LCOV - code coverage report
Current view: top level - src/bin/pg_resetwal - pg_resetwal.c (source / functions) Coverage Total Hit
Test: PostgreSQL 19devel Lines: 90.8 % 554 503
Test Date: 2026-03-21 10:16:05 Functions: 100.0 % 15 15
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) 1996-2026, 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 "fe_utils/version.h"
      59              : #include "getopt_long.h"
      60              : #include "pg_getopt.h"
      61              : #include "storage/large_object.h"
      62              : 
      63              : static ControlFileData ControlFile; /* pg_control values */
      64              : static XLogSegNo newXlogSegNo;  /* new XLOG segment # */
      65              : static bool guessed = false;    /* T if we had to guess at any values */
      66              : static const char *progname;
      67              : 
      68              : /*
      69              :  * New values given on the command-line
      70              :  */
      71              : static bool next_xid_epoch_given = false;
      72              : static uint32 next_xid_epoch_val;
      73              : 
      74              : static bool oldest_xid_given = false;
      75              : static TransactionId oldest_xid_val;
      76              : 
      77              : static bool next_xid_given = false;
      78              : static TransactionId next_xid_val;
      79              : 
      80              : static bool commit_ts_xids_given = false;
      81              : static TransactionId oldest_commit_ts_xid_val;
      82              : static TransactionId newest_commit_ts_xid_val;
      83              : 
      84              : static bool next_oid_given = false;
      85              : static Oid  next_oid_val;
      86              : 
      87              : static bool mxids_given = false;
      88              : static MultiXactId next_mxid_val;
      89              : static MultiXactId oldest_mxid_val = 0;
      90              : 
      91              : static bool next_mxoff_given = false;
      92              : static MultiXactOffset next_mxoff_val;
      93              : 
      94              : static bool wal_segsize_given = false;
      95              : static int  wal_segsize_val;
      96              : 
      97              : static bool char_signedness_given = false;
      98              : static bool char_signedness_val;
      99              : 
     100              : 
     101              : static TimeLineID minXlogTli = 0;
     102              : static XLogSegNo minXlogSegNo = 0;
     103              : static int  WalSegSz;
     104              : 
     105              : static void CheckDataVersion(void);
     106              : static bool read_controlfile(void);
     107              : static void GuessControlValues(void);
     108              : static void PrintControlValues(bool guessed);
     109              : static void PrintNewControlValues(void);
     110              : static void RewriteControlFile(void);
     111              : static void FindEndOfXLOG(void);
     112              : static void KillExistingXLOG(void);
     113              : static void KillExistingArchiveStatus(void);
     114              : static void KillExistingWALSummaries(void);
     115              : static void WriteEmptyXLOG(void);
     116              : static void usage(void);
     117              : static uint32 strtouint32_strict(const char *restrict s, char **restrict endptr, int base);
     118              : static uint64 strtouint64_strict(const char *restrict s, char **restrict endptr, int base);
     119              : 
     120              : 
     121              : int
     122          204 : main(int argc, char *argv[])
     123              : {
     124              :     static struct option long_options[] = {
     125              :         {"commit-timestamp-ids", required_argument, NULL, 'c'},
     126              :         {"pgdata", required_argument, NULL, 'D'},
     127              :         {"epoch", required_argument, NULL, 'e'},
     128              :         {"force", no_argument, NULL, 'f'},
     129              :         {"next-wal-file", required_argument, NULL, 'l'},
     130              :         {"multixact-ids", required_argument, NULL, 'm'},
     131              :         {"dry-run", no_argument, NULL, 'n'},
     132              :         {"next-oid", required_argument, NULL, 'o'},
     133              :         {"multixact-offset", required_argument, NULL, 'O'},
     134              :         {"oldest-transaction-id", required_argument, NULL, 'u'},
     135              :         {"next-transaction-id", required_argument, NULL, 'x'},
     136              :         {"wal-segsize", required_argument, NULL, 1},
     137              :         {"char-signedness", required_argument, NULL, 2},
     138              :         {NULL, 0, NULL, 0}
     139              :     };
     140              : 
     141              :     int         c;
     142          204 :     bool        force = false;
     143          204 :     bool        noupdate = false;
     144              :     char       *endptr;
     145              :     char       *endptr2;
     146          204 :     char       *DataDir = NULL;
     147          204 :     char       *log_fname = NULL;
     148              :     int         fd;
     149              : 
     150          204 :     pg_logging_init(argv[0]);
     151          204 :     set_pglocale_pgservice(argv[0], PG_TEXTDOMAIN("pg_resetwal"));
     152          204 :     progname = get_progname(argv[0]);
     153              : 
     154          204 :     if (argc > 1)
     155              :     {
     156          203 :         if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
     157              :         {
     158            1 :             usage();
     159            1 :             exit(0);
     160              :         }
     161          202 :         if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
     162              :         {
     163           49 :             puts("pg_resetwal (PostgreSQL) " PG_VERSION);
     164           49 :             exit(0);
     165              :         }
     166              :     }
     167              : 
     168              : 
     169          346 :     while ((c = getopt_long(argc, argv, "c:D:e:fl:m:no:O:u:x:", long_options, NULL)) != -1)
     170              :     {
     171          218 :         switch (c)
     172              :         {
     173            4 :             case 'D':
     174            4 :                 DataDir = optarg;
     175            4 :                 break;
     176              : 
     177           43 :             case 'f':
     178           43 :                 force = true;
     179           43 :                 break;
     180              : 
     181           43 :             case 'n':
     182           43 :                 noupdate = true;
     183           43 :                 break;
     184              : 
     185           15 :             case 'e':
     186           15 :                 errno = 0;
     187           15 :                 next_xid_epoch_val = strtouint32_strict(optarg, &endptr, 0);
     188           15 :                 if (endptr == optarg || *endptr != '\0' || errno != 0)
     189              :                 {
     190              :                     /*------
     191              :                       translator: %s is a command line argument (-e, etc) */
     192            2 :                     pg_log_error("invalid argument for option %s", "-e");
     193            2 :                     pg_log_error_hint("Try \"%s --help\" for more information.", progname);
     194            2 :                     exit(1);
     195              :                 }
     196           13 :                 next_xid_epoch_given = true;
     197           13 :                 break;
     198              : 
     199           14 :             case 'u':
     200           14 :                 errno = 0;
     201           14 :                 oldest_xid_val = strtouint32_strict(optarg, &endptr, 0);
     202           14 :                 if (endptr == optarg || *endptr != '\0' || errno != 0)
     203              :                 {
     204            1 :                     pg_log_error("invalid argument for option %s", "-u");
     205            1 :                     pg_log_error_hint("Try \"%s --help\" for more information.", progname);
     206            1 :                     exit(1);
     207              :                 }
     208           13 :                 if (!TransactionIdIsNormal(oldest_xid_val))
     209            1 :                     pg_fatal("oldest transaction ID (-u) must be greater than or equal to %u", FirstNormalTransactionId);
     210           12 :                 oldest_xid_given = true;
     211           12 :                 break;
     212              : 
     213           17 :             case 'x':
     214           17 :                 errno = 0;
     215           17 :                 next_xid_val = strtouint32_strict(optarg, &endptr, 0);
     216           17 :                 if (endptr == optarg || *endptr != '\0' || errno != 0)
     217              :                 {
     218            4 :                     pg_log_error("invalid argument for option %s", "-x");
     219            4 :                     pg_log_error_hint("Try \"%s --help\" for more information.", progname);
     220            4 :                     exit(1);
     221              :                 }
     222           13 :                 if (!TransactionIdIsNormal(next_xid_val))
     223            1 :                     pg_fatal("transaction ID (-x) must be greater than or equal to %u", FirstNormalTransactionId);
     224           12 :                 next_xid_given = true;
     225           12 :                 break;
     226              : 
     227           16 :             case 'c':
     228           16 :                 errno = 0;
     229           16 :                 oldest_commit_ts_xid_val = strtouint32_strict(optarg, &endptr, 0);
