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16#include <linux/dcache.h>
17#include <linux/fs.h>
18#include <linux/fsnotify_backend.h>
19#include <linux/inotify.h>
20#include <linux/path.h>
21#include <linux/slab.h>
22#include <linux/types.h>
23#include <linux/sched.h>
24#include <linux/sched/user.h>
25#include <linux/sched/mm.h>
26
27#include "inotify.h"
28
29
30
31
32static bool event_compare(struct fsnotify_event *old_fsn,
33 struct fsnotify_event *new_fsn)
34{
35 struct inotify_event_info *old, *new;
36
37 old = INOTIFY_E(old_fsn);
38 new = INOTIFY_E(new_fsn);
39 if (old->mask & FS_IN_IGNORED)
40 return false;
41 if ((old->mask == new->mask) &&
42 (old->wd == new->wd) &&
43 (old->name_len == new->name_len) &&
44 (!old->name_len || !strcmp(old->name, new->name)))
45 return true;
46 return false;
47}
48
49static int inotify_merge(struct fsnotify_group *group,
50 struct fsnotify_event *event)
51{
52 struct list_head *list = &group->notification_list;
53 struct fsnotify_event *last_event;
54
55 last_event = list_entry(list->prev, struct fsnotify_event, list);
56 return event_compare(last_event, event);
57}
58
59int inotify_handle_inode_event(struct fsnotify_mark *inode_mark, u32 mask,
60 struct inode *inode, struct inode *dir,
61 const struct qstr *name, u32 cookie)
62{
63 struct inotify_inode_mark *i_mark;
64 struct inotify_event_info *event;
65 struct fsnotify_event *fsn_event;
66 struct fsnotify_group *group = inode_mark->group;
67 int ret;
68 int len = 0;
69 int alloc_len = sizeof(struct inotify_event_info);
70 struct mem_cgroup *old_memcg;
71
72 if (name) {
73 len = name->len;
74 alloc_len += len + 1;
75 }
76
77 pr_debug("%s: group=%p mark=%p mask=%x\n", __func__, group, inode_mark,
78 mask);
79
80 i_mark = container_of(inode_mark, struct inotify_inode_mark,
81 fsn_mark);
82
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87
88 old_memcg = set_active_memcg(group->memcg);
89 event = kmalloc(alloc_len, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
90 set_active_memcg(old_memcg);
91
92 if (unlikely(!event)) {
93
94
95
96
97 fsnotify_queue_overflow(group);
98 return -ENOMEM;
99 }
100
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106
107 if (mask & (IN_MOVE_SELF | IN_DELETE_SELF))
108 mask &= ~IN_ISDIR;
109
110 fsn_event = &event->fse;
111 fsnotify_init_event(fsn_event);
112 event->mask = mask;
113 event->wd = i_mark->wd;
114 event->sync_cookie = cookie;
115 event->name_len = len;
116 if (len)
117 strcpy(event->name, name->name);
118
119 ret = fsnotify_add_event(group, fsn_event, inotify_merge, NULL);
120 if (ret) {
121
122 fsnotify_destroy_event(group, fsn_event);
123 }
124
125 if (inode_mark->mask & IN_ONESHOT)
126 fsnotify_destroy_mark(inode_mark, group);
127
128 return 0;
129}
130
131static void inotify_freeing_mark(struct fsnotify_mark *fsn_mark, struct fsnotify_group *group)
132{
133 inotify_ignored_and_remove_idr(fsn_mark, group);
134}
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142
143static int idr_callback(int id, void *p, void *data)
144{
145 struct fsnotify_mark *fsn_mark;
146 struct inotify_inode_mark *i_mark;
147 static bool warned = false;
148
149 if (warned)
150 return 0;
151
152 warned = true;
153 fsn_mark = p;
154 i_mark = container_of(fsn_mark, struct inotify_inode_mark, fsn_mark);
155
156 WARN(1, "inotify closing but id=%d for fsn_mark=%p in group=%p still in "
157 "idr. Probably leaking memory\n", id, p, data);
158
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164
165 if (fsn_mark)
166 printk(KERN_WARNING "fsn_mark->group=%p wd=%d\n",
167 fsn_mark->group, i_mark->wd);
168 return 0;
169}
170
171static void inotify_free_group_priv(struct fsnotify_group *group)
172{
173
174 idr_for_each(&group->inotify_data.idr, idr_callback, group);
175 idr_destroy(&group->inotify_data.idr);
176 if (group->inotify_data.ucounts)
177 dec_inotify_instances(group->inotify_data.ucounts);
178}
179
180static void inotify_free_event(struct fsnotify_event *fsn_event)
181{
182 kfree(INOTIFY_E(fsn_event));
183}
184
185
186static void inotify_free_mark(struct fsnotify_mark *fsn_mark)
187{
188 struct inotify_inode_mark *i_mark;
189
190 i_mark = container_of(fsn_mark, struct inotify_inode_mark, fsn_mark);
191
192 kmem_cache_free(inotify_inode_mark_cachep, i_mark);
193}
194
195const struct fsnotify_ops inotify_fsnotify_ops = {
196 .handle_inode_event = inotify_handle_inode_event,
197 .free_group_priv = inotify_free_group_priv,
198 .free_event = inotify_free_event,
199 .freeing_mark = inotify_freeing_mark,
200 .free_mark = inotify_free_mark,
201};
202