diff options
Diffstat (limited to 'block/blk-merge.c')
| -rw-r--r-- | block/blk-merge.c | 29 |
1 files changed, 26 insertions, 3 deletions
diff --git a/block/blk-merge.c b/block/blk-merge.c index 8452fc7164cc..782940c65d8a 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -550,6 +550,24 @@ static bool req_no_special_merge(struct request *req) return !q->mq_ops && req->special; } +static bool req_attempt_discard_merge(struct request_queue *q, struct request *req, + struct request *next) +{ + unsigned short segments = blk_rq_nr_discard_segments(req); + + if (segments >= queue_max_discard_segments(q)) + goto no_merge; + if (blk_rq_sectors(req) + bio_sectors(next->bio) > + blk_rq_get_max_sectors(req, blk_rq_pos(req))) + goto no_merge; + + req->nr_phys_segments = segments + blk_rq_nr_discard_segments(next); + return true; +no_merge: + req_set_nomerge(q, req); + return false; +} + static int ll_merge_requests_fn(struct request_queue *q, struct request *req, struct request *next) { @@ -683,9 +701,13 @@ static struct request *attempt_merge(struct request_queue *q, * If we are allowed to merge, then append bio list * from next to rq and release next. merge_requests_fn * will have updated segment counts, update sector - * counts here. + * counts here. Handle DISCARDs separately, as they + * have separate settings. */ - if (!ll_merge_requests_fn(q, req, next)) + if (req_op(req) == REQ_OP_DISCARD) { + if (!req_attempt_discard_merge(q, req, next)) + return NULL; + } else if (!ll_merge_requests_fn(q, req, next)) return NULL; /* @@ -715,7 +737,8 @@ static struct request *attempt_merge(struct request_queue *q, req->__data_len += blk_rq_bytes(next); - elv_merge_requests(q, req, next); + if (req_op(req) != REQ_OP_DISCARD) + elv_merge_requests(q, req, next); /* * 'next' is going away, so update stats accordingly |