Re: [PATCH] sync: wait_sb_inodes() calls iput() with spinlock held (was Re: [PATCH 0/7] super block scalabilit patches V3)

[Dave Chinner <david@fromorbit.com>]

On Tue, Jun 23, 2015 at 04:14:42PM -0700, Josef Bacik wrote:
> On 06/21/2015 07:26 PM, Dave Chinner wrote:
> >On Tue, Jun 16, 2015 at 07:34:29AM +1000, Dave Chinner wrote:
> >>On Thu, Jun 11, 2015 at 03:41:05PM -0400, Josef Bacik wrote:
> >>>Here are the cleaned up versions of Dave Chinners super block scalability
> >>>patches.  I've been testing them locally for a while and they are pretty solid.
> >>>They fix a few big issues, such as the global inode list and soft lockups on
> >>>boxes on unmount that have lots of inodes in cache.  Al if you would consider
> >>>pulling these in that would be great, you can pull from here
> >>>
> >>>git://git.kernel.org/pub/scm/linux/kernel/git/josef/btrfs-next.git superblock-scaling
> >>
> >>Passes all my smoke tests.
> >>
> >>Tested-by: Dave Chinner <dchinner@redhat.com>
> >
> >FWIW, I just updated my trees to whatever is in the above branch and
> >v4.1-rc8, and now I'm seeing problems with wb.list_lock recursion
> >and "sleeping in atomic" scehduling issues. generic/269 produced
> >this:
....
> >It looks to me like iput() is being called with the wb.list_lock
> >held in wait_sb_inodes(), and everything is going downhill from
> >there.  Patch below fixes the problem for me.
> >
> 
> I folded this into "bdi: add a new writeback list for sync" since it
> was there before and to be more bisect friendly.  Let me know if
> this isn't ok with you and I'll undo it.  Thanks,

That's fine - I was expecting you would fold it back in... ;)

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com