include/linux/fsnotify.h

   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 #include <linux/bug.h>
  18
  19 /* Notify this dentry's parent about a child's events. */
  20 static inline int fsnotify_parent(struct path *path, struct dentry *dentry, __u32 mask)
  21 {
  22         if (!dentry)
  23                 dentry = path->dentry;
  24
  25         return __fsnotify_parent(path, dentry, mask);
  26 }
  27
  28 /* simple call site for access decisions */
  29 static inline int fsnotify_perm(struct file *file, int mask)
  30 {
  31         struct path *path = &file->f_path;
  32         struct inode *inode = file_inode(file);
  33         __u32 fsnotify_mask = 0;
  34         int ret;
  35
  36         if (file->f_mode & FMODE_NONOTIFY)
  37                 return 0;
  38         if (!(mask & (MAY_READ | MAY_OPEN)))
  39                 return 0;
  40         if (mask & MAY_OPEN)
  41                 fsnotify_mask = FS_OPEN_PERM;
  42         else if (mask & MAY_READ)
  43                 fsnotify_mask = FS_ACCESS_PERM;
  44         else
  45                 BUG();
  46
  47         ret = fsnotify_parent(path, NULL, fsnotify_mask);
  48         if (ret)
  49                 return ret;
  50
  51         return fsnotify(inode, fsnotify_mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
  52 }
  53
  54 /*
  55  * fsnotify_d_move - dentry has been moved
  56  */
  57 static inline void fsnotify_d_move(struct dentry *dentry)
  58 {
  59         /*
  60          * On move we need to update dentry->d_flags to indicate if the new parent
  61          * cares about events from this dentry.
  62          */
  63         __fsnotify_update_dcache_flags(dentry);
  64 }
  65
  66 /*
  67  * fsnotify_link_count - inode's link count changed
  68  */
  69 static inline void fsnotify_link_count(struct inode *inode)
  70 {
  71         fsnotify(inode, FS_ATTRIB, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
  72 }
  73
  74 /*
  75  * fsnotify_move - file old_name at old_dir was moved to new_name at new_dir
  76  */
  77 static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir,
  78                                  const unsigned char *old_name,
  79                                  int isdir, struct inode *target, struct dentry *moved)
  80 {
  81         struct inode *source = moved->d_inode;
  82         u32 fs_cookie = fsnotify_get_cookie();
  83         __u32 old_dir_mask = (FS_EVENT_ON_CHILD | FS_MOVED_FROM);
  84         __u32 new_dir_mask = (FS_EVENT_ON_CHILD | FS_MOVED_TO);
  85         const unsigned char *new_name = moved->d_name.name;
  86
  87         if (old_dir == new_dir)
  88                 old_dir_mask |= FS_DN_RENAME;
  89
  90         if (isdir) {
  91                 old_dir_mask |= FS_ISDIR;
  92                 new_dir_mask |= FS_ISDIR;
  93         }
  94
  95         fsnotify(old_dir, old_dir_mask, source, FSNOTIFY_EVENT_INODE, old_name,
  96                  fs_cookie);
  97         fsnotify(new_dir, new_dir_mask, source, FSNOTIFY_EVENT_INODE, new_name,
  98                  fs_cookie);
  99
 100         if (target)
 101                 fsnotify_link_count(target);
 102
 103         if (source)
 104                 fsnotify(source, FS_MOVE_SELF, moved->d_inode, FSNOTIFY_EVENT_INODE, NULL, 0);
 105         audit_inode_child(new_dir, moved, AUDIT_TYPE_CHILD_CREATE);
 106 }
 107
 108 /*
 109  * fsnotify_inode_delete - and inode is being evicted from cache, clean up is needed
 110  */
 111 static inline void fsnotify_inode_delete(struct inode *inode)
 112 {
 113         __fsnotify_inode_delete(inode);
 114 }
 115
 116 /*
 117  * fsnotify_vfsmount_delete - a vfsmount is being destroyed, clean up is needed
 118  */
 119 static inline void fsnotify_vfsmount_delete(struct vfsmount *mnt)
 120 {
 121         __fsnotify_vfsmount_delete(mnt);
 122 }
 123
 124 /*
 125  * fsnotify_nameremove - a filename was removed from a directory
 126  */
 127 static inline void fsnotify_nameremove(struct dentry *dentry, int isdir)
 128 {
 129         __u32 mask = FS_DELETE;
 130
 131         if (isdir)
 132                 mask |= FS_ISDIR;
 133
 134         fsnotify_parent(NULL, dentry, mask);
 135 }
 136
 137 /*
 138  * fsnotify_inoderemove - an inode is going away
 139  */
 140 static inline void fsnotify_inoderemove(struct inode *inode)
 141 {
 142         fsnotify(inode, FS_DELETE_SELF, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
 143         __fsnotify_inode_delete(inode);
 144 }
 145
 146 /*
