On 2020-05-27 11:06, Christoph Hellwig wrote:
> @@ -308,21 +312,28 @@ static void bt_tags_for_each(struct blk_mq_tags *tags, struct sbitmap_queue *bt,
> }
>
> /**
> - * blk_mq_all_tag_busy_iter - iterate over all started requests in a tag map
> + * blk_mq_all_tag_iter - iterate over all requests in a tag map
> * @tags: Tag map to iterate over.
> - * @fn: Pointer to the function that will be called for each started
> + * @fn: Pointer to the function that will be called for each
> * request. @fn will be called as follows: @fn(rq, @priv,
> * reserved) where rq is a pointer to a request. 'reserved'
> * indicates whether or not @rq is a reserved request. Return
> * true to continue iterating tags, false to stop.
> * @priv: Will be passed as second argument to @fn.
> */
Please document the new 'flags' argument in the kernel-doc header.
> -static void blk_mq_all_tag_busy_iter(struct blk_mq_tags *tags,
> - busy_tag_iter_fn *fn, void *priv)
> +static void __blk_mq_all_tag_iter(struct blk_mq_tags *tags,
> + busy_tag_iter_fn *fn, void *priv, unsigned int flags)
> {
> if (tags->nr_reserved_tags)
> - bt_tags_for_each(tags, &tags->breserved_tags, fn, priv, true);
> - bt_tags_for_each(tags, &tags->bitmap_tags, fn, priv, false);
> + bt_tags_for_each(tags, &tags->breserved_tags, fn, priv,
> + flags | BT_TAG_ITER_RESERVED);
> + bt_tags_for_each(tags, &tags->bitmap_tags, fn, priv, flags);
> +}
The meaning of the 'reserved' argument passed to bt_for_each() and also
to busy_iter_fn is 'the request argument is a reserved request'. If
BT_TAG_ITER_RESERVED would be set in the 'flags' argument then the wrong
value will be passed for the 'reserved' argument in the second
bt_tags_for_each() call. So I think we need something like the following
at the start of __blk_mq_all_tag_iter():
WARN_ON_ONCE(flags & BT_TAG_ITER_RESERVED)
Otherwise this patch looks good to me.
Thanks,
Bart.
