From: Mingming Cao <cmm@us.ibm.com>
To: Yan Zheng <yanzheng@21cn.com>,
akpm@osdl.org, stable@kernel.org, tytso@mit.edu
Cc: linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [BUG?] "ext4_ext_put_in_cache" uses __u32 to receive physical block number.
Date: Fri, 27 Jul 2007 08:39:43 -0700 [thread overview]
Message-ID: <1185550783.6656.4.camel@localhost.localdomain> (raw)
In-Reply-To: <3d0408630707262216i3f8e1c35ub49be9c210f963d8@mail.gmail.com>
On Fri, 2007-07-27 at 13:16 +0800, Yan Zheng wrote:
> Hi, all
>
> 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.
>
> Regards
>
> YZ
You are right. Thanks for reporting this!
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Index: linux-2.6.22/fs/ext4/extents.c
===================================================================
--- linux-2.6.22.orig/fs/ext4/extents.c 2007-07-27 08:31:02.000000000 -0700
+++ linux-2.6.22/fs/ext4/extents.c 2007-07-27 08:31:48.000000000 -0700
@@ -1544,7 +1544,7 @@ 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);
prev parent reply other threads:[~2007-07-27 15:39 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-07-27 5:16 [BUG?] "ext4_ext_put_in_cache" uses __u32 to receive physical block number Yan Zheng
2007-07-27 15:39 ` Mingming Cao [this message]
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