xref: /linux-6.15/include/linux/fsnotify.h (revision a115bc07)
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/dnotify.h>
15 #include <linux/inotify.h>
16 #include <linux/fsnotify_backend.h>
17 #include <linux/audit.h>
18 
19 /*
20  * fsnotify_d_instantiate - instantiate a dentry for inode
21  * Called with dcache_lock held.
22  */
23 static inline void fsnotify_d_instantiate(struct dentry *entry,
24 						struct inode *inode)
25 {
26 	__fsnotify_d_instantiate(entry, inode);
27 
28 	inotify_d_instantiate(entry, inode);
29 }
30 
31 /* Notify this dentry's parent about a child's events. */
32 static inline void fsnotify_parent(struct dentry *dentry, __u32 mask)
33 {
34 	__fsnotify_parent(dentry, mask);
35 
36 	inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name);
37 }
38 
39 /*
40  * fsnotify_d_move - entry has been moved
41  * Called with dcache_lock and entry->d_lock held.
42  */
43 static inline void fsnotify_d_move(struct dentry *entry)
44 {
45 	/*
46 	 * On move we need to update entry->d_flags to indicate if the new parent
47 	 * cares about events from this entry.
48 	 */
49 	__fsnotify_update_dcache_flags(entry);
50 
51 	inotify_d_move(entry);
52 }
53 
54 /*
55  * fsnotify_link_count - inode's link count changed
56  */
57 static inline void fsnotify_link_count(struct inode *inode)
58 {
59 	inotify_inode_queue_event(inode, IN_ATTRIB, 0, NULL, NULL);
60 
61 	fsnotify(inode, FS_ATTRIB, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
62 }
63 
64 /*
65  * fsnotify_move - file old_name at old_dir was moved to new_name at new_dir
66  */
67 static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir,
68 				 const char *old_name,
69 				 int isdir, struct inode *target, struct dentry *moved)
70 {
71 	struct inode *source = moved->d_inode;
72 	u32 in_cookie = inotify_get_cookie();
73 	u32 fs_cookie = fsnotify_get_cookie();
74 	__u32 old_dir_mask = (FS_EVENT_ON_CHILD | FS_MOVED_FROM);
75 	__u32 new_dir_mask = (FS_EVENT_ON_CHILD | FS_MOVED_TO);
76 	const char *new_name = moved->d_name.name;
77 
78 	if (old_dir == new_dir)
79 		old_dir_mask |= FS_DN_RENAME;
80 
81 	if (isdir) {
82 		isdir = IN_ISDIR;
83 		old_dir_mask |= FS_IN_ISDIR;
84 		new_dir_mask |= FS_IN_ISDIR;
85 	}
86 
87 	inotify_inode_queue_event(old_dir, IN_MOVED_FROM|isdir, in_cookie, old_name,
88 				  source);
89 	inotify_inode_queue_event(new_dir, IN_MOVED_TO|isdir, in_cookie, new_name,
90 				  source);
91 
92 	fsnotify(old_dir, old_dir_mask, old_dir, FSNOTIFY_EVENT_INODE, old_name, fs_cookie);
93 	fsnotify(new_dir, new_dir_mask, new_dir, FSNOTIFY_EVENT_INODE, new_name, fs_cookie);
94 
95 	if (target) {
96 		inotify_inode_queue_event(target, IN_DELETE_SELF, 0, NULL, NULL);
97 		inotify_inode_is_dead(target);
98 
99 		/* this is really a link_count change not a removal */
100 		fsnotify_link_count(target);
101 	}
102 
103 	if (source) {
104 		inotify_inode_queue_event(source, IN_MOVE_SELF, 0, NULL, NULL);
105 		fsnotify(source, FS_MOVE_SELF, moved->d_inode, FSNOTIFY_EVENT_INODE, NULL, 0);
106 	}
107 	audit_inode_child(moved, new_dir);
108 }
109 
110 /*
111  * fsnotify_inode_delete - and inode is being evicted from cache, clean up is needed
112  */
113 static inline void fsnotify_inode_delete(struct inode *inode)
