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4
5
6#include <linux/list.h>
7#include <linux/mutex.h>
8#include <linux/slab.h>
9#include <linux/srcu.h>
10#include <linux/rculist.h>
11#include <linux/wait.h>
12#include <linux/memcontrol.h>
13
14#include <linux/fsnotify_backend.h>
15#include "fsnotify.h"
16
17#include <linux/atomic.h>
18
19
20
21
22static void fsnotify_final_destroy_group(struct fsnotify_group *group)
23{
24 if (group->ops->free_group_priv)
25 group->ops->free_group_priv(group);
26
27 mem_cgroup_put(group->memcg);
28 mutex_destroy(&group->mark_mutex);
29
30 kfree(group);
31}
32
33
34
35
36
37void fsnotify_group_stop_queueing(struct fsnotify_group *group)
38{
39 spin_lock(&group->notification_lock);
40 group->shutdown = true;
41 spin_unlock(&group->notification_lock);
42}
43
44
45
46
47
48
49
50void fsnotify_destroy_group(struct fsnotify_group *group)
51{
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53
54
55
56
57
58 fsnotify_group_stop_queueing(group);
59
60
61 fsnotify_clear_marks_by_group(group, FSNOTIFY_OBJ_ALL_TYPES_MASK);
62
63
64
65
66
67
68 wait_event(group->notification_waitq, !atomic_read(&group->user_waits));
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70
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73
74
75
76 fsnotify_wait_marks_destroyed();
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81
82
83
84 fsnotify_flush_notify(group);
85
86
87
88
89
90 if (group->overflow_event)
91 group->ops->free_event(group->overflow_event);
92
93 fsnotify_put_group(group);
94}
95
96
97
98
99void fsnotify_get_group(struct fsnotify_group *group)
100{
101 refcount_inc(&group->refcnt);
102}
103
104
105
106
107void fsnotify_put_group(struct fsnotify_group *group)
108{
109 if (refcount_dec_and_test(&group->refcnt))
110 fsnotify_final_destroy_group(group);
111}
112EXPORT_SYMBOL_GPL(fsnotify_put_group);
113
114static struct fsnotify_group *__fsnotify_alloc_group(
115 const struct fsnotify_ops *ops, gfp_t gfp)
116{
117 struct fsnotify_group *group;
118
119 group = kzalloc(sizeof(struct fsnotify_group), gfp);
120 if (!group)
121 return ERR_PTR(-ENOMEM);
122
123
124 refcount_set(&group->refcnt, 1);
125 atomic_set(&group->user_waits, 0);
126
127 spin_lock_init(&group->notification_lock);
128 INIT_LIST_HEAD(&group->notification_list);
129 init_waitqueue_head(&group->notification_waitq);
130 group->max_events = UINT_MAX;
131
132 mutex_init(&group->mark_mutex);
133 INIT_LIST_HEAD(&group->marks_list);
134
135 group->ops = ops;
136
137 return group;
138}
139
140
141
142
143struct fsnotify_group *fsnotify_alloc_group(const struct fsnotify_ops *ops)
144{
145 return __fsnotify_alloc_group(ops, GFP_KERNEL);
146}
147EXPORT_SYMBOL_GPL(fsnotify_alloc_group);
148
149
150
151
152struct fsnotify_group *fsnotify_alloc_user_group(const struct fsnotify_ops *ops)
153{
154 return __fsnotify_alloc_group(ops, GFP_KERNEL_ACCOUNT);
155}
156EXPORT_SYMBOL_GPL(fsnotify_alloc_user_group);
157
158int fsnotify_fasync(int fd, struct file *file, int on)
159{
160 struct fsnotify_group *group = file->private_data;
161
162 return fasync_helper(fd, file, on, &group->fsn_fa) >= 0 ? 0 : -EIO;
163}
164