Catching resource leaks during WAL replay

diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index e62286f..1558a8a 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -2282,7 +2282,7 @@ AbortTransaction(void)
 	 * Releasing LW locks is critical since we might try to grab them again
 	 * while cleaning up!
 	 */
-	LWLockReleaseAll();
+	LWLockReleaseAll(false);
 
 	/* Clean up buffer I/O and buffer context locks, too */
 	AbortBufferIO();
@@ -4194,7 +4194,7 @@ AbortSubTransaction(void)
 	 * FIXME This may be incorrect --- Are there some locks we should keep?
 	 * Buffer locks, for example?  I don't think so but I'm not sure.
 	 */
-	LWLockReleaseAll();
+	LWLockReleaseAll(false);
 
 	AbortBufferIO();
 	UnlockBuffers();
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 2f91bc8..0bf87f2 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -5515,6 +5515,7 @@ StartupXLOG(void)
 			bool		recoveryApply = true;
 			ErrorContextCallback errcallback;
 			TimestampTz xtime;
+			ResourceOwner redoOwner;
 
 			InRedo = true;
 
@@ -5523,6 +5524,13 @@ StartupXLOG(void)
 							(uint32) (ReadRecPtr >> 32), (uint32) ReadRecPtr)));
 
 			/*
+			 * Create a resource owner for running redo functions, to catch
+			 * resource leaks.
+			 */
+			redoOwner = ResourceOwnerCreate(NULL, "WAL redo");
+			CurrentResourceOwner = redoOwner;
+
+			/*
 			 * main redo apply loop
 			 */
 			do
@@ -5671,6 +5679,21 @@ StartupXLOG(void)
 				/* Now apply the WAL record itself */
 				RmgrTable[record->xl_rmid].rm_redo(EndRecPtr, record);
 
+				/*
+				 * The redo routine should've released all lwlocks and
+				 * other resources.
+				 */
+				LWLockReleaseAll(true);
+				ResourceOwnerRelease(redoOwner, RESOURCE_RELEASE_BEFORE_LOCKS,
+									 true, true);
+				/*
+				 * Locks are *not* released. In hot standby mode, the startup
+				 * process holds locks on behalf of transactions running in
+				 * the master.
+				 */
+				ResourceOwnerRelease(redoOwner, RESOURCE_RELEASE_AFTER_LOCKS,
+									 true, true);
+
 				/* Pop the error context stack */
 				error_context_stack = errcallback.previous;
 
@@ -5704,6 +5727,9 @@ StartupXLOG(void)
 				record = ReadRecord(xlogreader, InvalidXLogRecPtr, LOG, false);
 			} while (record != NULL);
 
+			CurrentResourceOwner = NULL;
+			ResourceOwnerDelete(redoOwner);
+
 			/*
 			 * end of main redo apply loop
 			 */
diff --git a/src/backend/bootstrap/bootstrap.c b/src/backend/bootstrap/bootstrap.c
index 287f19b..03554a1 100644
--- a/src/backend/bootstrap/bootstrap.c
+++ b/src/backend/bootstrap/bootstrap.c
@@ -582,7 +582,7 @@ bootstrap_signals(void)
 static void
 ShutdownAuxiliaryProcess(int code, Datum arg)
 {
-	LWLockReleaseAll();
+	LWLockReleaseAll(false);
 }
 
