From d8c3896626e9fa48c9ebadc31850d54a791a08e3 Mon Sep 17 00:00:00 2001 From: Robert Haas Date: Fri, 18 Jan 2013 11:49:52 -0500 Subject: [PATCH] Unbreak lock conflict detection for Hot Standby. This got broken in the original fast-path locking patch, because I failed to account for the fact that Hot Standby startup process might take a strong relation lock on a relation in a database to which it is not bound, and confused MyDatabaseId with the database ID of the relation being locked. Report and diagnosis by Andres Freund. Final form of patch by me. --- src/backend/storage/lmgr/lock.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index f2cf5c6b8e..84637fe581 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -2445,8 +2445,8 @@ FastPathTransferRelationLocks(LockMethod lockMethodTable, const LOCKTAG *locktag LWLockAcquire(proc->backendLock, LW_EXCLUSIVE); /* - * If the target backend isn't referencing the same database as we - * are, then we needn't examine the individual relation IDs at all; + * If the target backend isn't referencing the same database as the + * lock, then we needn't examine the individual relation IDs at all; * none of them can be relevant. * * proc->databaseId is set at backend startup time and never changes @@ -2459,7 +2459,7 @@ FastPathTransferRelationLocks(LockMethod lockMethodTable, const LOCKTAG *locktag * fencing operation since the other backend set proc->databaseId. So * for now, we test it after acquiring the LWLock just to be safe. */ - if (proc->databaseId != MyDatabaseId) + if (proc->databaseId != locktag->locktag_field1) { LWLockRelease(proc->backendLock); continue; @@ -2677,14 +2677,14 @@ GetLockConflicts(const LOCKTAG *locktag, LOCKMODE lockmode) LWLockAcquire(proc->backendLock, LW_SHARED); /* - * If the target backend isn't referencing the same database as we - * are, then we needn't examine the individual relation IDs at + * If the target backend isn't referencing the same database as the + * lock, then we needn't examine the individual relation IDs at * all; none of them can be relevant. * * See FastPathTransferLocks() for discussion of why we do this * test after acquiring the lock. */ - if (proc->databaseId != MyDatabaseId) + if (proc->databaseId != locktag->locktag_field1) { LWLockRelease(proc->backendLock); continue; -- 2.40.0