From fe2008640ae36e3920cf41507a84fb5d3227435a Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Wed, 15 May 2019 11:03:09 +0800 Subject: [PATCH] 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 Reviewed-by: Christoph Hellwig Signed-off-by: Ming Lei Signed-off-by: Jens Axboe --- block/blk-core.c | 37 ++++++------------------------------- 1 file changed, 6 insertions(+), 31 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 25faab079abf..e6a273da4559 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);