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 /*
20 * fsnotify_d_instantiate - instantiate a dentry for inode
21 */
fsnotify_d_instantiate(struct dentry * dentry,struct inode * inode)22 static inline void fsnotify_d_instantiate(struct dentry *dentry,
23 struct inode *inode)
24 {
25 __fsnotify_d_instantiate(dentry, inode);
26 }
27
28 /* Notify this dentry's parent about a child's events. */
fsnotify_parent(struct path * path,struct dentry * dentry,__u32 mask)29 static inline int fsnotify_parent(struct path *path, struct dentry *dentry, __u32 mask)
30 {
31 if (!dentry)
32 dentry = path->dentry;
33
34 return __fsnotify_parent(path, dentry, mask);
35 }
36
37 /* simple call site for access decisions */
fsnotify_perm(struct file * file,int mask)38 static inline int fsnotify_perm(struct file *file, int mask)
39 {
40 struct path *path = &file->f_path;
41 struct inode *inode = path->dentry->d_inode;
42 __u32 fsnotify_mask = 0;
43 int ret;
44
45 if (file->f_mode & FMODE_NONOTIFY)
46 return 0;
47 if (!(mask & (MAY_READ | MAY_OPEN)))
48 return 0;
49 if (mask & MAY_OPEN)
50 fsnotify_mask = FS_OPEN_PERM;
51 else if (mask & MAY_READ)
52 fsnotify_mask = FS_ACCESS_PERM;
53 else
54 BUG();
55
56 ret = fsnotify_parent(path, NULL, fsnotify_mask);
57 if (ret)
58 return ret;
59
60 return fsnotify(inode, fsnotify_mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
61 }
62
63 /*
64 * fsnotify_d_move - dentry has been moved
65 */
fsnotify_d_move(struct dentry * dentry)66 static inline void fsnotify_d_move(struct dentry *dentry)
67 {
68 /*
69 * On move we need to update dentry->d_flags to indicate if the new parent
70 * cares about events from this dentry.
71 */
72 __fsnotify_update_dcache_flags(dentry);
73 }
74
75 /*
76 * fsnotify_link_count - inode's link count changed
77 */
fsnotify_link_count(struct inode * inode)78 static inline void fsnotify_link_count(struct inode *inode)
79 {
80 fsnotify(inode, FS_ATTRIB, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
81 }
82
83 /*
84 * fsnotify_move - file old_name at old_dir was moved to new_name at new_dir
85 */
fsnotify_move(struct inode * old_dir,struct inode * new_dir,const unsigned char * old_name,int isdir,struct inode * target,struct dentry * moved)86 static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir,
87 const unsigned char *old_name,
88 int isdir, struct inode *target, struct dentry *moved)
89 {
90 struct inode *source = moved->d_inode;
91 u32 fs_cookie = fsnotify_get_cookie();
92 __u32 old_dir_mask = (FS_EVENT_ON_CHILD | FS_MOVED_FROM);
93 __u32 new_dir_mask = (FS_EVENT_ON_CHILD | FS_MOVED_TO);
94 const unsigned char *new_name = moved->d_name.name;
95
96 if (old_dir == new_dir)
97 old_dir_mask |= FS_DN_RENAME;
98
99 if (isdir) {
100 old_dir_mask |= FS_ISDIR;
101 new_dir_mask |= FS_ISDIR;
102 }
103
104 fsnotify(old_dir, old_dir_mask, old_dir, FSNOTIFY_EVENT_INODE, old_name, fs_cookie);
105 fsnotify(new_dir, new_dir_mask, new_dir, FSNOTIFY_EVENT_INODE, new_name, fs_cookie);
106
107 if (target)
108 fsnotify_link_count(target);
109
110 if (source)
111 fsnotify(source, FS_MOVE_SELF, moved->d_inode, FSNOTIFY_EVENT_INODE, NULL, 0);
112 audit_inode_child(moved, new_dir);
113 }
114
115 /*
116 * fsnotify_inode_delete - and inode is being evicted from cache, clean up is needed
117 */
fsnotify_inode_delete(struct inode * inode)118 static inline void fsnotify_inode_delete(struct inode *inode)
