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