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

From: Namhyung Kim
Date: Wed Sep 15 2010 - 08:33:45 EST


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@xxxxxxxxx>
---
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

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