1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_FS_NOTIFY_H
3 #define _LINUX_FS_NOTIFY_H
4
5 /*
6 * include/linux/fsnotify.h - generic hooks for filesystem notification, to
7 * reduce in-source duplication from both dnotify and inotify.
8 *
9 * We don't compile any of this away in some complicated menagerie of ifdefs.
10 * Instead, we rely on the code inside to optimize away as needed.
11 *
12 * (C) Copyright 2005 Robert Love
13 */
14
15 #include <linux/fsnotify_backend.h>
16 #include <linux/audit.h>
17 #include <linux/slab.h>
18 #include <linux/bug.h>
19
20 /*
21 * Notify this @dir inode about a change in the directory entry @dentry.
22 *
23 * Unlike fsnotify_parent(), the event will be reported regardless of the
24 * FS_EVENT_ON_CHILD mask on the parent inode.
25 */
fsnotify_dirent(struct inode * dir,struct dentry * dentry,__u32 mask)26 static inline int fsnotify_dirent(struct inode *dir, struct dentry *dentry,
27 __u32 mask)
28 {
29 return fsnotify(dir, mask, d_inode(dentry), FSNOTIFY_EVENT_INODE,
30 &dentry->d_name, 0);
31 }
32
33 /* Notify this dentry's parent about a child's events. */
fsnotify_parent(const struct path * path,struct dentry * dentry,__u32 mask)34 static inline int fsnotify_parent(const struct path *path,
35 struct dentry *dentry, __u32 mask)
36 {
37 if (!dentry)
38 dentry = path->dentry;
39
40 return __fsnotify_parent(path, dentry, mask);
41 }
42
43 /*
44 * Simple wrapper to consolidate calls fsnotify_parent()/fsnotify() when
45 * an event is on a path.
46 */
fsnotify_path(struct inode * inode,const struct path * path,__u32 mask)47 static inline int fsnotify_path(struct inode *inode, const struct path *path,
48 __u32 mask)
49 {
50 int ret = fsnotify_parent(path, NULL, mask);
51
52 if (ret)
53 return ret;
54 return fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
55 }
56
57 /* Simple call site for access decisions */
fsnotify_perm(struct file * file,int mask)58 static inline int fsnotify_perm(struct file *file, int mask)
59 {
60 int ret;
61 const struct path *path = &file->f_path;
62 struct inode *inode = file_inode(file);
63 __u32 fsnotify_mask = 0;
64
65 if (file->f_mode & FMODE_NONOTIFY)
66 return 0;
67 if (!(mask & (MAY_READ | MAY_OPEN)))
68 return 0;
69 if (mask & MAY_OPEN) {
70 fsnotify_mask = FS_OPEN_PERM;
71
72 if (file->f_flags & __FMODE_EXEC) {
73 ret = fsnotify_path(inode, path, FS_OPEN_EXEC_PERM);
74
75 if (ret)
76 return ret;
77 }
78 } else if (mask & MAY_READ) {
79 fsnotify_mask = FS_ACCESS_PERM;
80 }
81
82 if (S_ISDIR(inode->i_mode))
83 fsnotify_mask |= FS_ISDIR;
84
85 return fsnotify_path(inode, path, fsnotify_mask);
86 }
87
88 /*
89 * fsnotify_link_count - inode's link count changed
90 */
fsnotify_link_count(struct inode * inode)91 static inline void fsnotify_link_count(struct inode *inode)
92 {
93 __u32 mask = FS_ATTRIB;
94
95 if (S_ISDIR(inode->i_mode))
96 mask |= FS_ISDIR;
97
98 fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
99 }
100
101 /*
102 * fsnotify_move - file old_name at old_dir was moved to new_name at new_dir
103 */
fsnotify_move(struct inode * old_dir,struct inode * new_dir,const struct qstr * old_name,int isdir,struct inode * target,struct dentry * moved)104 static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir,
105 const struct qstr *old_name,
106 int isdir, struct inode *target,
107 struct dentry *moved)
108 {
109 struct inode *source = moved->d_inode;
110 u32 fs_cookie = fsnotify_get_cookie();
