postgres.git / summary / log / commit / refs

commit    ea8b3833ef064afacd8b8087e26744200f593b9b
Author:   Andres Freund <andres@anarazel.de>
Date:     Fri Nov 14 17:21:30 2014 +0000
First released in: 9.5.0, 9.1.15, 9.2.10, 9.3.6, 9.4.0

    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 1912dd8e7ae..6ffe29a4d52 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)
 
 		/* Done with the first pass. */
 		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);
 	}
 }
 


[parent: c5baa708fbae]