ControlFile.checkPointCopy.newestCommitTsXid);
     847             :     }
     848             : 
     849          50 :     if (set_wal_segsize != 0)
     850             :     {
     851           2 :         printf(_("Bytes per WAL segment:                %u\n"),
     852             :                ControlFile.xlog_seg_size);
     853             :     }
     854          50 : }
     855             : 
     856             : 
     857             : /*
     858             :  * Write out the new pg_control file.
     859             :  */
     860             : static void
     861          54 : RewriteControlFile(void)
     862             : {
     863             :     /*
     864             :      * Adjust fields as needed to force an empty XLOG starting at
     865             :      * newXlogSegNo.
     866             :      */
     867          54 :     XLogSegNoOffsetToRecPtr(newXlogSegNo, SizeOfXLogLongPHD, WalSegSz,
     868             :                             ControlFile.checkPointCopy.redo);
     869          54 :     ControlFile.checkPointCopy.time = (pg_time_t) time(NULL);
     870             : 
     871          54 :     ControlFile.state = DB_SHUTDOWNED;
     872          54 :     ControlFile.checkPoint = ControlFile.checkPointCopy.redo;
     873          54 :     ControlFile.minRecoveryPoint = 0;
     874          54 :     ControlFile.minRecoveryPointTLI = 0;
     875          54 :     ControlFile.backupStartPoint = 0;
     876          54 :     ControlFile.backupEndPoint = 0;
     877          54 :     ControlFile.backupEndRequired = false;
     878             : 
     879             :     /*
     880             :      * Force the defaults for max_* settings. The values don't really matter
     881             :      * as long as wal_level='minimal'; the postmaster will reset these fields
     882             :      * anyway at startup.
     883             :      */
     884          54 :     ControlFile.wal_level = WAL_LEVEL_MINIMAL;
     885          54 :     ControlFile.wal_log_hints = false;
     886          54 :     ControlFile.track_commit_timestamp = false;
     887          54 :     ControlFile.MaxConnections = 100;
     888          54 :     ControlFile.max_wal_senders = 10;
     889          54 :     ControlFile.max_worker_processes = 8;
     890          54 :     ControlFile.max_prepared_xacts = 0;
     891          54 :     ControlFile.max_locks_per_xact = 64;
     892             : 
     893             :     /* The control file gets flushed here. */
     894          54 :     update_controlfile(".", &ControlFile, true);
     895          54 : }
     896             : 
     897             : 
     898             : /*
     899             :  * Scan existing XLOG files and determine the highest existing WAL address
     900             :  *
     901             :  * On entry, ControlFile.checkPointCopy.redo and ControlFile.xlog_seg_size
     902             :  * are assumed valid (note that we allow the old xlog seg size to differ
     903             :  * from what we're using).  On exit, newXlogSegNo is set to suitable
     904             :  * value for the beginning of replacement WAL (in our seg size).
     905             :  */
     906             : static void
     907         106 : FindEndOfXLOG(void)
     908             : {
     909             :     DIR        *xldir;
     910             :     struct dirent *xlde;
     911             :     uint64      xlogbytepos;
     912             : 
     913             :     /*
     914             :      * Initialize the max() computation using the last checkpoint address from
     915             :      * old pg_control.  Note that for the moment we are working with segment
     916             :      * numbering according to the old xlog seg size.
     917             :      */
     918         106 :     XLByteToSeg(ControlFile.checkPointCopy.redo, newXlogSegNo,
     919             :                 ControlFile.xlog_seg_size);
     920             : 
     921             :     /*
     922             :      * Scan the pg_wal directory to find existing WAL segment files. We assume
     923             :      * any present have been used; in most scenarios this should be
     924             :      * conservative, because of xlog.c's attempts to pre-create files.
     925             :      */
     926         106 :     xldir = opendir(XLOGDIR);
     927         106 :     if (xldir == NULL)
     928           0 :         pg_fatal("could not open directory \"%s\": %m", XLOGDIR);
     929             : 
     930        1024 :     while (errno = 0, (xlde = readdir(xldir)) != NULL)
     931             :     {
     932        1344 :         if (IsXLogFileName(xlde->d_name) ||
     933         426 :             IsPartialXLogFileName(xlde->d_name))
     934             :         {
     935             :             TimeLineID  tli;
     936             :             XLogSegNo   segno;
     937             : 
     938             :             /* Use the segment size from the control file */
     939         492 :             XLogFromFileName(xlde->d_name, &tli, &segno,
     940         492 :                              ControlFile.xlog_seg_size);
     941             : 
     942             :             /*
     943             :              * Note: we take the max of all files found, regardless of their
     944             :              * timelines.  Another possibility would be to ignore files of
     945             :              * timelines other than the target TLI, but this seems safer.
