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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 */
26static 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. */
34static 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 */
47static 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 */
58static 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 */
91static 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 */
104static 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 */
141static 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 */
149static 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 */
157static 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 */
171static 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 */
183static 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_mkdir - directory 'name' was created
193 */
194static inline void fsnotify_mkdir(struct inode *inode, struct dentry *dentry)
195{
196 audit_inode_child(inode, dentry, AUDIT_TYPE_CHILD_CREATE);
197
198 fsnotify_dirent(inode, dentry, FS_CREATE | FS_ISDIR);
199}
200
201/*
202 * fsnotify_access - file was read
203 */
204static inline void fsnotify_access(struct file *file)
205{
206 const struct path *path = &file->f_path;
207 struct inode *inode = file_inode(file);
208 __u32 mask = FS_ACCESS;
209
210 if (S_ISDIR(inode->i_mode))
211 mask |= FS_ISDIR;
212
213 if (!(file->f_mode & FMODE_NONOTIFY))
214 fsnotify_path(inode, path, mask);
215}
216
217/*
218 * fsnotify_modify - file was modified
219 */
220static inline void fsnotify_modify(struct file *file)
221{
222 const struct path *path = &file->f_path;
223 struct inode *inode = file_inode(file);
224 __u32 mask = FS_MODIFY;
225
226 if (S_ISDIR(inode->i_mode))
227 mask |= FS_ISDIR;
228
229 if (!(file->f_mode & FMODE_NONOTIFY))
230 fsnotify_path(inode, path, mask);
231}
232
233/*
234 * fsnotify_open - file was opened
235 */
236static inline void fsnotify_open(struct file *file)
237{
238 const struct path *path = &file->f_path;
239 struct inode *inode = file_inode(file);
240 __u32 mask = FS_OPEN;
241
242 if (S_ISDIR(inode->i_mode))
243 mask |= FS_ISDIR;
244 if (file->f_flags & __FMODE_EXEC)
245 mask |= FS_OPEN_EXEC;
246
247 fsnotify_path(inode, path, mask);
248}
249
250/*
251 * fsnotify_close - file was closed
252 */
253static inline void fsnotify_close(struct file *file)
254{
255 const struct path *path = &file->f_path;
256 struct inode *inode = file_inode(file);
257 fmode_t mode = file->f_mode;
258 __u32 mask = (mode & FMODE_WRITE) ? FS_CLOSE_WRITE : FS_CLOSE_NOWRITE;
259
260 if (S_ISDIR(inode->i_mode))
261 mask |= FS_ISDIR;
262
263 if (!(file->f_mode & FMODE_NONOTIFY))
264 fsnotify_path(inode, path, mask);
265}
266
267/*
268 * fsnotify_xattr - extended attributes were changed
269 */
270static inline void fsnotify_xattr(struct dentry *dentry)
271{
272 struct inode *inode = dentry->d_inode;
273 __u32 mask = FS_ATTRIB;
274
275 if (S_ISDIR(inode->i_mode))
276 mask |= FS_ISDIR;
277
278 fsnotify_parent(NULL, dentry, mask);
279 fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
280}
281
282/*
283 * fsnotify_change - notify_change event. file was modified and/or metadata
284 * was changed.
285 */
286static inline void fsnotify_change(struct dentry *dentry, unsigned int ia_valid)
287{
288 struct inode *inode = dentry->d_inode;
289 __u32 mask = 0;
290
291 if (ia_valid & ATTR_UID)
292 mask |= FS_ATTRIB;
293 if (ia_valid & ATTR_GID)
294 mask |= FS_ATTRIB;
295 if (ia_valid & ATTR_SIZE)
296 mask |= FS_MODIFY;
297
298 /* both times implies a utime(s) call */
299 if ((ia_valid & (ATTR_ATIME | ATTR_MTIME)) == (ATTR_ATIME | ATTR_MTIME))
300 mask |= FS_ATTRIB;
301 else if (ia_valid & ATTR_ATIME)
302 mask |= FS_ACCESS;
303 else if (ia_valid & ATTR_MTIME)
304 mask |= FS_MODIFY;
305
306 if (ia_valid & ATTR_MODE)
307 mask |= FS_ATTRIB;
308
309 if (mask) {
310 if (S_ISDIR(inode->i_mode))
311 mask |= FS_ISDIR;
312
313 fsnotify_parent(NULL, dentry, mask);
314 fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
315 }
316}
317
318#endif /* _LINUX_FS_NOTIFY_H */