1 // SPDX-License-Identifier: GPL-2.0 1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/fs.h> 2 #include <linux/fs.h>
3 #include <linux/sched.h> 3 #include <linux/sched.h>
4 #include <linux/slab.h> 4 #include <linux/slab.h>
5 #include "internal.h" 5 #include "internal.h"
6 #include "mount.h" 6 #include "mount.h"
7 7
8 static DEFINE_SPINLOCK(pin_lock); 8 static DEFINE_SPINLOCK(pin_lock);
9 9
10 void pin_remove(struct fs_pin *pin) 10 void pin_remove(struct fs_pin *pin)
11 { 11 {
12 spin_lock(&pin_lock); 12 spin_lock(&pin_lock);
13 hlist_del_init(&pin->m_list); 13 hlist_del_init(&pin->m_list);
14 hlist_del_init(&pin->s_list); 14 hlist_del_init(&pin->s_list);
15 spin_unlock(&pin_lock); 15 spin_unlock(&pin_lock);
16 spin_lock_irq(&pin->wait.lock); 16 spin_lock_irq(&pin->wait.lock);
17 pin->done = 1; 17 pin->done = 1;
18 wake_up_locked(&pin->wait); 18 wake_up_locked(&pin->wait);
19 spin_unlock_irq(&pin->wait.lock); 19 spin_unlock_irq(&pin->wait.lock);
20 } 20 }
21 21
22 void pin_insert(struct fs_pin *pin, struct vfs !! 22 void pin_insert_group(struct fs_pin *pin, struct vfsmount *m, struct hlist_head *p)
23 { 23 {
24 spin_lock(&pin_lock); 24 spin_lock(&pin_lock);
25 hlist_add_head(&pin->s_list, &m->mnt_s !! 25 if (p)
>> 26 hlist_add_head(&pin->s_list, p);
26 hlist_add_head(&pin->m_list, &real_mou 27 hlist_add_head(&pin->m_list, &real_mount(m)->mnt_pins);
27 spin_unlock(&pin_lock); 28 spin_unlock(&pin_lock);
>> 29 }
>> 30
>> 31 void pin_insert(struct fs_pin *pin, struct vfsmount *m)
>> 32 {
>> 33 pin_insert_group(pin, m, &m->mnt_sb->s_pins);
28 } 34 }
29 35
30 void pin_kill(struct fs_pin *p) 36 void pin_kill(struct fs_pin *p)
31 { 37 {
32 wait_queue_entry_t wait; 38 wait_queue_entry_t wait;
33 39
34 if (!p) { 40 if (!p) {
35 rcu_read_unlock(); 41 rcu_read_unlock();
36 return; 42 return;
37 } 43 }
38 init_wait(&wait); 44 init_wait(&wait);
39 spin_lock_irq(&p->wait.lock); 45 spin_lock_irq(&p->wait.lock);
40 if (likely(!p->done)) { 46 if (likely(!p->done)) {
41 p->done = -1; 47 p->done = -1;
42 spin_unlock_irq(&p->wait.lock) 48 spin_unlock_irq(&p->wait.lock);
43 rcu_read_unlock(); 49 rcu_read_unlock();
44 p->kill(p); 50 p->kill(p);
45 return; 51 return;
46 } 52 }
47 if (p->done > 0) { 53 if (p->done > 0) {
48 spin_unlock_irq(&p->wait.lock) 54 spin_unlock_irq(&p->wait.lock);
49 rcu_read_unlock(); 55 rcu_read_unlock();
50 return; 56 return;
51 } 57 }
52 __add_wait_queue(&p->wait, &wait); 58 __add_wait_queue(&p->wait, &wait);
53 while (1) { 59 while (1) {
54 set_current_state(TASK_UNINTER 60 set_current_state(TASK_UNINTERRUPTIBLE);
55 spin_unlock_irq(&p->wait.lock) 61 spin_unlock_irq(&p->wait.lock);
56 rcu_read_unlock(); 62 rcu_read_unlock();
57 schedule(); 63 schedule();
58 rcu_read_lock(); 64 rcu_read_lock();
59 if (likely(list_empty(&wait.en 65 if (likely(list_empty(&wait.entry)))
60 break; 66 break;
61 /* OK, we know p couldn't have 67 /* OK, we know p couldn't have been freed yet */
62 spin_lock_irq(&p->wait.lock); 68 spin_lock_irq(&p->wait.lock);
63 if (p->done > 0) { 69 if (p->done > 0) {
64 spin_unlock_irq(&p->wa 70 spin_unlock_irq(&p->wait.lock);
65 break; 71 break;
66 } 72 }
67 } 73 }
68 rcu_read_unlock(); 74 rcu_read_unlock();
69 } 75 }
70 76
71 void mnt_pin_kill(struct mount *m) 77 void mnt_pin_kill(struct mount *m)
72 { 78 {
73 while (1) { 79 while (1) {
74 struct hlist_node *p; 80 struct hlist_node *p;
75 rcu_read_lock(); 81 rcu_read_lock();
76 p = READ_ONCE(m->mnt_pins.firs 82 p = READ_ONCE(m->mnt_pins.first);
77 if (!p) { 83 if (!p) {
78 rcu_read_unlock(); 84 rcu_read_unlock();
79 break; 85 break;
80 } 86 }
81 pin_kill(hlist_entry(p, struct 87 pin_kill(hlist_entry(p, struct fs_pin, m_list));
82 } 88 }
83 } 89 }
84 90
85 void group_pin_kill(struct hlist_head *p) 91 void group_pin_kill(struct hlist_head *p)
86 { 92 {
87 while (1) { 93 while (1) {
88 struct hlist_node *q; 94 struct hlist_node *q;
89 rcu_read_lock(); 95 rcu_read_lock();
90 q = READ_ONCE(p->first); 96 q = READ_ONCE(p->first);
91 if (!q) { 97 if (!q) {
92 rcu_read_unlock(); 98 rcu_read_unlock();
93 break; 99 break;
94 } 100 }
95 pin_kill(hlist_entry(q, struct 101 pin_kill(hlist_entry(q, struct fs_pin, s_list));
96 } 102 }
97 } 103 }
98 104
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