block: move the bio cgroup associatation helpers to blk-cgroup.c

Keep the cgroup code together.

Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/bio.c b/block/bio.c
index 901d227..fc1299f 100644 (file)
--- 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 0ecc897..bb0607b 100644 (file)
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -328,7 +328,7 @@ err_free_blkg:
  * 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 a57ebe2..60df972 100644 (file)
--- 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);
 
@@ -481,32 +477,6 @@ static inline bool blkg_tryget(struct blkcg_gq *blkg)
 }
 
 /**
- * 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
  */