Re: [PATCH v2 1/2] ext4: Close race between direct IO and ext4_break_layouts()

[Jan Kara <jack-AlSwsSmVLrQ@public.gmane.org>]

On Mon 10-09-18 11:23:56, Eric Sandeen wrote:
> On 8/8/18 12:25 PM, Dave Jiang wrote:
> > From: Ross Zwisler <zwisler-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
> > 
> > If the refcount of a page is lowered between the time that it is returned
> > by dax_busy_page() and when the refcount is again checked in
> > ext4_break_layouts() => ___wait_var_event(), the waiting function
> > ext4_wait_dax_page() will never be called.  This means that
> > ext4_break_layouts() will still have 'retry' set to false, so we'll stop
> > looping and never check the refcount of other pages in this inode.
> > 
> > Instead, always continue looping as long as dax_layout_busy_page() gives us
> > a page which it found with an elevated refcount.
> > 
> > Signed-off-by: Ross Zwisler <ross.zwisler-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
> > Reviewed-by: Jan Kara <jack-AlSwsSmVLrQ@public.gmane.org>
> 
> Ted - wondering if this one is still on your radar?

Resent the patch to Ted to catch more attention.

								Honza
-- 
Jan Kara <jack-IBi9RG/b67k@public.gmane.org>
SUSE Labs, CR