Re: pg_migrator issues - Mailing list pgsql-hackers

Bruce Momjian wrote:
> 2)  Right now pg_migrator renames old tablespaces to .old, which fails
> if the tablespaces are on mount points.  I have already received a
> report of such a failure.  $PGDATA also has that issue, but that
> renaming has to be done by the user before pg_migrator is run, and only
> if they want to keep the same $PGDATA value after migration, i.e. no
> version-specific directory path.  One idea we floated around was to have
> tablespaces use major version directory names under the tablespace
> directory so renaming would not be necessary.  I could implement a
> pg_migrator --delete-old flag to cleanly delete the old 8.4 server files
> which are not in a version-specific subdirectory.

I have created a patch to implement per-cluster directories in
tablespaces.  This is for use by pg_migrator so it doesn't have to
rename the tablespaces during the migration.  Users still need to remove
the old cluster's tablespace subdirectory, and I can add a --delete-old
option to pg_migrator to do that.

The old code used a symlink from pg_tblspc/#### to the location
directory specified in CREATE TABLESPACE.  During CREATE TABLESPACE, a
PG_VERSION file is created containing the major version number.  Anytime
a database object is created in the tablespace, a per-database directory
is created.

With the new code in this patch, pg_tblspc/#### points to the CREATE
TABLESPACE directory just like before, but a new directory, PG_ +
major_version + catalog_version, e.g. PG_8.5_201001061, is created and
all per-database directories are created under that directory.  This
directory has the same purpose as the old PG_VERSION file.  One
disadvantage of this approach is that functions that need to look inside
tablespaces must now also specify the version directory, e.g.
pg_tablespace_databases().

An alternative approach would be for the pg_tblspc/#### symbolic link to
point to the new version directory, PG_*, but that makes removal of the
version directory complicated, particularly during WAL replay where we
don't have access to the system catalogs, and readlink() to read the
symbolic link target is not supported on all operating systems
(particularly Win32).

I used the version directory pattern "PG_8.5_201001061" because "PG_"
helps people realize the directory is for the use of Postgres
(PG_VERSION is gone in tablespaces), and the catalog version number
enables alpha migrations.  The major version number is not necessary but
probably useful for administrators.

pg_migrator is going to need to know about the version directory too,
and it can't use the C macro --- it has to construct the directory
pattern based on the contents of pg_control from the old and new
servers. And, it is going to be difficult to run pg_control on the old
server for pg_migrator --delete-old after migration because it is
renamed to pg_control.old --- I will need to create a symbolic link
during the time I run pg_controldata.  Also, the contents of the
tablespace directory for an 8.4 to 8.5 migration is going to be ugly
because there will be many numeric directories (for databases), and
PG_VERSION (for 8.4), and the PG_8.5_201001061 directory which should
not be touched.

Can someone explain why TablespaceCreateDbspace() creates a non-symlink
directory during recovery if the symlink is missing?  Is it just for
robustness?  I would like to document that more clearly.

Comments?

