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 /*
  20  * fsnotify_d_instantiate - instantiate a dentry for inode
  21  */
  22 static inline void fsnotify_d_instantiate(struct dentry *dentry,
  23                                           struct inode *inode)
  24 {
  25         __fsnotify_d_instantiate(dentry, inode);
  26 }
  27
  28 /* Notify this dentry's parent about a child's events. */
  29 static inline int fsnotify_parent(struct path *path, struct dentry *dentry, __u32 mask)
  30 {
  31         if (!dentry)
  32                 dentry = path->dentry;
  33
  34         return __fsnotify_parent(path, dentry, mask);
  35 }
  36
  37 /* simple call site for access decisions */
  38 static inline int fsnotify_perm(struct file *file, int mask)
  39 {
  40         struct path *path = &file->f_path;
  41         struct inode *inode = file_inode(file);
  42         __u32 fsnotify_mask = 0;
  43         int ret;
  44
  45         if (file->f_mode & FMODE_NONOTIFY)
  46                 return 0;
  47         if (!(mask & (MAY_READ | MAY_OPEN)))
  48                 return 0;
  49         if (mask & MAY_OPEN)
  50                 fsnotify_mask = FS_OPEN_PERM;
  51         else if (mask & MAY_READ)
  52                 fsnotify_mask = FS_ACCESS_PERM;
  53         else
  54                 BUG();
  55
  56         ret = fsnotify_parent(path, NULL, fsnotify_mask);
  57         if (ret)
  58                 return ret;
  59
  60         return fsnotify(inode, fsnotify_mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
  61 }
  62
  63 /*
  64  * fsnotify_d_move - dentry has been moved
  65  */
  66 static inline void fsnotify_d_move(struct dentry *dentry)
  67 {
  68         /*
  69          * On move we need to update dentry->d_flags to indicate if the new parent
  70          * cares about events from this dentry.
  71          */
  72         __fsnotify_update_dcache_flags(dentry);
  73 }
  74
  75 /*
  76  * fsnotify_link_count - inode's link count changed
  77  */
  78 static inline void fsnotify_link_count(struct inode *inode)
  79 {
  80         fsnotify(inode, FS_ATTRIB, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
  81 }
  82
  83 /*
  84  * fsnotify_move - file old_name at old_dir was moved to new_name at new_dir
  85  */
  86 static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir,
  87                                  const unsigned char *old_name,
  88                                  int isdir, struct inode *target, struct dentry *moved)
  89 {
  90         struct inode *source = moved->d_inode;
  91         u32 fs_cookie = fsnotify_get_cookie();
  92         __u32 old_dir_mask = (FS_EVENT_ON_CHILD | FS_MOVED_FROM);
  93         __u32 new_dir_mask = (FS_EVENT_ON_CHILD | FS_MOVED_TO);
  94         const unsigned char *new_name = moved->d_name.name;
  95
  96         if (old_dir == new_dir)
  97                 old_dir_mask |= FS_DN_RENAME;
  98
  99         if (isdir) {
 100                 old_dir_mask |= FS_ISDIR;
 101                 new_dir_mask |= FS_ISDIR;
 102         }
 103
 104         fsnotify(old_dir, old_dir_mask, source, FSNOTIFY_EVENT_INODE, old_name,
 105                  fs_cookie);
 106         fsnotify(new_dir, new_dir_mask, source, FSNOTIFY_EVENT_INODE, new_name,
 107                  fs_cookie);
 108
 109         if (target)
 110                 fsnotify_link_count(target);
 111
 112         if (source)
 113                 fsnotify(source, FS_MOVE_SELF, moved->d_inode, FSNOTIFY_EVENT_INODE, NULL, 0);
 114         audit_inode_child(new_dir, moved, AUDIT_TYPE_CHILD_CREATE);
 115 }
 116
 117 /*
 118  * fsnotify_inode_delete - and inode is being evicted from cache, clean up is needed
 119  */
