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| author | Ming Lei <ming.lei@redhat.com> | 2021-07-29 11:42:26 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-08-09 14:37:47 -0600 |
| commit | 866663b7b52d2da267b28e12eed89ee781b8fed1 (patch) | |
| tree | dffdcd640e5dc188e662a604cffaa68daa54d349 /block/bfq-iosched.c | |
| parent | a11d7fc2d05fb509cd9e33d4093507d6eda3ad53 (diff) | |
| download | lwn-866663b7b52d2da267b28e12eed89ee781b8fed1.tar.gz lwn-866663b7b52d2da267b28e12eed89ee781b8fed1.zip | |
block: return ELEVATOR_DISCARD_MERGE if possible
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>
Diffstat (limited to 'block/bfq-iosched.c')
| -rw-r--r-- | block/bfq-iosched.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index 1576e858d3a5..e4a61eda2d0f 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; } |