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
  18 /*
  19  * fsnotify_d_instantiate - instantiate a dentry for inode
  20  * Called with dcache_lock held.
  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 = path->dentry->d_inode;
  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  * Called with dcache_lock and dentry->d_lock held.
  66  */
  67 static inline void fsnotify_d_move(struct dentry *dentry)
  68 {
  69         /*
  70          * On move we need to update dentry->d_flags to indicate if the new parent
  71          * cares about events from this dentry.
  72          */
  73         __fsnotify_update_dcache_flags(dentry);
  74 }
  75
  76 /*
  77  * fsnotify_link_count - inode's link count changed
  78  */
  79 static inline void fsnotify_link_count(struct inode *inode)
  80 {
  81         fsnotify(inode, FS_ATTRIB, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
  82 }
  83
  84 /*
  85  * fsnotify_move - file old_name at old_dir was moved to new_name at new_dir
  86  */
  87 static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir,
  88                                  const unsigned char *old_name,
  89                                  int isdir, struct inode *target, struct dentry *moved)
  90 {
  91         struct inode *source = moved->d_inode;
  92         u32 fs_cookie = fsnotify_get_cookie();
  93         __u32 old_dir_mask = (FS_EVENT_ON_CHILD | FS_MOVED_FROM);
  94         __u32 new_dir_mask = (FS_EVENT_ON_CHILD | FS_MOVED_TO);
  95         const unsigned char *new_name = moved->d_name.name;
  96
  97         if (old_dir == new_dir)
  98                 old_dir_mask |= FS_DN_RENAME;
  99
 100         if (isdir) {
 101                 old_dir_mask |= FS_ISDIR;
 102                 new_dir_mask |= FS_ISDIR;
 103         }
 104
 105         fsnotify(old_dir, old_dir_mask, old_dir, FSNOTIFY_EVENT_INODE, old_name, fs_cookie);
 106         fsnotify(new_dir, new_dir_mask, new_dir, FSNOTIFY_EVENT_INODE, new_name, fs_cookie);
 107
 108         if (target)
 109                 fsnotify_link_count(target);
 110
 111         if (source)
 112                 fsnotify(source, FS_MOVE_SELF, moved->d_inode, FSNOTIFY_EVENT_INODE, NULL, 0);
 113         audit_inode_child(moved, new_dir);
 114 }
 115
 116 /*
 117  * fsnotify_inode_delete - and inode is being evicted from cache, clean up is needed
 118  */
 119 static inline void fsnotify_inode_delete(struct inode *inode)
 120 {
 121         __fsnotify_inode_delete(inode);
 122 }
 123
 124 /*
 125  * fsnotify_vfsmount_delete - a vfsmount is being destroyed, clean up is needed
 126  */
 127 static inline void fsnotify_vfsmount_delete(struct vfsmount *mnt)
 128 {
 129         __fsnotify_vfsmount_delete(mnt);
 130 }
 131
 132 /*
 133  * fsnotify_nameremove - a filename was removed from a directory
 134  */
 135 static inline void fsnotify_nameremove(struct dentry *dentry, int isdir)
 136 {
 137         __u32 mask = FS_DELETE;
 138
 139         if (isdir)
 140                 mask |= FS_ISDIR;
 141
 142         fsnotify_parent(NULL, dentry, mask);
 143 }
 144
 145 /*
 146  * fsnotify_inoderemove - an inode is going away
 147  */
 148 static inline void fsnotify_inoderemove(struct inode *inode)
 149 {
 150         fsnotify(inode, FS_DELETE_SELF, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
 151         __fsnotify_inode_delete(inode);
 152 }
 153
 154 /*
 155  * fsnotify_create - 'name' was linked in
 156  */
 157 static inline void fsnotify_create(struct inode *inode, struct dentry *dentry)
 158 {
 159         audit_inode_child(dentry, inode);
 160
 161         fsnotify(inode, FS_CREATE, dentry->d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name, 0);
 162 }
 163
 164 /*
 165  * fsnotify_link - new hardlink in 'inode' directory
 166  * Note: We have to pass also the linked inode ptr as some filesystems leave
 167  *   new_dentry->d_inode NULL and instantiate inode pointer later
 168  */
 169 static inline void fsnotify_link(struct inode *dir, struct inode *inode, struct dentry *new_dentry)
 170 {
 171         fsnotify_link_count(inode);
 172         audit_inode_child(new_dentry, dir);
 173
 174         fsnotify(dir, FS_CREATE, inode, FSNOTIFY_EVENT_INODE, new_dentry->d_name.name, 0);
 175 }
 176
 177 /*
 178  * fsnotify_mkdir - directory 'name' was created
