1 files changed, 102 insertions, 14 deletions

diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index 84e58596594d..d6c0bc76e837 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -385,7 +385,7 @@ static int raid0_run(struct mddev *mddev)
                 blk_queue_max_hw_sectors(mddev->queue, mddev->chunk_sectors);
                 blk_queue_max_write_same_sectors(mddev->queue, mddev->chunk_sectors);
                 blk_queue_max_write_zeroes_sectors(mddev->queue, mddev->chunk_sectors);
-                blk_queue_max_discard_sectors(mddev->queue, mddev->chunk_sectors);
+                blk_queue_max_discard_sectors(mddev->queue, UINT_MAX);
 
                 blk_queue_io_min(mddev->queue, mddev->chunk_sectors << 9);
                 blk_queue_io_opt(mddev->queue,
@@ -459,6 +459,95 @@ static inline int is_io_in_chunk_boundary(struct mddev *mddev,
         }
 }
 
+static void raid0_handle_discard(struct mddev *mddev, struct bio *bio)
+{
+        struct r0conf *conf = mddev->private;
+        struct strip_zone *zone;
+        sector_t start = bio->bi_iter.bi_sector;
+        sector_t end;
+        unsigned int stripe_size;
+        sector_t first_stripe_index, last_stripe_index;
+        sector_t start_disk_offset;
+        unsigned int start_disk_index;
+        sector_t end_disk_offset;
+        unsigned int end_disk_index;
+        unsigned int disk;
+
+        zone = find_zone(conf, &start);
+
+        if (bio_end_sector(bio) > zone->zone_end) {
+                struct bio *split = bio_split(bio,
+                        zone->zone_end - bio->bi_iter.bi_sector, GFP_NOIO,
+                        mddev->bio_set);
+                bio_chain(split, bio);
+                generic_make_request(bio);
+                bio = split;
+                end = zone->zone_end;
+        } else
+                end = bio_end_sector(bio);
+
+        if (zone != conf->strip_zone)
+                end = end - zone[-1].zone_end;
+
+        /* Now start and end is the offset in zone */
+        stripe_size = zone->nb_dev * mddev->chunk_sectors;
+
+        first_stripe_index = start;
+        sector_div(first_stripe_index, stripe_size);
+        last_stripe_index = end;
+        sector_div(last_stripe_index, stripe_size);
+
+        start_disk_index = (int)(start - first_stripe_index * stripe_size) /
+                mddev->chunk_sectors;
+        start_disk_offset = ((int)(start - first_stripe_index * stripe_size) %
+                mddev->chunk_sectors) +
+                first_stripe_index * mddev->chunk_sectors;
+        end_disk_index = (int)(end - last_stripe_index * stripe_size) /
+                mddev->chunk_sectors;
+        end_disk_offset = ((int)(end - last_stripe_index * stripe_size) %
+                mddev->chunk_sectors) +
+                last_stripe_index * mddev->chunk_sectors;
+
+        for (disk = 0; disk < zone->nb_dev; disk++) {
+                sector_t dev_start, dev_end;
+                struct bio *discard_bio = NULL;
+                struct md_rdev *rdev;
+
+                if (disk < start_disk_index)
+                        dev_start = (first_stripe_index + 1) *
+                                mddev->chunk_sectors;
+                else if (disk > start_disk_index)
+                        dev_start = first_stripe_index * mddev->chunk_sectors;
+                else
+                        dev_start = start_disk_offset;
+
+                if (disk < end_disk_index)
+                        dev_end = (last_stripe_index + 1) * mddev->chunk_sectors;
+                else if (disk > end_disk_index)
+                        dev_end = last_stripe_index * mddev->chunk_sectors;
+                else
+                        dev_end = end_disk_offset;
+
+                if (dev_end <= dev_start)
+                        continue;
+
+                rdev = conf->devlist[(zone - conf->strip_zone) *
+                        conf->strip_zone[0].nb_dev + disk];
+                if (__blkdev_issue_discard(rdev->bdev,
+                        dev_start + zone->dev_start + rdev->data_offset,
+                        dev_end - dev_start, GFP_NOIO, 0, &discard_bio) ||
+                    !discard_bio)
+                        continue;
+                bio_chain(discard_bio, bio);
+                if (mddev->gendisk)
+                        trace_block_bio_remap(bdev_get_queue(rdev->bdev),
+                                discard_bio, disk_devt(mddev->gendisk),
+                                bio->bi_iter.bi_sector);
+                generic_make_request(discard_bio);
+        }
+        bio_endio(bio);
+}
+
 static void raid0_make_request(struct mddev *mddev, struct bio *bio)
 {
         struct strip_zone *zone;
@@ -473,6 +562,11 @@ static void raid0_make_request(struct mddev *mddev, struct bio *bio)
                 return;
         }
 
+        if (unlikely((bio_op(bio) == REQ_OP_DISCARD))) {
+                raid0_handle_discard(mddev, bio);
+                return;
+        }
+
         bio_sector = bio->bi_iter.bi_sector;
         sector = bio_sector;
         chunk_sects = mddev->chunk_sectors;
@@ -498,19 +592,13 @@ static void raid0_make_request(struct mddev *mddev, struct bio *bio)
         bio->bi_iter.bi_sector = sector + zone->dev_start +
                 tmp_dev->data_offset;
 
-        if (unlikely((bio_op(bio) == REQ_OP_DISCARD) &&
-                     !blk_queue_discard(bdev_get_queue(bio->bi_bdev)))) {
-                /* Just ignore it */
-                bio_endio(bio);
-        } else {
-                if (mddev->gendisk)
-                        trace_block_bio_remap(bdev_get_queue(bio->bi_bdev),
-                                              bio, disk_devt(mddev->gendisk),
-                                              bio_sector);
-                mddev_check_writesame(mddev, bio);
-                mddev_check_write_zeroes(mddev, bio);
-                generic_make_request(bio);
-        }
+        if (mddev->gendisk)
+                trace_block_bio_remap(bdev_get_queue(bio->bi_bdev),
+                                      bio, disk_devt(mddev->gendisk),
+                                      bio_sector);
+        mddev_check_writesame(mddev, bio);
+        mddev_check_write_zeroes(mddev, bio);
+        generic_make_request(bio);
 }
 
 static void raid0_status(struct seq_file *seq, struct mddev *mddev)