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 /* 30 * Simple wrapper to consolidate calls fsnotify_parent()/fsnotify() when 31 * an event is on a path. 32 */ 33 static inline int fsnotify_path(struct inode *inode, const struct path *path, 34 __u32 mask) 35 { 36 int ret = fsnotify_parent(path, NULL, mask); 37 38 if (ret) 39 return ret; 40 return fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0); 41 } 42 43 /* Simple call site for access decisions */ 44 static inline int fsnotify_perm(struct file *file, int mask) 45 { 46 int ret; 47 const struct path *path = &file->f_path; 48 struct inode *inode = file_inode(file); 49 __u32 fsnotify_mask = 0; 50 51 if (file->f_mode & FMODE_NONOTIFY) 52 return 0; 53 if (!(mask & (MAY_READ | MAY_OPEN))) 54 return 0; 55 if (mask & MAY_OPEN) { 56 fsnotify_mask = FS_OPEN_PERM; 57 58 if (file->f_flags & __FMODE_EXEC) { 59 ret = fsnotify_path(inode, path, FS_OPEN_EXEC_PERM); 60 61 if (ret) 62 return ret; 63 } 64 } else if (mask & MAY_READ) { 65 fsnotify_mask = FS_ACCESS_PERM; 66 } 67 68 return fsnotify_path(inode, path, fsnotify_mask); 69 } 70 71 /* 72 * fsnotify_link_count - inode's link count changed 73 */ 74 static inline void fsnotify_link_count(struct inode *inode) 75 { 76 fsnotify(inode, FS_ATTRIB, inode, FSNOTIFY_EVENT_INODE, NULL, 0); 77 } 78 79 /* 80 * fsnotify_move - file old_name at old_dir was moved to new_name at new_dir 81 */ 82 static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir, 83 const unsigned char *old_name, 84 int isdir, struct inode *target, struct dentry *moved) 85 { 86 struct inode *source = moved->d_inode; 87 u32 fs_cookie = fsnotify_get_cookie(); 88 __u32 old_dir_mask = (FS_EVENT_ON_CHILD | FS_MOVED_FROM); 89 __u32 new_dir_mask = (FS_EVENT_ON_CHILD | FS_MOVED_TO); 90 const unsigned char *new_name = moved->d_name.name; 91 92 if (old_dir == new_dir) 93 old_dir_mask |= FS_DN_RENAME; 94 95 if (isdir) { 96 old_dir_mask |= FS_ISDIR; 97 new_dir_mask |= FS_ISDIR; 98 } 99 100 fsnotify(old_dir, old_dir_mask, source, FSNOTIFY_EVENT_INODE, old_name, 101 fs_cookie); 102 fsnotify(new_dir, new_dir_mask, source, FSNOTIFY_EVENT_INODE, new_name, 103 fs_cookie); 104 105 if (target) 106 fsnotify_link_count(target); 107 108 if (source) 109 fsnotify(source, FS_MOVE_SELF, moved->d_inode, FSNOTIFY_EVENT_INODE, NULL, 0); 110 audit_inode_child(new_dir, moved, AUDIT_TYPE_CHILD_CREATE); 111 } 112 113 /* 114 * fsnotify_inode_delete - and inode is being evicted from cache, clean up is needed 115 */ 116 static inline void fsnotify_inode_delete(struct inode *inode) 117 { 118 __fsnotify_inode_delete(inode); 119 } 120 121 /* 122 * fsnotify_vfsmount_delete - a vfsmount is being destroyed, clean up is needed 123 */ 124 static inline void fsnotify_vfsmount_delete(struct vfsmount *mnt) 125 { 126 __fsnotify_vfsmount_delete(mnt); 127 } 128 129 /* 130 * fsnotify_nameremove - a filename was removed from a directory 131 */ 132 static inline void fsnotify_nameremove(struct dentry *dentry, int isdir) 133 { 134 __u32 mask = FS_DELETE; 135 136 if (isdir) 137 mask |= FS_ISDIR; 138 139 fsnotify_parent(NULL, dentry, mask); 140 } 141 142 /* 143 * fsnotify_inoderemove - an inode is going away 144 */ 145 static inline void fsnotify_inoderemove(struct inode *inode) 146 { 147 fsnotify(inode, FS_DELETE_SELF, inode, FSNOTIFY_EVENT_INODE, NULL, 0); 148 __fsnotify_inode_delete(inode); 149 } 150 151 /* 152 * fsnotify_create - 'name' was linked in 153 */ 154 static inline void fsnotify_create(struct inode *inode, struct dentry *dentry) 155 { 156 audit_inode_child(inode, dentry, AUDIT_TYPE_CHILD_CREATE); 157 158 fsnotify(inode, FS_CREATE, dentry->d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name, 0); 159 } 160 161 /* 162 * fsnotify_link - new hardlink in 'inode' directory 163 * Note: We have to pass also the linked inode ptr as some