111 __u32 old_dir_mask = FS_MOVED_FROM;
112 __u32 new_dir_mask = FS_MOVED_TO;
113 __u32 mask = FS_MOVE_SELF;
114 const struct qstr *new_name = &moved->d_name;
115
116 if (old_dir == new_dir)
117 old_dir_mask |= FS_DN_RENAME;
118
119 if (isdir) {
120 old_dir_mask |= FS_ISDIR;
121 new_dir_mask |= FS_ISDIR;
122 mask |= FS_ISDIR;
123 }
124
125 fsnotify(old_dir, old_dir_mask, source, FSNOTIFY_EVENT_INODE, old_name,
126 fs_cookie);
127 fsnotify(new_dir, new_dir_mask, source, FSNOTIFY_EVENT_INODE, new_name,
128 fs_cookie);
129
130 if (target)
131 fsnotify_link_count(target);
132
133 if (source)
134 fsnotify(source, mask, source, FSNOTIFY_EVENT_INODE, NULL, 0);
135 audit_inode_child(new_dir, moved, AUDIT_TYPE_CHILD_CREATE);
136 }
137
138 /*
139 * fsnotify_inode_delete - and inode is being evicted from cache, clean up is needed
140 */
fsnotify_inode_delete(struct inode * inode)141 static inline void fsnotify_inode_delete(struct inode *inode)
142 {
143 __fsnotify_inode_delete(inode);
144 }
145
146 /*
147 * fsnotify_vfsmount_delete - a vfsmount is being destroyed, clean up is needed
148 */
fsnotify_vfsmount_delete(struct vfsmount * mnt)149 static inline void fsnotify_vfsmount_delete(struct vfsmount *mnt)
150 {
151 __fsnotify_vfsmount_delete(mnt);
152 }
153
154 /*
155 * fsnotify_inoderemove - an inode is going away
156 */
fsnotify_inoderemove(struct inode * inode)157 static inline void fsnotify_inoderemove(struct inode *inode)
158 {
159 __u32 mask = FS_DELETE_SELF;
160
161 if (S_ISDIR(inode->i_mode))
162 mask |= FS_ISDIR;
163
164 fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
165 __fsnotify_inode_delete(inode);
166 }
167
168 /*
169 * fsnotify_create - 'name' was linked in
170 */
fsnotify_create(struct inode * inode,struct dentry * dentry)171 static inline void fsnotify_create(struct inode *inode, struct dentry *dentry)
172 {
173 audit_inode_child(inode, dentry, AUDIT_TYPE_CHILD_CREATE);
174
175 fsnotify_dirent(inode, dentry, FS_CREATE);
176 }
177
178 /*
179 * fsnotify_link - new hardlink in 'inode' directory
180 * Note: We have to pass also the linked inode ptr as some filesystems leave
181 * new_dentry->d_inode NULL and instantiate inode pointer later
182 */
fsnotify_link(struct inode * dir,struct inode * inode,struct dentry * new_dentry)183 static inline void fsnotify_link(struct inode *dir, struct inode *inode, struct dentry *new_dentry)
184 {
185 fsnotify_link_count(inode);
186 audit_inode_child(dir, new_dentry, AUDIT_TYPE_CHILD_CREATE);
187
188 fsnotify(dir, FS_CREATE, inode, FSNOTIFY_EVENT_INODE, &new_dentry->d_name, 0);
189 }
190
191 /*
192 * fsnotify_unlink - 'name' was unlinked
193 *
194 * Caller must make sure that dentry->d_name is stable.
195 */
fsnotify_unlink(struct inode * dir,struct dentry * dentry)196 static inline void fsnotify_unlink(struct inode *dir, struct dentry *dentry)
197 {
198 /* Expected to be called before d_delete() */
199 WARN_ON_ONCE(d_is_negative(dentry));
200
201 fsnotify_dirent(dir, dentry, FS_DELETE);
202 }
203
204 /*
205 * fsnotify_mkdir - directory 'name' was created
206 */
fsnotify_mkdir(struct inode * inode,struct dentry * dentry)207 static inline void fsnotify_mkdir(struct inode *inode, struct dentry *dentry)
208 {
209 audit_inode_child(inode, dentry, AUDIT_TYPE_CHILD_CREATE);
210
211 fsnotify_dirent(inode, dentry, FS_CREATE | FS_ISDIR);
212 }
213
214 /*
215 * fsnotify_rmdir - directory 'name' was removed
216 *
217 * Caller must make sure that dentry->d_name is stable.
