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Subject[PATCH 06/14] block: move the bio cgroup associatation helpers to blk-cgroup.c
Date
Keep the cgroup code together.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
block/bio.c | 75 ---------------------------
block/blk-cgroup.c | 103 ++++++++++++++++++++++++++++++++++++-
include/linux/blk-cgroup.h | 30 -----------
3 files changed, 101 insertions(+), 107 deletions(-)

diff --git a/block/bio.c b/block/bio.c
index 901d22715dd4f3..fc1299f9d86a24 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1627,81 +1627,6 @@ int bioset_init_from_src(struct bio_set *bs, struct bio_set *src)
}
EXPORT_SYMBOL(bioset_init_from_src);

-#ifdef CONFIG_BLK_CGROUP
-/**
- * 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. An association failure is handled by walking up
- * the blkg tree. Therefore, the blkg associated can be anything between @blkg
- * and q->root_blkg. This situation only happens when a cgroup is dying and
- * then the remaining bios will spill to the closest alive blkg.
- *
- * A reference will be taken on the blkg and will be released when @bio is
- * freed.
- */
-void bio_associate_blkg_from_css(struct bio *bio,
- struct cgroup_subsys_state *css)
-{
- struct request_queue *q = bio->bi_disk->queue;
- struct blkcg_gq *blkg = q->root_blkg;
-
- if (bio->bi_blkg)
- blkg_put(bio->bi_blkg);
-
- rcu_read_lock();
- if (css && css->parent)
- blkg = blkg_lookup_create(css_to_blkcg(css), q);
- bio->bi_blkg = blkg_tryget_closest(blkg);
- rcu_read_unlock();
-}
-EXPORT_SYMBOL_GPL(bio_associate_blkg_from_css);
-
-/**
- * bio_associate_blkg - associate a bio with a blkg
- * @bio: target bio
- *
- * Associate @bio with the blkg found from the bio's css and request_queue.
- * If one is not found, bio_lookup_blkg() creates the blkg. If a blkg is
- * already associated, the css is reused and association redone as the
- * request_queue may have changed.
- */
-void bio_associate_blkg(struct bio *bio)
-{
- struct cgroup_subsys_state *css;
-
- rcu_read_lock();
-
- if (bio->bi_blkg)
- css = &bio_blkcg(bio)->css;
- else
- css = blkcg_css();
-
- bio_associate_blkg_from_css(bio, css);
-
- rcu_read_unlock();
-}
-EXPORT_SYMBOL_GPL(bio_associate_blkg);
-
-/**
- * bio_clone_blkg_association - clone blkg association from src to dst bio
- * @dst: destination bio
- * @src: source bio
- */
-void bio_clone_blkg_association(struct bio *dst, struct bio *src)
-{
- if (src->bi_blkg) {
- if (dst->bi_blkg)
- blkg_put(dst->bi_blkg);
- blkg_get(src->bi_blkg);
- dst->bi_blkg = src->bi_blkg;
- }
-}
-EXPORT_SYMBOL_GPL(bio_clone_blkg_association);
-#endif /* CONFIG_BLK_CGROUP */
-
static void __init biovec_init_slabs(void)
{
int i;
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 0ecc897b225c96..bb0607bfd771cd 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -328,7 +328,7 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg,
* Returns the blkg or the closest blkg if blkg_create() fails as it walks
* down from root.
*/
-struct blkcg_gq *__blkg_lookup_create(struct blkcg *blkcg,
+static struct blkcg_gq *__blkg_lookup_create(struct blkcg *blkcg,
struct request_queue *q)
{
struct blkcg_gq *blkg;
@@ -377,7 +377,7 @@ struct blkcg_gq *__blkg_lookup_create(struct blkcg *blkcg,
* This looks up or creates the blkg representing the unique pair
* of the blkcg and the request_queue.
*/
-struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg,
+static struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg,
struct request_queue *q)
{
struct blkcg_gq *blkg = blkg_lookup(blkcg, q);
@@ -1727,6 +1727,105 @@ void blkcg_add_delay(struct blkcg_gq *blkg, u64 now, u64 delta)
atomic64_add(delta, &blkg->delay_nsec);
}