--
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + If your life is a hard drive, Christ can be your backup. +
Index: src/backend/catalog/catalog.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/catalog/catalog.c,v
retrieving revision 1.86
diff -c -c -r1.86 catalog.c
*** src/backend/catalog/catalog.c    6 Jan 2010 02:41:37 -0000    1.86
--- src/backend/catalog/catalog.c    8 Jan 2010 01:07:41 -0000
***************
*** 115,130 ****
      else
      {
          /* All other tablespaces are accessed via symlinks */
!         pathlen = 10 + OIDCHARS + 1 + OIDCHARS + 1 + OIDCHARS + 1
!             + FORKNAMECHARS + 1;
          path = (char *) palloc(pathlen);
          if (forknum != MAIN_FORKNUM)
!             snprintf(path, pathlen, "pg_tblspc/%u/%u/%u_%s",
!                      rnode.spcNode, rnode.dbNode, rnode.relNode,
!                      forkNames[forknum]);
          else
!             snprintf(path, pathlen, "pg_tblspc/%u/%u/%u",
!                      rnode.spcNode, rnode.dbNode, rnode.relNode);
      }
      return path;
  }
--- 115,131 ----
      else
      {
          /* All other tablespaces are accessed via symlinks */
!         pathlen = 9 + 1 + OIDCHARS + 1 + strlen(TABLESPACE_VERSION_DIRECTORY) +
!             1 + OIDCHARS + 1 + OIDCHARS + 1 + FORKNAMECHARS + 1;
          path = (char *) palloc(pathlen);
          if (forknum != MAIN_FORKNUM)
!             snprintf(path, pathlen, "pg_tblspc/%u/%s/%u/%u_%s",
!                      rnode.spcNode, TABLESPACE_VERSION_DIRECTORY,
!                      rnode.dbNode, rnode.relNode, forkNames[forknum]);
          else
!             snprintf(path, pathlen, "pg_tblspc/%u/%s/%u/%u",
!                      rnode.spcNode, TABLESPACE_VERSION_DIRECTORY,
!                      rnode.dbNode, rnode.relNode);
      }
      return path;
  }
***************
*** 161,170 ****
      else
      {
          /* All other tablespaces are accessed via symlinks */
!         pathlen = 10 + OIDCHARS + 1 + OIDCHARS + 1;
          path = (char *) palloc(pathlen);
!         snprintf(path, pathlen, "pg_tblspc/%u/%u",
!                  spcNode, dbNode);
      }
      return path;
  }
--- 162,172 ----
      else
      {
          /* All other tablespaces are accessed via symlinks */
!         pathlen = 9 + 1 + OIDCHARS + 1 + strlen(TABLESPACE_VERSION_DIRECTORY) +
!                   1 + OIDCHARS + 1;
          path = (char *) palloc(pathlen);
!         snprintf(path, pathlen, "pg_tblspc/%u/%s/%u",
!                  spcNode, TABLESPACE_VERSION_DIRECTORY, dbNode);
      }
      return path;
  }
Index: src/backend/commands/tablespace.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/commands/tablespace.c,v
retrieving revision 1.70
diff -c -c -r1.70 tablespace.c
*** src/backend/commands/tablespace.c    7 Jan 2010 04:10:39 -0000    1.70
--- src/backend/commands/tablespace.c    8 Jan 2010 01:07:41 -0000
***************
*** 15,22 ****
   * To support file access via the information given in RelFileNode, we
   * maintain a symbolic-link map in $PGDATA/pg_tblspc. The symlinks are
   * named by tablespace OIDs and point to the actual tablespace directories.
   * Thus the full path to an arbitrary file is
!  *            $PGDATA/pg_tblspc/spcoid/dboid/relfilenode
   *
   * There are two tablespaces created at initdb time: pg_global (for shared
   * tables) and pg_default (for everything else).  For backwards compatibility
--- 15,25 ----
   * To support file access via the information given in RelFileNode, we
   * maintain a symbolic-link map in $PGDATA/pg_tblspc. The symlinks are
   * named by tablespace OIDs and point to the actual tablespace directories.
+  * There is also a per-cluster version directory in each tablespace.
   * Thus the full path to an arbitrary file is
!  *            $PGDATA/pg_tblspc/spcoid/PG_MAJORVER_CATVER/dboid/relfilenode
!  * e.g.
!  *            $PGDATA/pg_tblspc/20981/PG_8.5_201001061/719849/83292814
   *
   * There are two tablespaces created at initdb time: pg_global (for shared
   * tables) and pg_default (for everything else).  For backwards compatibility
***************
*** 81,88 ****
  char       *temp_tablespaces = NULL;


! static bool remove_tablespace_directories(Oid tablespaceoid, bool redo);
! static void write_version_file(const char *path);


  /*
--- 84,92 ----
  char       *temp_tablespaces = NULL;


! static void create_tablespace_directories(const char *location,
!                                          const Oid tablespaceoid);
! static bool destroy_tablespace_directories(Oid tablespaceoid, bool redo);


  /*
***************
*** 146,163 ****
                  {
                      char       *parentdir;

!                     /* Failure other than not exists? */
                      if (errno != ENOENT || !isRedo)
                          ereport(ERROR,
                                  (errcode_for_file_access(),
                                errmsg("could not create directory \"%s\": %m",
                                       dir)));

!                     /* Parent directory must be missing */
                      parentdir = pstrdup(dir);
                      get_parent_directory(parentdir);
!                     /* Can't create parent either? */
!                     if (mkdir(parentdir, S_IRWXU) < 0)
                          ereport(ERROR,
                                  (errcode_for_file_access(),
                                errmsg("could not create directory \"%s\": %m",
--- 150,185 ----
                  {
                      char       *parentdir;

!                     /* Failure other than not exists or not in WAL replay? */
                      if (errno != ENOENT || !isRedo)
                          ereport(ERROR,
                                  (errcode_for_file_access(),
                                errmsg("could not create directory \"%s\": %m",
                                       dir)));

