From e26a920acb77b953d1034e243d6a8c7294dbd25d Mon Sep 17 00:00:00 2001 From: Andres Freund Date: Fri, 14 Nov 2014 18:21:30 +0100 Subject: [PATCH] Sync unlogged relations to disk after they have been reset. Unlogged relations are only reset when performing a unclean restart. That means they have to be synced to disk during clean shutdowns. During normal processing that's achieved by registering a buffer's file to be fsynced at the next checkpoint when flushed. But ResetUnloggedRelations() doesn't go through the buffer manager, so nothing will force reset relations to disk before the next shutdown checkpoint. So just make ResetUnloggedRelations() fsync the newly created main forks to disk. Discussion: 20140912112246.GA4984@alap3.anarazel.de Backpatch to 9.1 where unlogged tables were introduced. Abhijit Menon-Sen and Andres Freund --- src/backend/storage/file/reinit.c | 47 +++++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+) diff --git a/src/backend/storage/file/reinit.c b/src/backend/storage/file/reinit.c index 3229f41d62..2a31ace2c5 100644 --- a/src/backend/storage/file/reinit.c +++ b/src/backend/storage/file/reinit.c @@ -339,6 +339,53 @@ ResetUnloggedRelationsInDbspaceDir(const char *dbspacedirname, int op) } FreeDir(dbspace_dir); + + /* + * copy_file() above has already called pg_flush_data() on the + * files it created. Now we need to fsync those files, because + * a checkpoint won't do it for us while we're in recovery. We + * do this in a separate pass to allow the kernel to perform + * all the flushes (especially the metadata ones) at once. + */ + dbspace_dir = AllocateDir(dbspacedirname); + if (dbspace_dir == NULL) + { + /* we just saw this directory, so it really ought to be there */ + elog(LOG, + "could not open dbspace directory \"%s\": %m", + dbspacedirname); + return; + } + + while ((de = ReadDir(dbspace_dir, dbspacedirname)) != NULL) + { + ForkNumber forkNum; + int oidchars; + char oidbuf[OIDCHARS + 1]; + char mainpath[MAXPGPATH]; + + /* Skip anything that doesn't look like a relation data file. */ + if (!parse_filename_for_nontemp_relation(de->d_name, &oidchars, + &forkNum)) + continue; + + /* Also skip it unless this is the init fork. */ + if (forkNum != INIT_FORKNUM) + continue; + + /* Construct main fork pathname. */ + memcpy(oidbuf, de->d_name, oidchars); + oidbuf[oidchars] = '\0'; + snprintf(mainpath, sizeof(mainpath), "%s/%s%s", + dbspacedirname, oidbuf, de->d_name + oidchars + 1 + + strlen(forkNames[INIT_FORKNUM])); + + fsync_fname(mainpath, false); + } + + FreeDir(dbspace_dir); + + fsync_fname((char *) dbspacedirname, true); } } -- 2.40.0