block: don't protect generic_make_request_checks with blk_queue_enter
Now a063057d7c73 ("block: Fix a race between request queue removal and
the block cgroup controller") has been reverted, and blkcg_exit_queue()
won't be called in blk_cleanup_queue() any more.
So don't need to protect generic_make_request_checks() with
blk_queue_enter(), then the total mess can be cleaned.
37f9579f4c31 ("blk-mq: Avoid that submitting a bio concurrently with device
removal triggers a crash") is reverted.
Cc: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/block/blk-core.c b/block/blk-core.c
index 25faab0..e6a273da 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -957,22 +957,8 @@ blk_qc_t generic_make_request(struct bio *bio)
* yet.
*/
struct bio_list bio_list_on_stack[2];
- blk_mq_req_flags_t flags = 0;
- struct request_queue *q = bio->bi_disk->queue;
blk_qc_t ret = BLK_QC_T_NONE;
- if (bio->bi_opf & REQ_NOWAIT)
- flags = BLK_MQ_REQ_NOWAIT;
- if (bio_flagged(bio, BIO_QUEUE_ENTERED))
- blk_queue_enter_live(q);
- else if (blk_queue_enter(q, flags) < 0) {
- if (!blk_queue_dying(q) && (bio->bi_opf & REQ_NOWAIT))
- bio_wouldblock_error(bio);
- else
- bio_io_error(bio);
- return ret;
- }
-
if (!generic_make_request_checks(bio))
goto out;
@@ -1009,22 +995,11 @@ blk_qc_t generic_make_request(struct bio *bio)
bio_list_init(&bio_list_on_stack[0]);
current->bio_list = bio_list_on_stack;
do {
- bool enter_succeeded = true;
+ struct request_queue *q = bio->bi_disk->queue;
+ blk_mq_req_flags_t flags = bio->bi_opf & REQ_NOWAIT ?
+ BLK_MQ_REQ_NOWAIT : 0;
- if (unlikely(q != bio->bi_disk->queue)) {
- if (q)
- blk_queue_exit(q);
- q = bio->bi_disk->queue;
- flags = 0;
- if (bio->bi_opf & REQ_NOWAIT)
- flags = BLK_MQ_REQ_NOWAIT;
- if (blk_queue_enter(q, flags) < 0) {
- enter_succeeded = false;
- q = NULL;
- }
- }
-
- if (enter_succeeded) {
+ if (likely(blk_queue_enter(q, flags) == 0)) {
struct bio_list lower, same;
/* Create a fresh bio_list for all subordinate requests */
@@ -1032,6 +1007,8 @@ blk_qc_t generic_make_request(struct bio *bio)
bio_list_init(&bio_list_on_stack[0]);
ret = q->make_request_fn(q, bio);
+ blk_queue_exit(q);
+
/* sort new bios into those for a lower level
* and those for the same level
*/
@@ -1058,8 +1035,6 @@ blk_qc_t generic_make_request(struct bio *bio)
current->bio_list = NULL; /* deactivate */
out:
- if (q)
- blk_queue_exit(q);
return ret;
}
EXPORT_SYMBOL(generic_make_request);