!                     /*
!                      * Parent directories are missing during WAL replay, so
!                      * continue by creating simple parent directories
!                      * rather than a symlink.
!                      */
!
!                     /* create two parents up if not exist */
                      parentdir = pstrdup(dir);
                      get_parent_directory(parentdir);
!                     get_parent_directory(parentdir);
!                     /* Can't create parent and it doesn't already exist? */
!                     if (mkdir(parentdir, S_IRWXU) < 0 && errno != EEXIST)
!                         ereport(ERROR,
!                                 (errcode_for_file_access(),
!                               errmsg("could not create directory \"%s\": %m",
!                                      parentdir)));
!                     pfree(parentdir);
!
!                     /* create one parent up if not exist */
!                     parentdir = pstrdup(dir);
!                     get_parent_directory(parentdir);
!                     /* Can't create parent and it doesn't already exist? */
!                     if (mkdir(parentdir, S_IRWXU) < 0 && errno != EEXIST)
                          ereport(ERROR,
                                  (errcode_for_file_access(),
                                errmsg("could not create directory \"%s\": %m",
***************
*** 212,218 ****
      HeapTuple    tuple;
      Oid            tablespaceoid;
      char       *location;
-     char       *linkloc;
      Oid            ownerId;

      /* Must be super user */
--- 234,239 ----
***************
*** 251,260 ****

      /*
       * Check that location isn't too long. Remember that we're going to append
!      * '/<dboid>/<relid>.<nnn>'  (XXX but do we ever form the whole path
!      * explicitly?    This may be overly conservative.)
       */
!     if (strlen(location) >= MAXPGPATH - 1 - OIDCHARS - 1 - OIDCHARS - 1 - OIDCHARS)
          ereport(ERROR,
                  (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                   errmsg("tablespace location \"%s\" is too long",
--- 272,282 ----

      /*
       * Check that location isn't too long. Remember that we're going to append
!      * 'PG_XXX/<dboid>/<relid>.<nnn>'.  FYI, we never actually reference the
!      * whole path, but mkdir() uses the first two parts.
       */
!     if (strlen(location) + 1 + strlen(TABLESPACE_VERSION_DIRECTORY) + 1 +
!         OIDCHARS + 1 + OIDCHARS + 1 + OIDCHARS > MAXPGPATH)
          ereport(ERROR,
                  (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                   errmsg("tablespace location \"%s\" is too long",
***************
*** 311,355 ****
      /* Record dependency on owner */
      recordDependencyOnOwner(TableSpaceRelationId, tablespaceoid, ownerId);

!     /*
!      * Attempt to coerce target directory to safe permissions.    If this fails,
!      * it doesn't exist or has the wrong owner.
!      */
!     if (chmod(location, 0700) != 0)
!         ereport(ERROR,
!                 (errcode_for_file_access(),
!                  errmsg("could not set permissions on directory \"%s\": %m",
!                         location)));
!
!     /*
!      * Check the target directory is empty.
!      */
!     if (!directory_is_empty(location))
!         ereport(ERROR,
!                 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
!                  errmsg("directory \"%s\" is not empty",
!                         location)));
!
!     /*
!      * Create the PG_VERSION file in the target directory.    This has several
!      * purposes: to make sure we can write in the directory, to prevent
!      * someone from creating another tablespace pointing at the same directory
!      * (the emptiness check above will fail), and to label tablespace
!      * directories by PG version.
!      */
!     write_version_file(location);
!
!     /*
!      * All seems well, create the symlink
!      */
!     linkloc = (char *) palloc(OIDCHARS + OIDCHARS + 1);
!     sprintf(linkloc, "pg_tblspc/%u", tablespaceoid);
!
!     if (symlink(location, linkloc) < 0)
!         ereport(ERROR,
!                 (errcode_for_file_access(),
!                  errmsg("could not create symbolic link \"%s\": %m",
!                         linkloc)));

      /* Record the filesystem change in XLOG */
      {
--- 333,339 ----
      /* Record dependency on owner */
      recordDependencyOnOwner(TableSpaceRelationId, tablespaceoid, ownerId);

!     create_tablespace_directories(location, tablespaceoid);

      /* Record the filesystem change in XLOG */
      {
***************
*** 378,384 ****
       */
      ForceSyncCommit();

-     pfree(linkloc);
      pfree(location);