     230           16 :                 if (endptr == optarg || *endptr != ',' || errno != 0)
     231              :                 {
     232            1 :                     pg_log_error("invalid argument for option %s", "-c");
     233            1 :                     pg_log_error_hint("Try \"%s --help\" for more information.", progname);
     234            1 :                     exit(1);
     235              :                 }
     236           15 :                 newest_commit_ts_xid_val = strtoul(endptr + 1, &endptr2, 0);
     237           15 :                 if (endptr2 == endptr + 1 || *endptr2 != '\0' || errno != 0)
     238              :                 {
     239            1 :                     pg_log_error("invalid argument for option %s", "-c");
     240            1 :                     pg_log_error_hint("Try \"%s --help\" for more information.", progname);
     241            1 :                     exit(1);
     242              :                 }
     243              : 
     244           14 :                 if (oldest_commit_ts_xid_val < FirstNormalTransactionId &&
     245            1 :                     oldest_commit_ts_xid_val != InvalidTransactionId)
     246            1 :                     pg_fatal("transaction ID (-c) must be either %u or greater than or equal to %u", InvalidTransactionId, FirstNormalTransactionId);
     247              : 
     248           13 :                 if (newest_commit_ts_xid_val < FirstNormalTransactionId &&
     249            3 :                     newest_commit_ts_xid_val != InvalidTransactionId)
     250            1 :                     pg_fatal("transaction ID (-c) must be either %u or greater than or equal to %u", InvalidTransactionId, FirstNormalTransactionId);
     251           12 :                 commit_ts_xids_given = true;
     252           12 :                 break;
     253              : 
     254           14 :             case 'o':
     255           14 :                 errno = 0;
     256           14 :                 next_oid_val = strtouint32_strict(optarg, &endptr, 0);
     257           14 :                 if (endptr == optarg || *endptr != '\0' || errno != 0)
     258              :                 {
     259            1 :                     pg_log_error("invalid argument for option %s", "-o");
     260            1 :                     pg_log_error_hint("Try \"%s --help\" for more information.", progname);
     261            1 :                     exit(1);
     262              :                 }
     263           13 :                 if (next_oid_val == 0)
     264            1 :                     pg_fatal("OID (-o) must not be 0");
     265           12 :                 next_oid_given = true;
     266           12 :                 break;
     267              : 
     268           17 :             case 'm':
     269           17 :                 errno = 0;
     270           17 :                 next_mxid_val = strtouint32_strict(optarg, &endptr, 0);
     271           17 :                 if (endptr == optarg || *endptr != ',' || errno != 0)
     272              :                 {
     273            1 :                     pg_log_error("invalid argument for option %s", "-m");
     274            1 :                     pg_log_error_hint("Try \"%s --help\" for more information.", progname);
     275            1 :                     exit(1);
     276              :                 }
     277              : 
     278           16 :                 oldest_mxid_val = strtouint32_strict(endptr + 1, &endptr2, 0);
     279           16 :                 if (endptr2 == endptr + 1 || *endptr2 != '\0' || errno != 0)
     280              :                 {
     281            1 :                     pg_log_error("invalid argument for option %s", "-m");
     282            1 :                     pg_log_error_hint("Try \"%s --help\" for more information.", progname);
     283            1 :                     exit(1);
     284              :                 }
     285              : 
     286              :                 /*
     287              :                  * XXX It'd be nice to have more sanity checks here, e.g. so
     288              :                  * that oldest is not wrapped around w.r.t. nextMulti.
     289              :                  */
     290           15 :                 if (next_mxid_val == 0)
     291            1 :                     pg_fatal("next multitransaction ID (-m) must not be 0");
     292           14 :                 if (oldest_mxid_val == 0)
     293            1 :                     pg_fatal("oldest multitransaction ID (-m) must not be 0");
     294           13 :                 mxids_given = true;
     295           13 :                 break;
     296              : 
     297           14 :             case 'O':
     298           14 :                 errno = 0;
     299           14 :                 next_mxoff_val = strtouint64_strict(optarg, &endptr, 0);
     300           14 :                 if (endptr == optarg || *endptr != '\0' || errno != 0)
     301              :                 {
     302            2 :                     pg_log_error("invalid argument for option %s", "-O");
     303            2 :                     pg_log_error_hint("Try \"%s --help\" for more information.", progname);
     304            2 :                     exit(1);
     305              :                 }
     306           12 :                 next_mxoff_given = true;
     307           12 :                 break;
     308              : 
     309           13 :             case 'l':
     310           13 :                 if (strspn(optarg, "01234567890ABCDEFabcdef") != XLOG_FNAME_LEN)
     311              :                 {
     312            1 :                     pg_log_error("invalid argument for option %s", "-l");
     313            1 :                     pg_log_error_hint("Try \"%s --help\" for more information.", progname);
     314            1 :                     exit(1);
     315              :                 }
     316              : 
     317              :                 /*
     318              :                  * XLogFromFileName requires wal segment size which is not yet
     319              :                  * set. Hence wal details are set later on.
     320              :                  */
     321           12 :                 log_fname = pg_strdup(optarg);
     322           12 :                 break;
     323              : 
     324            4 :             case 1:
     325              :                 {
     326              :                     int         wal_segsize_mb;
     327              : 
     328            4 :                     if (!option_parse_int(optarg, "--wal-segsize", 1, 1024, &wal_segsize_mb))
     329            1 :                         exit(1);
     330            3 :                     wal_segsize_val = wal_segsize_mb * 1024 * 1024;
     331            3 :                     if (!IsValidWalSegSize(wal_segsize_val))
     332            1 :                         pg_fatal("argument of %s must be a power of two between 1 and 1024", "--wal-segsize");
     333            2 :                     wal_segsize_given = true;
     334            2 :                     break;
     335              :                 }
     336              : 
     337            3 :             case 2:
     338              :                 {
     339            3 :                     errno = 0;
     340              : 
     341            3 :                     if (pg_strcasecmp(optarg, "signed") == 0)
     342            0 :                         char_signedness_val = true;
     343            3 :                     else if (pg_strcasecmp(optarg, "unsigned") == 0)
     344            2 :                         char_signedness_val = false;
     345              :                     else
     346              :                     {
     347            1 :                         pg_log_error("invalid argument for option %s", "--char-signedness");
     348            1 :                         pg_log_error_hint("Try \"%s --help\" for more information.", progname);
     349            1 :                         exit(1);
     350              :                     }
     351            2 :                     char_signedness_given = true;
     352            2 :                     break;
     353              :                 }
     354              : 
     355            1 :             default:
     356              :                 /* getopt_long already emitted a complaint */
     357            1 :                 pg_log_error_hint("Try \"%s --help\" for more information.", progname);
     358            1 :                 exit(1);
     359              :         }
     360              :     }
     361              : 
     362          128 :     if (DataDir == NULL && optind < argc)
     363          123 :         DataDir = argv[optind++];
     364              : 
     365              :     /* Complain if any arguments remain */
     366          128 :     if (optind < argc)
     367              :     {
     368            1 :         pg_log_error("too many command-line arguments (first is \"%s\")",
     369              :                      argv[optind]);
     370            1 :         pg_log_error_hint("Try \"%s --help\" for more information.", progname);
     371            1 :         exit(1);
     372              :     }
     373              : 
     374          127 :     if (DataDir == NULL)
     375              :     {
     376            1 :         pg_log_error("no data directory specified");
     377            1 :         pg_log_error_hint("Try \"%s --help\" for more information.", progname);
     378            1 :         exit(1);
     379              :     }
     380              : 
     381              :     /*
     382              :      * Don't allow pg_resetwal to be run as root, to avoid overwriting the
     383              :      * ownership of files in the data directory. We need only check for root
     384              :      * -- any other user won't have sufficient permissions to modify files in
     385              :      * the data directory.
