diff options
| author | Ming Lei <ming.lei@redhat.com> | 2021-07-29 11:42:26 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-05-25 09:14:38 +0200 |
| commit | 9ea8e6a8323e063c42536f3f8c83d3768cff5f4d (patch) | |
| tree | b8d1e6596b2e41cabf45701a3e10ed1d79332995 /block | |
| parent | 36ac6caf742d9597a1ce3f2eeeb5de895fa75fd2 (diff) | |
block: return ELEVATOR_DISCARD_MERGE if possible
commit 866663b7b52d2da267b28e12eed89ee781b8fed1 upstream.
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: Gwendal Grignou <gwendal@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'block')
| -rw-r--r-- | block/bfq-iosched.c | 3 | ||||
| -rw-r--r-- | block/blk-merge.c | 15 | ||||
| -rw-r--r-- | block/elevator.c | 3 | ||||
| -rw-r--r-- | block/mq-deadline.c | 2 |
4 files changed, 8 insertions, 15 deletions
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index 1d443d17cf7c..d46806182b05 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -2251,6 +2251,9 @@ 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 a62692d13566..5219064cd72b 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -721,21 +721,6 @@ static void blk_account_io_merge(struct request *req) part_stat_unlock(); } } -/* - * 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 78805c74ea8a..3ba826230c57 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -337,6 +337,9 @@ 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 19c6922e85f1..6d6dda5cfffa 100644 --- a/block/mq-deadline.c +++ b/block/mq-deadline.c @@ -452,6 +452,8 @@ 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; } } |