 120 static inline void fsnotify_inode_delete(struct inode *inode)
 121 {
 122         __fsnotify_inode_delete(inode);
 123 }
 124
 125 /*
 126  * fsnotify_vfsmount_delete - a vfsmount is being destroyed, clean up is needed
 127  */
 128 static inline void fsnotify_vfsmount_delete(struct vfsmount *mnt)
 129 {
 130         __fsnotify_vfsmount_delete(mnt);
 131 }
 132
 133 /*
 134  * fsnotify_nameremove - a filename was removed from a directory
 135  */
 136 static inline void fsnotify_nameremove(struct dentry *dentry, int isdir)
 137 {
 138         __u32 mask = FS_DELETE;
 139
 140         if (isdir)
 141                 mask |= FS_ISDIR;
 142
 143         fsnotify_parent(NULL, dentry, mask);
 144 }
 145
 146 /*
 147  * fsnotify_inoderemove - an inode is going away
 148  */
 149 static inline void fsnotify_inoderemove(struct inode *inode)
 150 {
 151         fsnotify(inode, FS_DELETE_SELF, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
 152         __fsnotify_inode_delete(inode);
 153 }
 154
 155 /*
 156  * fsnotify_create - 'name' was linked in
 157  */
 158 static inline void fsnotify_create(struct inode *inode, struct dentry *dentry)
 159 {
 160         audit_inode_child(inode, dentry, AUDIT_TYPE_CHILD_CREATE);
 161
 162         fsnotify(inode, FS_CREATE, dentry->d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name, 0);
 163 }
 164
 165 /*
 166  * fsnotify_link - new hardlink in 'inode' directory
 167  * Note: We have to pass also the linked inode ptr as some filesystems leave
 168  *   new_dentry->d_inode NULL and instantiate inode pointer later
 169  */
 170 static inline void fsnotify_link(struct inode *dir, struct inode *inode, struct dentry *new_dentry)
 171 {
 172         fsnotify_link_count(inode);
 173         audit_inode_child(dir, new_dentry, AUDIT_TYPE_CHILD_CREATE);
 174
 175         fsnotify(dir, FS_CREATE, inode, FSNOTIFY_EVENT_INODE, new_dentry->d_name.name, 0);
 176 }
 177
 178 /*
 179  * fsnotify_mkdir - directory 'name' was created
 180  */
 181 static inline void fsnotify_mkdir(struct inode *inode, struct dentry *dentry)
 182 {
 183         __u32 mask = (FS_CREATE | FS_ISDIR);
 184         struct inode *d_inode = dentry->d_inode;
 185
 186         audit_inode_child(inode, dentry, AUDIT_TYPE_CHILD_CREATE);
 187
 188         fsnotify(inode, mask, d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name, 0);
 189 }
 190
 191 /*
 192  * fsnotify_access - file was read
 193  */
 194 static inline void fsnotify_access(struct file *file)
 195 {
 196         struct path *path = &file->f_path;
 197         struct inode *inode = file_inode(file);
 198         __u32 mask = FS_ACCESS;
 199
 200         if (is_sidechannel_device(inode))
 201                 return;
 202
 203         if (S_ISDIR(inode->i_mode))
 204                 mask |= FS_ISDIR;
 205
 206         if (!(file->f_mode & FMODE_NONOTIFY)) {
 207                 fsnotify_parent(path, NULL, mask);
 208                 fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
 209         }
 210 }
 211
 212 /*
 213  * fsnotify_modify - file was modified
 214  */
 215 static inline void fsnotify_modify(struct file *file)
 216 {
 217         struct path *path = &file->f_path;
 218         struct inode *inode = file_inode(file);
 219         __u32 mask = FS_MODIFY;
 220
 221         if (is_sidechannel_device(inode))
 222                 return;
 223
 224         if (S_ISDIR(inode->i_mode))
 225                 mask |= FS_ISDIR;
 226
 227         if (!(file->f_mode & FMODE_NONOTIFY)) {
 228                 fsnotify_parent(path, NULL, mask);
 229                 fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
 230         }
 231 }
 232
 233 /*
 234  * fsnotify_open - file was opened
