blkcg: introduce common blkg association logic
There are 3 ways blkg association can happen: association with the
current css, with the page css (swap), or from the wbc css (writeback).
This patch handles how association is done for the first case where we
are associating bsaed on the current css. If there is already a blkg
associated, the css will be reused and association will be redone as the
request_queue may have changed.
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 056fb62..62715a5 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -511,12 +511,15 @@ static inline int bio_associate_blkcg_from_page(struct bio *bio,
#ifdef CONFIG_BLK_CGROUP
int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css);
-int bio_associate_blkg(struct bio *bio, struct blkcg_gq *blkg);
+void bio_disassociate_blkg(struct bio *bio);
+void bio_associate_blkg(struct bio *bio);
void bio_disassociate_task(struct bio *bio);
void bio_clone_blkcg_association(struct bio *dst, struct bio *src);
#else /* CONFIG_BLK_CGROUP */
static inline int bio_associate_blkcg(struct bio *bio,
struct cgroup_subsys_state *blkcg_css) { return 0; }
+static inline void bio_disassociate_blkg(struct bio *bio) { }
+static inline void bio_associate_blkg(struct bio *bio) { }
static inline void bio_disassociate_task(struct bio *bio) { }
static inline void bio_clone_blkcg_association(struct bio *dst,
struct bio *src) { }