On Wed, Jun 01, 2022 at 06:34:05PM +0200, Jan Kara wrote: > --- a/block/blk-cgroup.c > +++ b/block/blk-cgroup.c > @@ -1975,10 +1975,9 @@ EXPORT_SYMBOL_GPL(bio_associate_blkg); > void bio_clone_blkg_association(struct bio *dst, struct bio *src) > { > if (src->bi_blkg) { > + rcu_read_lock(); > + bio_associate_blkg_from_css(dst, bio_blkcg_css(src)); > + rcu_read_unlock(); What do we even need the rcu critical section here? Otherwise looks good: Reviewed-by: Christoph Hellwig <hch@xxxxxx>