From a4f06606a328664d79f34b6041e816908d93e063 Mon Sep 17 00:00:00 2001 From: Alvaro Herrera Date: Thu, 22 Jun 2017 13:50:26 -0400 Subject: [PATCH] Fix autovacuum launcher attachment to its DSA The autovacuum launcher doesn't actually do anything with its DSA other than creating it and attaching to it, but it's been observed that after longjmp'ing to the standard error handling block (for example after getting SIGINT) the autovacuum enters an infinite loop reporting that it cannot attach to its DSA anymore (which is correct, because it's already attached to it.) Fix by only attempting to attach if not already attached. I introduced this bug together with BRIN autosummarization in 7526e10224f0. Reported-by: Yugo Nagata. Author: Thomas Munro. I added the comment to go with it. Discussion: https://postgr.es/m/20170621211538.0c9eae73.nagata@sraoss.co.jp --- src/backend/postmaster/autovacuum.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/src/backend/postmaster/autovacuum.c b/src/backend/postmaster/autovacuum.c index d75feda481d..00b1e823af4 100644 --- a/src/backend/postmaster/autovacuum.c +++ b/src/backend/postmaster/autovacuum.c @@ -612,7 +612,8 @@ AutoVacLauncherMain(int argc, char *argv[]) /* * Set up our DSA so that backends can install work-item requests. It may - * already exist as created by a previous launcher. + * already exist as created by a previous launcher; and we may even be + * already attached to it, if we're here after longjmp'ing above. */ if (!AutoVacuumShmem->av_dsa_handle) { @@ -626,7 +627,7 @@ AutoVacLauncherMain(int argc, char *argv[]) AutoVacuumShmem->av_workitems = InvalidDsaPointer; LWLockRelease(AutovacuumLock); } - else + else if (AutoVacuumDSA == NULL) { AutoVacuumDSA = dsa_attach(AutoVacuumShmem->av_dsa_handle); dsa_pin_mapping(AutoVacuumDSA);