Module Name: src
Committed By: hannken
Date: Sun Dec 12 10:30:10 UTC 2010
Modified Files:
src/sys/kern: vfs_bio.c
Log Message:
brelsel: Clear B_COWDONE flag on clean (! BO_DELWRI) buffer. B_COWDONE is set
if the buffer was read with intention to modify but the caller changed its mind.
This error could lead to snapshot corruption when a buffer with B_COWDONE set
resides on the freelist and we create a new snapshot.
To generate a diff of this commit:
cvs rdiff -u -r1.224 -r1.225 src/sys/kern/vfs_bio.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/kern/vfs_bio.c
diff -u src/sys/kern/vfs_bio.c:1.224 src/sys/kern/vfs_bio.c:1.225
--- src/sys/kern/vfs_bio.c:1.224 Tue Nov 2 15:09:52 2010
+++ src/sys/kern/vfs_bio.c Sun Dec 12 10:30:09 2010
@@ -1,4 +1,4 @@
-/* $NetBSD: vfs_bio.c,v 1.224 2010/11/02 15:09:52 pooka Exp $ */
+/* $NetBSD: vfs_bio.c,v 1.225 2010/12/12 10:30:09 hannken Exp $ */
/*-
* Copyright (c) 2007, 2008, 2009 The NetBSD Foundation, Inc.
@@ -123,7 +123,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vfs_bio.c,v 1.224 2010/11/02 15:09:52 pooka Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfs_bio.c,v 1.225 2010/12/12 10:30:09 hannken Exp $");
#include "opt_bufcache.h"
@@ -983,6 +983,14 @@
if (ISSET(bp->b_cflags, BC_WANTED))
CLR(bp->b_cflags, BC_WANTED|BC_AGE);
+ /* If it's clean clear the copy-on-write flag. */
+ if (ISSET(bp->b_flags, B_COWDONE)) {
+ mutex_enter(bp->b_objlock);
+ if (!ISSET(bp->b_oflags, BO_DELWRI))
+ CLR(bp->b_flags, B_COWDONE);
+ mutex_exit(bp->b_objlock);
+ }
+
/*
* Determine which queue the buffer should be on, then put it there.
*/
