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-rw-r--r--fs/notify/group.c107
1 files changed, 2 insertions, 105 deletions
diff --git a/fs/notify/group.c b/fs/notify/group.c
index fc0d966b270f..d309f38449cb 100644
--- a/fs/notify/group.c
+++ b/fs/notify/group.c
@@ -28,67 +28,6 @@
28 28
29#include <asm/atomic.h> 29#include <asm/atomic.h>
30 30
31/* protects writes to fsnotify_groups and fsnotify_mask */
32static DEFINE_MUTEX(fsnotify_grp_mutex);
33/* all groups registered to receive inode filesystem notifications */
34LIST_HEAD(fsnotify_inode_groups);
35/* all groups registered to receive mount point filesystem notifications */
36LIST_HEAD(fsnotify_vfsmount_groups);
37
38void fsnotify_add_vfsmount_group(struct fsnotify_group *group)
39{
40 struct fsnotify_group *group_iter;
41
42 mutex_lock(&fsnotify_grp_mutex);
43
44 if (!group->on_vfsmount_group_list) {
45 list_for_each_entry(group_iter, &fsnotify_vfsmount_groups,
46 vfsmount_group_list) {
47 /* insert in front of this one? */
48 if (group < group_iter) {
49 /* list_add_tail() insert in front of group_iter */
50 list_add_tail_rcu(&group->inode_group_list,
51 &group_iter->inode_group_list);
52 goto out;
53 }
54 }
55
56 /* apparently we need to be the last entry */
57 list_add_tail_rcu(&group->vfsmount_group_list, &fsnotify_vfsmount_groups);
58 }
59out:
60 group->on_vfsmount_group_list = 1;
61
62 mutex_unlock(&fsnotify_grp_mutex);
63}
64
65void fsnotify_add_inode_group(struct fsnotify_group *group)
66{
67 struct fsnotify_group *group_iter;
68
69 mutex_lock(&fsnotify_grp_mutex);
70
71 /* add to global group list */
72 if (!group->on_inode_group_list) {
73 list_for_each_entry(group_iter, &fsnotify_inode_groups,
74 inode_group_list) {
75 if (group < group_iter) {
76 /* list_add_tail() insert in front of group_iter */
77 list_add_tail_rcu(&group->inode_group_list,
78 &group_iter->inode_group_list);
79 goto out;
80 }
81 }
82
83 /* apparently we need to be the last entry */
84 list_add_tail_rcu(&group->inode_group_list, &fsnotify_inode_groups);
85 }
86out:
87 group->on_inode_group_list = 1;
88
89 mutex_unlock(&fsnotify_grp_mutex);
90}
91
92/* 31/*
93 * Final freeing of a group 32 * Final freeing of a group
94 */ 33 */
@@ -124,51 +63,12 @@ static void fsnotify_destroy_group(struct fsnotify_group *group)
124} 63}
125 64
126/* 65/*
127 * Remove this group from the global list of groups that will get events
128 * this can be done even if there are still references and things still using
129 * this group. This just stops the group from getting new events.
130 */
131static void __fsnotify_evict_group(struct fsnotify_group *group)
132{
133 BUG_ON(!mutex_is_locked(&fsnotify_grp_mutex));
134
135 if (group->on_inode_group_list)
136 list_del_rcu(&group->inode_group_list);
137 group->on_inode_group_list = 0;
138 if (group->on_vfsmount_group_list)
139 list_del_rcu(&group->vfsmount_group_list);
140 group->on_vfsmount_group_list = 0;
141}
142
143/*
144 * Called when a group is no longer interested in getting events. This can be
145 * used if a group is misbehaving or if for some reason a group should no longer
146 * get any filesystem events.
147 */
148void fsnotify_evict_group(struct fsnotify_group *group)
149{
150 mutex_lock(&fsnotify_grp_mutex);
151 __fsnotify_evict_group(group);
152 mutex_unlock(&fsnotify_grp_mutex);
153}
154
155/*
156 * Drop a reference to a group. Free it if it's through. 66 * Drop a reference to a group. Free it if it's through.
157 */ 67 */
158void fsnotify_put_group(struct fsnotify_group *group) 68void fsnotify_put_group(struct fsnotify_group *group)
159{ 69{
160 if (!atomic_dec_and_mutex_lock(&group->refcnt, &fsnotify_grp_mutex)) 70 if (atomic_dec_and_test(&group->refcnt))
161 return; 71 fsnotify_destroy_group(group);
162
163 /*
164 * OK, now we know that there's no other users *and* we hold mutex,
165 * so no new references will appear
166 */
167 __fsnotify_evict_group(group);
168
169 mutex_unlock(&fsnotify_grp_mutex);
170
171 fsnotify_destroy_group(group);
172} 72}
173 73
174/* 74/*
@@ -195,9 +95,6 @@ struct fsnotify_group *fsnotify_alloc_group(const struct fsnotify_ops *ops)
195 init_waitqueue_head(&group->notification_waitq); 95 init_waitqueue_head(&group->notification_waitq);
196 group->max_events = UINT_MAX; 96 group->max_events = UINT_MAX;
197 97
198 INIT_LIST_HEAD(&group->inode_group_list);
199 INIT_LIST_HEAD(&group->vfsmount_group_list);
200
201 spin_lock_init(&group->mark_lock); 98 spin_lock_init(&group->mark_lock);
202 INIT_LIST_HEAD(&group->marks_list); 99 INIT_LIST_HEAD(&group->marks_list);
203 100