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 a child directory entry. 22 * The directory entry may have turned positive or negative or its inode may 23 * have changed (i.e. renamed over). 24 * 25 * Unlike fsnotify_parent(), the event will be reported regardless of the 26 * FS_EVENT_ON_CHILD mask on the parent inode. 27 */ 28 static inline void fsnotify_name(struct inode *dir, __u32 mask, 29 struct inode *child, 30 const struct qstr *name, u32 cookie) 31 { 32 fsnotify(dir, mask, child, FSNOTIFY_EVENT_INODE, name, cookie); 33 /* 34 * Send another flavor of the event without child inode data and 35 * without the specific event type (e.g. FS_CREATE|FS_IS_DIR). 36 * The name is relative to the dir inode the event is reported to. 37 */ 38 fsnotify(dir, FS_DIR_MODIFY, dir, FSNOTIFY_EVENT_INODE, name, 0); 39 } 40 41 static inline void fsnotify_dirent(struct inode *dir, struct dentry *dentry, 42 __u32 mask) 43 { 44 fsnotify_name(dir, mask, d_inode(dentry), &dentry->d_name, 0); 45 } 46 47 /* 48 * Simple wrappers to consolidate calls fsnotify_parent()/fsnotify() when 49 * an event is on a file/dentry. 50 */ 51 static inline void fsnotify_dentry(struct dentry *dentry, __u32 mask) 52 { 53 struct inode *inode = d_inode(dentry); 54 55 if (S_ISDIR(inode->i_mode)) 56 mask |= FS_ISDIR; 57 58 fsnotify_parent(dentry, mask, inode, FSNOTIFY_EVENT_INODE); 59 fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0); 60 } 61 62 static inline int fsnotify_file(struct file *file, __u32 mask) 63 { 64 const struct path *path = &file->f_path; 65 struct inode *inode = file_inode(file); 66 int ret; 67 68 if (file->f_mode & FMODE_NONOTIFY) 69 return 0; 70 71 if (S_ISDIR(inode->i_mode)) 72 mask |= FS_ISDIR; 73 74 ret = fsnotify_parent(path->dentry, mask, path, FSNOTIFY_EVENT_PATH); 75 if (ret) 76 return ret; 77 78 return fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0); 79 } 80 81 /* Simple call site for access decisions */ 82 static inline int fsnotify_perm(struct file *file, int mask) 83 { 84 int ret; 85 __u32 fsnotify_mask = 0; 86 87 if (!(mask & (MAY_READ | MAY_OPEN))) 88 return 0; 89 90 if (mask & MAY_OPEN) { 91 fsnotify_mask = FS_OPEN_PERM; 92 93 if (file->f_flags & __FMODE_EXEC) { 94 ret = fsnotify_file(file, FS_OPEN_EXEC_PERM); 95 96 if (ret) 97 return ret; 98 } 99 } else if (mask & MAY_READ) { 100 fsnotify_mask = FS_ACCESS_PERM; 101 } 102 103 return fsnotify_file(file, fsnotify_mask); 104 } 105 106 /* 107 * fsnotify_link_count - inode's link count changed 108 */ 109 static inline void fsnotify_link_count(struct inode *inode) 110 { 111 __u32 mask = FS_ATTRIB; 112 113 if (S_ISDIR(inode->i_mode)) 114 mask |= FS_ISDIR; 115 116 fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0); 117 } 118 119 /* 120 * fsnotify_move - file old_name at old_dir was moved to new_name at new_dir 121 */ 122 static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir, 123 const struct qstr *old_name, 124 int isdir, struct inode *target, 125 struct dentry *moved) 126 { 127 struct inode *source = moved->d_inode; 128 u32 fs_cookie = fsnotify_get_cookie(); 129 __u32 old_dir_mask = FS_MOVED_FROM; 130 __u32 new_dir_mask = FS_MOVED_TO; 131 __u32 mask = FS_MOVE_SELF; 132 const struct qstr *new_name = &moved->d_name; 133 134 if (old_dir == new_dir) 135 old_dir_mask |= FS_DN_RENAME; 136 137 if (isdir) { 138 old_dir_mask |= FS_ISDIR; 139 new_dir_mask |= FS_ISDIR; 140 mask |= FS_ISDIR; 141 } 142 143 fsnotify_name(old_dir, old_dir_mask, source, old_name, fs_cookie); 144 fsnotify_name(new_dir, new_dir_mask, source, new_name, fs_cookie); 145 146 if (target) 147 fsnotify_link_count(target); 148 149 if (source) 150 fsnotify(source, mask, source, FSNOTIFY_EVENT_INODE, NULL, 0); 151 audit_inode_child(new_dir, moved, AUDIT_TYPE_CHILD_CREATE); 152 } 153 154 /* 155 * fsnotify_inode_delete - and inode is being evicted from cache, clean up is needed 156 */ 157 static inline void fsnotify_inode_delete(struct inode *inode) 158 { 159 __fsnotify_inode_delete(inode); 160 } 161 162 /* 163 * fsnotify_vfsmount_delete - a vfsmount is being destroyed, clean up is needed 164 */ 165 