1 files changed, 25 insertions, 4 deletions

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 1c2eb38f3c51..f92e0ed59be0 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -911,7 +911,12 @@ static void flush_pending_writes(struct r10conf *conf)
                 while (bio) { /* submit pending writes */
                         struct bio *next = bio->bi_next;
                         bio->bi_next = NULL;
-                        generic_make_request(bio);
+                        if (unlikely((bio->bi_rw & REQ_DISCARD) &&
+                            !blk_queue_discard(bdev_get_queue(bio->bi_bdev))))
+                                /* Just ignore it */
+                                bio_endio(bio, 0);
+                        else
+                                generic_make_request(bio);
                         bio = next;
                 }
         } else
@@ -1061,6 +1066,8 @@ static void make_request(struct mddev *mddev, struct bio * bio)
         const int rw = bio_data_dir(bio);
         const unsigned long do_sync = (bio->bi_rw & REQ_SYNC);
         const unsigned long do_fua = (bio->bi_rw & REQ_FUA);
+        const unsigned long do_discard = (bio->bi_rw
+                                          & (REQ_DISCARD | REQ_SECURE));
         unsigned long flags;
         struct md_rdev *blocked_rdev;
         int sectors_handled;
@@ -1081,7 +1088,7 @@ static void make_request(struct mddev *mddev, struct bio * bio)
                          || conf->prev.near_copies < conf->prev.raid_disks))) {
                 struct bio_pair *bp;
                 /* Sanity check -- queue functions should prevent this happening */
-                if (bio->bi_vcnt != 1 ||
+                if ((bio->bi_vcnt != 1 && bio->bi_vcnt != 0) ||
                     bio->bi_idx != 0)
                         goto bad_map;
                 /* This is a one page bio that upper layers
@@ -1410,7 +1417,7 @@ retry_write:
                                                       conf->mirrors[d].rdev));
                 mbio->bi_bdev = conf->mirrors[d].rdev->bdev;
                 mbio->bi_end_io = raid10_end_write_request;
-                mbio->bi_rw = WRITE | do_sync | do_fua;
+                mbio->bi_rw = WRITE | do_sync | do_fua | do_discard;
                 mbio->bi_private = r10_bio;
 
                 atomic_inc(&r10_bio->remaining);
@@ -1439,7 +1446,7 @@ retry_write:
                                            conf->mirrors[d].replacement));
                 mbio->bi_bdev = conf->mirrors[d].replacement->bdev;
                 mbio->bi_end_io = raid10_end_write_request;
-                mbio->bi_rw = WRITE | do_sync | do_fua;
+                mbio->bi_rw = WRITE | do_sync | do_fua | do_discard;
                 mbio->bi_private = r10_bio;
 
                 atomic_inc(&r10_bio->remaining);
@@ -1723,6 +1730,9 @@ static int raid10_add_disk(struct mddev *mddev, struct md_rdev *rdev)
                 clear_bit(Unmerged, &rdev->flags);
         }
         md_integrity_add_rdev(rdev, mddev);
+        if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
+                queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
+
         print_conf(conf);
         return err;
 }
@@ -3480,6 +3490,7 @@ static int run(struct mddev *mddev)
         sector_t size;
         sector_t min_offset_diff = 0;
         int first = 1;
+        bool discard_supported = false;
 
         if (mddev->private == NULL) {
                 conf = setup_conf(mddev);
@@ -3496,6 +3507,8 @@ static int run(struct mddev *mddev)
 
         chunk_size = mddev->chunk_sectors << 9;
         if (mddev->queue) {
+                blk_queue_max_discard_sectors(mddev->queue,
+                                              mddev->chunk_sectors);
                 blk_queue_io_min(mddev->queue, chunk_size);
                 if (conf->geo.raid_disks % conf->geo.near_copies)
                         blk_queue_io_opt(mddev->queue, chunk_size * conf->geo.raid_disks);
@@ -3541,8 +3554,16 @@ static int run(struct mddev *mddev)
                                           rdev->data_offset << 9);
 
                 disk->head_position = 0;
+
+                if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
+                        discard_supported = true;
         }
 
+        if (discard_supported)
+                queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
+        else
+                queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
+
         /* need to check that every block has at least one working mirror */
         if (!enough(conf, -1)) {
                 printk(KERN_ERR "md/raid10:%s: not enough operational mirrors.\n",