On Sat, May 31 2014 at 11:05am -0400,
Alasdair G Kergon <agk@xxxxxxxxxx> 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?
Thanks,
Mike
---
drivers/md/dm-mpath.c | 11 +----------
drivers/md/dm.c | 16 ++++++++++++++++
2 files changed, 17 insertions(+), 10 deletions(-)
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index fa0f6cb..9eb6dfd 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -1240,17 +1240,8 @@ static int do_end_io(struct multipath *m, struct request *clone,
if (!error && !clone->errors)
return 0; /* I/O complete */
- if (noretry_error(error)) {
- if ((clone->cmd_flags & REQ_WRITE_SAME) &&
- !clone->q->limits.max_write_same_sectors) {
- struct queue_limits *limits;
-
- /* device doesn't really support WRITE SAME, disable it */
- limits = dm_get_queue_limits(dm_table_get_md(m->ti->table));
- limits->max_write_same_sectors = 0;
- }
+ if (noretry_error(error))
return error;
- }
if (mpio->pgpath)
fail_path(mpio->pgpath);
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 97940fc..c37581c 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -755,6 +755,14 @@ static void dec_pending(struct dm_io *io, int error)
}
}
+static void disable_write_same(struct mapped_device *md)
+{
+ struct queue_limits *limits = dm_get_queue_limits(md);
+
+ /* device doesn't really support WRITE SAME, disable it */
+ limits->max_write_same_sectors = 0;
+}
+
static void clone_endio(struct bio *bio, int error)
{
int r = 0;
@@ -783,6 +791,10 @@ static void clone_endio(struct bio *bio, int error)
}
}
+ if (r < 0 && (bio->bi_rw & REQ_WRITE_SAME) &&
+ !bdev_get_queue(bio->bi_bdev)->limits.max_write_same_sectors)
+ disable_write_same(md);
+
free_tio(md, tio);
dec_pending(io, error);
}
@@ -977,6 +989,10 @@ static void dm_done(struct request *clone, int error, bool mapped)
r = rq_end_io(tio->ti, clone, error, &tio->info);
}
+ if (r < 0 && (clone->cmd_flags & REQ_WRITE_SAME) &&
+ !clone->q->limits.max_write_same_sectors)
+ disable_write_same(tio->md);
+
if (r <= 0)
/* The target wants to complete the I/O */
dm_end_request(clone, r);
--
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