clk: ti: Drop legacy compatibility clocks for am4
[linux-2.6-microblaze.git] / fs / fs_pin.c
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/fs.h>
3 #include <linux/sched.h>
4 #include <linux/slab.h>
5 #include "internal.h"
6 #include "mount.h"
7
8 static DEFINE_SPINLOCK(pin_lock);
9
10 void pin_remove(struct fs_pin *pin)
11 {
12         spin_lock(&pin_lock);
13         hlist_del_init(&pin->m_list);
14         hlist_del_init(&pin->s_list);
15         spin_unlock(&pin_lock);
16         spin_lock_irq(&pin->wait.lock);
17         pin->done = 1;
18         wake_up_locked(&pin->wait);
19         spin_unlock_irq(&pin->wait.lock);
20 }
21
22 void pin_insert(struct fs_pin *pin, struct vfsmount *m)
23 {
24         spin_lock(&pin_lock);
25         hlist_add_head(&pin->s_list, &m->mnt_sb->s_pins);
26         hlist_add_head(&pin->m_list, &real_mount(m)->mnt_pins);
27         spin_unlock(&pin_lock);
28 }
29
30 void pin_kill(struct fs_pin *p)
31 {
32         wait_queue_entry_t wait;
33
34         if (!p) {
35                 rcu_read_unlock();
36                 return;
37         }
38         init_wait(&wait);
39         spin_lock_irq(&p->wait.lock);
40         if (likely(!p->done)) {
41                 p->done = -1;
42                 spin_unlock_irq(&p->wait.lock);
43                 rcu_read_unlock();
44                 p->kill(p);
45                 return;
46         }
47         if (p->done > 0) {
48                 spin_unlock_irq(&p->wait.lock);
49                 rcu_read_unlock();
50                 return;
51         }
52         __add_wait_queue(&p->wait, &wait);
53         while (1) {
54                 set_current_state(TASK_UNINTERRUPTIBLE);
55                 spin_unlock_irq(&p->wait.lock);
56                 rcu_read_unlock();
57                 schedule();
58                 rcu_read_lock();
59                 if (likely(list_empty(&wait.entry)))
60                         break;
61                 /* OK, we know p couldn't have been freed yet */
62                 spin_lock_irq(&p->wait.lock);
63                 if (p->done > 0) {
64                         spin_unlock_irq(&p->wait.lock);
65                         break;
66                 }
67         }
68         rcu_read_unlock();
69 }
70
71 void mnt_pin_kill(struct mount *m)
72 {
73         while (1) {
74                 struct hlist_node *p;
75                 rcu_read_lock();
76                 p = READ_ONCE(m->mnt_pins.first);
77                 if (!p) {
78                         rcu_read_unlock();
79                         break;
80                 }
81                 pin_kill(hlist_entry(p, struct fs_pin, m_list));
82         }
83 }
84
85 void group_pin_kill(struct hlist_head *p)
86 {
87         while (1) {
88                 struct hlist_node *q;
89                 rcu_read_lock();
90                 q = READ_ONCE(p->first);
91                 if (!q) {
92                         rcu_read_unlock();
93                         break;
94                 }
95                 pin_kill(hlist_entry(q, struct fs_pin, s_list));
96         }
97 }