dm kcopyd: add WRITE SAME support to dm_kcopyd_zero

[uclinux-h8/linux.git] / drivers / md / dm-io.c

diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c
index 1c46f97..ea49834 100644 (file)
--- a/drivers/md/dm-io.c
+++ b/drivers/md/dm-io.c
@@ -287,7 +287,8 @@ static void do_region(int rw, unsigned region, struct dm_io_region *where,
        unsigned num_bvecs;
        sector_t remaining = where->count;
        struct request_queue *q = bdev_get_queue(where->bdev);
-       sector_t discard_sectors;
+       unsigned short logical_block_size = queue_logical_block_size(q);
+       sector_t num_sectors;
 
        /*
         * where->count may be zero if rw holds a flush and we need to
@@ -297,7 +298,7 @@ static void do_region(int rw, unsigned region, struct dm_io_region *where,
                /*
                 * Allocate a suitably sized-bio.
                 */
-               if (rw & REQ_DISCARD)
+               if ((rw & REQ_DISCARD) || (rw & REQ_WRITE_SAME))
                        num_bvecs = 1;
                else
                        num_bvecs = min_t(int, bio_get_nr_vecs(where->bdev),
@@ -310,9 +311,21 @@ 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) {
-                       discard_sectors = min_t(sector_t, q->limits.max_discard_sectors, remaining);
-                       bio->bi_size = discard_sectors << SECTOR_SHIFT;
-                       remaining -= discard_sectors;
+                       num_sectors = min_t(sector_t, q->limits.max_discard_sectors, remaining);
+                       bio->bi_size = num_sectors << SECTOR_SHIFT;
+                       remaining -= num_sectors;
+               } else if (rw & REQ_WRITE_SAME) {
+                       /*
+                        * WRITE SAME only uses a single page.
+                        */
+                       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);
+                       bio->bi_size = num_sectors << SECTOR_SHIFT;
+
+                       offset = 0;
+                       remaining -= num_sectors;
+                       dp->next_page(dp);
                } else while (remaining) {
                        /*
                         * Try and add as many pages as possible.