Re: dm: disable WRITE SAME if it fails

[Mike Snitzer <snitzer@redhat.com>]

On Mon, Jun 02 2014 at  2:36pm -0400,
Mike Snitzer <snitzer@redhat.com> wrote:

> On Sat, May 31 2014 at 11:05am -0400,
> Alasdair G Kergon <agk@redhat.com> wrote:
> 
> > On Sat, May 31, 2014 at 04:51:30PM +0800, alex chen wrote:
> > > The original commit f84cb8a46a771f36a04a02c61ea635c968ed5f6a("dm mpath:
> > > disable WRITE SAME if it fails") disables WRITE SAME in the DM multipath
> > > device if it fails, but when the DM linear device stacks ontop of the
> > > multipath device it doesn't help.
> > > this patch adds DM linear end_io method to catch WRITE SAME errors and
> > > disables WRITE SAME in the DM linear device's queue_limits if an
> > > underlying device disables it.
> > 
> > How does your patch address striped targets?
> >  
> > Shouldn't this code be taken out of mpath and moved to dm.c and applied to all
> > targets (both bio and rq-based, at least where WRITE SAME is supported)?
> 
> Alex,
> 
> I've implemented what Alasdair and I have been suggesting.
> Can you please test this untested patch?

FYI, I pushed a revised version of this patch to linux-next, please see:
https://git.kernel.org/cgit/linux/kernel/git/device-mapper/linux-dm.git/commit/?h=for-next&id=f314e7fff61dad0e9ed1c602bfd62cf722d476f7