[dm-devel] [PATCH] dm crypt: fix lost ioprio when queuing crypto bios from task with ioprio
Jens Axboe
axboe at kernel.dk
Thu Dec 6 23:04:42 UTC 2018
> diff --git a/block/bio.c b/block/bio.c
> index 0c2208a5446d..ed68fdd78547 100644
> --- a/block/bio.c
> +++ b/block/bio.c
> @@ -647,6 +647,30 @@ struct bio *bio_clone_fast(struct bio *bio, gfp_t gfp_mask, struct bio_set *bs)
> }
> EXPORT_SYMBOL(bio_clone_fast);
>
> +/**
> + * bio_set_task_prio - set bio's ioprio to task's ioprio, if any.
> + * @bio: bio to set the ioprio of, can be NULL
> + * @task: task of interest
> + * @gfp_flags: allocation flags, used if allocation is necessary
> + * @node: allocation node, used if allocation is necessary
> + */
> +void bio_set_task_prio(struct bio *bio, struct task_struct *task,
> + gfp_t gfp_flags, int node)
> +{
> + struct io_context *ioc;
> +
> + if (!bio)
> + return;
> +
> + ioc = get_task_io_context(current, gfp_flags, node);
> + if (ioc) {
> + if (ioprio_valid(ioc->ioprio))
> + bio_set_prio(bio, ioc->ioprio);
> + put_io_context(ioc);
> + }
> +}
> +EXPORT_SYMBOL(bio_set_task_prio);
>
Shouldn't this just be a lookup, not a create io context? If the io
priority has been set, the ioc would exist anyway.
void bio_set_prio_from_current(struct bio *bio)
{
struct io_context *ioc = current->io_context;
if (ioc && ioprio_valid(ioc->ioprio))
bio_set_prio(bio, ioc->ioprio);
}
and rename it like so. I don't like passing in the task, and all the
users are 'current' anyway. Passing in a task_struct implies that we
could have looked it up and would need a reference to it.
And don't make it pass in bio == NULL, that's just odd.
Apart from that, looks fine ;-)
--
Jens Axboe
More information about the dm-devel
mailing list