On 2024/12/17 14:38, Bart Van Assche wrote:
> The error handling code in blk_mq_get_new_requests() cannot be understood
> without knowing that this function is only called by blk_mq_submit_bio().
> Hence move the code for handling blk_mq_get_new_requests() failures into
> blk_mq_submit_bio().
>
> Cc: Damien Le Moal <dlemoal@xxxxxxxxxx>
> Cc: Christoph Hellwig <hch@xxxxxx>
> Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
> ---
> block/blk-mq.c | 14 +++++++-------
> 1 file changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/block/blk-mq.c b/block/blk-mq.c
> index 8d2aab4d9ba9..f4300e608ed8 100644
> --- a/block/blk-mq.c
> +++ b/block/blk-mq.c
> @@ -2968,12 +2968,9 @@ static struct request *blk_mq_get_new_requests(struct request_queue *q,
> }
>
> rq = __blk_mq_alloc_requests(&data);
> - if (rq)
> - return rq;
> - rq_qos_cleanup(q, bio);
> - if (bio->bi_opf & REQ_NOWAIT)
> - bio_wouldblock_error(bio);
> - return NULL;
> + if (!rq)
No unlikely() here ?
> + rq_qos_cleanup(q, bio);
> + return rq;
> }
>
> /*
> @@ -3106,8 +3103,11 @@ void blk_mq_submit_bio(struct bio *bio)
> blk_mq_use_cached_rq(rq, plug, bio);
> } else {
> rq = blk_mq_get_new_requests(q, plug, bio, nr_segs);
> - if (unlikely(!rq))
> + if (unlikely(!rq)) {
> + if (bio->bi_opf & REQ_NOWAIT)
> + bio_wouldblock_error(bio);
> goto queue_exit;
> + }
> }
>
> trace_block_getrq(bio);
--
Damien Le Moal
Western Digital Research