     386              :      */
     387              : #ifndef WIN32
     388          126 :     if (geteuid() == 0)
     389              :     {
     390            0 :         pg_log_error("cannot be executed by \"root\"");
     391            0 :         pg_log_error_hint("You must run %s as the PostgreSQL superuser.",
     392              :                           progname);
     393            0 :         exit(1);
     394              :     }
     395              : #endif
     396              : 
     397          126 :     get_restricted_token();
     398              : 
     399              :     /* Set mask based on PGDATA permissions */
     400          126 :     if (!GetDataDirectoryCreatePerm(DataDir))
     401            1 :         pg_fatal("could not read permissions of directory \"%s\": %m",
     402              :                  DataDir);
     403              : 
     404          125 :     umask(pg_mode_mask);
     405              : 
     406          125 :     if (chdir(DataDir) < 0)
     407            0 :         pg_fatal("could not change directory to \"%s\": %m",
     408              :                  DataDir);
     409              : 
     410              :     /* Check that data directory matches our server version */
     411          125 :     CheckDataVersion();
     412              : 
     413              :     /*
     414              :      * Check for a postmaster lock file --- if there is one, refuse to
     415              :      * proceed, on grounds we might be interfering with a live installation.
     416              :      */
     417          125 :     if ((fd = open("postmaster.pid", O_RDONLY, 0)) < 0)
     418              :     {
     419          124 :         if (errno != ENOENT)
     420            0 :             pg_fatal("could not open file \"%s\" for reading: %m",
     421              :                      "postmaster.pid");
     422              :     }
     423              :     else
     424              :     {
     425            1 :         pg_log_error("lock file \"%s\" exists", "postmaster.pid");
     426            1 :         pg_log_error_hint("Is a server running?  If not, delete the lock file and try again.");
     427            1 :         exit(1);
     428              :     }
     429              : 
     430              :     /*
     431              :      * Attempt to read the existing pg_control file
     432              :      */
     433          124 :     if (!read_controlfile())
     434            4 :         GuessControlValues();
     435              : 
     436              :     /*
     437              :      * If no new WAL segment size was specified, use the control file value.
     438              :      */
     439          124 :     if (wal_segsize_given)
     440            2 :         WalSegSz = wal_segsize_val;
     441              :     else
     442          122 :         WalSegSz = ControlFile.xlog_seg_size;
     443              : 
     444          124 :     if (log_fname != NULL)
     445           12 :         XLogFromFileName(log_fname, &minXlogTli, &minXlogSegNo, WalSegSz);
     446              : 
     447              :     /*
     448              :      * Also look at existing segment files to set up newXlogSegNo
     449              :      */
     450          124 :     FindEndOfXLOG();
     451              : 
     452              :     /*
     453              :      * If we're not going to proceed with the reset, print the current control
     454              :      * file parameters.
     455              :      */
     456          124 :     if ((guessed && !force) || noupdate)
     457           44 :         PrintControlValues(guessed);
     458              : 
     459              :     /*
     460              :      * Adjust fields if required by switches.  (Do this now so that printout,
     461              :      * if any, includes these values.)
     462              :      */
     463          124 :     if (next_xid_epoch_given)
     464              :         ControlFile.checkPointCopy.nextXid =
     465           13 :             FullTransactionIdFromEpochAndXid(next_xid_epoch_val,
     466           13 :                                              XidFromFullTransactionId(ControlFile.checkPointCopy.nextXid));
     467              : 
     468          124 :     if (oldest_xid_given)
     469              :     {
     470           12 :         ControlFile.checkPointCopy.oldestXid = oldest_xid_val;
     471           12 :         ControlFile.checkPointCopy.oldestXidDB = InvalidOid;
     472              :     }
     473              : 
     474          124 :     if (next_xid_given)
     475              :         ControlFile.checkPointCopy.nextXid =
     476           12 :             FullTransactionIdFromEpochAndXid(EpochFromFullTransactionId(ControlFile.checkPointCopy.nextXid),
     477              :                                              next_xid_val);
     478              : 
     479          124 :     if (commit_ts_xids_given)
     480              :     {
     481           12 :         ControlFile.checkPointCopy.oldestCommitTsXid = oldest_commit_ts_xid_val;
     482           12 :         ControlFile.checkPointCopy.newestCommitTsXid = newest_commit_ts_xid_val;
     483              :     }
     484              : 
     485          124 :     if (next_oid_given)
     486           12 :         ControlFile.checkPointCopy.nextOid = next_oid_val;
     487              : 
     488          124 :     if (mxids_given)
     489              :     {
     490           13 :         ControlFile.checkPointCopy.nextMulti = next_mxid_val;
     491              : 
     492           13 :         ControlFile.checkPointCopy.oldestMulti = oldest_mxid_val;
     493           13 :         if (ControlFile.checkPointCopy.oldestMulti < FirstMultiXactId)
     494            0 :             ControlFile.checkPointCopy.oldestMulti += FirstMultiXactId;
     495           13 :         ControlFile.checkPointCopy.oldestMultiDB = InvalidOid;
     496              :     }
     497              : 
     498          124 :     if (next_mxoff_given)
     499           12 :         ControlFile.checkPointCopy.nextMultiOffset = next_mxoff_val;
     500              : 
     501          124 :     if (minXlogTli > ControlFile.checkPointCopy.ThisTimeLineID)
     502              :     {
     503            0 :         ControlFile.checkPointCopy.ThisTimeLineID = minXlogTli;
     504            0 :         ControlFile.checkPointCopy.PrevTimeLineID = minXlogTli;
     505              :     }
     506              : 
     507          124 :     if (wal_segsize_given)
     508            2 :         ControlFile.xlog_seg_size = WalSegSz;
     509              : 
     510          124 :     if (char_signedness_given)
     511            2 :         ControlFile.default_char_signedness = char_signedness_val;
     512              : 
     513          124 :     if (minXlogSegNo > newXlogSegNo)
     514            3 :         newXlogSegNo = minXlogSegNo;
     515              : 
     516          124 :     if (noupdate)
     517              :     {
     518           43 :         PrintNewControlValues();
     519           43 :         exit(0);
     520              :     }
     521              : 
     522              :     /*
     523              :      * If we had to guess anything, and -f was not given, just print the
     524              :      * guessed values and exit.
     525              :      */
     526           81 :     if (guessed && !force)
     527              :     {
     528            1 :         PrintNewControlValues();
     529            1 :         pg_log_error("not proceeding because control file values were guessed");
     530            1 :         pg_log_error_hint("If these values seem acceptable, use -f to force reset.");
     531            1 :         exit(1);
     532              :     }
     533              : 
     534              :     /*
     535              :      * Don't reset from a dirty pg_control without -f, either.
     536              :      */
     537           80 :     if (ControlFile.state != DB_SHUTDOWNED && !force)
     538              :     {
     539            1 :         pg_log_error("database server was not shut down cleanly");
     540            1 :         pg_log_error_detail("Resetting the write-ahead log might cause data to be lost.");
     541            1 :         pg_log_error_hint("If you want to proceed anyway, use -f to force reset.");
     542            1 :         exit(1);
     543              :     }
     544              : 
     545              :     /*
     546              :      * Else, do the dirty deed.
     547              :      */
     548           79 :     RewriteControlFile();
     549           79 :     KillExistingXLOG();
     550           79 :     KillExistingArchiveStatus();
     551           79 :     KillExistingWALSummaries();
     552           79 :     WriteEmptyXLOG();
     553              : 
     554           79 :     printf(_("Write-ahead log reset\n"));
     555           79 :     return 0;
     556              : }
     557              : 
     558              : 
     559              : /*
     560              :  * Look at the version string stored in PG_VERSION and decide if this utility
     561              :  * can be run safely or not.
