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