static inline void fsnotify_vfsmount_delete(struct vfsmount *mnt) 166 { 167 __fsnotify_vfsmount_delete(mnt); 168 } 169 170 /* 171 * fsnotify_inoderemove - an inode is going away 172 */ 173 static inline void fsnotify_inoderemove(struct inode *inode) 174 { 175 __u32 mask = FS_DELETE_SELF; 176 177 if (S_ISDIR(inode->i_mode)) 178 mask |= FS_ISDIR; 179 180 fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0); 181 __fsnotify_inode_delete(inode); 182 } 183 184 /* 185 * fsnotify_create - 'name' was linked in 186 */ 187 static inline void fsnotify_create(struct inode *inode, struct dentry *dentry) 188 { 189 audit_inode_child(inode, dentry, AUDIT_TYPE_CHILD_CREATE); 190 191 fsnotify_dirent(inode, dentry, FS_CREATE); 192 } 193 194 /* 195 * fsnotify_link - new hardlink in 'inode' directory 196 * Note: We have to pass also the linked inode ptr as some filesystems leave 197 * new_dentry->d_inode NULL and instantiate inode pointer later 198 */ 199 static inline void fsnotify_link(struct inode *dir, struct inode *inode, 200 struct dentry *new_dentry) 201 { 202 fsnotify_link_count(inode); 203 audit_inode_child(dir, new_dentry, AUDIT_TYPE_CHILD_CREATE); 204 205 fsnotify_name(dir, FS_CREATE, inode, &new_dentry->d_name, 0); 206 } 207 208 /* 209 * fsnotify_unlink - 'name' was unlinked 210 * 211 * Caller must make sure that dentry->d_name is stable. 212 */ 213 static inline void fsnotify_unlink(struct inode *dir, struct dentry *dentry) 214 { 215 /* Expected to be called before d_delete() */ 216 WARN_ON_ONCE(d_is_negative(dentry)); 217 218 fsnotify_dirent(dir, dentry, FS_DELETE); 219 } 220 221 /* 222 * fsnotify_mkdir - directory 'name' was created 223 */ 224 static inline void fsnotify_mkdir(struct inode *inode, struct dentry *dentry) 225 { 226 audit_inode_child(inode, dentry, AUDIT_TYPE_CHILD_CREATE); 227 228 fsnotify_dirent(inode, dentry, FS_CREATE | FS_ISDIR); 229 } 230 231 /* 232 * fsnotify_rmdir - directory 'name' was removed 233 * 234 * Caller must make sure that dentry->d_name is stable. 235 */ 236 static inline void fsnotify_rmdir(struct inode *dir, struct dentry *dentry) 237 { 238 /* Expected to be called before d_delete() */ 239 WARN_ON_ONCE(d_is_negative(dentry)); 240 241 fsnotify_dirent(dir, dentry, FS_DELETE | FS_ISDIR); 242 } 243 244 /* 245 * fsnotify_access - file was read 246 */ 247 static inline void fsnotify_access(struct file *file) 248 { 249 fsnotify_file(file, FS_ACCESS); 250 } 251 252 /* 253 * fsnotify_modify - file was modified 254 */ 255 static inline void fsnotify_modify(struct file *file) 256 { 257 fsnotify_file(file, FS_MODIFY); 258 } 259 260 /* 261 * fsnotify_open - file was opened 262 */ 263 static inline void fsnotify_open(struct file *file) 264 { 265 __u32 mask = FS_OPEN; 266 267 if (file->f_flags & __FMODE_EXEC) 268 mask |= FS_OPEN_EXEC; 269 270 fsnotify_file(file, mask); 271 } 272 273 /* 274 * fsnotify_close - file was closed 275 */ 276 static inline void fsnotify_close(struct file *file) 277 { 278 __u32 mask = (file->f_mode & FMODE_WRITE) ? FS_CLOSE_WRITE : 279 FS_CLOSE_NOWRITE; 280 281 fsnotify_file(file, mask); 282 } 283 284 /* 285 * fsnotify_xattr - extended attributes were changed 286 */ 287 static inline void fsnotify_xattr(struct dentry *dentry) 288 { 289 fsnotify_dentry(dentry, FS_ATTRIB); 290 } 291 292 /* 293 * fsnotify_change - notify_change event. file was modified and/or metadata 294 * was changed. 295 */ 296 static inline void fsnotify_change(struct dentry *dentry, unsigned int ia_valid) 297 { 298 __u32 mask = 0; 299 300 if (ia_valid & ATTR_UID) 301 mask |= FS_ATTRIB; 302 if (ia_valid & ATTR_GID) 303 mask |= FS_ATTRIB; 304 if (ia_valid & ATTR_SIZE) 305 mask |= FS_MODIFY; 306 307 /* both times implies a utime(s) call */ 308 if ((ia_valid & (ATTR_ATIME | ATTR_MTIME)) == (ATTR_ATIME | ATTR_MTIME)) 309 mask |= FS_ATTRIB; 310 else if (ia_valid & ATTR_ATIME) 311 mask |= FS_ACCESS; 312 else if (ia_valid & ATTR_MTIME) 313 mask |= FS_MODIFY; 314 315 if (ia_valid & ATTR_MODE) 316 mask |= FS_ATTRIB; 317 318 if (mask) 319 fsnotify_dentry(dentry, mask); 320 } 321 322 #endif /* _LINUX_FS_NOTIFY_H */ 323