     562              :  *
     563              :  * We don't want to inject pg_control and WAL files that are for a different
     564              :  * major version; that can't do anything good.  Note that we don't treat
     565              :  * mismatching version info in pg_control as a reason to bail out, because
     566              :  * recovering from a corrupted pg_control is one of the main reasons for this
     567              :  * program to exist at all.  However, PG_VERSION is unlikely to get corrupted,
     568              :  * and if it were it would be easy to fix by hand.  So let's make this check
     569              :  * to prevent simple user errors.
     570              :  */
     571              : static void
     572          125 : CheckDataVersion(void)
     573              : {
     574              :     char       *version_str;
     575          125 :     uint32      version = get_pg_version(".", &version_str);
     576              : 
     577          125 :     if (GET_PG_MAJORVERSION_NUM(version) != PG_MAJORVERSION_NUM)
     578              :     {
     579            0 :         pg_log_error("data directory is of wrong version");
     580            0 :         pg_log_error_detail("File \"%s\" contains \"%s\", which is not compatible with this program's version \"%s\".",
     581              :                             "PG_VERSION",
     582              :                             version_str,
     583              :                             PG_MAJORVERSION);
     584            0 :         exit(1);
     585              :     }
     586          125 : }
     587              : 
     588              : 
     589              : /*
     590              :  * Try to read the existing pg_control file.
     591              :  *
     592              :  * This routine is also responsible for updating old pg_control versions
     593              :  * to the current format.  (Currently we don't do anything of the sort.)
     594              :  */
     595              : static bool
     596          124 : read_controlfile(void)
     597              : {
     598              :     int         fd;
     599              :     int         len;
     600              :     char       *buffer;
     601              :     pg_crc32c   crc;
     602              : 
     603          124 :     if ((fd = open(XLOG_CONTROL_FILE, O_RDONLY | PG_BINARY, 0)) < 0)
     604              :     {
     605              :         /*
     606              :          * If pg_control is not there at all, or we can't read it, the odds
     607              :          * are we've been handed a bad DataDir path, so give up. User can do
     608              :          * "touch pg_control" to force us to proceed.
     609              :          */
     610            0 :         pg_log_error("could not open file \"%s\" for reading: %m",
     611              :                      XLOG_CONTROL_FILE);
     612            0 :         if (errno == ENOENT)
     613            0 :             pg_log_error_hint("If you are sure the data directory path is correct, execute\n"
     614              :                               "  touch %s\n"
     615              :                               "and try again.",
     616              :                               XLOG_CONTROL_FILE);
     617            0 :         exit(1);
     618              :     }
     619              : 
     620              :     /* Use malloc to ensure we have a maxaligned buffer */
     621          124 :     buffer = (char *) pg_malloc(PG_CONTROL_FILE_SIZE);
     622              : 
     623          124 :     len = read(fd, buffer, PG_CONTROL_FILE_SIZE);
     624          124 :     if (len < 0)
     625            0 :         pg_fatal("could not read file \"%s\": %m", XLOG_CONTROL_FILE);
     626          124 :     close(fd);
     627              : 
     628          124 :     if (len >= sizeof(ControlFileData) &&
     629          124 :         ((ControlFileData *) buffer)->pg_control_version == PG_CONTROL_VERSION)
     630              :     {
     631              :         /* Check the CRC. */
     632          123 :         INIT_CRC32C(crc);
     633          123 :         COMP_CRC32C(crc,
     634              :                     buffer,
     635              :                     offsetof(ControlFileData, crc));
     636          123 :         FIN_CRC32C(crc);
     637              : 
     638          123 :         if (!EQ_CRC32C(crc, ((ControlFileData *) buffer)->crc))
     639              :         {
     640              :             /* We will use the data but treat it as guessed. */
     641            3 :             pg_log_warning("pg_control exists but has invalid CRC; proceed with caution");
     642            3 :             guessed = true;
     643              :         }
     644              : 
     645          123 :         memcpy(&ControlFile, buffer, sizeof(ControlFile));
     646              : 
     647              :         /* return false if WAL segment size is not valid */
     648          123 :         if (!IsValidWalSegSize(ControlFile.xlog_seg_size))
     649              :         {
     650            3 :             pg_log_warning(ngettext("pg_control specifies invalid WAL segment size (%d byte); proceed with caution",
     651              :                                     "pg_control specifies invalid WAL segment size (%d bytes); proceed with caution",
     652              :                                     ControlFile.xlog_seg_size),
     653              :                            ControlFile.xlog_seg_size);
     654            3 :             return false;
     655              :         }
     656              : 
     657          120 :         return true;
     658              :     }
     659              : 
     660              :     /* Looks like it's a mess. */
     661            1 :     pg_log_warning("pg_control exists but is broken or wrong version; ignoring it");
     662            1 :     return false;
     663              : }
     664              : 
     665              : 
     666              : /*
     667              :  * Guess at pg_control values when we can't read the old ones.
     668              :  */
     669              : static void
     670            4 : GuessControlValues(void)
     671              : {
     672              :     uint64      sysidentifier;
     673              :     struct timeval tv;
     674              : 
     675              :     /*
     676              :      * Set up a completely default set of pg_control values.
     677              :      */
     678            4 :     guessed = true;
     679            4 :     memset(&ControlFile, 0, sizeof(ControlFile));
     680              : 
     681            4 :     ControlFile.pg_control_version = PG_CONTROL_VERSION;
     682            4 :     ControlFile.catalog_version_no = CATALOG_VERSION_NO;
     683              : 
     684              :     /*
     685              :      * Create a new unique installation identifier, since we can no longer use
     686              :      * any old XLOG records.  See notes in xlog.c about the algorithm.
     687              :      */
     688            4 :     gettimeofday(&tv, NULL);
     689            4 :     sysidentifier = ((uint64) tv.tv_sec) << 32;
     690            4 :     sysidentifier |= ((uint64) tv.tv_usec) << 12;
     691            4 :     sysidentifier |= getpid() & 0xFFF;
     692              : 
     693            4 :     ControlFile.system_identifier = sysidentifier;
     694              : 
     695            4 :     ControlFile.checkPointCopy.redo = SizeOfXLogLongPHD;
     696            4 :     ControlFile.checkPointCopy.ThisTimeLineID = 1;
     697            4 :     ControlFile.checkPointCopy.PrevTimeLineID = 1;
     698            4 :     ControlFile.checkPointCopy.fullPageWrites = false;
     699              :     ControlFile.checkPointCopy.nextXid =
     700            4 :         FullTransactionIdFromEpochAndXid(0, FirstNormalTransactionId);
     701            4 :     ControlFile.checkPointCopy.nextOid = FirstGenbkiObjectId;
     702            4 :     ControlFile.checkPointCopy.nextMulti = FirstMultiXactId;
     703            4 :     ControlFile.checkPointCopy.nextMultiOffset = 0;
     704            4 :     ControlFile.checkPointCopy.oldestXid = FirstNormalTransactionId;
     705            4 :     ControlFile.checkPointCopy.oldestXidDB = InvalidOid;
     706            4 :     ControlFile.checkPointCopy.oldestMulti = FirstMultiXactId;
     707            4 :     ControlFile.checkPointCopy.oldestMultiDB = InvalidOid;
     708            4 :     ControlFile.checkPointCopy.time = (pg_time_t) time(NULL);
     709            4 :     ControlFile.checkPointCopy.oldestActiveXid = InvalidTransactionId;
     710              : 
     711            4 :     ControlFile.state = DB_SHUTDOWNED;
     712            4 :     ControlFile.time = (pg_time_t) time(NULL);
     713            4 :     ControlFile.checkPoint = ControlFile.checkPointCopy.redo;
     714            4 :     ControlFile.unloggedLSN = FirstNormalUnloggedLSN;
     715              : 
     716              :     /* minRecoveryPoint, backupStartPoint and backupEndPoint can be left zero */
     717              : 
     718            4 :     ControlFile.wal_level = WAL_LEVEL_MINIMAL;
     719            4 :     ControlFile.wal_log_hints = false;
     720            4 :     ControlFile.track_commit_timestamp = false;
     721            4 :     ControlFile.MaxConnections = 100;
     722            4 :     ControlFile.max_wal_senders = 10;
     723            4 :     ControlFile.max_worker_processes = 8;
     724            4 :     ControlFile.max_prepared_xacts = 0;
     725            4 :     ControlFile.max_locks_per_xact = 64;
     726              : 
     727            4 :     ControlFile.maxAlign = MAXIMUM_ALIGNOF;
     728            4 :     ControlFile.floatFormat = FLOATFORMAT_VALUE;
     729            4 :     ControlFile.blcksz = BLCKSZ;
     730            4 :     ControlFile.relseg_size = RELSEG_SIZE;
     731            4 :     ControlFile.slru_pages_per_segment = SLRU_PAGES_PER_SEGMENT;
     732            4 :     ControlFile.xlog_blcksz = XLOG_BLCKSZ;
     733            4 :     ControlFile.xlog_seg_size = DEFAULT_XLOG_SEG_SIZE;
     734            4 :     ControlFile.nameDataLen = NAMEDATALEN;
     735            4 :     ControlFile.indexMaxKeys = INDEX_MAX_KEYS;
     736            4 :     ControlFile.toast_max_chunk_size = TOAST_MAX_CHUNK_SIZE;
     737            4 :     ControlFile.loblksize = LOBLKSIZE;
     738            4 :     ControlFile.float8ByVal = true; /* vestigial */
     739              : 
     740              :     /*
     741              :      * XXX eventually, should try to grovel through old XLOG to develop more
     742              :      * accurate values for TimeLineID, nextXID, etc.
