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Diffstat (limited to 'fs/fs_pin.c')
-rw-r--r--fs/fs_pin.c96
1 files changed, 60 insertions, 36 deletions
diff --git a/fs/fs_pin.c b/fs/fs_pin.c
index 9368236ca100..b06c98796afb 100644
--- a/fs/fs_pin.c
+++ b/fs/fs_pin.c
@@ -1,78 +1,102 @@
#include <linux/fs.h>
+#include <linux/sched.h>
#include <linux/slab.h>
-#include <linux/fs_pin.h>
#include "internal.h"
#include "mount.h"
-static void pin_free_rcu(struct rcu_head *head)
-{
- kfree(container_of(head, struct fs_pin, rcu));
-}
-
static DEFINE_SPINLOCK(pin_lock);
-void pin_put(struct fs_pin *p)
-{
- if (atomic_long_dec_and_test(&p->count))
- call_rcu(&p->rcu, pin_free_rcu);
-}
-
void pin_remove(struct fs_pin *pin)
{
spin_lock(&pin_lock);
hlist_del(&pin->m_list);
hlist_del(&pin->s_list);
spin_unlock(&pin_lock);
+ spin_lock_irq(&pin->wait.lock);
+ pin->done = 1;
+ wake_up_locked(&pin->wait);
+ spin_unlock_irq(&pin->wait.lock);
}
-void pin_insert(struct fs_pin *pin, struct vfsmount *m)
+void pin_insert_group(struct fs_pin *pin, struct vfsmount *m, struct hlist_head *p)
{
spin_lock(&pin_lock);
- hlist_add_head(&pin->s_list, &m->mnt_sb->s_pins);
+ if (p)
+ hlist_add_head(&pin->s_list, p);
hlist_add_head(&pin->m_list, &real_mount(m)->mnt_pins);
spin_unlock(&pin_lock);
}
+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();
+}
+
void mnt_pin_kill(struct mount *m)
{
while (1) {
struct hlist_node *p;
- struct fs_pin *pin;
rcu_read_lock();
p = ACCESS_ONCE(m->mnt_pins.first);
if (!p) {
rcu_read_unlock();
break;
}
- pin = hlist_entry(p, struct fs_pin, m_list);
- if (!atomic_long_inc_not_zero(&pin->count)) {
- rcu_read_unlock();
- cpu_relax();
- continue;
- }
- rcu_read_unlock();
- pin->kill(pin);
+ pin_kill(hlist_entry(p, struct fs_pin, m_list));
}
}
-void sb_pin_kill(struct super_block *sb)
+void group_pin_kill(struct hlist_head *p)
{
while (1) {
- struct hlist_node *p;
- struct fs_pin *pin;
+ struct hlist_node *q;
rcu_read_lock();
- p = ACCESS_ONCE(sb->s_pins.first);
- if (!p) {
+ q = ACCESS_ONCE(p->first);
+ if (!q) {
rcu_read_unlock();
break;
}
- pin = hlist_entry(p, struct fs_pin, s_list);
- if (!atomic_long_inc_not_zero(&pin->count)) {
- rcu_read_unlock();
- cpu_relax();
- continue;
- }
- rcu_read_unlock();
- pin->kill(pin);
+ pin_kill(hlist_entry(q, struct fs_pin, s_list));
}
}