[dm-devel] [PATCH 8/9] dm: Fix two race conditions related to stopping and starting queues

[Mike Snitzer]

On Thu, Sep 01 2016 at 11:50am -0400,
Mike Snitzer <snitzer at redhat.com> wrote:

> On Thu, Sep 01 2016 at 11:31am -0400,
> Bart Van Assche <bart.vanassche at sandisk.com> wrote:
> 
> > On 09/01/2016 08:05 AM, Mike Snitzer wrote:
> > >I've staged most of your changes (with slight tweaks), see:
> > >https://git.kernel.org/cgit/linux/kernel/git/device-mapper/linux-dm.git/log/?h=dm-4.9
> > >
> > >Only remaining issue is the queue dying race(s) in dm-multipath.
> > 
> > Thanks Mike! Two minor comments though:
> > * In dm_start_queue(), I think that the queue_flag_clear_unlocked()
> >   call should be converted into queue_flag_clear() and that it should
> >   be protected by the block layer queue lock. Every call of
> >   queue_flag_clear_unlocked() after block device initialization has
> >   finished is wrong if blk_cleanup_queue() can be called concurrently.
> 
> OK, I'll have a look.

Please see/test the dm-4.8 and dm-4.9 branches (dm-4.9 being rebased
ontop of dm-4.8):
https://git.kernel.org/cgit/linux/kernel/git/device-mapper/linux-dm.git/log/?h=dm-4.8
https://git.kernel.org/cgit/linux/kernel/git/device-mapper/linux-dm.git/log/?h=dm-4.9

Thanks.