void blkg_conf_finish(struct blkg_conf_ctx *ctx);
-static inline struct blkcg *cgroup_to_blkcg(struct cgroup *cgroup)
+static inline struct blkcg *css_to_blkcg(struct cgroup_subsys_state *css)
{
- return container_of(cgroup_subsys_state(cgroup, blkio_subsys_id),
- struct blkcg, css);
+ return css ? container_of(css, struct blkcg, css) : NULL;
}
static inline struct blkcg *task_blkcg(struct task_struct *tsk)
{
- return container_of(task_subsys_state(tsk, blkio_subsys_id),
- struct blkcg, css);
+ return css_to_blkcg(task_css(tsk, blkio_subsys_id));
}
static inline struct blkcg *bio_blkcg(struct bio *bio)
{
if (bio && bio->bi_css)
- return container_of(bio->bi_css, struct blkcg, css);
+ return css_to_blkcg(bio->bi_css);
return task_blkcg(current);
}
*/
static inline struct blkcg *blkcg_parent(struct blkcg *blkcg)
{
- struct cgroup *pcg = blkcg->css.cgroup->parent;
-
- return pcg ? cgroup_to_blkcg(pcg) : NULL;
+ return css_to_blkcg(css_parent(&blkcg->css));
}
/**
blkg->refcnt++;
}
-void __blkg_release(struct blkcg_gq *blkg);
+void __blkg_release_rcu(struct rcu_head *rcu);
/**
* blkg_put - put a blkg reference
lockdep_assert_held(blkg->q->queue_lock);
WARN_ON_ONCE(blkg->refcnt <= 0);
if (!--blkg->refcnt)
- __blkg_release(blkg);
+ call_rcu(&blkg->rcu_head, __blkg_release_rcu);
}
+struct blkcg_gq *__blkg_lookup(struct blkcg *blkcg, struct request_queue *q,
+ bool update_hint);
+
+/**
+ * blkg_for_each_descendant_pre - pre-order walk of a blkg's descendants
+ * @d_blkg: loop cursor pointing to the current descendant
+ * @pos_css: used for iteration
+ * @p_blkg: target blkg to walk descendants of
+ *
+ * Walk @c_blkg through the descendants of @p_blkg. Must be used with RCU
+ * read locked. If called under either blkcg or queue lock, the iteration
+ * is guaranteed to include all and only online blkgs. The caller may
+ * update @pos_css by calling css_rightmost_descendant() to skip subtree.
+ * @p_blkg is included in the iteration and the first node to be visited.
+ */
+#define blkg_for_each_descendant_pre(d_blkg, pos_css, p_blkg) \
+ css_for_each_descendant_pre((pos_css), &(p_blkg)->blkcg->css) \
+ if (((d_blkg) = __blkg_lookup(css_to_blkcg(pos_css), \
+ (p_blkg)->q, false)))
+
+/**
+ * blkg_for_each_descendant_post - post-order walk of a blkg's descendants
+ * @d_blkg: loop cursor pointing to the current descendant
+ * @pos_css: used for iteration
+ * @p_blkg: target blkg to walk descendants of
+ *
+ * Similar to blkg_for_each_descendant_pre() but performs post-order
+ * traversal instead. Synchronization rules are the same. @p_blkg is
+ * included in the iteration and the last node to be visited.
+ */
+#define blkg_for_each_descendant_post(d_blkg, pos_css, p_blkg) \
+ css_for_each_descendant_post((pos_css), &(p_blkg)->blkcg->css) \
+ if (((d_blkg) = __blkg_lookup(css_to_blkcg(pos_css), \
+ (p_blkg)->q, false)))
+
/**
* blk_get_rl - get request_list to use
* @q: request_queue of interest
static inline void blkcg_deactivate_policy(struct request_queue *q,
const struct blkcg_policy *pol) { }
-static inline struct blkcg *cgroup_to_blkcg(struct cgroup *cgroup) { return NULL; }
static inline struct blkcg *bio_blkcg(struct bio *bio) { return NULL; }
static inline struct blkg_policy_data *blkg_to_pd(struct blkcg_gq *blkg,