     743              :      */
     744            4 : }
     745              : 
     746              : 
     747              : /*
     748              :  * Print the guessed pg_control values when we had to guess.
     749              :  *
     750              :  * NB: this display should be just those fields that will not be
     751              :  * reset by RewriteControlFile().
     752              :  */
     753              : static void
     754           44 : PrintControlValues(bool guessed)
     755              : {
     756           44 :     if (guessed)
     757            3 :         printf(_("Guessed pg_control values:\n\n"));
     758              :     else
     759           41 :         printf(_("Current pg_control values:\n\n"));
     760              : 
     761           44 :     printf(_("pg_control version number:            %u\n"),
     762              :            ControlFile.pg_control_version);
     763           44 :     printf(_("Catalog version number:               %u\n"),
     764              :            ControlFile.catalog_version_no);
     765           44 :     printf(_("Database system identifier:           %" PRIu64 "\n"),
     766              :            ControlFile.system_identifier);
     767           44 :     printf(_("Latest checkpoint's TimeLineID:       %u\n"),
     768              :            ControlFile.checkPointCopy.ThisTimeLineID);
     769           44 :     printf(_("Latest checkpoint's full_page_writes: %s\n"),
     770              :            ControlFile.checkPointCopy.fullPageWrites ? _("on") : _("off"));
     771           44 :     printf(_("Latest checkpoint's NextXID:          %u:%u\n"),
     772              :            EpochFromFullTransactionId(ControlFile.checkPointCopy.nextXid),
     773              :            XidFromFullTransactionId(ControlFile.checkPointCopy.nextXid));
     774           44 :     printf(_("Latest checkpoint's NextOID:          %u\n"),
     775              :            ControlFile.checkPointCopy.nextOid);
     776           44 :     printf(_("Latest checkpoint's NextMultiXactId:  %u\n"),
     777              :            ControlFile.checkPointCopy.nextMulti);
     778           44 :     printf(_("Latest checkpoint's NextMultiOffset:  %" PRIu64 "\n"),
     779              :            ControlFile.checkPointCopy.nextMultiOffset);
     780           44 :     printf(_("Latest checkpoint's oldestXID:        %u\n"),
     781              :            ControlFile.checkPointCopy.oldestXid);
     782           44 :     printf(_("Latest checkpoint's oldestXID's DB:   %u\n"),
     783              :            ControlFile.checkPointCopy.oldestXidDB);
     784           44 :     printf(_("Latest checkpoint's oldestActiveXID:  %u\n"),
     785              :            ControlFile.checkPointCopy.oldestActiveXid);
     786           44 :     printf(_("Latest checkpoint's oldestMultiXid:   %u\n"),
     787              :            ControlFile.checkPointCopy.oldestMulti);
     788           44 :     printf(_("Latest checkpoint's oldestMulti's DB: %u\n"),
     789              :            ControlFile.checkPointCopy.oldestMultiDB);
     790           44 :     printf(_("Latest checkpoint's oldestCommitTsXid:%u\n"),
     791              :            ControlFile.checkPointCopy.oldestCommitTsXid);
     792           44 :     printf(_("Latest checkpoint's newestCommitTsXid:%u\n"),
     793              :            ControlFile.checkPointCopy.newestCommitTsXid);
     794           44 :     printf(_("Maximum data alignment:               %u\n"),
     795              :            ControlFile.maxAlign);
     796              :     /* we don't print floatFormat since can't say much useful about it */
     797           44 :     printf(_("Database block size:                  %u\n"),
     798              :            ControlFile.blcksz);
     799           44 :     printf(_("Blocks per segment of large relation: %u\n"),
     800              :            ControlFile.relseg_size);
     801           44 :     printf(_("Pages per SLRU segment:               %u\n"),
     802              :            ControlFile.slru_pages_per_segment);
     803           44 :     printf(_("WAL block size:                       %u\n"),
     804              :            ControlFile.xlog_blcksz);
     805           44 :     printf(_("Bytes per WAL segment:                %u\n"),
     806              :            ControlFile.xlog_seg_size);
     807           44 :     printf(_("Maximum length of identifiers:        %u\n"),
     808              :            ControlFile.nameDataLen);
     809           44 :     printf(_("Maximum columns in an index:          %u\n"),
     810              :            ControlFile.indexMaxKeys);
     811           44 :     printf(_("Maximum size of a TOAST chunk:        %u\n"),
     812              :            ControlFile.toast_max_chunk_size);
     813           44 :     printf(_("Size of a large-object chunk:         %u\n"),
     814              :            ControlFile.loblksize);
     815              :     /* This is no longer configurable, but users may still expect to see it: */
     816           44 :     printf(_("Date/time type storage:               %s\n"),
     817              :            _("64-bit integers"));
     818           44 :     printf(_("Float8 argument passing:              %s\n"),
     819              :            (ControlFile.float8ByVal ? _("by value") : _("by reference")));
     820           44 :     printf(_("Data page checksum version:           %u\n"),
     821              :            ControlFile.data_checksum_version);
     822           44 :     printf(_("Default char data signedness:         %s\n"),
     823              :            (ControlFile.default_char_signedness ? _("signed") : _("unsigned")));
     824           44 : }
     825              : 
     826              : 
     827              : /*
     828              :  * Print the values to be changed.
