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. */ 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 */ 30 static inline int fsnotify_perm(struct file *file, int mask) 31 { 32 const struct path *path = &file->f_path; 33 /* 34 * Do not use file_inode() here or anywhere in this file to get the 35 * inode. That would break *notity on overlayfs. 36 */ 37 struct inode *inode = path->dentry->d_inode; 38 __u32 fsnotify_mask = 0; 39 int ret; 40 41 if (file->f_mode & FMODE_NONOTIFY) 42 return 0; 43 if (!(mask & (MAY_READ | MAY_OPEN))) 44 return 0; 45 if (mask & MAY_OPEN) 46 fsnotify_mask = FS_OPEN_PERM; 47 else if (mask & MAY_READ) 48 fsnotify_mask = FS_ACCESS_PERM; 49 else 50 BUG(); 51 52 ret = fsnotify_parent(path, NULL, fsnotify_mask); 53 if (ret) 54 return ret; 55 56 return fsnotify(inode, fsnotify_mask, path, FSNOTIFY_EVENT_PATH, NULL, 0); 57 } 58 59 /* 60 * fsnotify_link_count - inode's link count changed 61 */ 62 static inline void fsnotify_link_count(struct inode *inode) 63 { 64 fsnotify(inode, FS_ATTRIB, inode, FSNOTIFY_EVENT_INODE, NULL, 0); 65 } 66 67 /* 68 * fsnotify_move - file old_name at old_dir was moved to new_name at new_dir 69 */ 70 static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir, 71 const unsigned char *old_name, 72 int isdir, struct inode *target, struct dentry *moved) 73 { 74 struct inode *source = moved->d_inode; 75 u32 fs_cookie = fsnotify_get_cookie(); 76 __u32 old_dir_mask = (FS_EVENT_ON_CHILD | FS_MOVED_FROM); 77 __u32 new_dir_mask = (FS_EVENT_ON_CHILD | FS_MOVED_TO); 78 const unsigned char *new_name = moved->d_name.name; 79 80 if (old_dir == new_dir) 81 old_dir_mask |= FS_DN_RENAME; 82 83 if (isdir) { 84 old_dir_mask |= FS_ISDIR; 85 new_dir_mask |= FS_ISDIR; 86 } 87 88 fsnotify(old_dir, old_dir_mask, source, FSNOTIFY_EVENT_INODE, old_name, 89 fs_cookie); 90 fsnotify(new_dir, new_dir_mask, source, FSNOTIFY_EVENT_INODE, new_name, 91 fs_cookie); 92 93 if (target) 94 fsnotify_link_count(target); 95 96 if (source) 97 fsnotify(source, FS_MOVE_SELF, moved->d_inode, FSNOTIFY_EVENT_INODE, NULL, 0); 98 audit_inode_child(new_dir, moved, AUDIT_TYPE_CHILD_CREATE); 99 } 100 101 /* 102 * fsnotify_inode_delete - and inode is being evicted from cache, clean up is needed 103 */ 104 static inline void fsnotify_inode_delete(struct inode *inode) 105 { 106 __fsnotify_inode_delete(inode); 107 } 108 109 /* 110 * fsnotify_vfsmount_delete - a vfsmount is being destroyed, clean up is needed 111 */ 112 static inline void fsnotify_vfsmount_delete(struct vfsmount *mnt) 113 { 114 __fsnotify_vfsmount_delete(mnt); 115 } 116 117 /* 118 * fsnotify_nameremove - a filename was removed from a directory 119 */ 120 static inline void fsnotify_nameremove(struct dentry *dentry, int isdir) 121 { 122 __u32 mask = FS_DELETE; 123 124 if (isdir) 125 mask |= FS_ISDIR; 126 127 fsnotify_parent(NULL, dentry, mask); 128 } 129 130 /* 131 * fsnotify_inoderemove - an inode is going away 132 */ 133 static inline void fsnotify_inoderemove(struct inode *inode) 134 { 135 fsnotify(inode, FS_DELETE_SELF, inode, FSNOTIFY_EVENT_INODE, NULL, 0); 136 __fsnotify_inode_delete(inode); 137 } 138 139 /* 140 * fsnotify_create - 'name' was linked in 141 */ 142 static inline void fsnotify_create(struct inode *inode, struct dentry *dentry) 143 { 144 audit_inode_child(inode, dentry, AUDIT_TYPE_CHILD_CREATE); 145 146 fsnotify(inode, FS_CREATE, dentry->d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name, 0); 147 } 148 149 /* 150 * fsnotify_link - new hardlink in 'inode' directory 151 * Note: We have to pass also the linked inode ptr as some filesystems leave 152 * new_dentry->d_inode NULL and instantiate inode pointer later 153 */ 154 static inline void fsnotify_link(struct inode *dir, struct inode *inode, struct dentry *new_dentry) 155 { 156 fsnotify_link_count(inode); 157 