filesystems leave 164 * new_dentry->d_inode NULL and instantiate inode pointer later 165 */ 166 static inline void fsnotify_link(struct inode *dir, struct inode *inode, struct dentry *new_dentry) 167 { 168 fsnotify_link_count(inode); 169 audit_inode_child(dir, new_dentry, AUDIT_TYPE_CHILD_CREATE); 170 171 fsnotify(dir, FS_CREATE, inode, FSNOTIFY_EVENT_INODE, new_dentry->d_name.name, 0); 172 } 173 174 /* 175 * fsnotify_mkdir - directory 'name' was created 176 */ 177 static inline void fsnotify_mkdir(struct inode *inode, struct dentry *dentry) 178 { 179 __u32 mask = (FS_CREATE | FS_ISDIR); 180 struct inode *d_inode = dentry->d_inode; 181 182 audit_inode_child(inode, dentry, AUDIT_TYPE_CHILD_CREATE); 183 184 fsnotify(inode, mask, d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name, 0); 185 } 186 187 /* 188 * fsnotify_access - file was read 189 */ 190 static inline void fsnotify_access(struct file *file) 191 { 192 const struct path *path = &file->f_path; 193 struct inode *inode = file_inode(file); 194 __u32 mask = FS_ACCESS; 195 196 if (S_ISDIR(inode->i_mode)) 197 mask |= FS_ISDIR; 198 199 if (!(file->f_mode & FMODE_NONOTIFY)) 200 fsnotify_path(inode, path, mask); 201 } 202 203 /* 204 * fsnotify_modify - file was modified 205 */ 206 static inline void fsnotify_modify(struct file *file) 207 { 208 const struct path *path = &file->f_path; 209 struct inode *inode = file_inode(file); 210 __u32 mask = FS_MODIFY; 211 212 if (S_ISDIR(inode->i_mode)) 213 mask |= FS_ISDIR; 214 215 if (!(file->f_mode & FMODE_NONOTIFY)) 216 fsnotify_path(inode, path, mask); 217 } 218 219 /* 220 * fsnotify_open - file was opened 221 */ 222 static inline void fsnotify_open(struct file *file) 223 { 224 const struct path *path = &file->f_path; 225 struct inode *inode = file_inode(file); 226 __u32 mask = FS_OPEN; 227 228 if (S_ISDIR(inode->i_mode)) 229 mask |= FS_ISDIR; 230 if (file->f_flags & __FMODE_EXEC) 231 mask |= FS_OPEN_EXEC; 232 233 fsnotify_path(inode, path, mask); 234 } 235 236 /* 237 * fsnotify_close - file was closed 238 */ 239 static inline void fsnotify_close(struct file *file) 240 { 241 const struct path *path = &file->f_path; 242 struct inode *inode = file_inode(file); 243 fmode_t mode = file->f_mode; 244 __u32 mask = (mode & FMODE_WRITE) ? FS_CLOSE_WRITE : FS_CLOSE_NOWRITE; 245 246 if (S_ISDIR(inode->i_mode)) 247 mask |= FS_ISDIR; 248 249 if (!(file->f_mode & FMODE_NONOTIFY)) 250 fsnotify_path(inode, path, mask); 251 } 252 253 /* 254 * fsnotify_xattr - extended attributes were changed 255 */ 256 static inline void fsnotify_xattr(struct dentry *dentry) 257 { 258 struct inode *inode = dentry->d_inode; 259 __u32 mask = FS_ATTRIB; 260 261 if (S_ISDIR(inode->i_mode)) 262 mask |= FS_ISDIR; 263 264 fsnotify_parent(NULL, dentry, mask); 265 fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0); 266 } 267 268 /* 269 * fsnotify_change - notify_change event. file was modified and/or metadata 270 * was changed. 271 */ 272 static inline void fsnotify_change(struct dentry *dentry, unsigned int ia_valid) 273 { 274 struct inode *inode = dentry->d_inode; 275 __u32 mask = 0; 276 277 if (ia_valid & ATTR_UID) 278 mask |= FS_ATTRIB; 279 if (ia_valid & ATTR_GID) 280 mask |= FS_ATTRIB; 281 if (ia_valid & ATTR_SIZE) 282 mask |= FS_MODIFY; 283 284 /* both times implies a utime(s) call */ 285 if ((ia_valid & (ATTR_ATIME | ATTR_MTIME)) == (ATTR_ATIME | ATTR_MTIME)) 286 mask |= FS_ATTRIB; 287 else if (ia_valid & ATTR_ATIME) 288 mask |= FS_ACCESS; 289 else if (ia_valid & ATTR_MTIME) 290 mask |= FS_MODIFY; 291 292 if (ia_valid & ATTR_MODE) 293 mask |= FS_ATTRIB; 294 295 if (mask) { 296 if (S_ISDIR(inode->i_mode)) 297 mask |= FS_ISDIR; 298 299 fsnotify_parent(NULL, dentry, mask); 300 fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0); 301 } 302 } 303 304 #endif /* _LINUX_FS_NOTIFY_H */ 305