     829              :  */
     830              : static void
     831           44 : PrintNewControlValues(void)
     832              : {
     833              :     char        fname[MAXFNAMELEN];
     834              : 
     835              :     /* This will be always printed in order to keep format same. */
     836           44 :     printf(_("\n\nValues to be changed:\n\n"));
     837              : 
     838           44 :     XLogFileName(fname, ControlFile.checkPointCopy.ThisTimeLineID,
     839              :                  newXlogSegNo, WalSegSz);
     840           44 :     printf(_("First log segment after reset:        %s\n"), fname);
     841              : 
     842           44 :     if (mxids_given)
     843              :     {
     844            1 :         printf(_("NextMultiXactId:                      %u\n"),
     845              :                ControlFile.checkPointCopy.nextMulti);
     846            1 :         printf(_("OldestMultiXid:                       %u\n"),
     847              :                ControlFile.checkPointCopy.oldestMulti);
     848            1 :         printf(_("OldestMulti's DB:                     %u\n"),
     849              :                ControlFile.checkPointCopy.oldestMultiDB);
     850              :     }
     851              : 
     852           44 :     if (next_mxoff_given)
     853              :     {
     854            1 :         printf(_("NextMultiOffset:                      %" PRIu64 "\n"),
     855              :                ControlFile.checkPointCopy.nextMultiOffset);
     856              :     }
     857              : 
     858           44 :     if (next_oid_given)
     859              :     {
     860            1 :         printf(_("NextOID:                              %u\n"),
     861              :                ControlFile.checkPointCopy.nextOid);
     862              :     }
     863              : 
     864           44 :     if (next_xid_given)
     865              :     {
     866            1 :         printf(_("NextXID:                              %u\n"),
     867              :                XidFromFullTransactionId(ControlFile.checkPointCopy.nextXid));
     868              :     }
     869              : 
     870           44 :     if (oldest_xid_given)
     871              :     {
     872            1 :         printf(_("OldestXID:                            %u\n"),
     873              :                ControlFile.checkPointCopy.oldestXid);
     874            1 :         printf(_("OldestXID's DB:                       %u\n"),
     875              :                ControlFile.checkPointCopy.oldestXidDB);
     876              :     }
     877              : 
     878           44 :     if (next_xid_epoch_given)
     879              :     {
     880            1 :         printf(_("NextXID epoch:                        %u\n"),
     881              :                EpochFromFullTransactionId(ControlFile.checkPointCopy.nextXid));
     882              :     }
     883              : 
     884           44 :     if (commit_ts_xids_given)
     885              :     {
     886            1 :         printf(_("oldestCommitTsXid:                    %u\n"),
     887              :                ControlFile.checkPointCopy.oldestCommitTsXid);
     888            1 :         printf(_("newestCommitTsXid:                    %u\n"),
     889              :                ControlFile.checkPointCopy.newestCommitTsXid);
     890              :     }
     891              : 
     892           44 :     if (wal_segsize_given)
     893              :     {
     894            1 :         printf(_("Bytes per WAL segment:                %u\n"),
     895              :                ControlFile.xlog_seg_size);
     896              :     }
     897           44 : }
     898              : 
     899              : 
     900              : /*
     901              :  * Write out the new pg_control file.
     902              :  */
     903              : static void
     904           79 : RewriteControlFile(void)
     905              : {
     906              :     /*
     907              :      * Adjust fields as needed to force an empty XLOG starting at
     908              :      * newXlogSegNo.
     909              :      */
     910           79 :     XLogSegNoOffsetToRecPtr(newXlogSegNo, SizeOfXLogLongPHD, WalSegSz,
     911              :                             ControlFile.checkPointCopy.redo);
     912           79 :     ControlFile.checkPointCopy.time = (pg_time_t) time(NULL);
     913              : 
     914           79 :     ControlFile.state = DB_SHUTDOWNED;
     915           79 :     ControlFile.checkPoint = ControlFile.checkPointCopy.redo;
     916           79 :     ControlFile.minRecoveryPoint = InvalidXLogRecPtr;
     917           79 :     ControlFile.minRecoveryPointTLI = 0;
     918           79 :     ControlFile.backupStartPoint = InvalidXLogRecPtr;
     919           79 :     ControlFile.backupEndPoint = InvalidXLogRecPtr;
     920           79 :     ControlFile.backupEndRequired = false;
     921              : 
     922              :     /*
     923              :      * Force the defaults for max_* settings. The values don't really matter
     924              :      * as long as wal_level='minimal'; the postmaster will reset these fields
     925              :      * anyway at startup.
     926              :      */
     927           79 :     ControlFile.wal_level = WAL_LEVEL_MINIMAL;
     928           79 :     ControlFile.wal_log_hints = false;
     929           79 :     ControlFile.track_commit_timestamp = false;
     930           79 :     ControlFile.MaxConnections = 100;
     931           79 :     ControlFile.max_wal_senders = 10;
     932           79 :     ControlFile.max_worker_processes = 8;
     933           79 :     ControlFile.max_prepared_xacts = 0;
     934           79 :     ControlFile.max_locks_per_xact = 64;
     935              : 
     936              :     /* The control file gets flushed here. */
     937           79 :     update_controlfile(".", &ControlFile, true);
     938           79 : }
     939              : 
     940              : 
     941              : /*
     942              :  * Scan existing XLOG files and determine the highest existing WAL address
     943              :  *
     944              :  * On entry, ControlFile.checkPointCopy.redo and ControlFile.xlog_seg_size
     945              :  * are assumed valid (note that we allow the old xlog seg size to differ
     946              :  * from what we're using).  On exit, newXlogSegNo is set to suitable
     947              :  * value for the beginning of replacement WAL (in our seg size).
     948              :  */
     949              : static void
     950          124 : FindEndOfXLOG(void)
     951              : {
     952              :     DIR        *xldir;
     953              :     struct dirent *xlde;
     954              :     uint64      xlogbytepos;
     955              : 
     956              :     /*
     957              :      * Initialize the max() computation using the last checkpoint address from
     958              :      * old pg_control.  Note that for the moment we are working with segment
     959              :      * numbering according to the old xlog seg size.
     960              :      */
     961          124 :     XLByteToSeg(ControlFile.checkPointCopy.redo, newXlogSegNo,
     962              :                 ControlFile.xlog_seg_size);
     963              : 
     964              :     /*
     965              :      * Scan the pg_wal directory to find existing WAL segment files. We assume
     966              :      * any present have been used; in most scenarios this should be
     967              :      * conservative, because of xlog.c's attempts to pre-create files.
     968              :      */
     969          124 :     xldir = opendir(XLOGDIR);
     970          124 :     if (xldir == NULL)
     971            0 :         pg_fatal("could not open directory \"%s\": %m", XLOGDIR);
     972              : 
     973          897 :     while (errno = 0, (xlde = readdir(xldir)) != NULL)
     974              :     {
     975         1270 :         if (IsXLogFileName(xlde->d_name) ||
     976          497 :             IsPartialXLogFileName(xlde->d_name))
     977              :         {
     978              :             TimeLineID  tli;
     979              :             XLogSegNo   segno;
     980              : 
     981              :             /* Use the segment size from the control file */
     982          276 :             XLogFromFileName(xlde->d_name, &tli, &segno,
     983          276 :                              ControlFile.xlog_seg_size);
     984              : 
     985              :             /*
     986              :              * Note: we take the max of all files found, regardless of their
     987              :              * timelines.  Another possibility would be to ignore files of
     988              :              * timelines other than the target TLI, but this seems safer.
     989              :              * Better too large a result than too small...
     990              :              */
     991          276 :             if (segno > newXlogSegNo)
     992           40 :                 newXlogSegNo = segno;
     993              :         }
     994              :     }
     995              : 
     996          124 :     if (errno)
     997            0 :         pg_fatal("could not read directory \"%s\": %m", XLOGDIR);
     998              : 
     999          124 :     if (closedir(xldir))
    1000            0 :         pg_fatal("could not close directory \"%s\": %m", XLOGDIR);
    1001              : 
    1002              :     /*
    1003              :      * Finally, convert to new xlog seg size, and advance by one to ensure we
    1004              :      * are in virgin territory.
