dm: linear support flush

Flush support for the linear target.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c
index 79fb53e..ecbb174 100644 (file)
--- a/drivers/md/dm-linear.c
+++ b/drivers/md/dm-linear.c
@@ -53,6 +53,7 @@ static int linear_ctr(struct dm_target *ti, unsigned int argc, char **argv)
                goto bad;
        }
 
+       ti->num_flush_requests = 1;
        ti->private = lc;
        return 0;
 
@@ -81,7 +82,8 @@ static void linear_map_bio(struct dm_target *ti, struct bio *bio)
        struct linear_c *lc = ti->private;
 
        bio->bi_bdev = lc->dev->bdev;
-       bio->bi_sector = linear_map_sector(ti, bio->bi_sector);
+       if (bio_sectors(bio))
+               bio->bi_sector = linear_map_sector(ti, bio->bi_sector);
 }
 
 static int linear_map(struct dm_target *ti, struct bio *bio,