From a586cc4b6c568e88a459f1a69ac82aa42af7e5ba Mon Sep 17 00:00:00 2001 From: Andres Freund Date: Fri, 4 Oct 2019 13:08:51 -0700 Subject: [PATCH] Use a fd opened for read/write when syncing slots during startup, take 2. Cribbing from dfbaed45975: Some operating systems, including the reporter's windows, return EBADFD or similar when fsync() is invoked on a O_RDONLY file descriptor. Unfortunately RestoreSlotFromDisk() does exactly that; which causes failures after restarts in at least some scenarios. If you hit the bug the error message will be something like ERROR: could not fsync file "pg_replslot/$name/state": Bad file descriptor Simply use O_RDWR instead of O_RDONLY when opening the relevant file descriptor to fix the bug. Unfortunately this fix was undone in 82a5649fb9db. Re-apply, and add a comment. Bug: 16039 Reported-By: Hans Buschmann Author: Andres Freund Discussion: https://postgr.es/m/16039-196fc97cc05e141c@postgresql.org Backpatch: 12-, as 82a5649fb9db --- src/backend/replication/slot.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/src/backend/replication/slot.c b/src/backend/replication/slot.c index b1bcd93345d..21ae8531b3c 100644 --- a/src/backend/replication/slot.c +++ b/src/backend/replication/slot.c @@ -1386,7 +1386,8 @@ RestoreSlotFromDisk(const char *name) elog(DEBUG1, "restoring replication slot from \"%s\"", path); - fd = OpenTransientFile(path, O_RDONLY | PG_BINARY); + /* on some operating systems fsyncing a file requires O_RDWR */ + fd = OpenTransientFile(path, O_RDWR | PG_BINARY); /* * We do not need to handle this as we are rename()ing the directory into