    1005              :      */
    1006          124 :     xlogbytepos = newXlogSegNo * ControlFile.xlog_seg_size;
    1007          124 :     newXlogSegNo = (xlogbytepos + ControlFile.xlog_seg_size - 1) / WalSegSz;
    1008          124 :     newXlogSegNo++;
    1009          124 : }
    1010              : 
    1011              : 
    1012              : /*
    1013              :  * Remove existing XLOG files
    1014              :  */
    1015              : static void
    1016           79 : KillExistingXLOG(void)
    1017              : {
    1018              :     DIR        *xldir;
    1019              :     struct dirent *xlde;
    1020              :     char        path[MAXPGPATH + sizeof(XLOGDIR)];
    1021              : 
    1022           79 :     xldir = opendir(XLOGDIR);
    1023           79 :     if (xldir == NULL)
    1024            0 :         pg_fatal("could not open directory \"%s\": %m", XLOGDIR);
    1025              : 
    1026          499 :     while (errno = 0, (xlde = readdir(xldir)) != NULL)
    1027              :     {
    1028          737 :         if (IsXLogFileName(xlde->d_name) ||
    1029          317 :             IsPartialXLogFileName(xlde->d_name))
    1030              :         {
    1031          103 :             snprintf(path, sizeof(path), "%s/%s", XLOGDIR, xlde->d_name);
    1032          103 :             if (unlink(path) < 0)
    1033            0 :                 pg_fatal("could not delete file \"%s\": %m", path);
    1034              :         }
    1035              :     }
    1036              : 
    1037           79 :     if (errno)
    1038            0 :         pg_fatal("could not read directory \"%s\": %m", XLOGDIR);
    1039              : 
    1040           79 :     if (closedir(xldir))
    1041            0 :         pg_fatal("could not close directory \"%s\": %m", XLOGDIR);
    1042           79 : }
    1043              : 
    1044              : 
    1045              : /*
    1046              :  * Remove existing archive status files
    1047              :  */
    1048              : static void
    1049           79 : KillExistingArchiveStatus(void)
    1050              : {
    1051              : #define ARCHSTATDIR XLOGDIR "/archive_status"
    1052              : 
    1053              :     DIR        *xldir;
    1054              :     struct dirent *xlde;
    1055              :     char        path[MAXPGPATH + sizeof(ARCHSTATDIR)];
    1056              : 
    1057           79 :     xldir = opendir(ARCHSTATDIR);
    1058           79 :     if (xldir == NULL)
    1059            0 :         pg_fatal("could not open directory \"%s\": %m", ARCHSTATDIR);
    1060              : 
    1061          237 :     while (errno = 0, (xlde = readdir(xldir)) != NULL)
    1062              :     {
    1063          158 :         if (strspn(xlde->d_name, "0123456789ABCDEF") == XLOG_FNAME_LEN &&
    1064            0 :             (strcmp(xlde->d_name + XLOG_FNAME_LEN, ".ready") == 0 ||
    1065            0 :              strcmp(xlde->d_name + XLOG_FNAME_LEN, ".done") == 0 ||
    1066            0 :              strcmp(xlde->d_name + XLOG_FNAME_LEN, ".partial.ready") == 0 ||
    1067            0 :              strcmp(xlde->d_name + XLOG_FNAME_LEN, ".partial.done") == 0))
    1068              :         {
    1069            0 :             snprintf(path, sizeof(path), "%s/%s", ARCHSTATDIR, xlde->d_name);
    1070            0 :             if (unlink(path) < 0)
    1071            0 :                 pg_fatal("could not delete file \"%s\": %m", path);
    1072              :         }
    1073              :     }
    1074              : 
    1075           79 :     if (errno)
    1076            0 :         pg_fatal("could not read directory \"%s\": %m", ARCHSTATDIR);
    1077              : 
    1078           79 :     if (closedir(xldir))
    1079            0 :         pg_fatal("could not close directory \"%s\": %m", ARCHSTATDIR);
    1080              : 
    1081              : #undef ARCHSTATDIR
    1082           79 : }
    1083              : 
    1084              : /*
    1085              :  * Remove existing WAL summary files
    1086              :  */
    1087              : static void
    1088           79 : KillExistingWALSummaries(void)
    1089              : {
    1090              : #define WALSUMMARYDIR XLOGDIR   "/summaries"
    1091              : #define WALSUMMARY_NHEXCHARS    40
    1092              : 
    1093              :     DIR        *xldir;
    1094              :     struct dirent *xlde;
    1095              :     char        path[MAXPGPATH + sizeof(WALSUMMARYDIR)];
    1096              : 
    1097           79 :     xldir = opendir(WALSUMMARYDIR);
    1098           79 :     if (xldir == NULL)
    1099            0 :         pg_fatal("could not open directory \"%s\": %m", WALSUMMARYDIR);
    1100              : 
    1101          237 :     while (errno = 0, (xlde = readdir(xldir)) != NULL)
    1102              :     {
    1103          158 :         if (strspn(xlde->d_name, "0123456789ABCDEF") == WALSUMMARY_NHEXCHARS &&
    1104            0 :             strcmp(xlde->d_name + WALSUMMARY_NHEXCHARS, ".summary") == 0)
    1105              :         {
    1106            0 :             snprintf(path, sizeof(path), "%s/%s", WALSUMMARYDIR, xlde->d_name);
    1107            0 :             if (unlink(path) < 0)
    1108            0 :                 pg_fatal("could not delete file \"%s\": %m", path);
    1109              :         }
    1110              :     }
    1111              : 
    1112           79 :     if (errno)
    1113            0 :         pg_fatal("could not read directory \"%s\": %m", WALSUMMARYDIR);
    1114              : 
    1115           79 :     if (closedir(xldir))
    1116            0 :         pg_fatal("could not close directory \"%s\": %m", WALSUMMARYDIR);
    1117              : 
    1118              : #undef WALSUMMARY_NHEXCHARS
    1119              : #undef WALSUMMARYDIR
    1120           79 : }
    1121              : 
    1122              : /*
    1123              :  * Write an empty XLOG file, containing only the checkpoint record
    1124              :  * already set up in ControlFile.
