md: disable WRITE SAME if it fails in underlayer disks

This makes md do the same thing as dm for write same IO failure. Please
see 7eee4ae(dm: disable WRITE SAME if it fails) for details why we need
this.

We did a little bit different than dm. Instead of disabling writesame in
the first IO error, we disable it till next writesame IO coming after
the first IO error. This way we don't need to clone a bio.

Also reported here: https://bugzilla.kernel.org/show_bug.cgi?id=118581

Suggested-by: NeilBrown <neilb@suse.com>
Acked-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>

4 files changed, 10 insertions, 0 deletions

diff --git a/drivers/md/linear.c b/drivers/md/linear.c
index 26a73b2002cf..789008bc94ff 100644
--- a/drivers/md/linear.c
+++ b/drivers/md/linear.c
@@ -291,6 +291,7 @@ static void linear_make_request(struct mddev *mddev, struct bio *bio)
                                 trace_block_bio_remap(bdev_get_queue(split->bi_bdev),
                                                       split, disk_devt(mddev->gendisk),
                                                       bio_sector);
+                        mddev_check_writesame(mddev, split);
                         generic_make_request(split);
                 }
         } while (split != bio);
diff --git a/drivers/md/md.h b/drivers/md/md.h
index 2a514036a83d..42f8398181a8 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -710,4 +710,11 @@ static inline void mddev_clear_unsupported_flags(struct mddev *mddev,
 {
         mddev->flags &= ~unsupported_flags;
 }
+
+static inline void mddev_check_writesame(struct mddev *mddev, struct bio *bio)
+{
+        if (bio_op(bio) == REQ_OP_WRITE_SAME &&
+            !bdev_get_queue(bio->bi_bdev)->limits.max_write_same_sectors)
+                mddev->queue->limits.max_write_same_sectors = 0;
+}
 #endif /* _MD_MD_H */
diff --git a/drivers/md/multipath.c b/drivers/md/multipath.c
index aa8c4e5c1ee2..065fe2823285 100644
--- a/drivers/md/multipath.c
+++ b/drivers/md/multipath.c
@@ -138,6 +138,7 @@ static void multipath_make_request(struct mddev *mddev, struct bio * bio)
         mp_bh->bio.bi_opf |= REQ_FAILFAST_TRANSPORT;
         mp_bh->bio.bi_end_io = multipath_end_request;
         mp_bh->bio.bi_private = mp_bh;
+        mddev_check_writesame(mddev, &mp_bh->bio);
         generic_make_request(&mp_bh->bio);
         return;
 }
diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index 848365d474f3..b3d264452fd5 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -503,6 +503,7 @@ static void raid0_make_request(struct mddev *mddev, struct bio *bio)
                                 trace_block_bio_remap(bdev_get_queue(split->bi_bdev),
                                                       split, disk_devt(mddev->gendisk),
                                                       bio_sector);
+                        mddev_check_writesame(mddev, split);
                         generic_make_request(split);
                 }
         } while (split != bio);