[PATCH] block: add assert_spin_locked() to ensure lock is held

[Namhyung Kim <namhyung@gmail.com>]

Use assert_spin_locked() macro in order to ensure that queue_lock
must be held prior to calling some EXPORTed functions.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
---
 block/blk-core.c |   12 ++++++++++++
 1 files changed, 12 insertions(+), 0 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index 32a1c12..b849064 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -975,6 +975,8 @@ EXPORT_SYMBOL(blk_make_request);
  */
 void blk_requeue_request(struct request_queue *q, struct request *rq)
 {
+	assert_spin_locked(q->queue_lock);
+
 	blk_delete_timer(rq);
 	blk_clear_rq_complete(rq);
 	trace_block_rq_requeue(q, rq);
@@ -1098,6 +1100,8 @@ EXPORT_SYMBOL_GPL(part_round_stats);
  */
 void __blk_put_request(struct request_queue *q, struct request *req)
 {
+	assert_spin_locked(q->queue_lock);
+
 	if (unlikely(!q))
 		return;
 	if (unlikely(--req->ref_count))
@@ -1729,6 +1733,8 @@ unsigned int blk_rq_err_bytes(const struct request *rq)
 	unsigned int bytes = 0;
 	struct bio *bio;
 
+	assert_spin_locked(rq->q->queue_lock);
+
 	if (!(rq->cmd_flags & REQ_MIXED_MERGE))
 		return blk_rq_bytes(rq);
 
@@ -1811,6 +1817,8 @@ struct request *blk_peek_request(struct request_queue *q)
 	struct request *rq;
 	int ret;
 
+	assert_spin_locked(q->queue_lock);
+
 	while ((rq = __elv_next_request(q)) != NULL) {
 		if (!(rq->cmd_flags & REQ_STARTED)) {
 			/*
@@ -1926,6 +1934,8 @@ void blk_dequeue_request(struct request *rq)
  */
 void blk_start_request(struct request *req)
 {
+	assert_spin_locked(req->q->queue_lock);
+
 	blk_dequeue_request(req);
 
 	/*
@@ -1959,6 +1969,8 @@ struct request *blk_fetch_request(struct request_queue *q)
 {
 	struct request *rq;
 
+	assert_spin_locked(q->queue_lock);
+
 	rq = blk_peek_request(q);
 	if (rq)
 		blk_start_request(rq);
-- 
1.7.2.2