From: Mike Snitzer <snitzer@redhat.com>
To: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: "axboe@kernel.dk" <axboe@kernel.dk>,
device-mapper development <dm-devel@redhat.com>,
"hch@lst.de" <hch@lst.de>
Subject: Re: [PATCH 8/9] dm: Fix two race conditions related to stopping and starting queues
Date: Thu, 1 Sep 2016 15:35:28 -0400 [thread overview]
Message-ID: <20160901193528.GA12407@redhat.com> (raw)
In-Reply-To: <20160901190505.GA12106@redhat.com>
On Thu, Sep 01 2016 at 3:05pm -0400,
Mike Snitzer <snitzer@redhat.com> wrote:
> On Thu, Sep 01 2016 at 1:59pm -0400,
> Bart Van Assche <bart.vanassche@sandisk.com> wrote:
>
> > * A "if (!blk_queue_stopped(q))" test needs to be added in
> > dm_stop_queue() to avoid the following hang (that test was present
> > in my version of the patch that adds the
> > blk_mq_{freeze,unfreeze}_queue() calls):
> >
> > sysrq: SysRq : Show Blocked State
> > task PC stack pid father
> > multipathd D ffff8803c8d37b80 0 3242 1 0x00000000
> > Call Trace:
> > [<ffffffff81627087>] schedule+0x37/0x90
> > [<ffffffff813097e1>] blk_mq_freeze_queue_wait+0x51/0xb0
> > [<ffffffff8130be05>] blk_mq_freeze_queue+0x15/0x20
> > [<ffffffffa034d882>] dm_stop_queue+0x62/0xc0 [dm_mod]
> > [<ffffffffa0342a1b>] dm_swap_table+0x2fb/0x370 [dm_mod]
> > [<ffffffffa0347875>] dev_suspend+0x95/0x220 [dm_mod]
> > [<ffffffffa03480fc>] ctl_ioctl+0x1fc/0x550 [dm_mod]
> > [<ffffffffa034845e>] dm_ctl_ioctl+0xe/0x20 [dm_mod]
> > [<ffffffff811ee27f>] do_vfs_ioctl+0x8f/0x690
> > [<ffffffff811ee8bc>] SyS_ioctl+0x3c/0x70
> > [<ffffffff8162d125>] entry_SYSCALL_64_fastpath+0x18/0xa8
>
> OK, I've adjusted accordingly and pushed dm-4.8 and dm-4.9 again (with
> force, sorry about that).
I'm testing the result.. needs more time. I'll let you know once my
mptest-based testing passes. (I think I'm holding the q->lock too
long in dm_mq_stop_queue()).
next prev parent reply other threads:[~2016-09-01 19:35 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-31 22:14 [PATCH 0/9] dm patches for kernel v4.9 Bart Van Assche
2016-08-31 22:15 ` [PATCH 1/9] blk-mq: Introduce blk_mq_queue_stopped() Bart Van Assche
2016-08-31 22:16 ` [PATCH 2/9] dm: Rename a function argument Bart Van Assche
2016-09-01 3:29 ` Mike Snitzer
2016-09-01 14:17 ` Bart Van Assche
2016-08-31 22:16 ` [PATCH 3/9] dm: Introduce signal_pending_state() Bart Van Assche
2016-08-31 22:16 ` [PATCH 4/9] dm: Convert wait loops Bart Van Assche
2016-08-31 22:17 ` [PATCH 5/9] dm: Add two lockdep_assert_held() statements Bart Van Assche
2016-08-31 22:17 ` [PATCH 6/9] dm: Simplify dm_old_stop_queue() Bart Van Assche
2016-08-31 22:17 ` [PATCH 7/9] dm: Mark block layer queue dead before destroying the dm device Bart Van Assche
2016-08-31 22:18 ` [PATCH 8/9] dm: Fix two race conditions related to stopping and starting queues Bart Van Assche
2016-09-01 3:13 ` Mike Snitzer
2016-09-01 14:23 ` Bart Van Assche
2016-09-01 15:05 ` Mike Snitzer
2016-09-01 15:31 ` Bart Van Assche
2016-09-01 15:50 ` Mike Snitzer
2016-09-01 16:12 ` Mike Snitzer
2016-09-01 17:59 ` Bart Van Assche
2016-09-01 19:05 ` Mike Snitzer
2016-09-01 19:35 ` Mike Snitzer [this message]
2016-09-01 20:15 ` Bart Van Assche
2016-09-01 20:33 ` Mike Snitzer
2016-09-01 20:39 ` Bart Van Assche
2016-09-01 20:48 ` Mike Snitzer
2016-09-01 20:52 ` Bart Van Assche
2016-09-01 21:17 ` Mike Snitzer
2016-09-01 22:18 ` Mike Snitzer
2016-09-01 22:22 ` Bart Van Assche
2016-09-01 22:26 ` Mike Snitzer
2016-09-01 23:17 ` Bart Van Assche
2016-09-01 23:47 ` Mike Snitzer
2016-09-02 0:03 ` Bart Van Assche
2016-09-02 15:12 ` Mike Snitzer
2016-09-02 16:10 ` should blk-mq halt requeue processing while queue is frozen? [was: Re: [PATCH 8/9] dm: Fix two race conditions related to stopping and starting queues] Mike Snitzer
2016-09-02 22:42 ` [dm-devel] should blk-mq halt requeue processing while queue is frozen? Bart Van Assche
2016-09-03 0:34 ` Mike Snitzer
2016-09-07 16:41 ` Mike Snitzer
2016-09-13 8:01 ` [dm-devel] " Bart Van Assche
2016-09-13 14:36 ` Mike Snitzer
2016-08-31 22:18 ` [PATCH 9/9] dm path selector: Avoid that device removal triggers an infinite loop Bart Van Assche
2016-09-01 2:49 ` Mike Snitzer
2016-09-01 14:14 ` Bart Van Assche
2016-09-01 15:06 ` Mike Snitzer
2016-09-01 15:22 ` Bart Van Assche
2016-09-01 15:26 ` Mike Snitzer
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