Thread: pgsql: Fix inplace update buffer self-deadlock.

pgsql: Fix inplace update buffer self-deadlock.

From
Noah Misch
Date:
Fix inplace update buffer self-deadlock.

A CacheInvalidateHeapTuple* callee might call
CatalogCacheInitializeCache(), which needs a relcache entry.  Acquiring
a valid relcache entry might scan pg_class.  Hence, to prevent
undetected LWLock self-deadlock, CacheInvalidateHeapTuple* callers must
not hold BUFFER_LOCK_EXCLUSIVE on buffers of pg_class.  Move the
CacheInvalidateHeapTupleInplace() before the BUFFER_LOCK_EXCLUSIVE.  No
back-patch, since I've reverted commit
243e9b40f1b2dd09d6e5bf91ebf6e822a2cd3704 from non-master branches.

Reported by Alexander Lakhin.  Reviewed by Alexander Lakhin.

Discussion: https://postgr.es/m/10ec0bc3-5933-1189-6bb8-5dec4114558e@gmail.com

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/0bada39c83a150079567a6e97b1a25a198f30ea3

Modified Files
--------------
src/backend/access/heap/heapam.c | 21 +++++++++++++--------
src/backend/utils/cache/inval.c  | 12 ++++++++++++
src/include/utils/inval.h        |  1 +
3 files changed, 26 insertions(+), 8 deletions(-)