[PATCH v3 10/12] blk-mq: Document locking assumptions
From: Bart Van Assche <hidden>
Date: 2017-06-08 17:33:53
Subsystem:
block layer, the rest · Maintainers:
Jens Axboe, Linus Torvalds
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 <redacted> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.com> Cc: Omar Sandoval <redacted> Cc: Ming Lei <redacted> --- block/blk-mq-sched.c | 2 ++ block/blk-mq.c | 4 ++++ 2 files changed, 6 insertions(+)
diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c
index c4e2afb9d12d..88aa460b2e8a 100644
--- a/block/blk-mq-sched.c
+++ b/block/blk-mq-sched.c@@ -232,6 +232,8 @@ 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;
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 5d9cca62c2f0..0f8c011eff97 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c@@ -1274,6 +1274,8 @@ 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)
@@ -1287,6 +1289,8 @@ 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