dm bufio: use REQ_OP_READ and REQ_OP_WRITE

Use REQ_OP_READ and REQ_OP_WRITE macros instead of READ and WRITE.  They
have the same value, but the block layer uses REQ_OP so bufio should
too.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

drivers/md/dm-bufio.c

@@ -662,7 +662,7 @@ static void submit_io(struct dm_buffer *b, int rw, bio_end_io_t *end_io)
 
 	sector = (b->block << b->c->sectors_per_block_bits) + b->c->start;
 
-	if (rw != WRITE) {
+	if (rw != REQ_OP_WRITE) {
 		n_sectors = 1 << b->c->sectors_per_block_bits;
 		offset = 0;
 	} else {
@@ -740,7 +740,7 @@ static void __write_dirty_buffer(struct dm_buffer *b,
 	b->write_end = b->dirty_end;
 
 	if (!write_list)
-		submit_io(b, WRITE, write_endio);
+		submit_io(b, REQ_OP_WRITE, write_endio);
 	else
 		list_add_tail(&b->write_list, write_list);
 }
@@ -753,7 +753,7 @@ static void __flush_write_list(struct list_head *write_list)
 		struct dm_buffer *b =
 			list_entry(write_list->next, struct dm_buffer, write_list);
 		list_del(&b->write_list);
-		submit_io(b, WRITE, write_endio);
+		submit_io(b, REQ_OP_WRITE, write_endio);
 		cond_resched();
 	}
 	blk_finish_plug(&plug);
@@ -1123,7 +1123,7 @@ static void *new_read(struct dm_bufio_client *c, sector_t block,
 		return NULL;
 
 	if (need_submit)
-		submit_io(b, READ, read_endio);
+		submit_io(b, REQ_OP_READ, read_endio);
 
 	wait_on_bit_io(&b->state, B_READING, TASK_UNINTERRUPTIBLE);
 
@@ -1193,7 +1193,7 @@ void dm_bufio_prefetch(struct dm_bufio_client *c,
 			dm_bufio_unlock(c);
 
 			if (need_submit)
-				submit_io(b, READ, read_endio);
+				submit_io(b, REQ_OP_READ, read_endio);
 			dm_bufio_release(b);
 
 			cond_resched();
@@ -1454,7 +1454,7 @@ void dm_bufio_release_move(struct dm_buffer *b, sector_t new_block)
 		old_block = b->block;
 		__unlink_buffer(b);
 		__link_buffer(b, new_block, b->list_mode);
-		submit_io(b, WRITE, write_endio);
+		submit_io(b, REQ_OP_WRITE, write_endio);
 		wait_on_bit_io(&b->state, B_WRITING,
 			       TASK_UNINTERRUPTIBLE);
 		__unlink_buffer(b);