114 {
115 	__fsnotify_inode_delete(inode);
116 }
117 
118 /*
119  * fsnotify_nameremove - a filename was removed from a directory
120  */
121 static inline void fsnotify_nameremove(struct dentry *dentry, int isdir)
122 {
123 	__u32 mask = FS_DELETE;
124 
125 	if (isdir)
126 		mask |= FS_IN_ISDIR;
127 
128 	fsnotify_parent(dentry, mask);
129 }
130 
131 /*
132  * fsnotify_inoderemove - an inode is going away
133  */
134 static inline void fsnotify_inoderemove(struct inode *inode)
135 {
136 	inotify_inode_queue_event(inode, IN_DELETE_SELF, 0, NULL, NULL);
137 	inotify_inode_is_dead(inode);
138 
139 	fsnotify(inode, FS_DELETE_SELF, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
140 	__fsnotify_inode_delete(inode);
141 }
142 
143 /*
144  * fsnotify_create - 'name' was linked in
145  */
146 static inline void fsnotify_create(struct inode *inode, struct dentry *dentry)
147 {
148 	inotify_inode_queue_event(inode, IN_CREATE, 0, dentry->d_name.name,
149 				  dentry->d_inode);
150 	audit_inode_child(dentry, inode);
151 
152 	fsnotify(inode, FS_CREATE, dentry->d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name, 0);
153 }
154 
155 /*
156  * fsnotify_link - new hardlink in 'inode' directory
157  * Note: We have to pass also the linked inode ptr as some filesystems leave
158  *   new_dentry->d_inode NULL and instantiate inode pointer later
159  */
160 static inline void fsnotify_link(struct inode *dir, struct inode *inode, struct dentry *new_dentry)
161 {
162 	inotify_inode_queue_event(dir, IN_CREATE, 0, new_dentry->d_name.name,
163 				  inode);
164 	fsnotify_link_count(inode);
165 	audit_inode_child(new_dentry, dir);
166 
167 	fsnotify(dir, FS_CREATE, inode, FSNOTIFY_EVENT_INODE, new_dentry->d_name.name, 0);
168 }
169 
170 /*
171  * fsnotify_mkdir - directory 'name' was created
172  */
173 static inline void fsnotify_mkdir(struct inode *inode, struct dentry *dentry)
174 {
175 	__u32 mask = (FS_CREATE | FS_IN_ISDIR);
176 	struct inode *d_inode = dentry->d_inode;
177 
178 	inotify_inode_queue_event(inode, mask, 0, dentry->d_name.name, d_inode);
179 	audit_inode_child(dentry, inode);
180 
181 	fsnotify(inode, mask, d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name, 0);
182 }
183 
184 /*
185  * fsnotify_access - file was read
186  */
187 static inline void fsnotify_access(struct dentry *dentry)
188 {
189 	struct inode *inode = dentry->d_inode;
190 	__u32 mask = FS_ACCESS;
191 
192 	if (S_ISDIR(inode->i_mode))
193 		mask |= FS_IN_ISDIR;
194 
195 	inotify_inode_queue_event(inode, mask, 0, NULL, NULL);
196 
197 	fsnotify_parent(dentry, mask);
198 	fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
199 }
200 
201 /*
202  * fsnotify_modify - file was modified
203  */
204 static inline void fsnotify_modify(struct dentry *dentry)
205 {
206 	struct inode *inode = dentry->d_inode;
207 	__u32 mask = FS_MODIFY;
208 
209 	if (S_ISDIR(inode->i_mode))
210 		mask |= FS_IN_ISDIR;
211 
212 	inotify_inode_queue_event(inode, mask, 0, NULL, NULL);
213 
214 	fsnotify_parent(dentry, mask);
215 	fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
216 }
217 
218 /*
219  * fsnotify_open - file was opened
220  */
221 static inline void fsnotify_open(struct dentry *dentry)