audit_inode_child(dir, new_dentry, AUDIT_TYPE_CHILD_CREATE); 158 159 fsnotify(dir, FS_CREATE, inode, FSNOTIFY_EVENT_INODE, new_dentry->d_name.name, 0); 160 } 161 162 /* 163 * fsnotify_mkdir - directory 'name' was created 164 */ 165 static inline void fsnotify_mkdir(struct inode *inode, struct dentry *dentry) 166 { 167 __u32 mask = (FS_CREATE | FS_ISDIR); 168 struct inode *d_inode = dentry->d_inode; 169 170 audit_inode_child(inode, dentry, AUDIT_TYPE_CHILD_CREATE); 171 172 fsnotify(inode, mask, d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name, 0); 173 } 174 175 /* 176 * fsnotify_access - file was read 177 */ 178 static inline void fsnotify_access(struct file *file) 179 { 180 const struct path *path = &file->f_path; 181 struct inode *inode = path->dentry->d_inode; 182 __u32 mask = FS_ACCESS; 183 184 if (S_ISDIR(inode->i_mode)) 185 mask |= FS_ISDIR; 186 187 if (!(file->f_mode & FMODE_NONOTIFY)) { 188 fsnotify_parent(path, NULL, mask); 189 fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0); 190 } 191 } 192 193 /* 194 * fsnotify_modify - file was modified 195 */ 196 static inline void fsnotify_modify(struct file *file) 197 { 198 const struct path *path = &file->f_path; 199 struct inode *inode = path->dentry->d_inode; 200 __u32 mask = FS_MODIFY; 201 202 if (S_ISDIR(inode->i_mode)) 203 mask |= FS_ISDIR; 204 205 if (!(file->f_mode & FMODE_NONOTIFY)) { 206 fsnotify_parent(path, NULL, mask); 207 fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0); 208 } 209 } 210 211 /* 212 * fsnotify_open - file was opened 213 */ 214 static inline void fsnotify_open(struct file *file) 215 { 216 const struct path *path = &file->f_path; 217 struct inode *inode = path->dentry->d_inode; 218 __u32 mask = FS_OPEN; 219 220 if (S_ISDIR(inode->i_mode)) 221 mask |= FS_ISDIR; 222 223 fsnotify_parent(path, NULL, mask); 224 fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0); 225 } 226 227 /* 228 * fsnotify_close - file was closed 229 */ 230 static inline void fsnotify_close(struct file *file) 231 { 232 const struct path *path = &file->f_path; 233 struct inode *inode = path->dentry->d_inode; 234 fmode_t mode = file->f_mode; 235 __u32 mask = (mode & FMODE_WRITE) ? FS_CLOSE_WRITE : FS_CLOSE_NOWRITE; 236 237 if (S_ISDIR(inode->i_mode)) 238 mask |= FS_ISDIR; 239 240 if (!(file->f_mode & FMODE_NONOTIFY)) { 241 fsnotify_parent(path, NULL, mask); 242 fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0); 243 } 244 } 245 246 /* 247 * fsnotify_xattr - extended attributes were changed 248 */ 249 static inline void fsnotify_xattr(struct dentry *dentry) 250 { 251 struct inode *inode = dentry->d_inode; 252 __u32 mask = FS_ATTRIB; 253 254 if (S_ISDIR(inode->i_mode)) 255 mask |= FS_ISDIR; 256 257 fsnotify_parent(NULL, dentry, mask); 258 fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0); 259 } 260 261 /* 262 * fsnotify_change - notify_change event. file was modified and/or metadata 263 * was changed. 264 */ 265 static inline void fsnotify_change(struct dentry *dentry, unsigned int ia_valid) 266 { 267 struct inode *inode = dentry->d_inode; 268 __u32 mask = 0; 269 270 if (ia_valid & ATTR_UID) 271 mask |= FS_ATTRIB; 272 if (ia_valid & ATTR_GID) 273 mask |= FS_ATTRIB; 274 if (ia_valid & ATTR_SIZE) 275 mask |= FS_MODIFY; 276 277 /* both times implies a utime(s) call */ 278 if ((ia_valid & (ATTR_ATIME | ATTR_MTIME)) == (ATTR_ATIME | ATTR_MTIME)) 279 mask |= FS_ATTRIB; 280 else if (ia_valid & ATTR_ATIME) 281 mask |= FS_ACCESS; 282 else if (ia_valid & ATTR_MTIME) 283 mask |= FS_MODIFY; 284 285 if (ia_valid & ATTR_MODE) 286 mask |= FS_ATTRIB; 287 288 if (mask) { 289 if (S_ISDIR(inode->i_mode)) 290 mask |= FS_ISDIR; 291 292 fsnotify_parent(NULL, dentry, mask); 293 fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0); 294 } 295 } 296 297 #endif /* _LINUX_FS_NOTIFY_H */ 298