218 */
fsnotify_rmdir(struct inode * dir,struct dentry * dentry)219 static inline void fsnotify_rmdir(struct inode *dir, struct dentry *dentry)
220 {
221 /* Expected to be called before d_delete() */
222 WARN_ON_ONCE(d_is_negative(dentry));
223
224 fsnotify_dirent(dir, dentry, FS_DELETE | FS_ISDIR);
225 }
226
227 /*
228 * fsnotify_access - file was read
229 */
fsnotify_access(struct file * file)230 static inline void fsnotify_access(struct file *file)
231 {
232 const struct path *path = &file->f_path;
233 struct inode *inode = file_inode(file);
234 __u32 mask = FS_ACCESS;
235
236 if (S_ISDIR(inode->i_mode))
237 mask |= FS_ISDIR;
238
239 if (!(file->f_mode & FMODE_NONOTIFY))
240 fsnotify_path(inode, path, mask);
241 }
242
243 /*
244 * fsnotify_modify - file was modified
245 */
fsnotify_modify(struct file * file)246 static inline void fsnotify_modify(struct file *file)
247 {
248 const struct path *path = &file->f_path;
249 struct inode *inode = file_inode(file);
250 __u32 mask = FS_MODIFY;
251
252 if (S_ISDIR(inode->i_mode))
253 mask |= FS_ISDIR;
254
255 if (!(file->f_mode & FMODE_NONOTIFY))
256 fsnotify_path(inode, path, mask);
257 }
258
259 /*
260 * fsnotify_open - file was opened
261 */
fsnotify_open(struct file * file)262 static inline void fsnotify_open(struct file *file)
263 {
264 const struct path *path = &file->f_path;
265 struct inode *inode = file_inode(file);
266 __u32 mask = FS_OPEN;
267
268 if (S_ISDIR(inode->i_mode))
269 mask |= FS_ISDIR;
270 if (file->f_flags & __FMODE_EXEC)
271 mask |= FS_OPEN_EXEC;
272
273 fsnotify_path(inode, path, mask);
274 }
275
276 /*
277 * fsnotify_close - file was closed
278 */
fsnotify_close(struct file * file)279 static inline void fsnotify_close(struct file *file)
280 {
281 const struct path *path = &file->f_path;
282 struct inode *inode = file_inode(file);
283 fmode_t mode = file->f_mode;
284 __u32 mask = (mode & FMODE_WRITE) ? FS_CLOSE_WRITE : FS_CLOSE_NOWRITE;
285
286 if (S_ISDIR(inode->i_mode))
287 mask |= FS_ISDIR;
288
289 if (!(file->f_mode & FMODE_NONOTIFY))
290 fsnotify_path(inode, path, mask);
291 }
292
293 /*
294 * fsnotify_xattr - extended attributes were changed
295 */
fsnotify_xattr(struct dentry * dentry)296 static inline void fsnotify_xattr(struct dentry *dentry)
297 {
298 struct inode *inode = dentry->d_inode;
299 __u32 mask = FS_ATTRIB;
300
301 if (S_ISDIR(inode->i_mode))
302 mask |= FS_ISDIR;
303
304 fsnotify_parent(NULL, dentry, mask);
305 fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
306 }
307
308 /*
309 * fsnotify_change - notify_change event. file was modified and/or metadata
310 * was changed.
311 */
fsnotify_change(struct dentry * dentry,unsigned int ia_valid)312 static inline void fsnotify_change(struct dentry *dentry, unsigned int ia_valid)
313 {
314 struct inode *inode = dentry->d_inode;
315 __u32 mask = 0;
316
317 if (ia_valid & ATTR_UID)
318 mask |= FS_ATTRIB;
319 if (ia_valid & ATTR_GID)
320 mask |= FS_ATTRIB;
321 if (ia_valid & ATTR_SIZE)
322 mask |= FS_MODIFY;
323
324 /* both times implies a utime(s) call */
325 if ((ia_valid & (ATTR_ATIME | ATTR_MTIME)) == (ATTR_ATIME | ATTR_MTIME))
326 mask |= FS_ATTRIB;
327 else if (ia_valid & ATTR_ATIME)
328 mask |= FS_ACCESS;
329 else if (ia_valid & ATTR_MTIME)
330 mask |= FS_MODIFY;
331
332 if (ia_valid & ATTR_MODE)
333 mask |= FS_ATTRIB;
334
335 if (mask) {
336 if (S_ISDIR(inode->i_mode))
337 mask |= FS_ISDIR;
338
339 fsnotify_parent(NULL, dentry, mask);
340 fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
341 }
342 }
343
344 #endif /* _LINUX_FS_NOTIFY_H */
345
