diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/commands/dbcommands.c | 16 | ||||
| -rw-r--r-- | src/backend/storage/smgr/md.c | 33 | ||||
| -rw-r--r-- | src/port/dirmod.c | 25 |
3 files changed, 59 insertions, 15 deletions
diff --git a/src/backend/commands/dbcommands.c b/src/backend/commands/dbcommands.c index 857db388a8f..7055b0fe98e 100644 --- a/src/backend/commands/dbcommands.c +++ b/src/backend/commands/dbcommands.c @@ -13,7 +13,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/commands/dbcommands.c,v 1.206 2008/04/16 23:59:40 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/commands/dbcommands.c,v 1.207 2008/04/18 06:48:38 heikki Exp $ * *------------------------------------------------------------------------- */ @@ -715,18 +715,20 @@ dropdb(const char *dbname, bool missing_ok) pgstat_drop_database(db_id); /* - * Tell bgwriter to forget any pending fsync requests for files in the - * database; else it'll fail at next checkpoint. + * Tell bgwriter to forget any pending fsync and unlink requests for files + * in the database; else the fsyncs will fail at next checkpoint, or worse, + * it will delete files that belong to a newly created database with the + * same OID. */ ForgetDatabaseFsyncRequests(db_id); /* - * On Windows, force a checkpoint so that the bgwriter doesn't hold any - * open files, which would cause rmdir() to fail. + * Force a checkpoint to make sure the bgwriter has received the message + * sent by ForgetDatabaseFsyncRequests. On Windows, this also ensures that + * the bgwriter doesn't hold any open files, which would cause rmdir() to + * fail. */ -#ifdef WIN32 RequestCheckpoint(CHECKPOINT_IMMEDIATE | CHECKPOINT_FORCE | CHECKPOINT_WAIT); -#endif /* * Remove all tablespace subdirs belonging to the database. diff --git a/src/backend/storage/smgr/md.c b/src/backend/storage/smgr/md.c index 6ea4a00b017..fdc7c7d0726 100644 --- a/src/backend/storage/smgr/md.c +++ b/src/backend/storage/smgr/md.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/storage/smgr/md.c,v 1.136 2008/03/10 20:06:27 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/storage/smgr/md.c,v 1.137 2008/04/18 06:48:38 heikki Exp $ * *------------------------------------------------------------------------- */ @@ -1196,8 +1196,11 @@ mdpostckpt(void) if (unlink(path) < 0) { /* - * ENOENT shouldn't happen either, but it doesn't really matter - * because we would've deleted it now anyway. + * There's a race condition, when the database is dropped at the + * same time that we process the pending unlink requests. If the + * DROP DATABASE deletes the file before we do, we will get ENOENT + * here. rmtree() also has to ignore ENOENT errors, to deal with + * the possibility that we delete the file first. */ if (errno != ENOENT) ereport(WARNING, @@ -1321,7 +1324,11 @@ RememberFsyncRequest(RelFileNode rnode, BlockNumber segno) /* Remove any pending requests for the entire database */ HASH_SEQ_STATUS hstat; PendingOperationEntry *entry; + ListCell *cell, + *prev, + *next; + /* Remove fsync requests */ hash_seq_init(&hstat, pendingOpsTable); while ((entry = (PendingOperationEntry *) hash_seq_search(&hstat)) != NULL) { @@ -1331,6 +1338,22 @@ RememberFsyncRequest(RelFileNode rnode, BlockNumber segno) entry->canceled = true; } } + + /* Remove unlink requests */ + prev = NULL; + for (cell = list_head(pendingUnlinks); cell; cell = next) + { + PendingUnlinkEntry *entry = (PendingUnlinkEntry *) lfirst(cell); + + next = lnext(cell); + if (entry->rnode.dbNode == rnode.dbNode) + { + pendingUnlinks = list_delete_cell(pendingUnlinks, cell, prev); + pfree(entry); + } + else + prev = cell; + } } else if (segno == UNLINK_RELATION_REQUEST) { @@ -1386,7 +1409,7 @@ RememberFsyncRequest(RelFileNode rnode, BlockNumber segno) } /* - * ForgetRelationFsyncRequests -- ensure any fsyncs for a rel are forgotten + * ForgetRelationFsyncRequests -- forget any fsyncs for a rel */ void ForgetRelationFsyncRequests(RelFileNode rnode) @@ -1419,7 +1442,7 @@ ForgetRelationFsyncRequests(RelFileNode rnode) } /* - * ForgetDatabaseFsyncRequests -- ensure any fsyncs for a DB are forgotten + * ForgetDatabaseFsyncRequests -- forget any fsyncs and unlinks for a DB */ void ForgetDatabaseFsyncRequests(Oid dbid) diff --git a/src/port/dirmod.c b/src/port/dirmod.c index 087116c42cb..fa952549661 100644 --- a/src/port/dirmod.c +++ b/src/port/dirmod.c @@ -10,7 +10,7 @@ * Win32 (NT, Win2k, XP). replace() doesn't work on Win95/98/Me. * * IDENTIFICATION - * $PostgreSQL: pgsql/src/port/dirmod.c,v 1.53 2008/04/11 23:53:00 tgl Exp $ + * $PostgreSQL: pgsql/src/port/dirmod.c,v 1.54 2008/04/18 06:48:38 heikki Exp $ * *------------------------------------------------------------------------- */ @@ -406,8 +406,24 @@ rmtree(char *path, bool rmtopdir) { snprintf(filepath, MAXPGPATH, "%s/%s", path, *filename); + /* + * It's ok if the file is not there anymore; we were just about to + * delete it anyway. + * + * This is not an academic possibility. One scenario where this + * happens is when bgwriter has a pending unlink request for a file + * in a database that's being dropped. In dropdb(), we call + * ForgetDatabaseFsyncRequests() to flush out any such pending unlink + * requests, but because that's asynchronous, it's not guaranteed + * that the bgwriter receives the message in time. + */ if (lstat(filepath, &statbuf) != 0) - goto report_and_fail; + { + if (errno != ENOENT) + goto report_and_fail; + else + continue; + } if (S_ISDIR(statbuf.st_mode)) { @@ -422,7 +438,10 @@ rmtree(char *path, bool rmtopdir) else { if (unlink(filepath) != 0) - goto report_and_fail; + { + if (errno != ENOENT) + goto report_and_fail; + } } } |