222 {
223 	struct inode *inode = dentry->d_inode;
224 	__u32 mask = FS_OPEN;
225 
226 	if (S_ISDIR(inode->i_mode))
227 		mask |= FS_IN_ISDIR;
228 
229 	inotify_inode_queue_event(inode, mask, 0, NULL, NULL);
230 
231 	fsnotify_parent(dentry, mask);
232 	fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
233 }
234 
235 /*
236  * fsnotify_close - file was closed
237  */
238 static inline void fsnotify_close(struct file *file)
239 {
240 	struct dentry *dentry = file->f_path.dentry;
241 	struct inode *inode = dentry->d_inode;
242 	fmode_t mode = file->f_mode;
243 	__u32 mask = (mode & FMODE_WRITE) ? FS_CLOSE_WRITE : FS_CLOSE_NOWRITE;
244 
245 	if (S_ISDIR(inode->i_mode))
246 		mask |= FS_IN_ISDIR;
247 
248 	inotify_inode_queue_event(inode, mask, 0, NULL, NULL);
249 
250 	fsnotify_parent(dentry, mask);
251 	fsnotify(inode, mask, file, FSNOTIFY_EVENT_FILE, NULL, 0);
252 }
253 
254 /*
255  * fsnotify_xattr - extended attributes were changed
256  */
257 static inline void fsnotify_xattr(struct dentry *dentry)
258 {
259 	struct inode *inode = dentry->d_inode;
260 	__u32 mask = FS_ATTRIB;
261 
262 	if (S_ISDIR(inode->i_mode))
263 		mask |= FS_IN_ISDIR;
264 
265 	inotify_inode_queue_event(inode, mask, 0, NULL, NULL);
266 
267 	fsnotify_parent(dentry, mask);
268 	fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
269 }
270 
271 /*
272  * fsnotify_change - notify_change event.  file was modified and/or metadata
273  * was changed.
274  */
275 static inline void fsnotify_change(struct dentry *dentry, unsigned int ia_valid)
276 {
277 	struct inode *inode = dentry->d_inode;
278 	__u32 mask = 0;
279 
280 	if (ia_valid & ATTR_UID)
281 		mask |= FS_ATTRIB;
282 	if (ia_valid & ATTR_GID)
283 		mask |= FS_ATTRIB;
284 	if (ia_valid & ATTR_SIZE)
285 		mask |= FS_MODIFY;
286 
287 	/* both times implies a utime(s) call */
288 	if ((ia_valid & (ATTR_ATIME | ATTR_MTIME)) == (ATTR_ATIME | ATTR_MTIME))
289 		mask |= FS_ATTRIB;
290 	else if (ia_valid & ATTR_ATIME)
291 		mask |= FS_ACCESS;
292 	else if (ia_valid & ATTR_MTIME)
293 		mask |= FS_MODIFY;
294 
295 	if (ia_valid & ATTR_MODE)
296 		mask |= FS_ATTRIB;
297 
298 	if (mask) {
299 		if (S_ISDIR(inode->i_mode))
300 			mask |= FS_IN_ISDIR;
301 		inotify_inode_queue_event(inode, mask, 0, NULL, NULL);
302 
303 		fsnotify_parent(dentry, mask);
304 		fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
305 	}
306 }
307 
308 #if defined(CONFIG_INOTIFY) || defined(CONFIG_FSNOTIFY)	/* notify helpers */
309 
310 /*
311  * fsnotify_oldname_init - save off the old filename before we change it
312  */
313 static inline const char *fsnotify_oldname_init(const char *name)
314 {
315 	return kstrdup(name, GFP_KERNEL);
316 }
317 
318 /*
319  * fsnotify_oldname_free - free the name we got from fsnotify_oldname_init
320  */
321 static inline void fsnotify_oldname_free(const char *old_name)
322 {
323 	kfree(old_name);
324 }
325 
326 #else	/* CONFIG_INOTIFY || CONFIG_FSNOTIFY */
327 
328 static inline const char *fsnotify_oldname_init(const char *name)
329 {
330 	return NULL;
331 }
332 
333 static inline void fsnotify_oldname_free(const char *old_name)
334 {
335 }
336 
337 #endif	/* ! CONFIG_INOTIFY */
338 
339 #endif	/* _LINUX_FS_NOTIFY_H */
340