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Message-ID: <19f34abd0807181005m19f1770bka9d8bbac7a500d1@mail.gmail.com>
Date: Fri, 18 Jul 2008 19:05:31 +0200
From: "Vegard Nossum" <vegard.nossum@gmail.com>
To: "Duane Griffin" <duaneg@dghda.com>
Subject: Re: latest -git: A peculiar case of a stuck process (ext3/sched-related?)
Cc: linux-ext4@vger.kernel.org, sct@redhat.com, akpm@linux-foundation.org,
       adilger@sun.com, "Ingo Molnar" <mingo@elte.hu>,
       "Peter Zijlstra" <a.p.zijlstra@chello.nl>,
       "Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>
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On Fri, Jul 18, 2008 at 3:00 PM, Duane Griffin <duaneg@dghda.com> wrote:
> 2008/7/18 Vegard Nossum <vegard.nossum@gmail.com>:
>> And the ext3_find_entry() corresponds to this line:
>>
>>        for (; de < top; de = ext3_next_entry(de)) /* <--- HERE! */
>>        if (ext3_match (namelen, name, de)) {
>>                if (!ext3_check_dir_entry("ext3_find_entry",
>>                                          dir, de, bh,
>>                          (block<<EXT3_BLOCK_SIZE_BITS(sb))
>>                                  +((char *)de - bh->b_data))) {
>>                        brelse (bh);
>>                        *err = ERR_BAD_DX_DIR;
>>                        goto errout;
>>                }
>>                *res_dir = de;
>>                dx_release (frames);
>>                return bh;
>>        }
>>
>> Is it possible that this loop can get stuck with a corrupt filesystem image?
>
> It certainly is. This is the same problem as the first case reported
> at http://bugzilla.kernel.org/show_bug.cgi?id=10882. There is a patch
> in -mm for it already (2fde9f7a0faabe821b31ccd982d482c21f7c503f),
> posted here: http://marc.info/?l=linux-kernel&m=121486328013470.
>
> Hopefully that should fix the problem for you.

Oh, right. Thanks!

(This patch looks much shorter than the one I found for ext2, though,
i.e. commit aa4f3f285643956bb614cf7b8f88e15f3a375886 from the
historical git repository. Does it fix all the right cases? I don't
mean to troll -- I just wanted to be sure you knew about it.)

I'll try it and report back if there's any trouble. Thanks,

Vegard

-- 
"The animistic metaphor of the bug that maliciously sneaked in while
the programmer was not looking is intellectually dishonest as it
disguises that the error is the programmer's own creation."
	-- E. W. Dijkstra, EWD1036
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