+void pin_insert(struct fs_pin *pin, struct vfsmount *m)
+{
+ pin_insert_group(pin, m, &m->mnt_sb->s_pins);
+}
+
+void pin_kill(struct fs_pin *p)
+{
+ wait_queue_t wait;
+
+ if (!p) {
+ rcu_read_unlock();
+ return;
+ }
+ init_wait(&wait);
+ spin_lock_irq(&p->wait.lock);
+ if (likely(!p->done)) {
+ p->done = -1;
+ spin_unlock_irq(&p->wait.lock);
+ rcu_read_unlock();
+ p->kill(p);
+ return;
+ }
+ if (p->done > 0) {
+ spin_unlock_irq(&p->wait.lock);
+ rcu_read_unlock();
+ return;
+ }
+ __add_wait_queue(&p->wait, &wait);
+ while (1) {
+ set_current_state(TASK_UNINTERRUPTIBLE);
+ spin_unlock_irq(&p->wait.lock);
+ rcu_read_unlock();
+ schedule();
+ rcu_read_lock();
+ if (likely(list_empty(&wait.task_list)))
+ break;
+ /* OK, we know p couldn't have been freed yet */
+ spin_lock_irq(&p->wait.lock);
+ if (p->done > 0) {
+ spin_unlock_irq(&p->wait.lock);
+ break;
+ }
+ }
+ rcu_read_unlock();
+}
+