      /* We keep the lock on pg_tablespace until commit */
--- 362,367 ----
***************
*** 478,484 ****
      /*
       * Try to remove the physical infrastructure.
       */
!     if (!remove_tablespace_directories(tablespaceoid, false))
      {
          /*
           * Not all files deleted?  However, there can be lingering empty files
--- 461,467 ----
      /*
       * Try to remove the physical infrastructure.
       */
!     if (!destroy_tablespace_directories(tablespaceoid, false))
      {
          /*
           * Not all files deleted?  However, there can be lingering empty files
***************
*** 490,496 ****
           * out any lingering files, and try again.
           */
          RequestCheckpoint(CHECKPOINT_IMMEDIATE | CHECKPOINT_FORCE | CHECKPOINT_WAIT);
!         if (!remove_tablespace_directories(tablespaceoid, false))
          {
              /* Still not empty, the files must be important then */
              ereport(ERROR,
--- 473,479 ----
           * out any lingering files, and try again.
           */
          RequestCheckpoint(CHECKPOINT_IMMEDIATE | CHECKPOINT_FORCE | CHECKPOINT_WAIT);
!         if (!destroy_tablespace_directories(tablespaceoid, false))
          {
              /* Still not empty, the files must be important then */
              ereport(ERROR,
***************
*** 542,565 ****
  #endif   /* HAVE_SYMLINK */
  }

  /*
!  * remove_tablespace_directories: attempt to remove filesystem infrastructure
   *
!  * Returns TRUE if successful, FALSE if some subdirectory is not empty
   *
!  * redo indicates we are redoing a drop from XLOG; okay if nothing there
   */
  static bool
! remove_tablespace_directories(Oid tablespaceoid, bool redo)
  {
!     char       *location;
      DIR           *dirdesc;
      struct dirent *de;
      char       *subfile;
      struct stat st;

!     location = (char *) palloc(OIDCHARS + OIDCHARS + 1);
!     sprintf(location, "pg_tblspc/%u", tablespaceoid);

      /*
       * Check if the tablespace still contains any files.  We try to rmdir each
--- 525,621 ----
  #endif   /* HAVE_SYMLINK */
  }

+
  /*
!  * create_tablespace_directories
   *
!  *    Attempt to create filesystem infrastructure linking $PGDATA/pg_tblspc/
!  *    to the specified directory
!  */
! static void
! create_tablespace_directories(const char *location, const Oid tablespaceoid)
! {
!     char *linkloc = palloc(OIDCHARS + OIDCHARS + 1);
!     char *location_with_version_dir = palloc(strlen(location) + 1 +
!                                         strlen(TABLESPACE_VERSION_DIRECTORY) + 1);
!
!     sprintf(linkloc, "pg_tblspc/%u", tablespaceoid);
!     sprintf(location_with_version_dir, "%s/%s", location,
!                                         TABLESPACE_VERSION_DIRECTORY);
!
!     /*
!      * Attempt to coerce target directory to safe permissions.    If this fails,
!      * it doesn't exist or has the wrong owner.
!      */
!     if (chmod(location, 0700) != 0)
!     {
!         if (errno == ENOENT)
!             ereport(ERROR,
!                     (errcode(ERRCODE_UNDEFINED_FILE),
!                      errmsg("directory \"%s\" does not exist",
!                             location)));
!         else
!             ereport(ERROR,
!                 (errcode_for_file_access(),
!                  errmsg("could not set permissions on directory \"%s\": %m",
!                         location)));
!     }
!
!     /*
!      * The creation of the version directory prevents more than one
!      *     tablespace in a single location.
!      */
!     if (mkdir(location_with_version_dir, S_IRWXU) < 0)
!     {
!         if (errno == EEXIST)
!             ereport(ERROR,
!                     (errcode(ERRCODE_OBJECT_IN_USE),
!                      errmsg("directory \"%s\" already in use as a tablespace",
!                             location_with_version_dir)));
!         else
!             ereport(ERROR,
!                     (errcode_for_file_access(),
!                   errmsg("could not create directory \"%s\": %m",
!                          location_with_version_dir)));
!     }
!
!     /*
!      * Create the symlink under PGDATA
!      */
!     if (symlink(location, linkloc) < 0)
!         ereport(ERROR,
!                 (errcode_for_file_access(),
!                  errmsg("could not create symbolic link \"%s\": %m",
!                         linkloc)));
!
!     pfree(linkloc);
!     pfree(location_with_version_dir);
! }
!
!
! /*
!  * destroy_tablespace_directories
!  *
!  * Attempt to remove filesystem infrastructure
!  *
!  * 'redo' indicates we are redoing a drop from XLOG; okay if nothing there
   *
!  * Returns TRUE if successful, FALSE if some subdirectory is not empty
   */
  static bool
! destroy_tablespace_directories(Oid tablespaceoid, bool redo)
  {
!     char       *linkloc;
!     char       *linkloc_with_version_dir;
      DIR           *dirdesc;
      struct dirent *de;
      char       *subfile;
      struct stat st;

!     linkloc_with_version_dir = palloc(9 + 1 + OIDCHARS + 1 +
!                                     strlen(TABLESPACE_VERSION_DIRECTORY));
!     sprintf(linkloc_with_version_dir, "pg_tblspc/%u/%s", tablespaceoid,
!                                     TABLESPACE_VERSION_DIRECTORY);

