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_link_count - inode's link count changed
  56  */
  57 static inline void fsnotify_link_count(struct inode *inode)
  58 {
  59         fsnotify(inode, FS_ATTRIB, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
  60 }
  61
  62 /*
  63  * fsnotify_move - file old_name at old_dir was moved to new_name at new_dir
  64  */
  65 static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir,
  66                                  const unsigned char *old_name,
  67                                  int isdir, struct inode *target, struct dentry *moved)
  68 {
  69         struct inode *source = moved->d_inode;
  70         u32 fs_cookie = fsnotify_get_cookie();
  71         __u32 old_dir_mask = (FS_EVENT_ON_CHILD | FS_MOVED_FROM);
  72         __u32 new_dir_mask = (FS_EVENT_ON_CHILD | FS_MOVED_TO);
  73         const unsigned char *new_name = moved->d_name.name;
  74
  75         if (old_dir == new_dir)
  76                 old_dir_mask |= FS_DN_RENAME;
  77
  78         if (isdir) {
  79                 old_dir_mask |= FS_ISDIR;
  80                 new_dir_mask |= FS_ISDIR;
  81         }
  82
  83         fsnotify(old_dir, old_dir_mask, source, FSNOTIFY_EVENT_INODE, old_name,
  84                  fs_cookie);
  85         fsnotify(new_dir, new_dir_mask, source, FSNOTIFY_EVENT_INODE, new_name,
  86                  fs_cookie);
  87
  88         if (target)
  89                 fsnotify_link_count(target);
  90
  91         if (source)
  92                 fsnotify(source, FS_MOVE_SELF, moved->d_inode, FSNOTIFY_EVENT_INODE, NULL, 0);
  93         audit_inode_child(new_dir, moved, AUDIT_TYPE_CHILD_CREATE);
  94 }
  95
  96 /*
  97  * fsnotify_inode_delete - and inode is being evicted from cache, clean up is needed
  98  */
  99 static inline void fsnotify_inode_delete(struct inode *inode)
 100 {
 101         __fsnotify_inode_delete(inode);
 102 }
 103
 104 /*
 105  * fsnotify_vfsmount_delete - a vfsmount is being destroyed, clean up is needed
 106  */
 107 static inline void fsnotify_vfsmount_delete(struct vfsmount *mnt)
 108 {
 109         __fsnotify_vfsmount_delete(mnt);
 110 }
 111
 112 /*
 113  * fsnotify_nameremove - a filename was removed from a directory
 114  */
 115 static inline void fsnotify_nameremove(struct dentry *dentry, int isdir)
 116 {
 117         __u32 mask = FS_DELETE;
 118
 119         if (isdir)
 120                 mask |= FS_ISDIR;
 121
 122         fsnotify_parent(NULL, dentry, mask);
 123 }
 124
 125 /*
 126  * fsnotify_inoderemove - an inode is going away
 127  */
 128 static inline void fsnotify_inoderemove(struct inode *inode)
 129 {
 130         fsnotify(inode, FS_DELETE_SELF, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
 131         __fsnotify_inode_delete(inode);
 132 }
 133
 134 /*
 135  * fsnotify_create - 'name' was linked in
 136  */
 137 static inline void fsnotify_create(struct inode *inode, struct dentry *dentry)
 138 {
 139         audit_inode_child(inode, dentry, AUDIT_TYPE_CHILD_CREATE);
 140
 141         fsnotify(inode, FS_CREATE, dentry->d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name, 0);
 142 }
 143
 144 /*
 145  * fsnotify_link - new hardlink in 'inode' directory
 146  * Note: We have to pass also the linked inode ptr as some filesystems leave
 147  *   new_dentry->d_inode NULL and instantiate inode pointer later
 148  */
 149 static inline void fsnotify_link(struct inode *dir, struct inode *inode, struct dentry *new_dentry)
 150 {
 151         fsnotify_link_count(inode);
 152         audit_inode_child(dir, new_dentry, AUDIT_TYPE_CHILD_CREATE);
 153
 154         fsnotify(dir, FS_CREATE, inode, FSNOTIFY_EVENT_INODE, new_dentry->d_name.name, 0);
 155 }
 156
 157 /*
 158  * fsnotify_mkdir - directory 'name' was created
 159  */
 160 static inline void fsnotify_mkdir(struct inode *inode, struct dentry *dentry)
 161 {
 162         __u32 mask = (FS_CREATE | FS_ISDIR);
 163         struct inode *d_inode = dentry->d_inode;
 164
 165         audit_inode_child(inode, dentry, AUDIT_TYPE_CHILD_CREATE);
 166
 167         fsnotify(inode, mask, d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name, 0);
 168 }
 169
 170 /*
 171  * fsnotify_access - file was read
 172  */
 173 static inline void fsnotify_access(struct file *file)
 174 {
 175         struct path *path = &file->f_path;
 176         struct inode *inode = file_inode(file);
 177         __u32 mask = FS_ACCESS;
 178
 179         if (S_ISDIR(inode->i_mode))