 147  * fsnotify_create - 'name' was linked in
 148  */
 149 static inline void fsnotify_create(struct inode *inode, struct dentry *dentry)
 150 {
 151         audit_inode_child(inode, dentry, AUDIT_TYPE_CHILD_CREATE);
 152
 153         fsnotify(inode, FS_CREATE, dentry->d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name, 0);
 154 }
 155
 156 /*
 157  * fsnotify_link - new hardlink in 'inode' directory
 158  * Note: We have to pass also the linked inode ptr as some filesystems leave
 159  *   new_dentry->d_inode NULL and instantiate inode pointer later
 160  */
 161 static inline void fsnotify_link(struct inode *dir, struct inode *inode, struct dentry *new_dentry)
 162 {
 163         fsnotify_link_count(inode);
 164         audit_inode_child(dir, new_dentry, AUDIT_TYPE_CHILD_CREATE);
 165
 166         fsnotify(dir, FS_CREATE, inode, FSNOTIFY_EVENT_INODE, new_dentry->d_name.name, 0);
 167 }
 168
 169 /*
 170  * fsnotify_mkdir - directory 'name' was created
 171  */
 172 static inline void fsnotify_mkdir(struct inode *inode, struct dentry *dentry)
 173 {
 174         __u32 mask = (FS_CREATE | FS_ISDIR);
 175         struct inode *d_inode = dentry->d_inode;
 176
 177         audit_inode_child(inode, dentry, AUDIT_TYPE_CHILD_CREATE);
 178
 179         fsnotify(inode, mask, d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name, 0);
 180 }
 181
 182 /*
 183  * fsnotify_access - file was read
 184  */
 185 static inline void fsnotify_access(struct file *file)
 186 {
 187         struct path *path = &file->f_path;
 188         struct inode *inode = file_inode(file);
 189         __u32 mask = FS_ACCESS;
 190
 191         if (S_ISDIR(inode->i_mode))
 192                 mask |= FS_ISDIR;
 193
 194         if (!(file->f_mode & FMODE_NONOTIFY)) {
 195                 fsnotify_parent(path, NULL, mask);
 196                 fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
 197         }
 198 }
 199
 200 /*
 201  * fsnotify_modify - file was modified
 202  */
 203 static inline void fsnotify_modify(struct file *file)
 204 {
 205         struct path *path = &file->f_path;
 206         struct inode *inode = file_inode(file);
 207         __u32 mask = FS_MODIFY;
 208
 209         if (S_ISDIR(inode->i_mode))
 210                 mask |= FS_ISDIR;
 211
 212         if (!(file->f_mode & FMODE_NONOTIFY)) {
 213                 fsnotify_parent(path, NULL, mask);
 214                 fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
 215         }
 216 }
 217
 218 /*
 219  * fsnotify_open - file was opened
 220  */
 221 static inline void fsnotify_open(struct file *file)
 222 {
 223         struct path *path = &file->f_path;
 224         struct inode *inode = file_inode(file);
 225         __u32 mask = FS_OPEN;
 226
 227         if (S_ISDIR(inode->i_mode))
 228                 mask |= FS_ISDIR;
 229
 230         fsnotify_parent(path, NULL, mask);
 231         fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
 232 }
 233
 234 /*
 235  * fsnotify_close - file was closed
 236  */
 237 static inline void fsnotify_close(struct file *file)
 238 {
 239         struct path *path = &file->f_path;
 240         struct inode *inode = file_inode(file);
 241         fmode_t mode = file->f_mode;
 242         __u32 mask = (mode & FMODE_WRITE) ? FS_CLOSE_WRITE : FS_CLOSE_NOWRITE;
 243
 244         if (S_ISDIR(inode->i_mode))
 245                 mask |= FS_ISDIR;
 246
 247         if (!(file->f_mode & FMODE_NONOTIFY)) {
 248                 fsnotify_parent(path, NULL, mask);
 249                 fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
 250         }
 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 #if defined(CONFIG_FSNOTIFY)    /* notify helpers */
 305
 306 /*
 307  * fsnotify_oldname_init - save off the old filename before we change it
 308  */
 309 static inline const unsigned char *fsnotify_oldname_init(const unsigned char *name)
 310 {
 311         return kstrdup(name, GFP_KERNEL);
 312 }
 313
 314 /*
 315  * fsnotify_oldname_free - free the name we got from fsnotify_oldname_init
 316  */
 317 static inline void fsnotify_oldname_free(const unsigned char *old_name)
 318 {
 319         kfree(old_name);
 320 }
 321
 322 #else   /* CONFIG_FSNOTIFY */
 323
 324 static inline const char *fsnotify_oldname_init(const unsigned char *name)
 325 {
 326         return NULL;
 327 }
 328
 329 static inline void fsnotify_oldname_free(const unsigned char *old_name)
 330 {
 331 }
 332
 333 #endif  /*  CONFIG_FSNOTIFY */
 334
 335 #endif  /* _LINUX_FS_NOTIFY_H */