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 18 /* 19 * fsnotify_d_instantiate - instantiate a dentry for inode 20 * Called with dcache_lock held. 21 */ 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. */ 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 */ 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 * Called with dcache_lock and dentry->d_lock held. 66 */ 67 static inline void fsnotify_d_move(struct dentry *dentry) 68 { 69 /* 70 * On move we need to update dentry->d_flags to indicate if the new parent 71 * cares about events from this dentry. 72 */ 73 __fsnotify_update_dcache_flags(dentry); 74 } 75 76 /* 77 * fsnotify_link_count - inode's link count changed 78 */ 79 static inline void fsnotify_link_count(struct inode *inode) 80 { 81 fsnotify(inode, FS_ATTRIB, inode, FSNOTIFY_EVENT_INODE, NULL, 0); 82 } 83 84 /* 85 * fsnotify_move - file old_name at old_dir was moved to new_name at new_dir 86 */ 87 static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir, 88 const unsigned char *old_name, 89 int isdir, struct inode *target, struct dentry *moved) 90 { 91 struct inode *source = moved->d_inode; 92 u32 fs_cookie = fsnotify_get_cookie(); 93 __u32 old_dir_mask = (FS_EVENT_ON_CHILD | FS_MOVED_FROM); 94 __u32 new_dir_mask = (FS_EVENT_ON_CHILD | FS_MOVED_TO); 95 const unsigned char *new_name = moved->d_name.name; 96 97 if (old_dir == new_dir) 98 old_dir_mask |= FS_DN_RENAME; 99 100 if (isdir) { 101 old_dir_mask |= FS_ISDIR; 102 new_dir_mask |= FS_ISDIR; 103 } 104 105 fsnotify(old_dir, old_dir_mask, old_dir, FSNOTIFY_EVENT_INODE, old_name, fs_cookie); 106 fsnotify(new_dir, new_dir_mask, new_dir, FSNOTIFY_EVENT_INODE, new_name, fs_cookie); 107 108 if (target) 109 fsnotify_link_count(target); 110 111 if (source) 112 fsnotify(source, FS_MOVE_SELF, moved->d_inode, FSNOTIFY_EVENT_INODE, NULL, 0); 113 audit_inode_child(moved, new_dir); 114 } 115 116 /* 117 * fsnotify_inode_delete - and inode is being evicted from cache, clean up is needed 118 */ 119 static inline void fsnotify_inode_delete(struct inode *inode) 120 { 121 __fsnotify_inode_delete(inode); 122 } 123 124 /* 125 * fsnotify_vfsmount_delete - a vfsmount is being destroyed, clean up is needed 126 */ 127 static inline void fsnotify_vfsmount_delete(struct vfsmount *mnt) 128 { 129 __fsnotify_vfsmount_delete(mnt); 130 } 131 132 /* 133 * fsnotify_nameremove - a filename was removed from a directory 134 */ 135 static inline void fsnotify_nameremove(struct dentry *dentry, int isdir) 136 { 137 __u32 mask = FS_DELETE; 138 139 if (isdir) 140 mask |= FS_ISDIR; 141 142 fsnotify_parent(NULL, dentry, mask); 143 } 144 145 /* 146 * fsnotify_inoderemove - an inode is going away 147 */ 148 static inline void fsnotify_inoderemove(struct inode *inode) 149 { 150 fsnotify(inode, FS_DELETE_SELF, inode, FSNOTIFY_EVENT_INODE, NULL, 0); 151 __fsnotify_inode_delete(inode); 152 } 153 154 /* 155 * fsnotify_create - 'name' was linked in 156 */ 157 static inline void fsnotify_create(struct inode *inode, struct dentry *dentry) 158 { 159 audit_inode_child(dentry, inode); 160 161 fsnotify(inode, FS_CREATE, dentry->d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name, 0); 162 } 163 164 /* 165 * fsnotify_link - new hardlink in 'inode' directory 166 * Note: We have to pass also the linked inode ptr as some filesystems leave 167 * new_dentry->d_inode NULL and instantiate inode pointer later 168 */ 169 static inline void fsnotify_link(struct inode *dir, struct inode *inode, struct dentry *new_dentry) 170 { 171 fsnotify_link_count(inode); 172 audit_inode_child(new_dentry, dir); 173 174 fsnotify(dir, FS_CREATE, inode, FSNOTIFY_EVENT_INODE, new_dentry->d_name.name, 0); 175 } 176 177 /* 178 * fsnotify_mkdir - directory 'name' was created 179 */ 180 static inline void fsnotify_mkdir(struct inode *inode, struct dentry *dentry) 181 { 182 __u32 mask = (FS_CREATE | FS_ISDIR); 183 struct inode *d_inode = dentry->d_inode; 184 185 audit_inode_child(dentry, inode); 186 187 fsnotify(inode, mask, d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name, 0); 188 } 189 190 /* 191 * fsnotify_access - file was read 192 */ 193 static inline void fsnotify_access(struct file *file) 194 { 195 struct path *path = &file->f_path; 196 struct inode *inode = path->dentry->d_inode; 197 __u32 mask = FS_ACCESS; 198 199 if (S_ISDIR(inode->i_mode)) 200 mask |= FS_ISDIR; 201 202 if (!