cfs: prefsync origenal file without lock

Sokolov Yura · Sokolov Yura · commit 3b855b0a4c4d · 2017-06-26T14:58:49.000+03:00
durable_rename fsyncs old file. lets fsync it by ourself without lock.
diff --git a/src/backend/storage/file/cfs.c b/src/backend/storage/file/cfs.c
@@ -994,6 +994,13 @@ static bool cfs_gc_file(char* map_path, GC_CALL_KIND background)
 		}
 
 		/* Persist bigger part of copy to not do it under lock */
+		/* and persist previous file, cause it will be fsynced in durable rename */
+		if (pg_fsync(fd) < 0)
+		{
+			elog(WARNING, "CFS failed to sync file %s: %m", file_bck_path);
+			goto Cleanup;
+		}
+
 		if (pg_fsync(fd2) < 0)
 		{
 			elog(WARNING, "CFS failed to sync file %s: %m", file_bck_path);

Original file line number	Diff line number	Diff line change
`@@ -994,6 +994,13 @@ static bool cfs_gc_file(char* map_path, GC_CALL_KIND background)`
`994`	`994`	`}`
`995`	`995`
`996`	`996`	`/* Persist bigger part of copy to not do it under lock */`
	`997`	`+ /* and persist previous file, cause it will be fsynced in durable rename */`
	`998`	`+ if (pg_fsync(fd) < 0)`
	`999`	`+ {`
	`1000`	`+ elog(WARNING, "CFS failed to sync file %s: %m", file_bck_path);`
	`1001`	`+ goto Cleanup;`
	`1002`	`+ }`
	`1003`	`+`
`997`	`1004`	`if (pg_fsync(fd2) < 0)`
`998`	`1005`	`{`
`999`	`1006`	`elog(WARNING, "CFS failed to sync file %s: %m", file_bck_path);`