      /*
       * Check if the tablespace still contains any files.  We try to rmdir each
***************
*** 582,588 ****
       * and symlink.  We want to allow a new DROP attempt to succeed at
       * removing the catalog entries, so we should not give a hard error here.
       */
!     dirdesc = AllocateDir(location);
      if (dirdesc == NULL)
      {
          if (errno == ENOENT)
--- 638,644 ----
       * and symlink.  We want to allow a new DROP attempt to succeed at
       * removing the catalog entries, so we should not give a hard error here.
       */
!     dirdesc = AllocateDir(linkloc_with_version_dir);
      if (dirdesc == NULL)
      {
          if (errno == ENOENT)
***************
*** 591,622 ****
                  ereport(WARNING,
                          (errcode_for_file_access(),
                           errmsg("could not open directory \"%s\": %m",
!                                 location)));
!             pfree(location);
              return true;
          }
          /* else let ReadDir report the error */
      }

!     while ((de = ReadDir(dirdesc, location)) != NULL)
      {
-         /* Note we ignore PG_VERSION for the nonce */
          if (strcmp(de->d_name, ".") == 0 ||
!             strcmp(de->d_name, "..") == 0 ||
!             strcmp(de->d_name, "PG_VERSION") == 0)
              continue;

!         subfile = palloc(strlen(location) + 1 + strlen(de->d_name) + 1);
!         sprintf(subfile, "%s/%s", location, de->d_name);

          /* This check is just to deliver a friendlier error message */
          if (!directory_is_empty(subfile))
          {
              FreeDir(dirdesc);
              return false;
          }

!         /* Do the real deed */
          if (rmdir(subfile) < 0)
              ereport(ERROR,
                      (errcode_for_file_access(),
--- 647,678 ----
                  ereport(WARNING,
                          (errcode_for_file_access(),
                           errmsg("could not open directory \"%s\": %m",
!                                 linkloc_with_version_dir)));
!             pfree(linkloc_with_version_dir);
              return true;
          }
          /* else let ReadDir report the error */
      }

!     while ((de = ReadDir(dirdesc, linkloc_with_version_dir)) != NULL)
      {
          if (strcmp(de->d_name, ".") == 0 ||
!             strcmp(de->d_name, "..") == 0)
              continue;

!         subfile = palloc(strlen(linkloc_with_version_dir) + 1 + strlen(de->d_name) + 1);
!         sprintf(subfile, "%s/%s", linkloc_with_version_dir, de->d_name);

          /* This check is just to deliver a friendlier error message */
          if (!directory_is_empty(subfile))
          {
              FreeDir(dirdesc);
+             pfree(subfile);
+             pfree(linkloc_with_version_dir);
              return false;
          }

!         /* remove empty directory */
          if (rmdir(subfile) < 0)
              ereport(ERROR,
                      (errcode_for_file_access(),
***************
*** 628,706 ****

      FreeDir(dirdesc);

      /*
!      * Okay, try to unlink PG_VERSION (we allow it to not be there, even in
!      * non-REDO case, for robustness).
!      */
!     subfile = palloc(strlen(location) + 11 + 1);
!     sprintf(subfile, "%s/PG_VERSION", location);
!
!     if (unlink(subfile) < 0)
!     {
!         if (errno != ENOENT)
!             ereport(ERROR,
!                     (errcode_for_file_access(),
!                      errmsg("could not remove file \"%s\": %m",
!                             subfile)));
!     }
!
!     pfree(subfile);
!
!     /*
!      * Okay, try to remove the symlink.  We must however deal with the
       * possibility that it's a directory instead of a symlink --- this could
       * happen during WAL replay (see TablespaceCreateDbspace), and it is also
!      * the normal case on Windows.
       */
!     if (lstat(location, &st) == 0 && S_ISDIR(st.st_mode))
      {
!         if (rmdir(location) < 0)
              ereport(ERROR,
                      (errcode_for_file_access(),
                       errmsg("could not remove directory \"%s\": %m",
!                             location)));
      }
      else
      {
!         if (unlink(location) < 0)
              ereport(ERROR,
                      (errcode_for_file_access(),
                       errmsg("could not remove symbolic link \"%s\": %m",
!                             location)));
      }

