On Thu, 2 Jun 2022 10:12:42 +0200, Jan Kara wrote:
> Commit d92c370a16cb ("block: really clone the block cgroup in
> bio_clone_blkg_association") changed bio_clone_blkg_association() to
> just clone bio->bi_blkg reference from source to destination bio. This
> is however wrong if the source and destination bios are against
> different block devices because struct blkcg_gq is different for each
> bdev-blkcg pair. This will result in IOs being accounted (and throttled
> as a result) multiple times against the same device (src bdev) while
> throttling of the other device (dst bdev) is ignored. In case of BFQ the
> inconsistency can even result in crashes in bfq_bic_update_cgroup().
> Fix the problem by looking up correct blkcg_gq for the cloned bio.
>
> [...]
Applied, thanks!
[1/1] block: fix bio_clone_blkg_association() to associate with proper blkcg_gq
(no commit info)
Best regards,
--
Jens Axboe
