From: Arnd Bergmann <arnd@arndb.de>
To: Erez Zadok <ezk@cs.sunysb.edu>
Cc: "linux-fsdevel" <linux-fsdevel@vger.kernel.org>, viro@zeniv.linux.org.uk
Subject: Re: 2.6.39-rc7 BUG in fs/namei.c:1362, bisected -- BKL, symlinks, and rename
Date: Sat, 14 May 2011 22:40:19 +0200 [thread overview]
Message-ID: <201105142240.19190.arnd@arndb.de> (raw)
In-Reply-To: <F8765C36-6DDC-4BC0-A4B3-A9977815A099@cs.sunysb.edu>
On Saturday 14 May 2011, Erez Zadok wrote:
>
> Today 18:56:09
>
> Easily reproducible bug found in v2.6.39-rc7-174-gddb503b. This line in fs/namei.c:nested_symlink() is triggered:
>
> BUG_ON(nd->depth >= MAX_NESTED_LINKS);
>
> To reproduce: run racer on any f/s. I narrowed it down to just 'rename' and 'symlink' ops (verified that other ops aren't involved).
>
> Bisection narrowed the bug down to this one commit:
Hi Erez,
Thanks for the report and the work you put into bisecting it.
> commit f74b9444192c60603020c61d7915b72893137edc
> Merge: 7a63628 4ba8216
> Author: Linus Torvalds <torvalds@linux-foundation.org>
> Date: Wed Mar 16 17:21:00 2011 -0700
>
> Merge branch 'config' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl
>
> * 'config' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
> BKL: That's all, folks
> fs/locks.c: Remove stale FIXME left over from BKL conversion
> ipx: remove the BKL
> appletalk: remove the BKL
> x25: remove the BKL
> ufs: remove the BKL
> hpfs: remove the BKL
> drivers: remove extraneous includes of smp_lock.h
> tracing: don't trace the BKL
> adfs: remove the big kernel lock
>
> I'm happy to test a fix if someone has one for me. I suspect that once BKL was removed, some lock might
> now be missing somewhere in the VFS that relates to rename/symlink/lookup. I'll keep digging.
As the above commit is a merge commit, it seems an unlikely candidate for causing the bug. That would
indicate that something went wrong with Linus merging my patches, which I find less likely than
a bug in one of my patches.
Are you 100% sure that 4ba8216cd9 "BKL: That's all, folks" is actually working while the merged
commit f74b94441 is broken?
Arnd
next prev parent reply other threads:[~2011-05-14 20:40 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-14 16:56 2.6.39-rc7 BUG in fs/namei.c:1362, bisected -- BKL, symlinks, and rename Erez Zadok
2011-05-14 20:40 ` Arnd Bergmann [this message]
[not found] ` <1f1e296c81ca48ad8083f86d11db0116@HUBCAS1.cs.stonybrook.edu>
2011-05-15 5:30 ` Erez Zadok
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=201105142240.19190.arnd@arndb.de \
--to=arnd@arndb.de \
--cc=ezk@cs.sunysb.edu \
--cc=linux-fsdevel@vger.kernel.org \
--cc=viro@zeniv.linux.org.uk \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).