     946             :              * Better too large a result than too small...
     947             :              */
     948         492 :             if (segno > newXlogSegNo)
     949          70 :                 newXlogSegNo = segno;
     950             :         }
     951             :     }
     952             : 
     953         106 :     if (errno)
     954           0 :         pg_fatal("could not read directory \"%s\": %m", XLOGDIR);
     955             : 
     956         106 :     if (closedir(xldir))
     957           0 :         pg_fatal("could not close directory \"%s\": %m", XLOGDIR);
     958             : 
     959             :     /*
     960             :      * Finally, convert to new xlog seg size, and advance by one to ensure we
     961             :      * are in virgin territory.
     962             :      */
     963         106 :     xlogbytepos = newXlogSegNo * ControlFile.xlog_seg_size;
     964         106 :     newXlogSegNo = (xlogbytepos + ControlFile.xlog_seg_size - 1) / WalSegSz;
     965         106 :     newXlogSegNo++;
     966         106 : }
     967             : 
     968             : 
     969             : /*
     970             :  * Remove existing XLOG files
     971             :  */
     972             : static void
     973          54 : KillExistingXLOG(void)
     974             : {
     975             :     DIR        *xldir;
     976             :     struct dirent *xlde;
     977             :     char        path[MAXPGPATH + sizeof(XLOGDIR)];
     978             : 
     979          54 :     xldir = opendir(XLOGDIR);
     980          54 :     if (xldir == NULL)
     981           0 :         pg_fatal("could not open directory \"%s\": %m", XLOGDIR);
     982             : 
     983         436 :     while (errno = 0, (xlde = readdir(xldir)) != NULL)
     984             :     {
     985         600 :         if (IsXLogFileName(xlde->d_name) ||
     986         218 :             IsPartialXLogFileName(xlde->d_name))
     987             :         {
     988         164 :             snprintf(path, sizeof(path), "%s/%s", XLOGDIR, xlde->d_name);
     989         164 :             if (unlink(path) < 0)
     990           0 :                 pg_fatal("could not delete file \"%s\": %m", path);
     991             :         }
     992             :     }
     993             : 
     994          54 :     if (errno)
     995           0 :         pg_fatal("could not read directory \"%s\": %m", XLOGDIR);
     996             : 
     997          54 :     if (closedir(xldir))
     998           0 :         pg_fatal("could not close directory \"%s\": %m", XLOGDIR);
     999          54 : }
    1000             : 
    1001             : 
    1002             : /*
    1003             :  * Remove existing archive status files
    1004             :  */
    1005             : static void
    1006          54 : KillExistingArchiveStatus(void)
    1007             : {
    1008             : #define ARCHSTATDIR XLOGDIR "/archive_status"
    1009             : 
    1010             :     DIR        *xldir;
    1011             :     struct dirent *xlde;
    1012             :     char        path[MAXPGPATH + sizeof(ARCHSTATDIR)];
    1013             : 
    1014          54 :     xldir = opendir(ARCHSTATDIR);
    1015          54 :     if (xldir == NULL)
    1016           0 :         pg_fatal("could not open directory \"%s\": %m", ARCHSTATDIR);
    1017             : 
    1018         162 :     while (errno = 0, (xlde = readdir(xldir)) != NULL)
    1019             :     {
    1020         108 :         if (strspn(xlde->d_name, "0123456789ABCDEF") == XLOG_FNAME_LEN &&
    1021           0 :             (strcmp(xlde->d_name + XLOG_FNAME_LEN, ".ready") == 0 ||
    1022           0 :              strcmp(xlde->d_name + XLOG_FNAME_LEN, ".done") == 0 ||
    1023           0 :              strcmp(xlde->d_name + XLOG_FNAME_LEN, ".partial.ready") == 0 ||
    1024           0 :              strcmp(xlde->d_name + XLOG_FNAME_LEN, ".partial.done") == 0))
    1025             :         {
    1026           0 :             snprintf(path, sizeof(path), "%s/%s", ARCHSTATDIR, xlde->d_name);
    1027           0 :             if (unlink(path) < 0)
    1028           0 :                 pg_fatal("could not delete file \"%s\": %m", path);
    1029             :         }
    1030             :     }
    1031             : 
    1032          54 :     if (errno)
    1033           0 :         pg_fatal("could not read directory \"%s\": %m", ARCHSTATDIR);
    1034             : 
    1035          54 :     if (closedir(xldir))
    1036           0 :         pg_fatal("could not close directory \"%s\": %m", ARCHSTATDIR);
