From 34fe7c05400663e01e23cddd1fea68bb7a2b3d29 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 8 Feb 2017 14:46:48 +0100 Subject: block: enumify ELEVATOR_*_MERGE Switch these constants to an enum, and make let the compiler ensure that all callers of blk_try_merge and elv_merge handle all potential values. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/blk-core.c | 76 +++++++++++++++++++++++++++++--------------------------- 1 file changed, 40 insertions(+), 36 deletions(-) (limited to 'block/blk-core.c') diff --git a/block/blk-core.c b/block/blk-core.c index 1d263311353a..00e053c704a1 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1511,12 +1511,11 @@ bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio, { struct blk_plug *plug; struct request *rq; - bool ret = false; struct list_head *plug_list; plug = current->plug; if (!plug) - goto out; + return false; *request_count = 0; if (q->mq_ops) @@ -1525,7 +1524,7 @@ bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio, plug_list = &plug->list; list_for_each_entry_reverse(rq, plug_list, queuelist) { - int el_ret; + bool merged = false; if (rq->q == q) { (*request_count)++; @@ -1541,19 +1540,22 @@ bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio, if (rq->q != q || !blk_rq_merge_ok(rq, bio)) continue; - el_ret = blk_try_merge(rq, bio); - if (el_ret == ELEVATOR_BACK_MERGE) { - ret = bio_attempt_back_merge(q, rq, bio); - if (ret) - break; - } else if (el_ret == ELEVATOR_FRONT_MERGE) { - ret = bio_attempt_front_merge(q, rq, bio); - if (ret) - break; + switch (blk_try_merge(rq, bio)) { + case ELEVATOR_BACK_MERGE: + merged = bio_attempt_back_merge(q, rq, bio); + break; + case ELEVATOR_FRONT_MERGE: + merged = bio_attempt_front_merge(q, rq, bio); + break; + default: + break; } + + if (merged) + return true; } -out: - return ret; + + return false; } unsigned int blk_plug_queued_count(struct request_queue *q) @@ -1595,7 +1597,7 @@ void init_request_from_bio(struct request *req, struct bio *bio) static blk_qc_t blk_queue_bio(struct request_queue *q, struct bio *bio) { struct blk_plug *plug; - int el_ret, where = ELEVATOR_INSERT_SORT; + int where = ELEVATOR_INSERT_SORT; struct request *req, *free; unsigned int request_count = 0; unsigned int wb_acct; @@ -1633,27 +1635,29 @@ static blk_qc_t blk_queue_bio(struct request_queue *q, struct bio *bio) spin_lock_irq(q->queue_lock); - el_ret = elv_merge(q, &req, bio); - if (el_ret == ELEVATOR_BACK_MERGE) { - if (bio_attempt_back_merge(q, req, bio)) { - elv_bio_merged(q, req, bio); - free = attempt_back_merge(q, req); - if (!free) - elv_merged_request(q, req, el_ret); - else - __blk_put_request(q, free); - goto out_unlock; - } - } else if (el_ret == ELEVATOR_FRONT_MERGE) { - if (bio_attempt_front_merge(q, req, bio)) { - elv_bio_merged(q, req, bio); - free = attempt_front_merge(q, req); - if (!free) - elv_merged_request(q, req, el_ret); - else - __blk_put_request(q, free); - goto out_unlock; - } + switch (elv_merge(q, &req, bio)) { + case ELEVATOR_BACK_MERGE: + if (!bio_attempt_back_merge(q, req, bio)) + break; + elv_bio_merged(q, req, bio); + free = attempt_back_merge(q, req); + if (free) + __blk_put_request(q, free); + else + elv_merged_request(q, req, ELEVATOR_BACK_MERGE); + goto out_unlock; + case ELEVATOR_FRONT_MERGE: + if (!bio_attempt_front_merge(q, req, bio)) + break; + elv_bio_merged(q, req, bio); + free = attempt_front_merge(q, req); + if (free) + __blk_put_request(q, free); + else + elv_merged_request(q, req, ELEVATOR_FRONT_MERGE); + goto out_unlock; + default: + break; } get_rq: -- cgit v1.2.3