Messages in this thread Patch in this message | | | Date | Fri, 16 Jul 2021 17:33:05 +0800 | From | Ming Lei <> | Subject | Re: New warning in nvme_setup_discard |
| |
On Fri, Jul 16, 2021 at 07:53:28AM +0200, Oleksandr Natalenko wrote: > Hello. > > On pátek 16. července 2021 4:16:18 CEST Ming Lei wrote: > > > 850 if (WARN_ON_ONCE(n != segments)) { > > > > What is 'n' and 'segments'? > > So, I used this change to check that: > > ``` > diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c > index 66973bb56305..0a64f2f77daf 100644 > --- a/drivers/nvme/host/core.c > +++ b/drivers/nvme/host/core.c > @@ -847,7 +847,8 @@ static blk_status_t nvme_setup_discard(struct nvme_ns *ns, > struct request *req, > n++; > } > > - if (WARN_ON_ONCE(n != segments)) { > + if (unlikely(n != segments)) { > + pr_warn("nvme_setup_discard: n != segments (%u != %u)\n", n, > segments); > if (virt_to_page(range) == ns->ctrl->discard_page) > clear_bit_unlock(0, &ns->ctrl->discard_page_busy); > else > > ``` > > and the result is: > > ``` > nvme_setup_discard: n != segments (3 != 2) > nvme_setup_discard: n != segments (12 != 11) > ```
Can you test the following patch?
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 a11b3b53717e..f8707ff7e2fc 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -705,22 +705,6 @@ 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-main.c b/block/mq-deadline-main.c index 6f612e6dc82b..294be0c0db65 100644 --- a/block/mq-deadline-main.c +++ b/block/mq-deadline-main.c @@ -677,6 +677,8 @@ 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; } } diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 3177181c4326..87f00292fd7a 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1521,6 +1521,22 @@ static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector return offset << SECTOR_SHIFT; } +/* + * 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 inline int bdev_discard_alignment(struct block_device *bdev) { struct request_queue *q = bdev_get_queue(bdev); Thanks, Ming
| |