md/raid5: activate raid6 rmw feature

[deliverable/linux.git] / drivers / md / dm-io.c

diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c
index 37de0173b6d2324ed15de95442df37bc5a990e16..74adcd2c967ec8680d0cfd5c9d876c93074dbe10 100644 (file)
--- a/drivers/md/dm-io.c
+++ b/drivers/md/dm-io.c
@@ -289,9 +289,16 @@ static void do_region(int rw, unsigned region, struct dm_io_region *where,
        struct request_queue *q = bdev_get_queue(where->bdev);
        unsigned short logical_block_size = queue_logical_block_size(q);
        sector_t num_sectors;
+       unsigned int uninitialized_var(special_cmd_max_sectors);
 
-       /* Reject unsupported discard requests */
-       if ((rw & REQ_DISCARD) && !blk_queue_discard(q)) {
+       /*
+        * Reject unsupported discard and write same requests.
+        */
+       if (rw & REQ_DISCARD)
+               special_cmd_max_sectors = q->limits.max_discard_sectors;
+       else if (rw & REQ_WRITE_SAME)
+               special_cmd_max_sectors = q->limits.max_write_same_sectors;
+       if ((rw & (REQ_DISCARD | REQ_WRITE_SAME)) && special_cmd_max_sectors == 0) {
                dec_count(io, region, -EOPNOTSUPP);
                return;
        }
@@ -317,7 +324,7 @@ static void do_region(int rw, unsigned region, struct dm_io_region *where,
                store_io_and_region_in_bio(bio, io, region);
 
                if (rw & REQ_DISCARD) {
-                       num_sectors = min_t(sector_t, q->limits.max_discard_sectors, remaining);
+                       num_sectors = min_t(sector_t, special_cmd_max_sectors, remaining);
                        bio->bi_iter.bi_size = num_sectors << SECTOR_SHIFT;
                        remaining -= num_sectors;
                } else if (rw & REQ_WRITE_SAME) {
@@ -326,7 +333,7 @@ static void do_region(int rw, unsigned region, struct dm_io_region *where,
                         */
                        dp->get_page(dp, &page, &len, &offset);
                        bio_add_page(bio, page, logical_block_size, offset);
-                       num_sectors = min_t(sector_t, q->limits.max_write_same_sectors, remaining);
+                       num_sectors = min_t(sector_t, special_cmd_max_sectors, remaining);
                        bio->bi_iter.bi_size = num_sectors << SECTOR_SHIFT;
 
                        offset = 0;