    1037          54 : }
    1038             : 
    1039             : /*
    1040             :  * Remove existing WAL summary files
    1041             :  */
    1042             : static void
    1043          54 : KillExistingWALSummaries(void)
    1044             : {
    1045             : #define WALSUMMARYDIR XLOGDIR   "/summaries"
    1046             : #define WALSUMMARY_NHEXCHARS    40
    1047             : 
    1048             :     DIR        *xldir;
    1049             :     struct dirent *xlde;
    1050             :     char        path[MAXPGPATH + sizeof(WALSUMMARYDIR)];
    1051             : 
    1052          54 :     xldir = opendir(WALSUMMARYDIR);
    1053          54 :     if (xldir == NULL)
    1054           0 :         pg_fatal("could not open directory \"%s\": %m", WALSUMMARYDIR);
    1055             : 
    1056         162 :     while (errno = 0, (xlde = readdir(xldir)) != NULL)
    1057             :     {
    1058         108 :         if (strspn(xlde->d_name, "0123456789ABCDEF") == WALSUMMARY_NHEXCHARS &&
    1059           0 :             strcmp(xlde->d_name + WALSUMMARY_NHEXCHARS, ".summary") == 0)
    1060             :         {
    1061           0 :             snprintf(path, sizeof(path), "%s/%s", WALSUMMARYDIR, xlde->d_name);
    1062           0 :             if (unlink(path) < 0)
    1063           0 :                 pg_fatal("could not delete file \"%s\": %m", path);
    1064             :         }
    1065             :     }
    1066             : 
    1067          54 :     if (errno)
    1068           0 :         pg_fatal("could not read directory \"%s\": %m", WALSUMMARYDIR);
    1069             : 
    1070          54 :     if (closedir(xldir))
    1071           0 :         pg_fatal("could not close directory \"%s\": %m", ARCHSTATDIR);
    1072          54 : }
    1073             : 
    1074             : /*
    1075             :  * Write an empty XLOG file, containing only the checkpoint record
    1076             :  * already set up in ControlFile.
    1077             :  */
    1078             : static void
    1079          54 : WriteEmptyXLOG(void)
    1080             : {
    1081             :     PGAlignedXLogBlock buffer;
    1082             :     XLogPageHeader page;
    1083             :     XLogLongPageHeader longpage;
    1084             :     XLogRecord *record;
    1085             :     pg_crc32c   crc;
    1086             :     char        path[MAXPGPATH];
    1087             :     int         fd;
    1088             :     int         nbytes;
    1089             :     char       *recptr;
    1090             : 
    1091          54 :     memset(buffer.data, 0, XLOG_BLCKSZ);
    1092             : 
    1093             :     /* Set up the XLOG page header */
    1094          54 :     page = (XLogPageHeader) buffer.data;
    1095          54 :     page->xlp_magic = XLOG_PAGE_MAGIC;
    1096          54 :     page->xlp_info = XLP_LONG_HEADER;
    1097          54 :     page->xlp_tli = ControlFile.checkPointCopy.ThisTimeLineID;
    1098          54 :     page->xlp_pageaddr = ControlFile.checkPointCopy.redo - SizeOfXLogLongPHD;
    1099          54 :     longpage = (XLogLongPageHeader) page;
    1100          54 :     longpage->xlp_sysid = ControlFile.system_identifier;
    1101          54 :     longpage->xlp_seg_size = WalSegSz;
    1102          54 :     longpage->xlp_xlog_blcksz = XLOG_BLCKSZ;
    1103             : 
    1104             :     /* Insert the initial checkpoint record */
    1105          54 :     recptr = (char *) page + SizeOfXLogLongPHD;
    1106          54 :     record = (XLogRecord *) recptr;
    1107          54 :     record->xl_prev = 0;
    1108          54 :     record->xl_xid = InvalidTransactionId;
    1109          54 :     record->xl_tot_len = SizeOfXLogRecord + SizeOfXLogRecordDataHeaderShort + sizeof(CheckPoint);
    1110          54 :     record->xl_info = XLOG_CHECKPOINT_SHUTDOWN;
    1111          54 :     record->xl_rmid = RM_XLOG_ID;
    1112             : 
    1113          54 :     recptr += SizeOfXLogRecord;
    1114          54 :     *(recptr++) = (char) XLR_BLOCK_ID_DATA_SHORT;
    1115          54 :     *(recptr++) = sizeof(CheckPoint);
    1116          54 :     memcpy(recptr, &ControlFile.checkPointCopy,
    1117             :            sizeof(CheckPoint));
    1118             : 
    1119          54 :     INIT_CRC32C(crc);
    1120          54 :     COMP_CRC32C(crc, ((char *) record) + SizeOfXLogRecord, record->xl_tot_len - SizeOfXLogRecord);
    1121          54 :     COMP_CRC32C(crc, (char *) record, offsetof(XLogRecord, xl_crc));
