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authorMing Lei <ming.lei@redhat.com>2021-07-29 05:42:26 +0200
committerJens Axboe <axboe@kernel.dk>2021-08-09 22:37:47 +0200
commit866663b7b52d2da267b28e12eed89ee781b8fed1 (patch)
treedffdcd640e5dc188e662a604cffaa68daa54d349 /block/bfq-iosched.c
parentblock: remove the bd_bdi in struct block_device (diff)
downloadlinux-866663b7b52d2da267b28e12eed89ee781b8fed1.tar.xz
linux-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.c3
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;
}