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| author | Jens Axboe <axboe@fb.com> | 2015-09-03 18:28:20 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2015-09-03 18:33:09 +0200 |
| commit | 5e7c4274a70aa2d6f485996d0ca1dad52d0039ca (patch) | |
| tree | dce51421028d162af78514b631dc75a6be92cf11 /block/blk-merge.c | |
| parent | null_blk: fix wrong capacity when bs is not 512 bytes (diff) | |
| download | linux-5e7c4274a70aa2d6f485996d0ca1dad52d0039ca.tar.xz linux-5e7c4274a70aa2d6f485996d0ca1dad52d0039ca.zip | |
block: Check for gaps on front and back merges
We are checking for gaps to previous bio_vec, which can
only detect back merges gaps. Moreover, at the point where
we check for a gap, we don't know if we will attempt a back
or a front merge. Thus, check for gap to prev in a back merge
attempt and check for a gap to next in a front merge attempt.
Signed-off-by: Jens Axboe <axboe@fb.com>
[sagig: Minor rename change]
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Diffstat (limited to 'block/blk-merge.c')
| -rw-r--r-- | block/blk-merge.c | 19 |
1 files changed, 6 insertions, 13 deletions
diff --git a/block/blk-merge.c b/block/blk-merge.c index cce23ba1ae5f..d9eddbc189f5 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -438,6 +438,8 @@ no_merge: int ll_back_merge_fn(struct request_queue *q, struct request *req, struct bio *bio) { + if (req_gap_back_merge(req, bio)) + return 0; if (blk_rq_sectors(req) + bio_sectors(bio) > blk_rq_get_max_sectors(req)) { req->cmd_flags |= REQ_NOMERGE; @@ -456,6 +458,9 @@ int ll_back_merge_fn(struct request_queue *q, struct request *req, int ll_front_merge_fn(struct request_queue *q, struct request *req, struct bio *bio) { + + if (req_gap_front_merge(req, bio)) + return 0; if (blk_rq_sectors(req) + bio_sectors(bio) > blk_rq_get_max_sectors(req)) { req->cmd_flags |= REQ_NOMERGE; @@ -482,14 +487,6 @@ static bool req_no_special_merge(struct request *req) return !q->mq_ops && req->special; } -static int req_gap_to_prev(struct request *req, struct bio *next) -{ - struct bio *prev = req->biotail; - - return bvec_gap_to_prev(req->q, &prev->bi_io_vec[prev->bi_vcnt - 1], - next->bi_io_vec[0].bv_offset); -} - static int ll_merge_requests_fn(struct request_queue *q, struct request *req, struct request *next) { @@ -504,7 +501,7 @@ static int ll_merge_requests_fn(struct request_queue *q, struct request *req, if (req_no_special_merge(req) || req_no_special_merge(next)) return 0; - if (req_gap_to_prev(req, next->bio)) + if (req_gap_back_merge(req, next->bio)) return 0; /* @@ -712,10 +709,6 @@ bool blk_rq_merge_ok(struct request *rq, struct bio *bio) !blk_write_same_mergeable(rq->bio, bio)) return false; - /* Only check gaps if the bio carries data */ - if (bio_has_data(bio) && req_gap_to_prev(rq, bio)) - return false; - return true; } |