Re: R.I.P. pdflush

From: Artem Bityutskiy
Date: Fri Aug 03 2012 - 02:48:57 EST


On Thu, 2012-08-02 at 17:27 -0400, Jeff Mahoney wrote:
> On 7/25/12 11:11 AM, Artem Bityutskiy wrote:
> > For example, reiserfs deadlocked quickly when I tested it using
> > xfstests with resierfs quota support enabled. I spend several days
> > trying to fix this, but reiserfs is quite complex and I'd say its
> > locking is crazy (partially because of the BKL push-down). But I
> > gave up after I realized that the dead-lock is related to the quota
> > support. I disabled quotas and xfstests passed.
>
> Thanks for mentioning this. This is due to both reiserfs_write_dquot
> and reiserfs_evict_inode taking the reiserfs_write_lock. The old
> reiserfs locking code depended on the recursive locking ability of the
> BKL and the push-down made that a special case. This case isn't
> handled so even though the write lock is supposed to be dropped to
> take the journal lock safely, it's not and we end up with an ABBA case
> there.
>
> I'll work up a fix.

Thanks Jeff. Note, I sent the bug-report as well:
http://thread.gmane.org/gmane.linux.file-systems/64794/focus=23910

--
Best Regards,
Artem Bityutskiy

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