dm ebs: use dm_bufio_forget_buffers

Use dm_bufio_forget_buffers instead of a block-by-block loop that
calls dm_bufio_forget. dm_bufio_forget_buffers is faster than the loop
because it searches for used buffers using rb-tree.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

drivers/md/dm-ebs-target.c

@@ -167,8 +167,8 @@ static void __ebs_forget_bio(struct ebs_c *ec, struct bio *bio)
 	sector_t blocks, sector = bio->bi_iter.bi_sector;
 
 	blocks = __nr_blocks(ec, bio);
-	for (; blocks--; sector += ec->u_bs)
-		dm_bufio_forget(ec->bufio, __sector_to_block(ec, sector));
+
+	dm_bufio_forget_buffers(ec->bufio, __sector_to_block(ec, sector), blocks);
 }
 
 /* Worker funtion to process incoming bios. */