|
@@ -4341,47 +4341,6 @@ static int cgroup_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
|
|
|
return cgroup_create(c_parent, dentry, mode | S_IFDIR);
|
|
|
}
|
|
|
|
|
|
-/*
|
|
|
- * Check the reference count on each subsystem. Since we already
|
|
|
- * established that there are no tasks in the cgroup, if the css refcount
|
|
|
- * is also 1, then there should be no outstanding references, so the
|
|
|
- * subsystem is safe to destroy. We scan across all subsystems rather than
|
|
|
- * using the per-hierarchy linked list of mounted subsystems since we can
|
|
|
- * be called via check_for_release() with no synchronization other than
|
|
|
- * RCU, and the subsystem linked list isn't RCU-safe.
|
|
|
- */
|
|
|
-static int cgroup_has_css_refs(struct cgroup *cgrp)
|
|
|
-{
|
|
|
- int i;
|
|
|
-
|
|
|
- /*
|
|
|
- * We won't need to lock the subsys array, because the subsystems
|
|
|
- * we're concerned about aren't going anywhere since our cgroup root
|
|
|
- * has a reference on them.
|
|
|
- */
|
|
|
- for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
|
|
|
- struct cgroup_subsys *ss = subsys[i];
|
|
|
- struct cgroup_subsys_state *css;
|
|
|
-
|
|
|
- /* Skip subsystems not present or not in this hierarchy */
|
|
|
- if (ss == NULL || ss->root != cgrp->root)
|
|
|
- continue;
|
|
|
-
|
|
|
- css = cgrp->subsys[ss->subsys_id];
|
|
|
- /*
|
|
|
- * When called from check_for_release() it's possible
|
|
|
- * that by this point the cgroup has been removed
|
|
|
- * and the css deleted. But a false-positive doesn't
|
|
|
- * matter, since it can only happen if the cgroup
|
|
|
- * has been deleted and hence no longer needs the
|
|
|
- * release agent to be called anyway.
|
|
|
- */
|
|
|
- if (css && css_refcnt(css) > 1)
|
|
|
- return 1;
|
|
|
- }
|
|
|
- return 0;
|
|
|
-}
|
|
|
-
|
|
|
static int cgroup_destroy_locked(struct cgroup *cgrp)
|
|
|
__releases(&cgroup_mutex) __acquires(&cgroup_mutex)
|
|
|
{
|
|
@@ -5108,12 +5067,15 @@ static void check_for_release(struct cgroup *cgrp)
|
|
|
{
|
|
|
/* All of these checks rely on RCU to keep the cgroup
|
|
|
* structure alive */
|
|
|
- if (cgroup_is_releasable(cgrp) && !atomic_read(&cgrp->count)
|
|
|
- && list_empty(&cgrp->children) && !cgroup_has_css_refs(cgrp)) {
|
|
|
- /* Control Group is currently removeable. If it's not
|
|
|
+ if (cgroup_is_releasable(cgrp) &&
|
|
|
+ !atomic_read(&cgrp->count) && list_empty(&cgrp->children)) {
|
|
|
+ /*
|
|
|
+ * Control Group is currently removeable. If it's not
|
|
|
* already queued for a userspace notification, queue
|
|
|
- * it now */
|
|
|
+ * it now
|
|
|
+ */
|
|
|
int need_schedule_work = 0;
|
|
|
+
|
|
|
raw_spin_lock(&release_list_lock);
|
|
|
if (!cgroup_is_removed(cgrp) &&
|
|
|
list_empty(&cgrp->release_list)) {
|
|
@@ -5146,24 +5108,11 @@ EXPORT_SYMBOL_GPL(__css_tryget);
|
|
|
/* Caller must verify that the css is not for root cgroup */
|
|
|
void __css_put(struct cgroup_subsys_state *css)
|
|
|
{
|
|
|
- struct cgroup *cgrp = css->cgroup;
|
|
|
int v;
|
|
|
|
|
|
- rcu_read_lock();
|
|
|
v = css_unbias_refcnt(atomic_dec_return(&css->refcnt));
|
|
|
-
|
|
|
- switch (v) {
|
|
|
- case 1:
|
|
|
- if (notify_on_release(cgrp)) {
|
|
|
- set_bit(CGRP_RELEASABLE, &cgrp->flags);
|
|
|
- check_for_release(cgrp);
|
|
|
- }
|
|
|
- break;
|
|
|
- case 0:
|
|
|
+ if (v == 0)
|
|
|
schedule_work(&css->dput_work);
|
|
|
- break;
|
|
|
- }
|
|
|
- rcu_read_unlock();
|
|
|
}
|
|
|
EXPORT_SYMBOL_GPL(__css_put);
|
|
|
|