From: Ben Myers <bpm@sgi.com>
To: Dave Chinner <david@fromorbit.com>
Cc: xfs@oss.sgi.com
Subject: Re: [PATCH 1/4] xfs: lockdep needs to know about 3 dquot-deep nesting
Date: Mon, 30 Sep 2013 16:19:17 -0500 [thread overview]
Message-ID: <20130930211917.GN1935@sgi.com> (raw)
In-Reply-To: <1380497826-13474-2-git-send-email-david@fromorbit.com>
On Mon, Sep 30, 2013 at 09:37:03AM +1000, Dave Chinner wrote:
> From: Dave Chinner <dchinner@redhat.com>
>
> Michael Semon reported that xfs/299 generated this lockdep warning:
>
> =============================================
> [ INFO: possible recursive locking detected ]
> 3.12.0-rc2+ #2 Not tainted
> ---------------------------------------------
> touch/21072 is trying to acquire lock:
> (&xfs_dquot_other_class){+.+...}, at: [<c12902fb>] xfs_trans_dqlockedjoin+0x57/0x64
>
> but task is already holding lock:
> (&xfs_dquot_other_class){+.+...}, at: [<c12902fb>] xfs_trans_dqlockedjoin+0x57/0x64
>
> other info that might help us debug this:
> Possible unsafe locking scenario:
>
> CPU0
> ----
> lock(&xfs_dquot_other_class);
> lock(&xfs_dquot_other_class);
>
> *** DEADLOCK ***
>
> May be due to missing lock nesting notation
>
> 7 locks held by touch/21072:
> #0: (sb_writers#10){++++.+}, at: [<c11185b6>] mnt_want_write+0x1e/0x3e
> #1: (&type->i_mutex_dir_key#4){+.+.+.}, at: [<c11078ee>] do_last+0x245/0xe40
> #2: (sb_internal#2){++++.+}, at: [<c122c9e0>] xfs_trans_alloc+0x1f/0x35
> #3: (&(&ip->i_lock)->mr_lock/1){+.+...}, at: [<c126cd1b>] xfs_ilock+0x100/0x1f1
> #4: (&(&ip->i_lock)->mr_lock){++++-.}, at: [<c126cf52>] xfs_ilock_nowait+0x105/0x22f
> #5: (&dqp->q_qlock){+.+...}, at: [<c12902fb>] xfs_trans_dqlockedjoin+0x57/0x64
> #6: (&xfs_dquot_other_class){+.+...}, at: [<c12902fb>] xfs_trans_dqlockedjoin+0x57/0x64
>
> The lockdep annotation for dquot lock nesting only understands
> locking for user and "other" dquots, not user, group and quota
> dquots. Fix the annotations to match the locking heirarchy we now
> have.
>
> Reported-by: Michael L. Semon <mlsemon35@gmail.com>
> Signed-off-by: Dave Chinner <dchinner@redhat.com>
Looks good.
Reviewed-by: Ben Myers <bpm@sgi.com>
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next prev parent reply other threads:[~2013-09-30 21:19 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-29 23:37 [PATCH 0/4] xfs: candidate fixes for 3.12-rc4 Dave Chinner
2013-09-29 23:37 ` [PATCH 1/4] xfs: lockdep needs to know about 3 dquot-deep nesting Dave Chinner
2013-09-30 21:19 ` Ben Myers [this message]
2013-09-29 23:37 ` [PATCH 2/4] xfs: dirent dtype presence is dependent on directory magic numbers Dave Chinner
2013-09-30 22:02 ` Ben Myers
2013-10-18 16:56 ` Rich Johnston
2013-10-18 22:30 ` Dave Chinner
2013-10-18 22:41 ` Rich Johnston
2013-09-29 23:37 ` [PATCH 3/4] xfs: xfs_remove deadlocks due to inverted AGF vs AGI lock ordering Dave Chinner
2013-09-30 22:14 ` Ben Myers
2013-10-01 10:57 ` Dave Chinner
2013-09-29 23:37 ` [PATCH 4/4] xfs: open code inc_inode_iversion when logging an inode Dave Chinner
2013-09-30 22:24 ` Eric Sandeen
2013-09-30 22:39 ` Ben Myers
2013-10-01 11:12 ` Dave Chinner
2013-10-01 23:04 ` Ben Myers
2013-09-30 22:52 ` [PATCH 0/4] xfs: candidate fixes for 3.12-rc4 Ben Myers
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