From: Greg KH Subject: [2.6.22.2 review 43/84] "ext4_ext_put_in_cache" uses __u32 to receive physical block number Date: Tue, 7 Aug 2007 13:47:01 -0700 Message-ID: <20070807204701.GS23028@kroah.com> References: <20070807204034.882009319@mini.kroah.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Justin Forbes , Zwane Mwaikambo , Theodore Ts'o , Randy Dunlap , Dave Jones , Chuck Wolber , Chris Wedgwood , Michael Krufky , Chuck Ebbert , Domenico Andreoli , akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, linux-ext4@vger.kernel.org, cmm@us.ibm.com, yanzheng@21cn.com To: linux-kernel@vger.kernel.org, stable@kernel.org, torvalds@linux-foundation.org Return-path: Received: from pentafluge.infradead.org ([213.146.154.40]:59476 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935699AbXHGUx3 (ORCPT ); Tue, 7 Aug 2007 16:53:29 -0400 Content-Disposition: inline; filename="ext4_ext_put_in_cache-uses-__u32-to-receive-physical-block-number.patch" In-Reply-To: <20070807204157.GA23028@kroah.com> Sender: linux-ext4-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org From: Mingming Cao Yan Zheng wrote: > I think I found a bug in ext4/extents.c, "ext4_ext_put_in_cache" uses > "__u32" to receive physical block number. "ext4_ext_put_in_cache" is > used in "ext4_ext_get_blocks", it sets ext4 inode's extent cache > according most recently tree lookup (higher 16 bits of saved physical > block number are always zero). when serving a mapping request, > "ext4_ext_get_blocks" first check whether the logical block is in > inode's extent cache. if the logical block is in the cache and the > cached region isn't a gap, "ext4_ext_get_blocks" gets physical block > number by using cached region's physical block number and offset in > the cached region. as described above, "ext4_ext_get_blocks" may > return wrong result when there are physical block numbers bigger than > 0xffffffff. > You are right. Thanks for reporting this! Signed-off-by: Mingming Cao Cc: Yan Zheng Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- fs/ext4/extents.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -1445,7 +1445,7 @@ int ext4_ext_walk_space(struct inode *in static void ext4_ext_put_in_cache(struct inode *inode, __u32 block, - __u32 len, __u32 start, int type) + __u32 len, ext4_fsblk_t start, int type) { struct ext4_ext_cache *cex; BUG_ON(len == 0); --