lkml.org 
[lkml]   [2007]   [Apr]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: 2.6.21 reiserfs -- cicular locking?
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
Jeff Mahoney wrote:
> Takashi Iwai wrote:
>>> At Fri, 27 Apr 2007 07:09:01 -0400,
>>> Jeff Mahoney wrote:
>>>> -----BEGIN PGP SIGNED MESSAGE-----
>>>> Hash: SHA1
>>>>
>>>> Takashi Iwai wrote:
>>>>> At Fri, 27 Apr 2007 12:09:03 +0200,
>>>>> I wrote:
>>>>>> I got a similar bug right now at the fresh boot of 2.6.21.
>>>>>>
>>>>>>
>>>>>> ReiserFS: sda2: found reiserfs format "3.6" with standard journal
>>>>>> ReiserFS: sda2: using ordered data mode
>>>>>> ReiserFS: sda2: journal params: device sda2, size 8192, journal first block 18, max trans len 1024, max batch 900, max commit age 30, max trans age 30
>>>>>> ReiserFS: sda2: checking transaction log (sda2)
>>>>>> ReiserFS: sda2: Using r5 hash to sort names
>>>>>> ReiserFS: sda2: Removing [3613 1354701 0x0 SD]..done
>>>>>> ReiserFS: sda2: There were 1 uncompleted unlinks/truncates. Completed
>>>>>>
>>>>>> =======================================================
>>>>>> [ INFO: possible circular locking dependency detected ]
>>>>>> 2.6.21-work #1
>>>>>> -------------------------------------------------------
>>>>>> mktemp/1459 is trying to acquire lock:
>>>>>> (&REISERFS_I(inode)->xattr_sem){..--}, at: [<e08a5236>] reiserfs_cache_default_acl+0x2a/0x9c [reiserfs]
>>>>>>
>>>>>> but task is already holding lock:
>>>>>> (&inode->i_mutex){--..}, at: [<c016d7dc>] open_namei+0xe2/0x5a2
>>>>>>
>>>>>> which lock already depends on the new lock.
>>>>> The message disappears when I revert the patch:
>>>>>
>>>>> commit 9b7f375505f5611efb562065b57814b28a81abc3
>>>>> Author: Jeff Mahoney <jeffm@suse.com>
>>>>> Date: Mon Apr 23 14:41:17 2007 -0700
>>>>>
>>>>> reiserfs: fix xattr root locking/refcount bug
>>>>>
>>>>>
>>>>> So, likely a newly introduced bug after rc7...
>>>> I got a message with a trace similar to this from Vladimir before I
>>>> submitted that patch. I'm not sure how to annotate this, since the
>>>> xattr_sem can never be taken in the manner described. Internal inodes
>>>> are protected by I_PRIVATE.
>>> Hm, then maybe my case was just a coincidence.
>>>
>>> FWIW, I can reproduce the deadlock warning at each time I boot
>>> non-patched 2.6.21, and after reverting the patch, it disappeared.
>
> Ok, so I took another look at the report Vladimir sent me. The trace he
> ran into was in the delete inode path, but was still a race between the
> xattr_sem and the inode sem. Since we're locking the xattr root on the
> xattr read path now, this condition arises more freqently, but it's
> really the same one he reported.
>
> I'm using the default openSUSE config, which doesn't enable mutex
> debugging. I'll rebuild with it, and hopefully come up with a way to
> kill the warning.

I still didn't get the warning, but can you try this and let me know
if it fixes it?

- -Jeff

- --- a/fs/reiserfs/xattr.c 2007-04-22 10:53:10.000000000 -0400
+++ b/fs/reiserfs/xattr.c 2007-04-27 12:09:02.000000000 -0400
@@ -68,7 +68,7 @@
if (!privroot)
return ERR_PTR(-ENODATA);

- - mutex_lock(&privroot->d_inode->i_mutex);
+ mutex_lock_nested(&privroot->d_inode->i_mutex, I_MUTEX_XATTR);
if (REISERFS_SB(sb)->xattr_root) {
xaroot = dget(REISERFS_SB(sb)->xattr_root);
goto out;
- --
Jeff Mahoney
SUSE Labs
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.5 (GNU/Linux)
Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org
iD8DBQFGMiL1LPWxlyuTD7IRAuwoAKCob0DLVBcmeOApOr9vA5cVFRwBewCfTU/U
jwIjK+Uy4RfXKsag5Uamzew=
=svba
-----END PGP SIGNATURE-----
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
\
 
 \ /
  Last update: 2007-04-27 18:23    [from the cache]
©2003-2014 Jasper Spaans. Advertise on this site