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| author | Ming Lei <ming.lei@redhat.com> | 2021-07-29 11:42:26 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-09-15 10:02:07 +0200 |
| commit | f845a7caf953271385315418bb54ea8b9be6770e (patch) | |
| tree | 24dab6bba6e80f9eb1d5900197d7dd05671a43fb /block | |
| parent | acfa62bd28ae895338f77d1f6c0377e48050167e (diff) | |
| download | linux-stable-f845a7caf953271385315418bb54ea8b9be6770e.tar.gz linux-stable-f845a7caf953271385315418bb54ea8b9be6770e.tar.bz2 linux-stable-f845a7caf953271385315418bb54ea8b9be6770e.zip | |
block: return ELEVATOR_DISCARD_MERGE if possible
[ Upstream commit 866663b7b52d2da267b28e12eed89ee781b8fed1 ]
When merging one bio to request, if they are discard IO and the queue
supports multi-range discard, we need to return ELEVATOR_DISCARD_MERGE
because both block core and related drivers(nvme, virtio-blk) doesn't
handle mixed discard io merge(traditional IO merge together with
discard merge) well.
Fix the issue by returning ELEVATOR_DISCARD_MERGE in this situation,
so both blk-mq and drivers just need to handle multi-range discard.
Reported-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Fixes: 2705dfb20947 ("block: fix discard request merge")
Link: https://lore.kernel.org/r/20210729034226.1591070-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'block')
| -rw-r--r-- | block/bfq-iosched.c | 3 | ||||
| -rw-r--r-- | block/blk-merge.c | 16 | ||||
| -rw-r--r-- | block/elevator.c | 3 | ||||
| -rw-r--r-- | block/mq-deadline.c | 2 |
4 files changed, 8 insertions, 16 deletions
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index 727955918563..673a634eadd9 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -2361,6 +2361,9 @@ static int bfq_request_merge(struct request_queue *q, struct request **req, __rq = bfq_find_rq_fmerge(bfqd, bio, q); if (__rq && elv_bio_merge_ok(__rq, bio)) { *req = __rq; + + if (blk_discard_mergable(__rq)) + return ELEVATOR_DISCARD_MERGE; return ELEVATOR_FRONT_MERGE; } diff --git a/block/blk-merge.c b/block/blk-merge.c index 22eeaad190d7..eeba8422ae82 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -707,22 +707,6 @@ static void blk_account_io_merge_request(struct request *req) } } -/* - * Two cases of handling DISCARD merge: - * If max_discard_segments > 1, the driver takes every bio - * as a range and send them to controller together. The ranges - * needn't to be contiguous. - * Otherwise, the bios/requests will be handled as same as - * others which should be contiguous. - */ -static inline bool blk_discard_mergable(struct request *req) -{ - if (req_op(req) == REQ_OP_DISCARD && - queue_max_discard_segments(req->q) > 1) - return true; - return false; -} - static enum elv_merge blk_try_req_merge(struct request *req, struct request *next) { diff --git a/block/elevator.c b/block/elevator.c index 52ada14cfe45..a5fe2615ec0f 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -336,6 +336,9 @@ enum elv_merge elv_merge(struct request_queue *q, struct request **req, __rq = elv_rqhash_find(q, bio->bi_iter.bi_sector); if (__rq && elv_bio_merge_ok(__rq, bio)) { *req = __rq; + + if (blk_discard_mergable(__rq)) + return ELEVATOR_DISCARD_MERGE; return ELEVATOR_BACK_MERGE; } diff --git a/block/mq-deadline.c b/block/mq-deadline.c index 36920670dccc..3c3693c34f06 100644 --- a/block/mq-deadline.c +++ b/block/mq-deadline.c @@ -629,6 +629,8 @@ static int dd_request_merge(struct request_queue *q, struct request **rq, if (elv_bio_merge_ok(__rq, bio)) { *rq = __rq; + if (blk_discard_mergable(__rq)) + return ELEVATOR_DISCARD_MERGE; return ELEVATOR_FRONT_MERGE; } } |