+/**
+ * blkg_tryget_closest - try and get a blkg ref on the closet blkg
+ * @blkg: blkg to get
+ *
+ * This needs to be called rcu protected. As the failure mode here is to walk
+ * up the blkg tree, this ensure that the blkg->parent pointers are always
+ * valid. This returns the blkg that it ended up taking a reference on or %NULL
+ * if no reference was taken.
+ */
+static inline struct blkcg_gq *blkg_tryget_closest(struct blkcg_gq *blkg)
+{
+ struct blkcg_gq *ret_blkg = NULL;
+
+ WARN_ON_ONCE(!rcu_read_lock_held());
+
+ while (blkg) {
+ if (blkg_tryget(blkg)) {
+ ret_blkg = blkg;
+ break;
+ }
+ blkg = blkg->parent;
+ }
+
+ return ret_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. An association failure is handled by walking up
+ * the blkg tree. Therefore, the blkg associated can be anything between @blkg
+ * and q->root_blkg. This situation only happens when a cgroup is dying and
+ * then the remaining bios will spill to the closest alive blkg.
+ *
+ * A reference will be taken on the blkg and will be released when @bio is
+ * freed.
+ */
+void bio_associate_blkg_from_css(struct bio *bio,
+ struct cgroup_subsys_state *css)
+{
+ struct request_queue *q = bio->bi_disk->queue;
+ struct blkcg_gq *blkg = q->root_blkg;
+
+ if (bio->bi_blkg)
+ blkg_put(bio->bi_blkg);
+
+ rcu_read_lock();
+ if (css && css->parent)
+ blkg = blkg_lookup_create(css_to_blkcg(css), q);
+ bio->bi_blkg = blkg_tryget_closest(blkg);
+ rcu_read_unlock();
+}
+EXPORT_SYMBOL_GPL(bio_associate_blkg_from_css);
+
+/**
+ * bio_associate_blkg - associate a bio with a blkg
+ * @bio: target bio
+ *
+ * Associate @bio with the blkg found from the bio's css and request_queue.
+ * If one is not found, bio_lookup_blkg() creates the blkg. If a blkg is
+ * already associated, the css is reused and association redone as the
+ * request_queue may have changed.
+ */
+void bio_associate_blkg(struct bio *bio)
+{
+ struct cgroup_subsys_state *css;
+
+ rcu_read_lock();
+
+ if (bio->bi_blkg)
+ css = &bio_blkcg(bio)->css;
+ else
+ css = blkcg_css();
+
+ bio_associate_blkg_from_css(bio, css);
+
+ rcu_read_unlock();
+}
+EXPORT_SYMBOL_GPL(bio_associate_blkg);
+
+/**
+ * bio_clone_blkg_association - clone blkg association from src to dst bio
+ * @dst: destination bio
+ * @src: source bio
+ */
+void bio_clone_blkg_association(struct bio *dst, struct bio *src)
+{
+ if (src->bi_blkg) {
+ if (dst->bi_blkg)
+ blkg_put(dst->bi_blkg);
+ blkg_get(src->bi_blkg);
+ dst->bi_blkg = src->bi_blkg;
+ }
+}
+EXPORT_SYMBOL_GPL(bio_clone_blkg_association);
+
static int __init blkcg_init(void)
{
blkcg_punt_bio_wq = alloc_workqueue("blkcg_punt_bio",
diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
index a57ebe2f00abd8..60df97202314c7 100644
--- a/include/linux/blk-cgroup.h
+++ b/include/linux/blk-cgroup.h
@@ -183,10 +183,6 @@ extern bool blkcg_debug_stats;

struct blkcg_gq *blkg_lookup_slowpath(struct blkcg *blkcg,
struct request_queue *q, bool update_hint);
-struct blkcg_gq *__blkg_lookup_create(struct blkcg *blkcg,
- struct request_queue *q);
-struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg,
- struct request_queue *q);
int blkcg_init_queue(struct request_queue *q);
void blkcg_exit_queue(struct request_queue *q);

@@ -480,32 +476,6 @@ static inline bool blkg_tryget(struct blkcg_gq *blkg)
return blkg && percpu_ref_tryget(&blkg->refcnt);
}

-/**
- * blkg_tryget_closest - try and get a blkg ref on the closet blkg
- * @blkg: blkg to get
- *
- * This needs to be called rcu protected. As the failure mode here is to walk
- * up the blkg tree, this ensure that the blkg->parent pointers are always
- * valid. This returns the blkg that it ended up taking a reference on or %NULL
- * if no reference was taken.
- */
-static inline struct blkcg_gq *blkg_tryget_closest(struct blkcg_gq *blkg)
-{
- struct blkcg_gq *ret_blkg = NULL;
-
- WARN_ON_ONCE(!rcu_read_lock_held());
-
- while (blkg) {
- if (blkg_tryget(blkg)) {
- ret_blkg = blkg;
- break;
- }
- blkg = blkg->parent;
- }
-
- return ret_blkg;
-}
-
/**
* blkg_put - put a blkg reference
* @blkg: blkg to put
--
2.26.2
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