Add new -x XID option to /contrib/pg_resetxlog for future pg_upgrade use.

diff --git a/contrib/pg_resetxlog/README.pg_resetxlog b/contrib/pg_resetxlog/README.pg_resetxlog
index f9521ee0d63043ee7203696e0df0390a4f337c9a..943b2a1b0c1337b68540e8b4ec23e0a526647042 100644 (file)
--- a/contrib/pg_resetxlog/README.pg_resetxlog
+++ b/contrib/pg_resetxlog/README.pg_resetxlog
@@ -21,6 +21,9 @@ module pg_controldata and run it to be sure the DB state is SHUTDOWN).
 Then run pg_resetxlog, and finally install and start the new version of
 the database software.
 
+A tertiary purpose it its use by pg_upgrade to set the next transaction
+id in pg_control.
+
 To run the program, make sure your postmaster is not running, then
 (as the Postgres admin user) do
 

diff --git a/contrib/pg_resetxlog/pg_resetxlog.c b/contrib/pg_resetxlog/pg_resetxlog.c
index 554bc83939974bbb91d64b5e649c38138699f9cf..7889cdcf3333f5ec595fb95a98a83825b473a259 100644 (file)
--- a/contrib/pg_resetxlog/pg_resetxlog.c
+++ b/contrib/pg_resetxlog/pg_resetxlog.c
@@ -23,7 +23,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Header: /cvsroot/pgsql/contrib/pg_resetxlog/Attic/pg_resetxlog.c,v 1.10 2001/11/05 17:46:23 momjian Exp $
+ * $Header: /cvsroot/pgsql/contrib/pg_resetxlog/Attic/pg_resetxlog.c,v 1.11 2002/01/10 17:51:52 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -709,34 +709,39 @@ PrintControlValues(void)
  * Write out the new pg_control file.
  */
 static void
-RewriteControlFile(void)
+RewriteControlFile(TransactionId set_xid)
 {
        int                     fd;
        char            buffer[BLCKSZ]; /* need not be aligned */
 
-       /*
-        * Adjust fields as needed to force an empty XLOG starting at the next
-        * available segment.
-        */
-       newXlogId = ControlFile.logId;
-       newXlogSeg = ControlFile.logSeg;
-       /* be sure we wrap around correctly at end of a logfile */
-       NextLogSeg(newXlogId, newXlogSeg);
-
-       ControlFile.checkPointCopy.redo.xlogid = newXlogId;
-       ControlFile.checkPointCopy.redo.xrecoff =
-               newXlogSeg * XLogSegSize + SizeOfXLogPHD;
-       ControlFile.checkPointCopy.undo = ControlFile.checkPointCopy.redo;
-       ControlFile.checkPointCopy.time = time(NULL);
-
-       ControlFile.state = DB_SHUTDOWNED;
-       ControlFile.time = time(NULL);
-       ControlFile.logId = newXlogId;
-       ControlFile.logSeg = newXlogSeg + 1;
-       ControlFile.checkPoint = ControlFile.checkPointCopy.redo;
-       ControlFile.prevCheckPoint.xlogid = 0;
-       ControlFile.prevCheckPoint.xrecoff = 0;
-
+       if (set_xid == 0)
+       {
+               /*
+                * Adjust fields as needed to force an empty XLOG starting at the next
+                * available segment.
+                */
+               newXlogId = ControlFile.logId;
+               newXlogSeg = ControlFile.logSeg;
+               /* be sure we wrap around correctly at end of a logfile */
+               NextLogSeg(newXlogId, newXlogSeg);
+       
+               ControlFile.checkPointCopy.redo.xlogid = newXlogId;
+               ControlFile.checkPointCopy.redo.xrecoff =
+                       newXlogSeg * XLogSegSize + SizeOfXLogPHD;
+               ControlFile.checkPointCopy.undo = ControlFile.checkPointCopy.redo;
+               ControlFile.checkPointCopy.time = time(NULL);
+       
+               ControlFile.state = DB_SHUTDOWNED;
+               ControlFile.time = time(NULL);
+               ControlFile.logId = newXlogId;
+               ControlFile.logSeg = newXlogSeg + 1;
+               ControlFile.checkPoint = ControlFile.checkPointCopy.redo;
+               ControlFile.prevCheckPoint.xlogid = 0;
+               ControlFile.prevCheckPoint.xrecoff = 0;
+       }
+       else
+               ControlFile.checkPointCopy.nextXid = set_xid;
+       
        /* Contents are protected with a CRC */
        INIT_CRC64(ControlFile.crc);
        COMP_CRC64(ControlFile.crc,
@@ -926,9 +931,10 @@ WriteEmptyXLOG(void)
 static void
 usage(void)
 {
-       fprintf(stderr, "Usage: pg_resetxlog [-f] [-n] PGDataDirectory\n\n"
-                       "  -f\tforce update to be done\n"
-                       "  -n\tno update, just show extracted pg_control values (for testing)\n");
+       fprintf(stderr, "Usage: pg_resetxlog [-f] [-n] [-x xid] PGDataDirectory\n"
+                       " -f\tforce update to be done\n"
+                       " -n\tno update, just show extracted pg_control values (for testing)\n"
+                       " -x XID\tset XID in pg_control\n");
        exit(1);
 }
 
@@ -939,6 +945,7 @@ main(int argc, char **argv)
        int                     argn;
        bool            force = false;
        bool            noupdate = false;
+       TransactionId set_xid = 0;
        int                     fd;
        char            path[MAXPGPATH];
 
@@ -950,6 +957,18 @@ main(int argc, char **argv)
                        force = true;
                else if (strcmp(argv[argn], "-n") == 0)
                        noupdate = true;
+               else if (strcmp(argv[argn], "-x") == 0)
+               {
+                       argn++;
+                       if (argn == argc)
+                               usage();
+                       set_xid = strtoul(argv[argn], NULL, 0);
+                       if (set_xid == 0)
+                       {
+                               fprintf(stderr, "XID can not be 0.");
+                               exit(1);
+                       }
+               }
                else
                        usage();
        }
@@ -992,6 +1011,20 @@ main(int argc, char **argv)
        if (!ReadControlFile())
                GuessControlValues();
 
+       /*
+        * Set XID in pg_control and exit
+        */
+       if (set_xid)
+       {
+               if (guessed)
+               {
+                       printf("\npg_control appears corrupt.  Can not update XID.\n");
+                       exit(1);
+               }
+               RewriteControlFile(set_xid);
+               exit(0);
+       }
+
        /*
         * If we had to guess anything, and -f was not given, just print the
         * guessed values and exit.  Also print if -n is given.
@@ -1018,7 +1051,7 @@ main(int argc, char **argv)
        /*
         * Else, do the dirty deed.
         */
-       RewriteControlFile();
+       RewriteControlFile(0);
        KillExistingXLOG();
        WriteEmptyXLOG();