!     pfree(location);

      return true;
  }

- /*
-  * write out the PG_VERSION file in the specified directory
-  */
- static void
- write_version_file(const char *path)
- {
-     char       *fullname;
-     FILE       *version_file;
-
-     /* Now write the file */
-     fullname = palloc(strlen(path) + 11 + 1);
-     sprintf(fullname, "%s/PG_VERSION", path);
-
-     if ((version_file = AllocateFile(fullname, PG_BINARY_W)) == NULL)
-         ereport(ERROR,
-                 (errcode_for_file_access(),
-                  errmsg("could not write to file \"%s\": %m",
-                         fullname)));
-     fprintf(version_file, "%s\n", PG_MAJORVERSION);
-     if (FreeFile(version_file))
-         ereport(ERROR,
-                 (errcode_for_file_access(),
-                  errmsg("could not write to file \"%s\": %m",
-                         fullname)));
-
-     pfree(fullname);
- }

  /*
   * Check if a directory is empty.
--- 684,727 ----

      FreeDir(dirdesc);

+     /* remove version directory */
+     if (rmdir(linkloc_with_version_dir) < 0)
+         ereport(ERROR,
+                 (errcode_for_file_access(),
+                  errmsg("could not remove directory \"%s\": %m",
+                         linkloc_with_version_dir)));
+
      /*
!      * Try to remove the symlink.  We must however deal with the
       * possibility that it's a directory instead of a symlink --- this could
       * happen during WAL replay (see TablespaceCreateDbspace), and it is also
!      * the case on Windows where junction points lstat() as directories.
       */
!     linkloc = pstrdup(linkloc_with_version_dir);
!     get_parent_directory(linkloc);
!     if (lstat(linkloc, &st) == 0 && S_ISDIR(st.st_mode))
      {
!         if (rmdir(linkloc) < 0)
              ereport(ERROR,
                      (errcode_for_file_access(),
                       errmsg("could not remove directory \"%s\": %m",
!                             linkloc)));
      }
      else
      {
!         if (unlink(linkloc) < 0)
              ereport(ERROR,
                      (errcode_for_file_access(),
                       errmsg("could not remove symbolic link \"%s\": %m",
!                             linkloc)));
      }

!     pfree(linkloc_with_version_dir);
!     pfree(linkloc);

      return true;
  }


  /*
   * Check if a directory is empty.
***************
*** 728,733 ****
--- 749,755 ----
      return true;
  }

+
  /*
   * Rename a tablespace
   */
***************
*** 1336,1370 ****
      {
          xl_tblspc_create_rec *xlrec = (xl_tblspc_create_rec *) XLogRecGetData(record);
          char       *location = xlrec->ts_path;
-         char       *linkloc;
-
-         /*
-          * Attempt to coerce target directory to safe permissions.    If this
-          * fails, it doesn't exist or has the wrong owner.
-          */
-         if (chmod(location, 0700) != 0)
-             ereport(ERROR,
-                     (errcode_for_file_access(),
-                   errmsg("could not set permissions on directory \"%s\": %m",
-                          location)));
-
-         /* Create or re-create the PG_VERSION file in the target directory */
-         write_version_file(location);
-
-         /* Create the symlink if not already present */
-         linkloc = (char *) palloc(OIDCHARS + OIDCHARS + 1);
-         sprintf(linkloc, "pg_tblspc/%u", xlrec->ts_id);
-
-         if (symlink(location, linkloc) < 0)
-         {
-             if (errno != EEXIST)
-                 ereport(ERROR,
-                         (errcode_for_file_access(),
-                          errmsg("could not create symbolic link \"%s\": %m",
-                                 linkloc)));
-         }

!         pfree(linkloc);
      }
      else if (info == XLOG_TBLSPC_DROP)
      {
--- 1358,1365 ----
      {
          xl_tblspc_create_rec *xlrec = (xl_tblspc_create_rec *) XLogRecGetData(record);
          char       *location = xlrec->ts_path;

!         create_tablespace_directories(location, xlrec->ts_id);
      }
      else if (info == XLOG_TBLSPC_DROP)
      {
***************
*** 1380,1386 ****
           * remove all files then do conflict processing and try again,
           * if currently enabled.
           */
!         if (!remove_tablespace_directories(xlrec->ts_id, true))
          {
              VirtualTransactionId *temp_file_users;

--- 1375,1381 ----
           * remove all files then do conflict processing and try again,
           * if currently enabled.
           */
!         if (!destroy_tablespace_directories(xlrec->ts_id, true))
          {
              VirtualTransactionId *temp_file_users;

