From 506130b087fb49d326fc55dc36cf2c6771b2b96a Mon Sep 17 00:00:00 2001
From: ad <ad@NetBSD.org>
Date: Sat, 31 May 2008 13:41:44 +0000
Subject: [PATCH] biodone2: if the buffer is async or has a callback method,
 assert that there are no waiters on b_done (threads in biowait()).

---
 sys/kern/vfs_bio.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/sys/kern/vfs_bio.c b/sys/kern/vfs_bio.c
index 18d009d47927..aae2e8588d29 100644
--- a/sys/kern/vfs_bio.c
+++ b/sys/kern/vfs_bio.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: vfs_bio.c,v 1.200 2008/05/31 13:26:29 ad Exp $	*/
+/*	$NetBSD: vfs_bio.c,v 1.201 2008/05/31 13:41:44 ad Exp $	*/
 
 /*-
  * Copyright (c) 2007, 2008 The NetBSD Foundation, Inc.
@@ -107,7 +107,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vfs_bio.c,v 1.200 2008/05/31 13:26:29 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfs_bio.c,v 1.201 2008/05/31 13:41:44 ad Exp $");
 
 #include "fs_ffs.h"
 #include "opt_bufcache.h"
@@ -1511,6 +1511,7 @@ biodone2(buf_t *bp)
 
 	if ((callout = bp->b_iodone) != NULL) {
 		/* Note callout done, then call out. */
+		KASSERT(!cv_has_waiters(&bp->b_done));
 		KERNEL_LOCK(1, NULL);		/* XXXSMP */
 		bp->b_iodone = NULL;
 		mutex_exit(bp->b_objlock);
@@ -1518,6 +1519,7 @@ biodone2(buf_t *bp)
 		KERNEL_UNLOCK_ONE(NULL);	/* XXXSMP */
 	} else if (ISSET(bp->b_flags, B_ASYNC)) {
 		/* If async, release. */
+		KASSERT(!cv_has_waiters(&bp->b_done));
 		mutex_exit(bp->b_objlock);
 		brelse(bp, 0);
 	} else {