Fix crash if LockErrorCleanup() is called twice

hlinnaka · hlinnaka · commit 51a0382e8d87 · 2025-03-28T20:19:17.000+02:00
The refactoring in commit 3c0fd64 removed the clearing of awaitedLock from LockErrorCleanup(). It's still needed, otherwise LockErrorCleanup() during abort processing will try to update the LOCALLOCK struct even after the lock has already been released. Put it back. Reported-by: Richard Guo <guofenglinux@gmail.com> Reported-by: Robins Tharakan <tharakan@gmail.com> Reported-by: Alexander Lakhin <exclusion@gmail.com> Discussion: https://www.postgresql.org/message-id/flat/CAMbWs4_dNX1SzBmvFdoY-LxJh_4W_BjtVd5i008ihfU-wFF=eg@mail.gmail.com Discussion: https://www.postgresql.org/message-id/18832-38e5575b1bbd7277@postgresql.org Discussion: https://www.postgresql.org/message-id/e11a30e5-c0d8-491d-8546-3a1b50c10ad4@gmail.com
diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c
@@ -1896,6 +1896,15 @@ GetAwaitedLock(void)
 	return awaitedLock;
 }
 
+/*
+ * ResetAwaitedLock -- Forget that we are waiting on a lock.
+ */
+void
+ResetAwaitedLock(void)
+{
+	awaitedLock = NULL;
+}
+
 /*
  * MarkLockClear -- mark an acquired lock as "clear"
  *
diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c
@@ -814,6 +814,8 @@ LockErrorCleanup(void)
 			GrantAwaitedLock();
 	}
 
+	ResetAwaitedLock();
+
 	LWLockRelease(partitionLock);
 
 	RESUME_INTERRUPTS();
diff --git a/src/include/storage/lock.h b/src/include/storage/lock.h
@@ -588,6 +588,7 @@ extern bool LockCheckConflicts(LockMethod lockMethodTable,
 extern void GrantLock(LOCK *lock, PROCLOCK *proclock, LOCKMODE lockmode);
 extern void GrantAwaitedLock(void);
 extern LOCALLOCK *GetAwaitedLock(void);
+extern void ResetAwaitedLock(void);
 
 extern void RemoveFromWaitQueue(PGPROC *proc, uint32 hashcode);
 extern LockData *GetLockStatusData(void);

Original file line number	Diff line number	Diff line change
`@@ -814,6 +814,8 @@ LockErrorCleanup(void)`
`814`	`814`	`GrantAwaitedLock();`
`815`	`815`	`}`
`816`	`816`
	`817`	`+ ResetAwaitedLock();`
	`818`	`+`
`817`	`819`	`LWLockRelease(partitionLock);`
`818`	`820`
`819`	`821`	`RESUME_INTERRUPTS();`