***************
*** 1416,1422 ****
               * exited by now. So lets recheck before we throw an error.
               * If !process_conflicts then this will just fail again.
               */
!             if (!remove_tablespace_directories(xlrec->ts_id, true))
                  ereport(ERROR,
                      (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
                       errmsg("tablespace %u is not empty",
--- 1411,1417 ----
               * exited by now. So lets recheck before we throw an error.
               * If !process_conflicts then this will just fail again.
               */
!             if (!destroy_tablespace_directories(xlrec->ts_id, true))
                  ereport(ERROR,
                      (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
                       errmsg("tablespace %u is not empty",
Index: src/backend/storage/file/fd.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/storage/file/fd.c,v
retrieving revision 1.152
diff -c -c -r1.152 fd.c
*** src/backend/storage/file/fd.c    2 Jan 2010 16:57:51 -0000    1.152
--- src/backend/storage/file/fd.c    8 Jan 2010 01:07:41 -0000
***************
*** 51,56 ****
--- 51,57 ----

  #include "miscadmin.h"
  #include "access/xact.h"
+ #include "catalog/catalog.h"
  #include "catalog/pg_tablespace.h"
  #include "storage/fd.h"
  #include "storage/ipc.h"
***************
*** 963,970 ****
      else
      {
          /* All other tablespaces are accessed via symlinks */
!         snprintf(tempdirpath, sizeof(tempdirpath), "pg_tblspc/%u/%s",
!                  tblspcOid, PG_TEMP_FILES_DIR);
      }

      /*
--- 964,971 ----
      else
      {
          /* All other tablespaces are accessed via symlinks */
!         snprintf(tempdirpath, sizeof(tempdirpath), "pg_tblspc/%u/%s/%s",
!                  tblspcOid, TABLESPACE_VERSION_DIRECTORY, PG_TEMP_FILES_DIR);
      }

      /*
***************
*** 1841,1848 ****
              strcmp(spc_de->d_name, "..") == 0)
              continue;

!         snprintf(temp_path, sizeof(temp_path), "pg_tblspc/%s/%s",
!                  spc_de->d_name, PG_TEMP_FILES_DIR);
          RemovePgTempFilesInDir(temp_path);
      }

--- 1842,1849 ----
              strcmp(spc_de->d_name, "..") == 0)
              continue;

!         snprintf(temp_path, sizeof(temp_path), "pg_tblspc/%s/%s/%s",
!                  spc_de->d_name, TABLESPACE_VERSION_DIRECTORY, PG_TEMP_FILES_DIR);
          RemovePgTempFilesInDir(temp_path);
      }

Index: src/backend/utils/adt/dbsize.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/utils/adt/dbsize.c,v
retrieving revision 1.25
diff -c -c -r1.25 dbsize.c
*** src/backend/utils/adt/dbsize.c    2 Jan 2010 16:57:53 -0000    1.25
--- src/backend/utils/adt/dbsize.c    8 Jan 2010 01:07:41 -0000
***************
*** 108,115 ****
              strcmp(direntry->d_name, "..") == 0)
              continue;

!         snprintf(pathname, MAXPGPATH, "pg_tblspc/%s/%u",
!                  direntry->d_name, dbOid);
          totalsize += db_dir_size(pathname);
      }

--- 108,115 ----
              strcmp(direntry->d_name, "..") == 0)
              continue;

!         snprintf(pathname, MAXPGPATH, "pg_tblspc/%s/%s/%u",
!                  direntry->d_name, TABLESPACE_VERSION_DIRECTORY, dbOid);
          totalsize += db_dir_size(pathname);
      }

***************
*** 179,185 ****
      else if (tblspcOid == GLOBALTABLESPACE_OID)
          snprintf(tblspcPath, MAXPGPATH, "global");
      else
!         snprintf(tblspcPath, MAXPGPATH, "pg_tblspc/%u", tblspcOid);

      dirdesc = AllocateDir(tblspcPath);

--- 179,186 ----
      else if (tblspcOid == GLOBALTABLESPACE_OID)
          snprintf(tblspcPath, MAXPGPATH, "global");
      else
!         snprintf(tblspcPath, MAXPGPATH, "pg_tblspc/%u/%s", tblspcOid,
!                                          TABLESPACE_VERSION_DIRECTORY);

      dirdesc = AllocateDir(tblspcPath);

Index: src/backend/utils/adt/misc.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/utils/adt/misc.c,v
retrieving revision 1.73
diff -c -c -r1.73 misc.c
*** src/backend/utils/adt/misc.c    2 Jan 2010 16:57:54 -0000    1.73
--- src/backend/utils/adt/misc.c    8 Jan 2010 01:07:41 -0000
***************
*** 20,25 ****
--- 20,26 ----
  #include <math.h>

