fsync pg_logical/mappings in CheckPointLogicalRewriteHeap().

While individual logical rewrite files were synced to disk, the directory was
not. On some filesystems that could lead to loosing directory entries after a
crash.

Reported-By: Tom Lane 
Author: Nathan Bossart 
Discussion: https://postgr.es/m/867F2E29-2782-4869-970E-B984C6D35A8F@amazon.com
Backpatch: 10-

diff --git a/src/backend/access/heap/rewriteheap.c b/src/backend/access/heap/rewriteheap.c
index 1aff62cd423a14314e8c3a6343f6c28c88953368..15bef9f7d3039d9d26324f750523bd07c098aa85 100644 (file)
--- a/src/backend/access/heap/rewriteheap.c
+++ b/src/backend/access/heap/rewriteheap.c
@@ -1289,4 +1289,7 @@ CheckPointLogicalRewriteHeap(void)
        }
    }
    FreeDir(mappings_dir);
+
+   /* persist directory entries to disk */
+   fsync_fname("pg_logical/mappings", true);
 }