 180                 mask |= FS_ISDIR;
 181
 182         if (!(file->f_mode & FMODE_NONOTIFY)) {
 183                 fsnotify_parent(path, NULL, mask);
 184                 fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
 185         }
 186 }
 187
 188 /*
 189  * fsnotify_modify - file was modified
 190  */
 191 static inline void fsnotify_modify(struct file *file)
 192 {
 193         struct path *path = &file->f_path;
 194         struct inode *inode = file_inode(file);
 195         __u32 mask = FS_MODIFY;
 196
 197         if (S_ISDIR(inode->i_mode))
 198                 mask |= FS_ISDIR;
 199
 200         if (!(file->f_mode & FMODE_NONOTIFY)) {
 201                 fsnotify_parent(path, NULL, mask);
 202                 fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
 203         }
 204 }
 205
 206 /*
 207  * fsnotify_open - file was opened
 208  */
 209 static inline void fsnotify_open(struct file *file)
 210 {
 211         struct path *path = &file->f_path;
 212         struct inode *inode = file_inode(file);
 213         __u32 mask = FS_OPEN;
 214
 215         if (S_ISDIR(inode->i_mode))
 216                 mask |= FS_ISDIR;
 217
 218         fsnotify_parent(path, NULL, mask);
 219         fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
 220 }
 221
 222 /*
 223  * fsnotify_close - file was closed
 224  */
 225 static inline void fsnotify_close(struct file *file)
 226 {
 227         struct path *path = &file->f_path;
 228         struct inode *inode = file_inode(file);
 229         fmode_t mode = file->f_mode;
 230         __u32 mask = (mode & FMODE_WRITE) ? FS_CLOSE_WRITE : FS_CLOSE_NOWRITE;
 231
 232         if (S_ISDIR(inode->i_mode))
 233                 mask |= FS_ISDIR;
 234
 235         if (!(file->f_mode & FMODE_NONOTIFY)) {
 236                 fsnotify_parent(path, NULL, mask);
 237                 fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
 238         }
 239 }
 240
 241 /*
 242  * fsnotify_xattr - extended attributes were changed
 243  */
 244 static inline void fsnotify_xattr(struct dentry *dentry)
 245 {
 246         struct inode *inode = dentry->d_inode;
 247         __u32 mask = FS_ATTRIB;
 248
 249         if (S_ISDIR(inode->i_mode))
 250                 mask |= FS_ISDIR;
 251
 252         fsnotify_parent(NULL, dentry, mask);
 253         fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
 254 }
 255
 256 /*
 257  * fsnotify_change - notify_change event.  file was modified and/or metadata
 258  * was changed.
 259  */
 260 static inline void fsnotify_change(struct dentry *dentry, unsigned int ia_valid)
 261 {
 262         struct inode *inode = dentry->d_inode;
 263         __u32 mask = 0;
 264
 265         if (ia_valid & ATTR_UID)
 266                 mask |= FS_ATTRIB;
 267         if (ia_valid & ATTR_GID)
 268                 mask |= FS_ATTRIB;
 269         if (ia_valid & ATTR_SIZE)
 270                 mask |= FS_MODIFY;
 271
 272         /* both times implies a utime(s) call */
 273         if ((ia_valid & (ATTR_ATIME | ATTR_MTIME)) == (ATTR_ATIME | ATTR_MTIME))
 274                 mask |= FS_ATTRIB;
 275         else if (ia_valid & ATTR_ATIME)
 276                 mask |= FS_ACCESS;
 277         else if (ia_valid & ATTR_MTIME)
 278                 mask |= FS_MODIFY;
 279
 280         if (ia_valid & ATTR_MODE)
 281                 mask |= FS_ATTRIB;
 282
 283         if (mask) {
 284                 if (S_ISDIR(inode->i_mode))
 285                         mask |= FS_ISDIR;
 286
 287                 fsnotify_parent(NULL, dentry, mask);
 288                 fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
 289         }
 290 }
 291
 292 #if defined(CONFIG_FSNOTIFY)    /* notify helpers */
 293
 294 /*
 295  * fsnotify_oldname_init - save off the old filename before we change it
 296  */
 297 static inline const unsigned char *fsnotify_oldname_init(const unsigned char *name)
 298 {
 299         return kstrdup(name, GFP_KERNEL);
 300 }
 301
 302 /*
 303  * fsnotify_oldname_free - free the name we got from fsnotify_oldname_init
 304  */
 305 static inline void fsnotify_oldname_free(const unsigned char *old_name)
 306 {
 307         kfree(old_name);
 308 }
 309
 310 #else   /* CONFIG_FSNOTIFY */
 311
 312 static inline const char *fsnotify_oldname_init(const unsigned char *name)
 313 {
 314         return NULL;
 315 }
 316
 317 static inline void fsnotify_oldname_free(const unsigned char *old_name)
 318 {
 319 }
 320
 321 #endif  /*  CONFIG_FSNOTIFY */
 322
 323 #endif  /* _LINUX_FS_NOTIFY_H */