On Mon, Nov 30, 2020 at 01:36:25AM +0000, Pavel Begunkov wrote:
> blk_mq_get_tag() selects tag_offset in the beginning and doesn't update
> it even though the tag set it may have changed hw queue during waiting.
>
> Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
> ---
> block/blk-mq-tag.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
> index 9c92053e704d..dbbf11edf9a6 100644
> --- a/block/blk-mq-tag.c
> +++ b/block/blk-mq-tag.c
> @@ -101,10 +101,8 @@ unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data)
> return BLK_MQ_NO_TAG;
> }
> bt = tags->breserved_tags;
> - tag_offset = 0;
> } else {
> bt = tags->bitmap_tags;
> - tag_offset = tags->nr_reserved_tags;
> }
>
> tag = __blk_mq_get_tag(data, bt);
> @@ -167,6 +165,11 @@ unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data)
> sbitmap_finish_wait(bt, ws, &wait);
>
> found_tag:
> + if (data->flags & BLK_MQ_REQ_RESERVED)
> + tag_offset = 0;
> + else
> + tag_offset = tags->nr_reserved_tags;
> +
So far, the tag offset is tag-set wide, and 'tag_offset' is same for all tags,
looks no need to add the extra check.
thanks,
Ming