119 {
120 __fsnotify_inode_delete(inode);
121 }
122
123 /*
124 * fsnotify_vfsmount_delete - a vfsmount is being destroyed, clean up is needed
125 */
fsnotify_vfsmount_delete(struct vfsmount * mnt)126 static inline void fsnotify_vfsmount_delete(struct vfsmount *mnt)
127 {
128 __fsnotify_vfsmount_delete(mnt);
129 }
130
131 /*
132 * fsnotify_nameremove - a filename was removed from a directory
133 */
fsnotify_nameremove(struct dentry * dentry,int isdir)134 static inline void fsnotify_nameremove(struct dentry *dentry, int isdir)
135 {
136 __u32 mask = FS_DELETE;
137
138 if (isdir)
139 mask |= FS_ISDIR;
140
141 fsnotify_parent(NULL, dentry, mask);
142 }
143
144 /*
145 * fsnotify_inoderemove - an inode is going away
146 */
fsnotify_inoderemove(struct inode * inode)147 static inline void fsnotify_inoderemove(struct inode *inode)
148 {
149 fsnotify(inode, FS_DELETE_SELF, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
150 __fsnotify_inode_delete(inode);
151 }
152
153 /*
154 * fsnotify_create - 'name' was linked in
155 */
fsnotify_create(struct inode * inode,struct dentry * dentry)156 static inline void fsnotify_create(struct inode *inode, struct dentry *dentry)
157 {
158 audit_inode_child(dentry, inode);
159
160 fsnotify(inode, FS_CREATE, dentry->d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name, 0);
161 }
162
163 /*
164 * fsnotify_link - new hardlink in 'inode' directory
165 * Note: We have to pass also the linked inode ptr as some filesystems leave
166 * new_dentry->d_inode NULL and instantiate inode pointer later
167 */
fsnotify_link(struct inode * dir,struct inode * inode,struct dentry * new_dentry)168 static inline void fsnotify_link(struct inode *dir, struct inode *inode, struct dentry *new_dentry)
169 {
170 fsnotify_link_count(inode);
171 audit_inode_child(new_dentry, dir);
172
173 fsnotify(dir, FS_CREATE, inode, FSNOTIFY_EVENT_INODE, new_dentry->d_name.name, 0);
174 }
175
176 /*
177 * fsnotify_mkdir - directory 'name' was created
178 */
fsnotify_mkdir(struct inode * inode,struct dentry * dentry)179 static inline void fsnotify_mkdir(struct inode *inode, struct dentry *dentry)
180 {
181 __u32 mask = (FS_CREATE | FS_ISDIR);
182 struct inode *d_inode = dentry->d_inode;
183
184 audit_inode_child(dentry, inode);
185
186 fsnotify(inode, mask, d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name, 0);
187 }
188
189 /*
190 * fsnotify_access - file was read
191 */
fsnotify_access(struct file * file)192 static inline void fsnotify_access(struct file *file)
193 {
194 struct path *path = &file->f_path;
195 struct inode *inode = path->dentry->d_inode;
196 __u32 mask = FS_ACCESS;
197
198 if (S_ISDIR(inode->i_mode))
199 mask |= FS_ISDIR;
200
201 if (!(file->f_mode & FMODE_NONOTIFY)) {
202 fsnotify_parent(path, NULL, mask);
203 fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
204 }
205 }
206
207 /*
208 * fsnotify_modify - file was modified
209 */
fsnotify_modify(struct file * file)210 static inline void fsnotify_modify(struct file *file)
211 {
212 struct path *path = &file->f_path;
213 struct inode *inode = path->dentry->d_inode;
214 __u32 mask = FS_MODIFY;
215
216 if (S_ISDIR(inode->i_mode))
217 mask |= FS_ISDIR;
218
219 if (!(file->f_mode & FMODE_NONOTIFY)) {
220 fsnotify_parent(path, NULL, mask);
221 fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
222 }
223 }
224
225 /*
226 * fsnotify_open - file was opened
227 */