(file->f_mode & FMODE_NONOTIFY)) { 203 fsnotify_parent(path, NULL, mask); 204 fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0); 205 } 206 } 207 208 /* 209 * fsnotify_modify - file was modified 210 */ 211 static inline void fsnotify_modify(struct file *file) 212 { 213 struct path *path = &file->f_path; 214 struct inode *inode = path->dentry->d_inode; 215 __u32 mask = FS_MODIFY; 216 217 if (S_ISDIR(inode->i_mode)) 218 mask |= FS_ISDIR; 219 220 if (!(file->f_mode & FMODE_NONOTIFY)) { 221 fsnotify_parent(path, NULL, mask); 222 fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0); 223 } 224 } 225 226 /* 227 * fsnotify_open - file was opened 228 */ 229 static inline void fsnotify_open(struct file *file) 230 { 231 struct path *path = &file->f_path; 232 struct inode *inode = path->dentry->d_inode; 233 __u32 mask = FS_OPEN; 234 235 if (S_ISDIR(inode->i_mode)) 236 mask |= FS_ISDIR; 237 238 /* FMODE_NONOTIFY must never be set from user */ 239 file->f_mode &= ~FMODE_NONOTIFY; 240 241 fsnotify_parent(path, NULL, mask); 242 fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0); 243 } 244 245 /* 246 * fsnotify_close - file was closed 247 */ 248 static inline void fsnotify_close(struct file *file) 249 { 250 struct path *path = &file->f_path; 251 struct inode *inode = file->f_path.dentry->d_inode; 252 fmode_t mode = file->f_mode; 253 __u32 mask = (mode & FMODE_WRITE) ? FS_CLOSE_WRITE : FS_CLOSE_NOWRITE; 254 255 if (S_ISDIR(inode->i_mode)) 256 mask |= FS_ISDIR; 257 258 if (!(file->f_mode & FMODE_NONOTIFY)) { 259 fsnotify_parent(path, NULL, mask); 260 fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0); 261 } 262 } 263 264 /* 265 * fsnotify_xattr - extended attributes were changed 266 */ 267 static inline void fsnotify_xattr(struct dentry *dentry) 268 { 269 struct inode *inode = dentry->d_inode; 270 __u32 mask = FS_ATTRIB; 271 272 if (S_ISDIR(inode->i_mode)) 273 mask |= FS_ISDIR; 274 275 fsnotify_parent(NULL, dentry, mask); 276 fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0); 277 } 278 279 /* 280 * fsnotify_change - notify_change event. file was modified and/or metadata 281 * was changed. 282 */ 283 static inline void fsnotify_change(struct dentry *dentry, unsigned int ia_valid) 284 { 285 struct inode *inode = dentry->d_inode; 286 __u32 mask = 0; 287 288 if (ia_valid & ATTR_UID) 289 mask |= FS_ATTRIB; 290 if (ia_valid & ATTR_GID) 291 mask |= FS_ATTRIB; 292 if (ia_valid & ATTR_SIZE) 293 mask |= FS_MODIFY; 294 295 /* both times implies a utime(s) call */ 296 if ((ia_valid & (ATTR_ATIME | ATTR_MTIME)) == (ATTR_ATIME | ATTR_MTIME)) 297 mask |= FS_ATTRIB; 298 else if (ia_valid & ATTR_ATIME) 299 mask |= FS_ACCESS; 300 else if (ia_valid & ATTR_MTIME) 301 mask |= FS_MODIFY; 302 303 if (ia_valid & ATTR_MODE) 304 mask |= FS_ATTRIB; 305 306 if (mask) { 307 if (S_ISDIR(inode->i_mode)) 308 mask |= FS_ISDIR; 309 310 fsnotify_parent(NULL, dentry, mask); 311 fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0); 312 } 313 } 314 315 #if defined(CONFIG_FSNOTIFY) /* notify helpers */ 316 317 /* 318 * fsnotify_oldname_init - save off the old filename before we change it 319 */ 320 static inline const unsigned char *fsnotify_oldname_init(const unsigned char *name) 321 { 322 return kstrdup(name, GFP_KERNEL); 323 } 324 325 /* 326 * fsnotify_oldname_free - free the name we got from fsnotify_oldname_init 327 */ 328 static inline void fsnotify_oldname_free(const unsigned char *old_name) 329 { 330 kfree(old_name); 331 } 332 333 #else /* CONFIG_FSNOTIFY */ 334 335 static inline const char *fsnotify_oldname_init(const unsigned char *name) 336 { 337 return NULL; 338 } 339 340 static inline void fsnotify_oldname_free(const unsigned char *old_name) 341 { 342 } 343 344 #endif /* CONFIG_FSNOTIFY */ 345 346 #endif /* _LINUX_FS_NOTIFY_H */ 347