Fix missing fsync of SLRU directories.

macdice · macdice · commit aca74843e40f · 2020-09-24T10:39:52.000+12:00
Harmonize behavior by moving reponsibility for fsyncing directories down into slru.c. In 10 and later, only the multixact directories were missed (see commit 1b02be2), and in older branches all SLRUs were missed. Back-patch to all supported releases. Reviewed-by: Andres Freund <andres@anarazel.de> Reviewed-by: Michael Paquier <michael@paquier.xyz> Discussion: https://postgr.es/m/CA%2BhUKGLtsTUOScnNoSMZ-2ZLv%2BwGh01J6kAo_DM8mTRq1sKdSQ%40mail.gmail.com
diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c
@@ -836,13 +836,6 @@ CheckPointCLOG(void)
 	/* Flush dirty CLOG pages to disk */
 	TRACE_POSTGRESQL_CLOG_CHECKPOINT_START(true);
 	SimpleLruFlush(XactCtl, true);
-
-	/*
-	 * fsync pg_xact to ensure that any files flushed previously are durably
-	 * on disk.
-	 */
-	fsync_fname("pg_xact", true);
-
 	TRACE_POSTGRESQL_CLOG_CHECKPOINT_DONE(true);
 }
 
diff --git a/src/backend/access/transam/commit_ts.c b/src/backend/access/transam/commit_ts.c
@@ -822,12 +822,6 @@ CheckPointCommitTs(void)
 {
 	/* Flush dirty CommitTs pages to disk */
 	SimpleLruFlush(CommitTsCtl, true);
-
-	/*
-	 * fsync pg_commit_ts to ensure that any files flushed previously are
-	 * durably on disk.
-	 */
-	fsync_fname("pg_commit_ts", true);
 }
 
 /*
diff --git a/src/backend/access/transam/slru.c b/src/backend/access/transam/slru.c
@@ -1187,6 +1187,10 @@ SimpleLruFlush(SlruCtl ctl, bool allow_redirtied)
 	}
 	if (!ok)
 		SlruReportIOError(ctl, pageno, InvalidTransactionId);
+
+	/* Ensure that directory entries for new files are on disk. */
+	if (ctl->do_fsync)
+		fsync_fname(ctl->Dir, true);
 }
 
 /*

Original file line number	Diff line number	Diff line change
`@@ -822,12 +822,6 @@ CheckPointCommitTs(void)`
`822`	`822`	`{`
`823`	`823`	`/* Flush dirty CommitTs pages to disk */`
`824`	`824`	`SimpleLruFlush(CommitTsCtl, true);`
`825`		`-`
`826`		`- /*`
`827`		`- * fsync pg_commit_ts to ensure that any files flushed previously are`
`828`		`- * durably on disk.`
`829`		`- */`
`830`		`- fsync_fname("pg_commit_ts", true);`
`831`	`825`	`}`
`832`	`826`
`833`	`827`	`/*`
Original file line number	Diff line number	Diff line change
`@@ -1187,6 +1187,10 @@ SimpleLruFlush(SlruCtl ctl, bool allow_redirtied)`
`1187`	`1187`	`}`
`1188`	`1188`	`if (!ok)`
`1189`	`1189`	`SlruReportIOError(ctl, pageno, InvalidTransactionId);`
	`1190`	`+`
	`1191`	`+ /* Ensure that directory entries for new files are on disk. */`
	`1192`	`+ if (ctl->do_fsync)`
	`1193`	`+ fsync_fname(ctl->Dir, true);`
`1190`	`1194`	`}`
`1191`	`1195`
`1192`	`1196`	`/*`