    1125              :  */
    1126              : static void
    1127           79 : WriteEmptyXLOG(void)
    1128              : {
    1129              :     PGAlignedXLogBlock buffer;
    1130              :     XLogPageHeader page;
    1131              :     XLogLongPageHeader longpage;
    1132              :     XLogRecord *record;
    1133              :     pg_crc32c   crc;
    1134              :     char        path[MAXPGPATH];
    1135              :     int         fd;
    1136              :     int         nbytes;
    1137              :     char       *recptr;
    1138              : 
    1139           79 :     memset(buffer.data, 0, XLOG_BLCKSZ);
    1140              : 
    1141              :     /* Set up the XLOG page header */
    1142           79 :     page = (XLogPageHeader) buffer.data;
    1143           79 :     page->xlp_magic = XLOG_PAGE_MAGIC;
    1144           79 :     page->xlp_info = XLP_LONG_HEADER;
    1145           79 :     page->xlp_tli = ControlFile.checkPointCopy.ThisTimeLineID;
    1146           79 :     page->xlp_pageaddr = ControlFile.checkPointCopy.redo - SizeOfXLogLongPHD;
    1147           79 :     longpage = (XLogLongPageHeader) page;
    1148           79 :     longpage->xlp_sysid = ControlFile.system_identifier;
    1149           79 :     longpage->xlp_seg_size = WalSegSz;
    1150           79 :     longpage->xlp_xlog_blcksz = XLOG_BLCKSZ;
    1151              : 
    1152              :     /* Insert the initial checkpoint record */
    1153           79 :     recptr = (char *) page + SizeOfXLogLongPHD;
    1154           79 :     record = (XLogRecord *) recptr;
    1155           79 :     record->xl_prev = InvalidXLogRecPtr;
    1156           79 :     record->xl_xid = InvalidTransactionId;
    1157           79 :     record->xl_tot_len = SizeOfXLogRecord + SizeOfXLogRecordDataHeaderShort + sizeof(CheckPoint);
    1158           79 :     record->xl_info = XLOG_CHECKPOINT_SHUTDOWN;
    1159           79 :     record->xl_rmid = RM_XLOG_ID;
    1160              : 
    1161           79 :     recptr += SizeOfXLogRecord;
    1162           79 :     *(recptr++) = (char) XLR_BLOCK_ID_DATA_SHORT;
    1163           79 :     *(recptr++) = sizeof(CheckPoint);
    1164           79 :     memcpy(recptr, &ControlFile.checkPointCopy,
    1165              :            sizeof(CheckPoint));
    1166              : 
    1167           79 :     INIT_CRC32C(crc);
    1168           79 :     COMP_CRC32C(crc, ((char *) record) + SizeOfXLogRecord, record->xl_tot_len - SizeOfXLogRecord);
    1169           79 :     COMP_CRC32C(crc, (char *) record, offsetof(XLogRecord, xl_crc));
    1170           79 :     FIN_CRC32C(crc);
    1171           79 :     record->xl_crc = crc;
    1172              : 
    1173              :     /* Write the first page */
    1174           79 :     XLogFilePath(path, ControlFile.checkPointCopy.ThisTimeLineID,
    1175              :                  newXlogSegNo, WalSegSz);
    1176              : 
    1177           79 :     unlink(path);
    1178              : 
    1179           79 :     fd = open(path, O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
    1180              :               pg_file_create_mode);
    1181           79 :     if (fd < 0)
    1182            0 :         pg_fatal("could not open file \"%s\": %m", path);
    1183              : 
    1184           79 :     errno = 0;
    1185           79 :     if (write(fd, buffer.data, XLOG_BLCKSZ) != XLOG_BLCKSZ)
    1186              :     {
    1187              :         /* if write didn't set errno, assume problem is no disk space */
    1188            0 :         if (errno == 0)
    1189            0 :             errno = ENOSPC;
    1190            0 :         pg_fatal("could not write file \"%s\": %m", path);
    1191              :     }
    1192              : 
    1193              :     /* Fill the rest of the file with zeroes */
    1194           79 :     memset(buffer.data, 0, XLOG_BLCKSZ);
    1195       146432 :     for (nbytes = XLOG_BLCKSZ; nbytes < WalSegSz; nbytes += XLOG_BLCKSZ)
    1196              :     {
    1197       146353 :         errno = 0;
    1198       146353 :         if (write(fd, buffer.data, XLOG_BLCKSZ) != XLOG_BLCKSZ)
    1199              :         {
    1200            0 :             if (errno == 0)
    1201            0 :                 errno = ENOSPC;
    1202            0 :             pg_fatal("could not write file \"%s\": %m", path);
    1203              :         }
    1204              :     }
    1205              : 
    1206           79 :     if (fsync(fd) != 0)
    1207            0 :         pg_fatal("fsync error: %m");
    1208              : 
    1209           79 :     close(fd);
    1210           79 : }
    1211              : 
    1212              : 
    1213              : static void
    1214            1 : usage(void)
    1215              : {
    1216            1 :     printf(_("%s resets the PostgreSQL write-ahead log.\n\n"), progname);
    1217            1 :     printf(_("Usage:\n"));
    1218            1 :     printf(_("  %s [OPTION]... DATADIR\n"), progname);
    1219              : 
    1220            1 :     printf(_("\nOptions:\n"));
    1221            1 :     printf(_(" [-D, --pgdata=]DATADIR  data directory\n"));
    1222            1 :     printf(_("  -f, --force            force update to be done even after unclean shutdown or\n"
    1223              :              "                         if pg_control values had to be guessed\n"));
    1224            1 :     printf(_("  -n, --dry-run          no update, just show what would be done\n"));
    1225            1 :     printf(_("  -V, --version          output version information, then exit\n"));
    1226            1 :     printf(_("  -?, --help             show this help, then exit\n"));
    1227              : 
    1228            1 :     printf(_("\nOptions to override control file values:\n"));
    1229            1 :     printf(_("  -c, --commit-timestamp-ids=XID,XID\n"
    1230              :              "                                   set oldest and newest transactions bearing\n"
    1231              :              "                                   commit timestamp (zero means no change)\n"));
    1232            1 :     printf(_("  -e, --epoch=XIDEPOCH             set next transaction ID epoch\n"));
    1233            1 :     printf(_("  -l, --next-wal-file=WALFILE      set minimum starting location for new WAL\n"));
    1234            1 :     printf(_("  -m, --multixact-ids=MXID,MXID    set next and oldest multitransaction ID\n"));
    1235            1 :     printf(_("  -o, --next-oid=OID               set next OID\n"));
    1236            1 :     printf(_("  -O, --multixact-offset=OFFSET    set next multitransaction offset\n"));
    1237            1 :     printf(_("  -u, --oldest-transaction-id=XID  set oldest transaction ID\n"));
    1238            1 :     printf(_("  -x, --next-transaction-id=XID    set next transaction ID\n"));
    1239            1 :     printf(_("      --char-signedness=OPTION     set char signedness to \"signed\" or \"unsigned\"\n"));
    1240            1 :     printf(_("      --wal-segsize=SIZE           size of WAL segments, in megabytes\n"));
    1241              : 
    1242            1 :     printf(_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
    1243            1 :     printf(_("%s home page: <%s>\n"), PACKAGE_NAME, PACKAGE_URL);
    1244            1 : }
    1245              : 
    1246              : /*
    1247              :  * strtouint32_strict -- like strtoul(), but returns uint32 and doesn't accept
    1248              :  * negative values
    1249              :  */
    1250              : static uint32
    1251          109 : strtouint32_strict(const char *restrict s, char **restrict endptr, int base)
    1252              : {
    1253              :     unsigned long val;
    1254              :     bool        is_neg;
    1255              : 
    1256              :     /* skip leading whitespace */
    1257          109 :     while (isspace((unsigned char) *s))
    1258            0 :         s++;
    1259              : 
    1260              :     /*
    1261              :      * Is it negative?  We still call strtoul() if it was, to set 'endptr'.
    1262              :      * (The current callers don't care though.)
    1263              :      */
    1264          109 :     is_neg = (*s == '-');
    1265              : 
    1266          109 :     val = strtoul(s, endptr, base);
    1267              : 
    1268              :     /* reject if it was negative */
    1269          109 :     if (errno == 0 && is_neg)
    1270              :     {
    1271            3 :         errno = ERANGE;
    1272            3 :         val = 0;
    1273              :     }
    1274              : 
    1275              :     /*
    1276              :      * reject values larger than UINT32_MAX on platforms where long is 64 bits
    1277              :      * wide.
    1278              :      */
    1279          109 :     if (errno == 0 && val != (uint32) val)
    1280              :     {
    1281            1 :         errno = ERANGE;
    1282            1 :         val = UINT32_MAX;
    1283              :     }
    1284              : 
    1285          109 :     return (uint32) val;
    1286              : }
    1287              : 
    1288              : /*
    1289              :  * strtouint64_strict -- like strtou64(), but doesn't accept negative values
    1290              :  */
    1291              : static uint64
    1292           14 : strtouint64_strict(const char *restrict s, char **restrict endptr, int base)
    1293              : {
    1294              :     uint64      val;
    1295              :     bool        is_neg;
    1296              : 
    1297              :     /* skip leading whitespace */
    1298           14 :     while (isspace((unsigned char) *s))
    1299            0 :         s++;
    1300              : 
    1301              :     /*
    1302              :      * Is it negative?  We still call strtou64() if it was, to set 'endptr'.
    1303              :      * (The current callers don't care though.)
    1304              :      */
    1305           14 :     is_neg = (*s == '-');
    1306              : 
    1307           14 :     val = strtou64(s, endptr, base);
    1308              : 
    1309              :     /* reject if it was negative */
    1310           14 :     if (errno == 0 && is_neg)
    1311              :     {
    1312            1 :         errno = ERANGE;
    1313            1 :         val = 0;
    1314              :     }
    1315              : 
    1316           14 :     return val;
    1317              : }
        

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