diff options
Diffstat (limited to 'block/bio.c')
| -rw-r--r-- | block/bio.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/block/bio.c b/block/bio.c index 03895cc0d74a..346a7f5cb2dd 100644 --- a/block/bio.c +++ b/block/bio.c @@ -1990,13 +1990,19 @@ int bio_associate_blkcg_from_page(struct bio *bio, struct page *page) * * This function takes an extra reference of @blkcg_css which will be put * when @bio is released. The caller must own @bio and is responsible for - * synchronizing calls to this function. + * synchronizing calls to this function. If @blkcg_css is %NULL, a call to + * blkcg_get_css() finds the current css from the kthread or task. */ int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css) { if (unlikely(bio->bi_css)) return -EBUSY; - css_get(blkcg_css); + + if (blkcg_css) + css_get(blkcg_css); + else + blkcg_css = blkcg_get_css(); + bio->bi_css = blkcg_css; return 0; } |