diff options
Diffstat (limited to 'block/bio.c')
| -rw-r--r-- | block/bio.c | 83 |
1 files changed, 59 insertions, 24 deletions
diff --git a/block/bio.c b/block/bio.c index 80c948da061c..387480de6992 100644 --- a/block/bio.c +++ b/block/bio.c @@ -1956,30 +1956,6 @@ EXPORT_SYMBOL(bioset_init_from_src); #ifdef CONFIG_BLK_CGROUP -#ifdef CONFIG_MEMCG -/** - * bio_associate_blkcg_from_page - associate a bio with the page's blkcg - * @bio: target bio - * @page: the page to lookup the blkcg from - * - * Associate @bio with the blkcg from @page's owning memcg. This works like - * every other associate function wrt references. - */ -int bio_associate_blkcg_from_page(struct bio *bio, struct page *page) -{ - struct cgroup_subsys_state *blkcg_css; - - if (unlikely(bio->bi_css)) - return -EBUSY; - if (!page->mem_cgroup) - return 0; - blkcg_css = cgroup_get_e_css(page->mem_cgroup->css.cgroup, - &io_cgrp_subsys); - bio->bi_css = blkcg_css; - return 0; -} -#endif /* CONFIG_MEMCG */ - /** * bio_associate_blkcg - associate a bio with the specified blkcg * @bio: target bio @@ -2030,6 +2006,65 @@ int bio_associate_blkg(struct bio *bio, struct blkcg_gq *blkg) return 0; } +static int __bio_associate_blkg_from_css(struct bio *bio, + struct cgroup_subsys_state *css) +{ + struct blkcg_gq *blkg; + + rcu_read_lock(); + + blkg = blkg_lookup_create(css_to_blkcg(css), bio->bi_disk->queue); + + rcu_read_unlock(); + + return bio_associate_blkg(bio, blkg); +} + +/** + * bio_associate_blkg_from_css - associate a bio with a specified css + * @bio: target bio + * @css: target css + * + * Associate @bio with the blkg found by combining the css's blkg and the + * request_queue of the @bio. This takes a reference on the css that will + * be put upon freeing of @bio. + */ +int bio_associate_blkg_from_css(struct bio *bio, + struct cgroup_subsys_state *css) +{ + css_get(css); + bio->bi_css = css; + return __bio_associate_blkg_from_css(bio, css); +} +EXPORT_SYMBOL_GPL(bio_associate_blkg_from_css); + +#ifdef CONFIG_MEMCG +/** + * bio_associate_blkg_from_page - associate a bio with the page's blkg + * @bio: target bio + * @page: the page to lookup the blkcg from + * + * Associate @bio with the blkg from @page's owning memcg and the respective + * request_queue. This works like every other associate function wrt + * references. + * + * Note: this must be called after bio has an associated device. + */ +int bio_associate_blkg_from_page(struct bio *bio, struct page *page) +{ + struct cgroup_subsys_state *css; + + if (unlikely(bio->bi_css)) + return -EBUSY; + if (!page->mem_cgroup) + return 0; + css = cgroup_get_e_css(page->mem_cgroup->css.cgroup, &io_cgrp_subsys); + bio->bi_css = css; + + return __bio_associate_blkg_from_css(bio, css); +} +#endif /* CONFIG_MEMCG */ + /** * bio_associate_create_blkg - associate a bio with a blkg from q * @q: request_queue where bio is going |