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From: Jeff Mahoney <jeffm@suse.com>
To: Andrew Morton <akpm@osdl.org>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: ext3_orphan_del may double-decrement bh->b_count
Date: Wed, 02 Jun 2004 16:01:57 -0400	[thread overview]
Message-ID: <40BE3235.5060906@suse.com> (raw)

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Andrew -

Chris Mason and I ran across this one while hunting down another bug.

If ext3_mark_iloc_dirty() fails in ext3_orphan_del() on the outer
buffer, bh->b_count will be decremented twice. ext3_mark_iloc_dirty()
will brelse the buffer, even on error. ext3_orphan_del() is explicity
brelse'ing the buffer on error. Prior to calling ext3_mark_iloc_dirty(),
this is the correct behavior.

Fix attached.

- -Jeff

- --
Jeff Mahoney
SuSE Labs
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#
# ext3_mark_iloc_dirty brelse's the buffer even on error,
# jumping to the out_brelse label causes a double decrement to occur.
#
--- linux-2.5.orig/fs/ext3/namei.c.orig	2004-06-02 11:46:52.903565552 -0400
+++ linux-2.5/fs/ext3/namei.c	2004-06-02 11:47:00.494411568 -0400
@@ -1963,7 +1963,7 @@
 	NEXT_ORPHAN(inode) = 0;
 	err = ext3_mark_iloc_dirty(handle, inode, &iloc);
 	if (err)
-		goto out_brelse;
+		goto out_err;
 
 out_err:
 	ext3_std_error(inode->i_sb, err);

             reply	other threads:[~2004-06-02 20:00 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-06-02 20:01 Jeff Mahoney [this message]
2004-06-02 22:06 ` ext3_orphan_del may double-decrement bh->b_count Andrew Morton
2004-06-02 23:30   ` Chris Mason
2004-06-03  1:00     ` Andrew Morton
2004-06-03  2:18       ` Chris Mason
2004-06-03  2:43         ` Andrew Morton
2004-06-03 18:21           ` Chris Mason

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