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1#ifndef _LINUX_FS_NOTIFY_H
2#define _LINUX_FS_NOTIFY_H
3
4/*
5 * include/linux/fsnotify.h - generic hooks for filesystem notification, to
6 * reduce in-source duplication from both dnotify and inotify.
7 *
8 * We don't compile any of this away in some complicated menagerie of ifdefs.
9 * Instead, we rely on the code inside to optimize away as needed.
10 *
11 * (C) Copyright 2005 Robert Love
12 */
13
14#include <linux/fsnotify_backend.h>
15#include <linux/audit.h>
16#include <linux/slab.h>
17#include <linux/bug.h>
18
19/* Notify this dentry's parent about a child's events. */
20static inline int fsnotify_parent(const struct path *path, struct dentry *dentry, __u32 mask)
21{
22 if (!dentry)
23 dentry = path->dentry;
24
25 return __fsnotify_parent(path, dentry, mask);
26}
27
28/* simple call site for access decisions */
29static inline int fsnotify_perm(struct file *file, int mask)
30{
31 const struct path *path = &file->f_path;
32 /*
33 * Do not use file_inode() here or anywhere in this file to get the
34 * inode. That would break *notity on overlayfs.
35 */
36 struct inode *inode = path->dentry->d_inode;
37 __u32 fsnotify_mask = 0;
38 int ret;
39
40 if (file->f_mode & FMODE_NONOTIFY)
41 return 0;
42 if (!(mask & (MAY_READ | MAY_OPEN)))
43 return 0;
44 if (mask & MAY_OPEN)
45 fsnotify_mask = FS_OPEN_PERM;
46 else if (mask & MAY_READ)
47 fsnotify_mask = FS_ACCESS_PERM;
48 else
49 BUG();
50
51 ret = fsnotify_parent(path, NULL, fsnotify_mask);
52 if (ret)
53 return ret;
54
55 return fsnotify(inode, fsnotify_mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
56}
57
58/*
59 * fsnotify_link_count - inode's link count changed
60 */
61static inline void fsnotify_link_count(struct inode *inode)
62{
63 fsnotify(inode, FS_ATTRIB, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
64}
65
66/*
67 * fsnotify_move - file old_name at old_dir was moved to new_name at new_dir
68 */
69static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir,
70 const unsigned char *old_name,
71 int isdir, struct inode *target, struct dentry *moved)
72{
73 struct inode *source = moved->d_inode;
74 u32 fs_cookie = fsnotify_get_cookie();
75 __u32 old_dir_mask = (FS_EVENT_ON_CHILD | FS_MOVED_FROM);
76 __u32 new_dir_mask = (FS_EVENT_ON_CHILD | FS_MOVED_TO);
77 const unsigned char *new_name = moved->d_name.name;
78
79 if (old_dir == new_dir)
80 old_dir_mask |= FS_DN_RENAME;
81
82 if (isdir) {
83 old_dir_mask |= FS_ISDIR;
84 new_dir_mask |= FS_ISDIR;
85 }
86
87 fsnotify(old_dir, old_dir_mask, source, FSNOTIFY_EVENT_INODE, old_name,
88 fs_cookie);
89 fsnotify(new_dir, new_dir_mask, source, FSNOTIFY_EVENT_INODE, new_name,
90 fs_cookie);
91
92 if (target)
93 fsnotify_link_count(target);
94
95 if (source)
96 fsnotify(source, FS_MOVE_SELF, moved->d_inode, FSNOTIFY_EVENT_INODE, NULL, 0);
97 audit_inode_child(new_dir, moved, AUDIT_TYPE_CHILD_CREATE);
98}
99
100/*
101 * fsnotify_inode_delete - and inode is being evicted from cache, clean up is needed
102 */
103static inline void fsnotify_inode_delete(struct inode *inode)
104{
105 __fsnotify_inode_delete(inode);
106}
107
108/*
109 * fsnotify_vfsmount_delete - a vfsmount is being destroyed, clean up is needed
110 */
111static inline void fsnotify_vfsmount_delete(struct vfsmount *mnt)
112{
113 __fsnotify_vfsmount_delete(mnt);
114}
115
116/*
117 * fsnotify_nameremove - a filename was removed from a directory
118 */
119static inline void fsnotify_nameremove(struct dentry *dentry, int isdir)
120{
121 __u32 mask = FS_DELETE;
122
123 if (isdir)
124 mask |= FS_ISDIR;
125
126 fsnotify_parent(NULL, dentry, mask);
127}
128
129/*
130 * fsnotify_inoderemove - an inode is going away
131 */
132static inline void fsnotify_inoderemove(struct inode *inode)
133{
134 fsnotify(inode, FS_DELETE_SELF, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
135 __fsnotify_inode_delete(inode);
136}
137
138/*
139 * fsnotify_create - 'name' was linked in
140 */
141static inline void fsnotify_create(struct inode *inode, struct dentry *dentry)
142{
143 audit_inode_child(inode, dentry, AUDIT_TYPE_CHILD_CREATE);
144
145 fsnotify(inode, FS_CREATE, dentry->d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name, 0);
