[dm-devel] [PATCH] dm-integrity: Do not check integrity for failed read operations

[Mikulas Patocka]

On Tue, 1 Aug 2017, Milan Broz wrote:

> On 07/31/2017 09:22 AM, Hyunchul Lee wrote:
> > From: Hyunchul Lee <cheol.lee at lge.com>
> > 
> > Even though read operations fail, dm_integrity_map_continue()
> > calls integrity_metadata() to check integrity. In this case,
> > just complete these.
> 
> Yes this makes sense to me.
> 
> If bio->bi_status is set, it is directly propagated and the whole
> bio is failed.
> 
> But this is just shortcut, the bio will fail the same way (with bi_status),
> just integrity calculation code is skipped, so I think it should go to 4.13.
> 
> Thanks,
> Milan

I would also mark this patch for backporting to the stable kernels - so 
that I/O errors do not generate integrity warnings in the log.

Mikulas

> > Signed-off-by: Hyunchul Lee <cheol.lee at lge.com>
> > ---
> >  drivers/md/dm-integrity.c | 6 +++++-
> >  1 file changed, 5 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c
> > index 10f123e..f99eee9 100644
> > --- a/drivers/md/dm-integrity.c
> > +++ b/drivers/md/dm-integrity.c
> > @@ -1697,7 +1697,11 @@ static void dm_integrity_map_continue(struct dm_integrity_io *dio, bool from_map
> >  
> >  	if (need_sync_io) {
> >  		wait_for_completion_io(&read_comp);
> > -		integrity_metadata(&dio->work);
> > +		if (likely(!bio->bi_status))
> > +			integrity_metadata(&dio->work);
> > +		else
> > +			dec_in_flight(dio);
> > +
> >  	} else {
> >  		INIT_WORK(&dio->work, integrity_metadata);
> >  		queue_work(ic->metadata_wq, &dio->work);
> > 
>