On 11/12/18 2:23 AM, Jianchao Wang wrote:
> Merge blk_mq_try_issue_directly and __blk_mq_try_issue_directly
> into one interface to unify the interfaces to issue requests
> directly. The merged interface takes over the requests totally,
> it could insert, end or do nothing based on the return value of
> .queue_rq and 'bypass' parameter. Then caller needn't any other
> handling any more.
>
> To make code clearer, introduce new helpers enum mq_issue_decision
> and blk_mq_make_decision to decide how to handle the non-issued
> requests.
>
> Signed-off-by: Jianchao Wang <jianchao.w.wang@xxxxxxxxxx>
> ---
> block/blk-mq.c | 108 +++++++++++++++++++++++++++++++++------------------------
> 1 file changed, 63 insertions(+), 45 deletions(-)
>
> diff --git a/block/blk-mq.c b/block/blk-mq.c
> index 364a53f..48b7a7c 100644
> --- a/block/blk-mq.c
> +++ b/block/blk-mq.c
> @@ -1766,77 +1766,95 @@ static blk_status_t __blk_mq_issue_directly(struct blk_mq_hw_ctx *hctx,
> return ret;
> }
>
> -static blk_status_t __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx,
> +enum mq_issue_decision {
> + MQ_ISSUE_INSERT_QUEUE,
> + MQ_ISSUE_END_REQUEST,
> + MQ_ISSUE_DO_NOTHING,
> +};
> +
> +static inline enum mq_issue_decision
> + blk_mq_make_dicision(blk_status_t ret, bool bypass)
> +{
> + enum mq_issue_decision dec;
> +
> + switch(ret) {
> + case BLK_STS_OK:
> + dec = MQ_ISSUE_DO_NOTHING;
> + break;
> + case BLK_STS_DEV_RESOURCE:
> + case BLK_STS_RESOURCE:
> + dec = bypass ? MQ_ISSUE_DO_NOTHING : MQ_ISSUE_INSERT_QUEUE;
> + break;
> + default:
> + dec = bypass ? MQ_ISSUE_DO_NOTHING : MQ_ISSUE_END_REQUEST;
> + break;
> + }
> +
> + return dec;
> +}
You seem to mix and match decision and dicision, the former is the
right spelling.
But more importantly, not sure I like where this is going, wrapping
the return value in some other status code. That also makes it a bit
fragile in terms of adding other status codes, another spot to update.
Like the decent distinction between RESOURCE and DEV_RESOURCE.
Maybe it is cleaner to just handle this in the caller still?
--
Jens Axboe
