Re: BUG: sleeping function called from invalid context at kernel/rwsem.c:131 XFS? (was: Re: linux-next: Tree for October 17)

From: Alexander Beregalov
Date: Wed Oct 22 2008 - 05:12:33 EST


2008/10/22 Dave Chinner <david@xxxxxxxxxxxxx>:
> On Wed, Oct 22, 2008 at 06:58:38PM +1100, Dave Chinner wrote:
>> On Tue, Oct 21, 2008 at 03:42:16PM +0400, Alexander Beregalov wrote:
>> > Bisected to:
>> > dd509097cb0b76d3836385f80d6b2d6fd3b97757 is first bad commit
>> > commit dd509097cb0b76d3836385f80d6b2d6fd3b97757
>> > Author: Lachlan McIlroy <lachlan@xxxxxxx>
>> > Date: Mon Sep 29 14:56:40 2008 +1000
>> >
>> > [XFS] Unlock inode before calling xfs_idestroy()
>> >
>> > Lock debugging reported the ilock was being destroyed without being
>> > unlocked. We don't need to lock the inode until we are going to insert it
>> > into the radix tree.
>>
>> Ah, OK, I see the problem, though I don't understand why I'm not
>> seeing the might_sleep() triggering all the time given that I always
>> build with:
>>
>> $ grep SLEEP .config
>> CONFIG_DEBUG_SPINLOCK_SLEEP=y
>>
>> Basically the above commit moved xfs_ilock() inside
>> radix_tree_preload()/radix_tree_preload_end(), which means we are
>> taking a rwsem() while we have an elevated preempt count. I'll
>> get a patch out to fix it.
>
> Patch below (against the xfs master/linux-next branch) should fix the
> regression. I've just started QA on it. Can you please check that
> it works for you, Alexander?
>
> Cheers,
>
> Dave.
> --
> Dave Chinner
> david@xxxxxxxxxxxxx
>
> XFS: Can't lock inodes in radix tree preload region
>
> When we are inside a radix tree preload region, we cannot
> sleep. Recently we moved the inode locking inside the
> preload region for the inode radix tree. Fix that,
> and fix a missed unlock in another error path in the
> same code at the same time.
>
> Signed-off-by: Dave Chinner <david@xxxxxxxxxxxxx>
Tested-by: Alexander Beregalov <a.beregalov@xxxxxxxxx>

Yes, it fixes the issue. Thanks
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