Document the locking assumptions in functions that modify
blk_mq_ctx.rq_list to make it easier for humans to verify
this code.
Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Hannes Reinecke <hare@xxxxxxxx>
Cc: Omar Sandoval <osandov@xxxxxx>
Cc: Ming Lei <ming.lei@xxxxxxxxxx>
---
block/blk-mq.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index b230038eba1d..4b1b2c7b4344 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -785,6 +785,8 @@ static bool blk_mq_attempt_merge(struct request_queue *q,
struct request *rq;
int checked = 8;
+ lockdep_assert_held(&ctx->lock);
+
list_for_each_entry_reverse(rq, &ctx->rq_list, queuelist) {
bool merged = false;
@@ -1338,6 +1340,8 @@ static inline void __blk_mq_insert_req_list(struct blk_mq_hw_ctx *hctx,
{
struct blk_mq_ctx *ctx = rq->mq_ctx;
+ lockdep_assert_held(&ctx->lock);
+
trace_block_rq_insert(hctx->queue, rq);
if (at_head)
@@ -1351,6 +1355,8 @@ void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
{
struct blk_mq_ctx *ctx = rq->mq_ctx;
+ lockdep_assert_held(&ctx->lock);
+
__blk_mq_insert_req_list(hctx, rq, at_head);
blk_mq_hctx_mark_pending(hctx, ctx);
}
--
2.12.2