 235  */
 236 static inline void fsnotify_open(struct file *file)
 237 {
 238         struct path *path = &file->f_path;
 239         struct inode *inode = file_inode(file);
 240         __u32 mask = FS_OPEN;
 241
 242         if (S_ISDIR(inode->i_mode))
 243                 mask |= FS_ISDIR;
 244
 245         fsnotify_parent(path, NULL, mask);
 246         fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
 247 }
 248
 249 /*
 250  * fsnotify_close - file was closed
 251  */
 252 static inline void fsnotify_close(struct file *file)
 253 {
 254         struct path *path = &file->f_path;
 255         struct inode *inode = file_inode(file);
 256         fmode_t mode = file->f_mode;
 257         __u32 mask = (mode & FMODE_WRITE) ? FS_CLOSE_WRITE : FS_CLOSE_NOWRITE;
 258
 259         if (S_ISDIR(inode->i_mode))
 260                 mask |= FS_ISDIR;
 261
 262         if (!(file->f_mode & FMODE_NONOTIFY)) {
 263                 fsnotify_parent(path, NULL, mask);
 264                 fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
 265         }
 266 }
 267
 268 /*
 269  * fsnotify_xattr - extended attributes were changed
 270  */
 271 static inline void fsnotify_xattr(struct dentry *dentry)
 272 {
 273         struct inode *inode = dentry->d_inode;
 274         __u32 mask = FS_ATTRIB;
 275
 276         if (S_ISDIR(inode->i_mode))
 277                 mask |= FS_ISDIR;
 278
 279         fsnotify_parent(NULL, dentry, mask);
 280         fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
 281 }
 282
 283 /*
 284  * fsnotify_change - notify_change event.  file was modified and/or metadata
 285  * was changed.
 286  */
 287 static inline void fsnotify_change(struct dentry *dentry, unsigned int ia_valid)
 288 {
 289         struct inode *inode = dentry->d_inode;
 290         __u32 mask = 0;
 291
 292         if (ia_valid & ATTR_UID)
 293                 mask |= FS_ATTRIB;
 294         if (ia_valid & ATTR_GID)
 295                 mask |= FS_ATTRIB;
 296         if (ia_valid & ATTR_SIZE)
 297                 mask |= FS_MODIFY;
 298
 299         /* both times implies a utime(s) call */
 300         if ((ia_valid & (ATTR_ATIME | ATTR_MTIME)) == (ATTR_ATIME | ATTR_MTIME))
 301                 mask |= FS_ATTRIB;
 302         else if (ia_valid & ATTR_ATIME)
 303                 mask |= FS_ACCESS;
 304         else if (ia_valid & ATTR_MTIME)
 305                 mask |= FS_MODIFY;
 306
 307         if (ia_valid & ATTR_MODE)
 308                 mask |= FS_ATTRIB;
 309
 310         if (mask) {
 311                 if (S_ISDIR(inode->i_mode))
 312                         mask |= FS_ISDIR;
 313
 314                 fsnotify_parent(NULL, dentry, mask);
 315                 fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
 316         }
 317 }
 318
 319 #if defined(CONFIG_FSNOTIFY)    /* notify helpers */
 320
 321 /*
 322  * fsnotify_oldname_init - save off the old filename before we change it
 323  */
 324 static inline const unsigned char *fsnotify_oldname_init(const unsigned char *name)
 325 {
 326         return (const unsigned char *)kstrdup((const char *)name, GFP_KERNEL);
 327 }
 328
 329 /*
 330  * fsnotify_oldname_free - free the name we got from fsnotify_oldname_init
 331  */
 332 static inline void fsnotify_oldname_free(const unsigned char *old_name)
 333 {
 334         kfree(old_name);
 335 }
 336
 337 #else   /* CONFIG_FSNOTIFY */
 338
 339 static inline const char *fsnotify_oldname_init(const unsigned char *name)
 340 {
 341         return NULL;
 342 }
 343
 344 static inline void fsnotify_oldname_free(const unsigned char *old_name)
 345 {
 346 }
 347
 348 #endif  /*  CONFIG_FSNOTIFY */
 349
 350 #endif  /* _LINUX_FS_NOTIFY_H */