diff options
| -rw-r--r-- | kernel/cgroup.c | 58 |
1 files changed, 28 insertions, 30 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index cbbb46f783de..dffa54041d4a 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -2705,36 +2705,6 @@ static ssize_t cgroup_subtree_control_write(struct kernfs_open_file *of, ret = -ENOENT; goto out_unlock; } - - /* - * @ss is already enabled through dependency and - * we'll just make it visible. Skip draining. - */ - if (cgrp->child_subsys_mask & (1 << ssid)) - continue; - - /* - * Because css offlining is asynchronous, userland - * might try to re-enable the same controller while - * the previous instance is still around. In such - * cases, wait till it's gone using offline_waitq. - */ - cgroup_for_each_live_child(child, cgrp) { - DEFINE_WAIT(wait); - - if (!cgroup_css(child, ss)) - continue; - - cgroup_get(child); - prepare_to_wait(&child->offline_waitq, &wait, - TASK_UNINTERRUPTIBLE); - cgroup_kn_unlock(of->kn); - schedule(); - finish_wait(&child->offline_waitq, &wait); - cgroup_put(child); - - return restart_syscall(); - } } else if (disable & (1 << ssid)) { if (!(cgrp->subtree_control & (1 << ssid))) { disable &= ~(1 << ssid); @@ -2780,6 +2750,34 @@ static ssize_t cgroup_subtree_control_write(struct kernfs_open_file *of, enable |= css_enable; disable |= css_disable; + /* + * Because css offlining is asynchronous, userland might try to + * re-enable the same controller while the previous instance is + * still around. In such cases, wait till it's gone using + * offline_waitq. + */ + for_each_subsys(ss, ssid) { + if (!(css_enable & (1 << ssid))) + continue; + + cgroup_for_each_live_child(child, cgrp) { + DEFINE_WAIT(wait); + + if (!cgroup_css(child, ss)) + continue; + + cgroup_get(child); + prepare_to_wait(&child->offline_waitq, &wait, + TASK_UNINTERRUPTIBLE); + cgroup_kn_unlock(of->kn); + schedule(); + finish_wait(&child->offline_waitq, &wait); + cgroup_put(child); + + return restart_syscall(); + } + } + cgrp->subtree_control = new_sc; cgrp->child_subsys_mask = new_ss; |