  #include "access/xact.h"
+ #include "catalog/catalog.h"
  #include "catalog/pg_type.h"
  #include "catalog/pg_tablespace.h"
  #include "commands/dbcommands.h"
***************
*** 185,191 ****
          /*
           * size = tablespace dirname length + dir sep char + oid + terminator
           */
!         fctx->location = (char *) palloc(10 + 10 + 1);
          if (tablespaceOid == GLOBALTABLESPACE_OID)
          {
              fctx->dirdesc = NULL;
--- 186,193 ----
          /*
           * size = tablespace dirname length + dir sep char + oid + terminator
           */
!         fctx->location = (char *) palloc(9 + 1 + OIDCHARS + 1 +
!                          strlen(TABLESPACE_VERSION_DIRECTORY) + 1);
          if (tablespaceOid == GLOBALTABLESPACE_OID)
          {
              fctx->dirdesc = NULL;
***************
*** 197,203 ****
              if (tablespaceOid == DEFAULTTABLESPACE_OID)
                  sprintf(fctx->location, "base");
              else
!                 sprintf(fctx->location, "pg_tblspc/%u", tablespaceOid);

              fctx->dirdesc = AllocateDir(fctx->location);

--- 199,206 ----
              if (tablespaceOid == DEFAULTTABLESPACE_OID)
                  sprintf(fctx->location, "base");
              else
!                 sprintf(fctx->location, "pg_tblspc/%u/%s", tablespaceOid,
!                         TABLESPACE_VERSION_DIRECTORY);

              fctx->dirdesc = AllocateDir(fctx->location);

Index: src/backend/utils/cache/relcache.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/utils/cache/relcache.c,v
retrieving revision 1.296
diff -c -c -r1.296 relcache.c
*** src/backend/utils/cache/relcache.c    5 Jan 2010 01:06:56 -0000    1.296
--- src/backend/utils/cache/relcache.c    8 Jan 2010 01:07:50 -0000
***************
*** 4297,4304 ****
          if (strspn(de->d_name, "0123456789") == strlen(de->d_name))
          {
              /* Scan the tablespace dir for per-database dirs */
!             snprintf(path, sizeof(path), "%s/%s",
!                      tblspcdir, de->d_name);
              RelationCacheInitFileRemoveInDir(path);
          }
      }
--- 4297,4304 ----
          if (strspn(de->d_name, "0123456789") == strlen(de->d_name))
          {
              /* Scan the tablespace dir for per-database dirs */
!             snprintf(path, sizeof(path), "%s/%s/%s",
!                      tblspcdir, de->d_name, TABLESPACE_VERSION_DIRECTORY);
              RelationCacheInitFileRemoveInDir(path);
          }
      }
Index: src/include/catalog/catalog.h
===================================================================
RCS file: /cvsroot/pgsql/src/include/catalog/catalog.h,v
retrieving revision 1.46
diff -c -c -r1.46 catalog.h
*** src/include/catalog/catalog.h    6 Jan 2010 02:41:37 -0000    1.46
--- src/include/catalog/catalog.h    8 Jan 2010 01:07:50 -0000
***************
*** 14,24 ****
--- 14,27 ----
  #ifndef CATALOG_H
  #define CATALOG_H

+ #include "catalog/catversion.h"
  #include "catalog/pg_class.h"
  #include "storage/relfilenode.h"
  #include "utils/relcache.h"

  #define OIDCHARS        10        /* max chars printed by %u */
+ #define TABLESPACE_VERSION_DIRECTORY    "PG_" PG_MAJORVERSION "_" \
+                                     CppAsString2(CATALOG_VERSION_NO)

  extern const char *forkNames[];
  extern ForkNumber forkname_to_number(char *forkName);
Index: src/test/regress/output/tablespace.source
===================================================================
RCS file: /cvsroot/pgsql/src/test/regress/output/tablespace.source,v
retrieving revision 1.9
diff -c -c -r1.9 tablespace.source
*** src/test/regress/output/tablespace.source    5 Jan 2010 21:54:00 -0000    1.9
--- src/test/regress/output/tablespace.source    8 Jan 2010 01:07:50 -0000
***************
*** 65,71 ****

  -- Will fail with bad path
  CREATE TABLESPACE badspace LOCATION '/no/such/location';
! ERROR:  could not set permissions on directory "/no/such/location": No such file or directory
  -- No such tablespace
  CREATE TABLE bar (i int) TABLESPACE nosuchspace;
  ERROR:  tablespace "nosuchspace" does not exist
--- 65,71 ----

  -- Will fail with bad path
  CREATE TABLESPACE badspace LOCATION '/no/such/location';
! ERROR:  directory "/no/such/location" does not exist
  -- No such tablespace
  CREATE TABLE bar (i int) TABLESPACE nosuchspace;
  ERROR:  tablespace "nosuchspace" does not exist