static struct blkcg_policy *blkcg_policy[BLKCG_MAX_POLS];
-static 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_cgrp: 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_cgrp by calling cgroup_rightmost_descendant() to skip
- * subtree.
- */
-#define blkg_for_each_descendant_pre(d_blkg, pos_cgrp, p_blkg) \
- cgroup_for_each_descendant_pre((pos_cgrp), (p_blkg)->blkcg->css.cgroup) \
- if (((d_blkg) = __blkg_lookup(cgroup_to_blkcg(pos_cgrp), \
- (p_blkg)->q, false)))
-
static bool blkcg_policy_enabled(struct request_queue *q,
const struct blkcg_policy *pol)
{
if (!blkg)
return;
- for (i = 0; i < BLKCG_MAX_POLS; i++) {
- struct blkcg_policy *pol = blkcg_policy[i];
- struct blkg_policy_data *pd = blkg->pd[i];
-
- if (!pd)
- continue;
-
- if (pol && pol->pd_exit_fn)
- pol->pd_exit_fn(blkg);
-
- kfree(pd);
- }
+ for (i = 0; i < BLKCG_MAX_POLS; i++)
+ kfree(blkg->pd[i]);
blk_exit_rl(&blkg->rl);
kfree(blkg);
blkg->pd[i] = pd;
pd->blkg = blkg;
pd->plid = i;
-
- /* invoke per-policy init */
- if (pol->pd_init_fn)
- pol->pd_init_fn(blkg);
}
return blkg;
* @q's bypass state. If @update_hint is %true, the caller should be
* holding @q->queue_lock and lookup hint is updated on success.
*/
-static struct blkcg_gq *__blkg_lookup(struct blkcg *blkcg,
- struct request_queue *q, bool update_hint)
+struct blkcg_gq *__blkg_lookup(struct blkcg *blkcg, struct request_queue *q,
+ bool update_hint)
{
struct blkcg_gq *blkg;
}
blkg = new_blkg;
- /* link parent and insert */
+ /* link parent */
if (blkcg_parent(blkcg)) {
blkg->parent = __blkg_lookup(blkcg_parent(blkcg), q, false);
if (WARN_ON_ONCE(!blkg->parent)) {
- blkg = ERR_PTR(-EINVAL);
+ ret = -EINVAL;
goto err_put_css;
}
blkg_get(blkg->parent);
}
+ /* invoke per-policy init */
+ for (i = 0; i < BLKCG_MAX_POLS; i++) {
+ struct blkcg_policy *pol = blkcg_policy[i];
+
+ if (blkg->pd[i] && pol->pd_init_fn)
+ pol->pd_init_fn(blkg);
+ }
+
+ /* insert */
spin_lock(&blkcg->lock);
ret = radix_tree_insert(&blkcg->blkg_tree, q->id, blkg);
if (likely(!ret)) {
q->root_rl.blkg = NULL;
}
-static void blkg_rcu_free(struct rcu_head *rcu_head)
+/*
+ * A group is RCU protected, but having an rcu lock does not mean that one
+ * can access all the fields of blkg and assume these are valid. For
+ * example, don't try to follow throtl_data and request queue links.
+ *
+ * Having a reference to blkg under an rcu allows accesses to only values
+ * local to groups like group stats and group rate limits.
+ */
+void __blkg_release_rcu(struct rcu_head *rcu_head)
{
- blkg_free(container_of(rcu_head, struct blkcg_gq, rcu_head));
-}
+ struct blkcg_gq *blkg = container_of(rcu_head, struct blkcg_gq, rcu_head);
+ int i;
+
+ /* tell policies that this one is being freed */
+ for (i = 0; i < BLKCG_MAX_POLS; i++) {
+ struct blkcg_policy *pol = blkcg_policy[i];
+
+ if (blkg->pd[i] && pol->pd_exit_fn)
+ pol->pd_exit_fn(blkg);
+ }
-void __blkg_release(struct blkcg_gq *blkg)
-{
/* release the blkcg and parent blkg refs this blkg has been holding */
css_put(&blkg->blkcg->css);
- if (blkg->parent)
+ if (blkg->parent) {
+ spin_lock_irq(blkg->q->queue_lock);
blkg_put(blkg->parent);
+ spin_unlock_irq(blkg->q->queue_lock);
+ }
- /*
- * A group is freed in rcu manner. But having an rcu lock does not
- * mean that one can access all the fields of blkg and assume these
- * are valid. For example, don't try to follow throtl_data and
- * request queue links.
- *
- * Having a reference to blkg under an rcu allows acess to only
- * values local to groups like group stats and group rate limits
- */
- call_rcu(&blkg->rcu_head, blkg_rcu_free);
+ blkg_free(blkg);
}
-EXPORT_SYMBOL_GPL(__blkg_release);
+EXPORT_SYMBOL_GPL(__blkg_release_rcu);
/*
* The next function used by blk_queue_for_each_rl(). It's a bit tricky
.subsys_id = blkio_subsys_id,
.base_cftypes = blkcg_files,
.module = THIS_MODULE,
-
- /*
- * blkio subsystem is utterly broken in terms of hierarchy support.
- * It treats all cgroups equally regardless of where they're
- * located in the hierarchy - all cgroups are treated as if they're
- * right below the root. Fix it and remove the following.
- */
- .broken_hierarchy = true,
};
EXPORT_SYMBOL_GPL(blkio_subsys);
projects / cascardo / linux.git / blobdiff