2 files changed, 5 insertions, 1 deletions

diff --git a/block/blk-core.c b/block/blk-core.c
index b8ffbfe85ca4..fa212348c4c9 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -574,7 +574,8 @@ blk_init_queue_node(request_fn_proc *rfn, spinlock_t *lock, int node_id)
         q->request_fn           = rfn;
         q->prep_rq_fn           = NULL;
         q->unplug_fn            = generic_unplug_device;
-        q->queue_flags          = (1 << QUEUE_FLAG_CLUSTER);
+        q->queue_flags          = (1 << QUEUE_FLAG_CLUSTER |
+                                   1 << QUEUE_FLAG_STACKABLE);
         q->queue_lock           = lock;
 
         blk_queue_segment_boundary(q, 0xffffffff);
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 964c246bc271..86f77ef127f4 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -441,6 +441,7 @@ struct request_queue
 #define QUEUE_FLAG_NOMERGES    10       /* disable merge attempts */
 #define QUEUE_FLAG_SAME_COMP   11       /* force complete on same CPU */
 #define QUEUE_FLAG_FAIL_IO     12       /* fake timeout */
+#define QUEUE_FLAG_STACKABLE   13       /* supports request stacking */
 
 static inline int queue_is_locked(struct request_queue *q)
 {
@@ -547,6 +548,8 @@ enum {
 #define blk_queue_stopped(q)    test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
 #define blk_queue_nomerges(q)   test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
 #define blk_queue_flushing(q)   ((q)->ordseq)
+#define blk_queue_stackable(q)  \
+        test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
 
 #define blk_fs_request(rq)      ((rq)->cmd_type == REQ_TYPE_FS)
 #define blk_pc_request(rq)      ((rq)->cmd_type == REQ_TYPE_BLOCK_PC)