On 8/28/25 15:57, Yu Kuai wrote:
> From: Yu Kuai <yukuai3@xxxxxxxxxx>
>
> Lots of checks are already done while submitting this bio the first
> time, and there is no need to check them again when this bio is
> resubmitted after split.
>
> Hence factor out a helper submit_split_bio_noacct() for resubmitting
> bio after splitting, only should_fail_bio() and blk_throtl_bio() are
> keeped.
s/keeped/kept
>
> Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
> ---
> block/blk-core.c | 15 +++++++++++++++
> block/blk-merge.c | 2 +-
> block/blk.h | 1 +
> 3 files changed, 17 insertions(+), 1 deletion(-)
>
> diff --git a/block/blk-core.c b/block/blk-core.c
> index 4201504158a1..37836446f365 100644
> --- a/block/blk-core.c
> +++ b/block/blk-core.c
> @@ -765,6 +765,21 @@ static blk_status_t blk_validate_atomic_write_op_size(struct request_queue *q,
> return BLK_STS_OK;
> }
>
> +void submit_split_bio_noacct(struct bio *bio)
> +{
> + might_sleep();
> +
> + if (should_fail_bio(bio)) {
> + bio_io_error(bio);
> + return;
> + }
> +
> + if (blk_throtl_bio(bio))
> + return;
> +
> + submit_bio_noacct_nocheck(bio);
> +}
> +
> /**
> * submit_bio_noacct - re-submit a bio to the block device layer for I/O
> * @bio: The bio describing the location in memory and on the device.
> diff --git a/block/blk-merge.c b/block/blk-merge.c
> index 3d6dc9cc4f61..fa2c3d98b277 100644
> --- a/block/blk-merge.c
> +++ b/block/blk-merge.c
> @@ -131,7 +131,7 @@ struct bio *bio_submit_split_bioset(struct bio *bio, int split_sectors,
> bio_chain(split, bio);
> trace_block_split(split, bio->bi_iter.bi_sector);
> WARN_ON_ONCE(bio_zone_write_plugging(bio));
> - submit_bio_noacct(bio);
> + submit_split_bio_noacct(bio);
If this helper is used only here, I would just open-code it here as otherwise it
is confusing: its name has "split" in it but nothing of its code checks that the
BIO was actually split.
>
> return split;
> }
> diff --git a/block/blk.h b/block/blk.h
> index 46f566f9b126..80375374ef55 100644
> --- a/block/blk.h
> +++ b/block/blk.h
> @@ -54,6 +54,7 @@ bool blk_queue_start_drain(struct request_queue *q);
> bool __blk_freeze_queue_start(struct request_queue *q,
> struct task_struct *owner);
> int __bio_queue_enter(struct request_queue *q, struct bio *bio);
> +void submit_split_bio_noacct(struct bio *bio);
> void submit_bio_noacct_nocheck(struct bio *bio);
> void bio_await_chain(struct bio *bio);
>
--
Damien Le Moal
Western Digital Research
