From 7eee4ae2dbb2be0a15a4406718806e48b18ba831 Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Mon, 2 Jun 2014 15:50:06 -0400 Subject: dm: disable WRITE SAME if it fails Add DM core support for disabling WRITE SAME on first failure to both request-based and bio-based targets. The need to disable WRITE SAME stems from SCSI enabling it by default but then disabling it when it fails. When SCSI does this it returns "permanent target failure, do not retry" using -EREMOTEIO. Update DM core to only disable WRITE SAME on failure if the returned error is -EREMOTEIO. Commit f84cb8a4 ("dm mpath: disable WRITE SAME if it fails") implemented multipath specific disabling of WRITE SAME if it fails. However, as that commit detailed, the multipath-only solution doesn't go far enough if bio-based DM targets are stacked ontop of the request-based dm-multipath target (as is commonly done using dm-linear to support partitions on multipath devices, via kpartx). Signed-off-by: Mike Snitzer Acked-by: Martin K. Petersen Tested-by: Alex Chen --- drivers/md/dm.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'drivers/md/dm.c') diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 97940fc..3234a75 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 (unlikely(r == -EREMOTEIO && (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 (unlikely(r == -EREMOTEIO && (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); -- cgit v1.1