146}
147
148/*
149 * fsnotify_link - new hardlink in 'inode' directory
150 * Note: We have to pass also the linked inode ptr as some filesystems leave
151 * new_dentry->d_inode NULL and instantiate inode pointer later
152 */
153static inline void fsnotify_link(struct inode *dir, struct inode *inode, struct dentry *new_dentry)
154{
155 fsnotify_link_count(inode);
156 audit_inode_child(dir, new_dentry, AUDIT_TYPE_CHILD_CREATE);
157
158 fsnotify(dir, FS_CREATE, inode, FSNOTIFY_EVENT_INODE, new_dentry->d_name.name, 0);
159}
160
161/*
162 * fsnotify_mkdir - directory 'name' was created
163 */
164static inline void fsnotify_mkdir(struct inode *inode, struct dentry *dentry)
165{
166 __u32 mask = (FS_CREATE | FS_ISDIR);
167 struct inode *d_inode = dentry->d_inode;
168
169 audit_inode_child(inode, dentry, AUDIT_TYPE_CHILD_CREATE);
170
171 fsnotify(inode, mask, d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name, 0);
172}
173
174/*
175 * fsnotify_access - file was read
176 */
177static inline void fsnotify_access(struct file *file)
178{
179 const struct path *path = &file->f_path;
180 struct inode *inode = path->dentry->d_inode;
181 __u32 mask = FS_ACCESS;
182
183 if (S_ISDIR(inode->i_mode))
184 mask |= FS_ISDIR;
185
186 if (!(file->f_mode & FMODE_NONOTIFY)) {
187 fsnotify_parent(path, NULL, mask);
188 fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
189 }
190}
191
192/*
193 * fsnotify_modify - file was modified
194 */
195static inline void fsnotify_modify(struct file *file)
196{
197 const struct path *path = &file->f_path;
198 struct inode *inode = path->dentry->d_inode;
199 __u32 mask = FS_MODIFY;
200
201 if (S_ISDIR(inode->i_mode))
202 mask |= FS_ISDIR;
203
204 if (!(file->f_mode & FMODE_NONOTIFY)) {
205 fsnotify_parent(path, NULL, mask);
206 fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
207 }
208}
209
210/*
211 * fsnotify_open - file was opened
212 */
213static inline void fsnotify_open(struct file *file)
214{
215 const struct path *path = &file->f_path;
216 struct inode *inode = path->dentry->d_inode;
217 __u32 mask = FS_OPEN;
218
219 if (S_ISDIR(inode->i_mode))
220 mask |= FS_ISDIR;
221
222 fsnotify_parent(path, NULL, mask);
223 fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
224}
225
226/*
227 * fsnotify_close - file was closed
228 */
229static inline void fsnotify_close(struct file *file)
230{
231 const struct path *path = &file->f_path;
232 struct inode *inode = path->dentry->d_inode;
233 fmode_t mode = file->f_mode;
234 __u32 mask = (mode & FMODE_WRITE) ? FS_CLOSE_WRITE : FS_CLOSE_NOWRITE;
235
236 if (S_ISDIR(inode->i_mode))
237 mask |= FS_ISDIR;
238
239 if (!(file->f_mode & FMODE_NONOTIFY)) {
240 fsnotify_parent(path, NULL, mask);
241 fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
242 }
243}
244
245/*
246 * fsnotify_xattr - extended attributes were changed
247 */
248static inline void fsnotify_xattr(struct dentry *dentry)
249{
250 struct inode *inode = dentry->d_inode;
251 __u32 mask = FS_ATTRIB;
252
253 if (S_ISDIR(inode->i_mode))
254 mask |= FS_ISDIR;
255
256 fsnotify_parent(NULL, dentry, mask);
257 fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
258}
259
260/*
261 * fsnotify_change - notify_change event. file was modified and/or metadata
262 * was changed.
263 */
264static inline void fsnotify_change(struct dentry *dentry, unsigned int ia_valid)
265{
266 struct inode *inode = dentry->d_inode;
267 __u32 mask = 0;
268
269 if (ia_valid & ATTR_UID)
270 mask |= FS_ATTRIB;
271 if (ia_valid & ATTR_GID)
272 mask |= FS_ATTRIB;
273 if (ia_valid & ATTR_SIZE)
274 mask |= FS_MODIFY;
275
276 /* both times implies a utime(s) call */
277 if ((ia_valid & (ATTR_ATIME | ATTR_MTIME)) == (ATTR_ATIME | ATTR_MTIME))
278 mask |= FS_ATTRIB;
279 else if (ia_valid & ATTR_ATIME)
280 mask |= FS_ACCESS;
281 else if (ia_valid & ATTR_MTIME)
282 mask |= FS_MODIFY;
283
284 if (ia_valid & ATTR_MODE)
285 mask |= FS_ATTRIB;
286
287 if (mask) {
288 if (S_ISDIR(inode->i_mode))
289 mask |= FS_ISDIR;
290
291 fsnotify_parent(NULL, dentry, mask);
292 fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
293 }
294}
295
296#endif /* _LINUX_FS_NOTIFY_H */