 /* ----------------------------------------------------------------
diff --git a/src/backend/postmaster/bgwriter.c b/src/backend/postmaster/bgwriter.c
index 286ae86..ea0e59d 100644
--- a/src/backend/postmaster/bgwriter.c
+++ b/src/backend/postmaster/bgwriter.c
@@ -175,7 +175,7 @@ BackgroundWriterMain(void)
 		 * AbortTransaction().	We don't have very many resources to worry
 		 * about in bgwriter, but we do have LWLocks, buffers, and temp files.
 		 */
-		LWLockReleaseAll();
+		LWLockReleaseAll(false);
 		AbortBufferIO();
 		UnlockBuffers();
 		/* buffer pins are released here: */
diff --git a/src/backend/postmaster/checkpointer.c b/src/backend/postmaster/checkpointer.c
index 5fb2d81..a29fc54 100644
--- a/src/backend/postmaster/checkpointer.c
+++ b/src/backend/postmaster/checkpointer.c
@@ -283,7 +283,7 @@ CheckpointerMain(void)
 		 * about in checkpointer, but we do have LWLocks, buffers, and temp
 		 * files.
 		 */
-		LWLockReleaseAll();
+		LWLockReleaseAll(false);
 		AbortBufferIO();
 		UnlockBuffers();
 		/* buffer pins are released here: */
diff --git a/src/backend/postmaster/walwriter.c b/src/backend/postmaster/walwriter.c
index 8359da6..fe58e8f 100644
--- a/src/backend/postmaster/walwriter.c
+++ b/src/backend/postmaster/walwriter.c
@@ -179,7 +179,7 @@ WalWriterMain(void)
 		 * AbortTransaction().	We don't have very many resources to worry
 		 * about in walwriter, but we do have LWLocks, and perhaps buffers?
 		 */
-		LWLockReleaseAll();
+		LWLockReleaseAll(false);
 		AbortBufferIO();
 		UnlockBuffers();
 		/* buffer pins are released here: */
diff --git a/src/backend/storage/lmgr/lwlock.c b/src/backend/storage/lmgr/lwlock.c
index 4f88d3f..b09135b 100644
--- a/src/backend/storage/lmgr/lwlock.c
+++ b/src/backend/storage/lmgr/lwlock.c
@@ -856,17 +856,21 @@ LWLockRelease(LWLockId lockid)
  * decrement it below zero if we allow it to drop for each released lock!
  */
 void
-LWLockReleaseAll(void)
+LWLockReleaseAll(bool warn)
 {
 	while (num_held_lwlocks > 0)
 	{
+		LWLockId lockid = held_lwlocks[num_held_lwlocks - 1];
+
 		HOLD_INTERRUPTS();		/* match the upcoming RESUME_INTERRUPTS */
 
-		LWLockRelease(held_lwlocks[num_held_lwlocks - 1]);
+		if (warn)
+			elog(WARNING, "lwlock leak: %d", lockid);
+
+		LWLockRelease(lockid);
 	}
 }
 
-
 /*
  * LWLockHeldByMe - test whether my process currently holds a lock
  *
diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c
index 5809a79..d635411 100644
--- a/src/backend/storage/lmgr/proc.c
+++ b/src/backend/storage/lmgr/proc.c
@@ -796,7 +796,7 @@ ProcKill(int code, Datum arg)
 	 * it's cheap to check again before we cut the knees off the LWLock
 	 * facility by releasing our PGPROC ...
 	 */
-	LWLockReleaseAll();
+	LWLockReleaseAll(false);
 
 	/* Release ownership of the process's latch, too */
 	DisownLatch(&MyProc->procLatch);
@@ -859,7 +859,7 @@ AuxiliaryProcKill(int code, Datum arg)
 	Assert(MyProc == auxproc);
 
 	/* Release any LW locks I am holding (see notes above) */
-	LWLockReleaseAll();
+	LWLockReleaseAll(false);
 
 	/* Release ownership of the process's latch, too */
 	DisownLatch(&MyProc->procLatch);
diff --git a/src/include/storage/lwlock.h b/src/include/storage/lwlock.h
index d8f7e9d..e678bda 100644
--- a/src/include/storage/lwlock.h
+++ b/src/include/storage/lwlock.h
@@ -110,7 +110,7 @@ extern void LWLockAcquire(LWLockId lockid, LWLockMode mode);
 extern bool LWLockConditionalAcquire(LWLockId lockid, LWLockMode mode);
 extern bool LWLockAcquireOrWait(LWLockId lockid, LWLockMode mode);
 extern void LWLockRelease(LWLockId lockid);
-extern void LWLockReleaseAll(void);
+extern void LWLockReleaseAll(bool warn);
 extern bool LWLockHeldByMe(LWLockId lockid);
 
 extern int	NumLWLocks(void);