On Tue, 5 Nov 2013 14:25:19 +0000 "Baldysiak, Pawel" <pawel.baldys...@intel.com> wrote:
> On Thursday, October 31, 2013 1:16 AM NeilBrown <ne...@suse.de> wrote:
> > On Wed, 30 Oct 2013 13:20:22 +0100 Pawel Baldysiak
> > <pawel.baldys...@intel.com> wrote:
> >
> > > In case of reshape of raid0 through raid4 a value of
> > > discard_granularity will be set to stripe size. MD driver should
> > > re-set this value to correct one when migration will be finished.
> > > Otherwise array will be left with wrong value and discard operations will
> > > not
> > work properly.
> > >
> > > Signed-off-by: Pawel Baldysiak <pawel.baldys...@intel.com>
> > > Cc: Shaohua Li <s...@kernel.org>
> > > ---
> > > drivers/md/raid0.c | 2 ++
> > > 1 file changed, 2 insertions(+)
> > >
> > > diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c index
> > > c4d420b..807ca3a 100644
> > > --- a/drivers/md/raid0.c
> > > +++ b/drivers/md/raid0.c
> > > @@ -266,6 +266,8 @@ static int create_strip_zones(struct mddev *mddev,
> > struct r0conf **private_conf)
> > > }
> > > mddev->queue->backing_dev_info.congested_fn = raid0_congested;
> > > mddev->queue->backing_dev_info.congested_data = mddev;
> > > + mddev->queue->limits.discard_granularity =
> > > + queue_logical_block_size(mddev->queue);
> > >
> > > /*
> > > * now since we have the hard sector sizes, we can make sure
> >
> > Thanks, but this doesn't seem like the right sort of fix. It is to
> > specific to the
> > symptom rather than trying to address the underlying problem.
> >
> > Maybe something like this? Can you review and test?
> >
> > Thanks,
> > NeilBrown
> >
> >
> > diff --git a/drivers/md/md.c b/drivers/md/md.c index
> > 628cd529343f..740b6340f980 100644
> > --- a/drivers/md/md.c
> > +++ b/drivers/md/md.c
> > @@ -3620,6 +3620,7 @@ level_store(struct mddev *mddev, const char
> > *buf, size_t len)
> > mddev->in_sync = 1;
> > del_timer_sync(&mddev->safemode_timer);
> > }
> > + blk_set_stacking_limit(&mddev->queue->limits);
> > pers->run(mddev);
> > set_bit(MD_CHANGE_DEVS, &mddev->flags);
> > mddev_resume(mddev);
> Hi Neil,
> I have tested Yours patch, and everything works well.
> TRIM operation are made correctly.
> Could You apply it to upstream?
>
> BTW. Correct name of this function is blk_set_stacking_limits();
>
> Thanks,
> Paweł Baldysiak
Thanks for testing. I've queue the following up for submission soonish.
NeilBrown
From 3d2b31bb23ccb8170fafdf358098bb3cb0836080 Mon Sep 17 00:00:00 2001
From: NeilBrown <ne...@suse.de>
Date: Thu, 7 Nov 2013 13:36:36 +1100
Subject: [PATCH] md: fix calculation of stacking limits on level change.
The various ->run routines of md personalities assume that the 'queue'
has been initialised by the blk_set_stacking_limits() call in
md_alloc().
However when the level is changed (by level_store()) the ->run routine
for the new level is called for an array which has already had the
stacking limits modified. This can result in incorrect final
settings.
So call blk_set_stacking_limits() before ->run in level_store().
A specific consequence of this bug is that it causes
discard_granularity to be set incorrectly when reshaping a RAID4 to a
RAID0.
This is suitable for any -stable kernel since 3.3 in which
blk_set_stacking_limits() was introduced.
Cc: sta...@vger.kernel.org (3.3+)
Reported-by: "Baldysiak, Pawel" <pawel.baldys...@intel.com>
Signed-off-by: NeilBrown <ne...@suse.de>
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 628cd529343f..b3a75afee560 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -3620,6 +3620,7 @@ level_store(struct mddev *mddev, const char *buf, size_t
len)
mddev->in_sync = 1;
del_timer_sync(&mddev->safemode_timer);
}
+ blk_set_stacking_limits(&mddev->queue->limits);
pers->run(mddev);
set_bit(MD_CHANGE_DEVS, &mddev->flags);
mddev_resume(mddev);
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