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| author | Bart Van Assche <bart.vanassche@sandisk.com> | 2017-06-20 11:15:45 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2017-06-20 19:27:14 -0600 |
| commit | 2fff8a924d4c614b5a17b2a236a2cf09aa51af5f (patch) | |
| tree | 46f7b27ff3593ddeabaadd0032e5449825995fde /block/blk-tag.c | |
| parent | 9e0c829906b9aa1e7ad84689f2bcd56457bdb417 (diff) | |
| download | linux-0-day-2fff8a924d4c614b5a17b2a236a2cf09aa51af5f.tar.gz linux-0-day-2fff8a924d4c614b5a17b2a236a2cf09aa51af5f.tar.xz | |
block: Check locking assumptions at runtime
Instead of documenting the locking assumptions of most block layer
functions as a comment, use lockdep_assert_held() to verify locking
assumptions at runtime.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-tag.c')
| -rw-r--r-- | block/blk-tag.c | 15 |
1 files changed, 6 insertions, 9 deletions
diff --git a/block/blk-tag.c b/block/blk-tag.c index 07cc329fa4b0a..2290f65b9d736 100644 --- a/block/blk-tag.c +++ b/block/blk-tag.c @@ -258,15 +258,14 @@ EXPORT_SYMBOL(blk_queue_resize_tags); * all transfers have been done for a request. It's important to call * this function before end_that_request_last(), as that will put the * request back on the free list thus corrupting the internal tag list. - * - * Notes: - * queue lock must be held. **/ void blk_queue_end_tag(struct request_queue *q, struct request *rq) { struct blk_queue_tag *bqt = q->queue_tags; unsigned tag = rq->tag; /* negative tags invalid */ + lockdep_assert_held(q->queue_lock); + BUG_ON(tag >= bqt->real_max_depth); list_del_init(&rq->queuelist); @@ -307,9 +306,6 @@ EXPORT_SYMBOL(blk_queue_end_tag); * calling this function. The request will also be removed from * the request queue, so it's the drivers responsibility to readd * it if it should need to be restarted for some reason. - * - * Notes: - * queue lock must be held. **/ int blk_queue_start_tag(struct request_queue *q, struct request *rq) { @@ -317,6 +313,8 @@ int blk_queue_start_tag(struct request_queue *q, struct request *rq) unsigned max_depth; int tag; + lockdep_assert_held(q->queue_lock); + if (unlikely((rq->rq_flags & RQF_QUEUED))) { printk(KERN_ERR "%s: request %p for device [%s] already tagged %d", @@ -389,14 +387,13 @@ EXPORT_SYMBOL(blk_queue_start_tag); * Hardware conditions may dictate a need to stop all pending requests. * In this case, we will safely clear the block side of the tag queue and * readd all requests to the request queue in the right order. - * - * Notes: - * queue lock must be held. **/ void blk_queue_invalidate_tags(struct request_queue *q) { struct list_head *tmp, *n; + lockdep_assert_held(q->queue_lock); + list_for_each_safe(tmp, n, &q->tag_busy_list) blk_requeue_request(q, list_entry_rq(tmp)); } |