fsnotify_open(struct file * file)228 static inline void fsnotify_open(struct file *file)
229 {
230 struct path *path = &file->f_path;
231 struct inode *inode = path->dentry->d_inode;
232 __u32 mask = FS_OPEN;
233
234 if (S_ISDIR(inode->i_mode))
235 mask |= FS_ISDIR;
236
237 fsnotify_parent(path, NULL, mask);
238 fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
239 }
240
241 /*
242 * fsnotify_close - file was closed
243 */
fsnotify_close(struct file * file)244 static inline void fsnotify_close(struct file *file)
245 {
246 struct path *path = &file->f_path;
247 struct inode *inode = file->f_path.dentry->d_inode;
248 fmode_t mode = file->f_mode;
249 __u32 mask = (mode & FMODE_WRITE) ? FS_CLOSE_WRITE : FS_CLOSE_NOWRITE;
250
251 if (S_ISDIR(inode->i_mode))
252 mask |= FS_ISDIR;
253
254 if (!(file->f_mode & FMODE_NONOTIFY)) {
255 fsnotify_parent(path, NULL, mask);
256 fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
257 }
258 }
259
260 /*
261 * fsnotify_xattr - extended attributes were changed
262 */
fsnotify_xattr(struct dentry * dentry)263 static inline void fsnotify_xattr(struct dentry *dentry)
264 {
265 struct inode *inode = dentry->d_inode;
266 __u32 mask = FS_ATTRIB;
267
268 if (S_ISDIR(inode->i_mode))
269 mask |= FS_ISDIR;
270
271 fsnotify_parent(NULL, dentry, mask);
272 fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
273 }
274
275 /*
276 * fsnotify_change - notify_change event. file was modified and/or metadata
277 * was changed.
278 */
fsnotify_change(struct dentry * dentry,unsigned int ia_valid)279 static inline void fsnotify_change(struct dentry *dentry, unsigned int ia_valid)
280 {
281 struct inode *inode = dentry->d_inode;
282 __u32 mask = 0;
283
284 if (ia_valid & ATTR_UID)
285 mask |= FS_ATTRIB;
286 if (ia_valid & ATTR_GID)
287 mask |= FS_ATTRIB;
288 if (ia_valid & ATTR_SIZE)
289 mask |= FS_MODIFY;
290
291 /* both times implies a utime(s) call */
292 if ((ia_valid & (ATTR_ATIME | ATTR_MTIME)) == (ATTR_ATIME | ATTR_MTIME))
293 mask |= FS_ATTRIB;
294 else if (ia_valid & ATTR_ATIME)
295 mask |= FS_ACCESS;
296 else if (ia_valid & ATTR_MTIME)
297 mask |= FS_MODIFY;
298
299 if (ia_valid & ATTR_MODE)
300 mask |= FS_ATTRIB;
301
302 if (mask) {
303 if (S_ISDIR(inode->i_mode))
304 mask |= FS_ISDIR;
305
306 fsnotify_parent(NULL, dentry, mask);
307 fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
308 }
309 }
310
311 #if defined(CONFIG_FSNOTIFY) /* notify helpers */
312
313 /*
314 * fsnotify_oldname_init - save off the old filename before we change it
315 */
fsnotify_oldname_init(const unsigned char * name)316 static inline const unsigned char *fsnotify_oldname_init(const unsigned char *name)
317 {
318 return kstrdup(name, GFP_KERNEL);
319 }
320
321 /*
322 * fsnotify_oldname_free - free the name we got from fsnotify_oldname_init
323 */
fsnotify_oldname_free(const unsigned char * old_name)324 static inline void fsnotify_oldname_free(const unsigned char *old_name)
325 {
326 kfree(old_name);
327 }
328
329 #else /* CONFIG_FSNOTIFY */
330
fsnotify_oldname_init(const unsigned char * name)331 static inline const char *fsnotify_oldname_init(const unsigned char *name)
332 {
333 return NULL;
334 }
335
fsnotify_oldname_free(const unsigned char * old_name)336 static inline void fsnotify_oldname_free(const unsigned char *old_name)
337 {
338 }
339
340 #endif /* CONFIG_FSNOTIFY */
341
342 #endif /* _LINUX_FS_NOTIFY_H */
343