    1122          54 :     FIN_CRC32C(crc);
    1123          54 :     record->xl_crc = crc;
    1124             : 
    1125             :     /* Write the first page */
    1126          54 :     XLogFilePath(path, ControlFile.checkPointCopy.ThisTimeLineID,
    1127             :                  newXlogSegNo, WalSegSz);
    1128             : 
    1129          54 :     unlink(path);
    1130             : 
    1131          54 :     fd = open(path, O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
    1132             :               pg_file_create_mode);
    1133          54 :     if (fd < 0)
    1134           0 :         pg_fatal("could not open file \"%s\": %m", path);
    1135             : 
    1136          54 :     errno = 0;
    1137          54 :     if (write(fd, buffer.data, XLOG_BLCKSZ) != XLOG_BLCKSZ)
    1138             :     {
    1139             :         /* if write didn't set errno, assume problem is no disk space */
    1140           0 :         if (errno == 0)
    1141           0 :             errno = ENOSPC;
    1142           0 :         pg_fatal("could not write file \"%s\": %m", path);
    1143             :     }
    1144             : 
    1145             :     /* Fill the rest of the file with zeroes */
    1146          54 :     memset(buffer.data, 0, XLOG_BLCKSZ);
    1147       79872 :     for (nbytes = XLOG_BLCKSZ; nbytes < WalSegSz; nbytes += XLOG_BLCKSZ)
    1148             :     {
    1149       79818 :         errno = 0;
    1150       79818 :         if (write(fd, buffer.data, XLOG_BLCKSZ) != XLOG_BLCKSZ)
    1151             :         {
    1152           0 :             if (errno == 0)
    1153           0 :                 errno = ENOSPC;
    1154           0 :             pg_fatal("could not write file \"%s\": %m", path);
    1155             :         }
    1156             :     }
    1157             : 
    1158          54 :     if (fsync(fd) != 0)
    1159           0 :         pg_fatal("fsync error: %m");
    1160             : 
    1161          54 :     close(fd);
    1162          54 : }
    1163             : 
    1164             : 
    1165             : static void
    1166           2 : usage(void)
    1167             : {
    1168           2 :     printf(_("%s resets the PostgreSQL write-ahead log.\n\n"), progname);
    1169           2 :     printf(_("Usage:\n"));
    1170           2 :     printf(_("  %s [OPTION]... DATADIR\n"), progname);
    1171             : 
    1172           2 :     printf(_("\nOptions:\n"));
    1173           2 :     printf(_(" [-D, --pgdata=]DATADIR  data directory\n"));
    1174           2 :     printf(_("  -f, --force            force update to be done even after unclean shutdown or\n"
    1175             :              "                         if pg_control values had to be guessed\n"));
    1176           2 :     printf(_("  -n, --dry-run          no update, just show what would be done\n"));
    1177           2 :     printf(_("  -V, --version          output version information, then exit\n"));
    1178           2 :     printf(_("  -?, --help             show this help, then exit\n"));
    1179             : 
    1180           2 :     printf(_("\nOptions to override control file values:\n"));
    1181           2 :     printf(_("  -c, --commit-timestamp-ids=XID,XID\n"
    1182             :              "                                   set oldest and newest transactions bearing\n"
    1183             :              "                                   commit timestamp (zero means no change)\n"));
    1184           2 :     printf(_("  -e, --epoch=XIDEPOCH             set next transaction ID epoch\n"));
    1185           2 :     printf(_("  -l, --next-wal-file=WALFILE      set minimum starting location for new WAL\n"));
    1186           2 :     printf(_("  -m, --multixact-ids=MXID,MXID    set next and oldest multitransaction ID\n"));
    1187           2 :     printf(_("  -o, --next-oid=OID               set next OID\n"));
    1188           2 :     printf(_("  -O, --multixact-offset=OFFSET    set next multitransaction offset\n"));
    1189           2 :     printf(_("  -u, --oldest-transaction-id=XID  set oldest transaction ID\n"));
    1190           2 :     printf(_("  -x, --next-transaction-id=XID    set next transaction ID\n"));
    1191           2 :     printf(_("      --wal-segsize=SIZE           size of WAL segments, in megabytes\n"));
    1192             : 
    1193           2 :     printf(_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
    1194           2 :     printf(_("%s home page: <%s>\n"), PACKAGE_NAME, PACKAGE_URL);
    1195           2 : }

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