 179  */
 180 static inline void fsnotify_mkdir(struct inode *inode, struct dentry *dentry)
 181 {
 182         __u32 mask = (FS_CREATE | FS_ISDIR);
 183         struct inode *d_inode = dentry->d_inode;
 184
 185         audit_inode_child(dentry, inode);
 186
 187         fsnotify(inode, mask, d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name, 0);
 188 }
 189
 190 /*
 191  * fsnotify_access - file was read
 192  */
 193 static inline void fsnotify_access(struct file *file)
 194 {
 195         struct path *path = &file->f_path;
 196         struct inode *inode = path->dentry->d_inode;
 197         __u32 mask = FS_ACCESS;
 198
 199         if (S_ISDIR(inode->i_mode))
 200                 mask |= FS_ISDIR;
 201
 202         if (!(file->f_mode & FMODE_NONOTIFY)) {
 203                 fsnotify_parent(path, NULL, mask);
 204                 fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
 205         }
 206 }
 207
 208 /*
 209  * fsnotify_modify - file was modified
 210  */
 211 static inline void fsnotify_modify(struct file *file)
 212 {
 213         struct path *path = &file->f_path;
 214         struct inode *inode = path->dentry->d_inode;
 215         __u32 mask = FS_MODIFY;
 216
 217         if (S_ISDIR(inode->i_mode))
 218                 mask |= FS_ISDIR;
 219
 220         if (!(file->f_mode & FMODE_NONOTIFY)) {
 221                 fsnotify_parent(path, NULL, mask);
 222                 fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
 223         }
 224 }
 225
 226 /*
 227  * fsnotify_open - file was opened
 228  */
 229 static inline void fsnotify_open(struct file *file)
 230 {
 231         struct path *path = &file->f_path;
 232         struct inode *inode = path->dentry->d_inode;
 233         __u32 mask = FS_OPEN;
 234
 235         if (S_ISDIR(inode->i_mode))
 236                 mask |= FS_ISDIR;
 237
 238         /* FMODE_NONOTIFY must never be set from user */
 239         file->f_mode &= ~FMODE_NONOTIFY;
 240
 241         fsnotify_parent(path, NULL, mask);
 242         fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
 243 }
 244
 245 /*
 246  * fsnotify_close - file was closed
 247  */
 248 static inline void fsnotify_close(struct file *file)
 249 {
 250         struct path *path = &file->f_path;
 251         struct inode *inode = file->f_path.dentry->d_inode;
 252         fmode_t mode = file->f_mode;
 253         __u32 mask = (mode & FMODE_WRITE) ? FS_CLOSE_WRITE : FS_CLOSE_NOWRITE;
 254
 255         if (S_ISDIR(inode->i_mode))
 256                 mask |= FS_ISDIR;
 257
 258         if (!(file->f_mode & FMODE_NONOTIFY)) {
 259                 fsnotify_parent(path, NULL, mask);
 260                 fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
 261         }
 262 }
 263
 264 /*
 265  * fsnotify_xattr - extended attributes were changed
 266  */
 267 static inline void fsnotify_xattr(struct dentry *dentry)
 268 {
 269         struct inode *inode = dentry->d_inode;
 270         __u32 mask = FS_ATTRIB;
 271
 272         if (S_ISDIR(inode->i_mode))
 273                 mask |= FS_ISDIR;
 274
 275         fsnotify_parent(NULL, dentry, mask);
 276         fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
 277 }
 278
 279 /*
 280  * fsnotify_change - notify_change event.  file was modified and/or metadata
 281  * was changed.
 282  */
 283 static inline void fsnotify_change(struct dentry *dentry, unsigned int ia_valid)
 284 {
 285         struct inode *inode = dentry->d_inode;
 286         __u32 mask = 0;
 287
 288         if (ia_valid & ATTR_UID)
 289                 mask |= FS_ATTRIB;
 290         if (ia_valid & ATTR_GID)
 291                 mask |= FS_ATTRIB;
 292         if (ia_valid & ATTR_SIZE)
 293                 mask |= FS_MODIFY;
 294
 295         /* both times implies a utime(s) call */
 296         if ((ia_valid & (ATTR_ATIME | ATTR_MTIME)) == (ATTR_ATIME | ATTR_MTIME))
 297                 mask |= FS_ATTRIB;
 298         else if (ia_valid & ATTR_ATIME)
 299                 mask |= FS_ACCESS;
 300         else if (ia_valid & ATTR_MTIME)
 301                 mask |= FS_MODIFY;
 302
 303         if (ia_valid & ATTR_MODE)
 304                 mask |= FS_ATTRIB;
 305
 306         if (mask) {
 307                 if (S_ISDIR(inode->i_mode))
 308                         mask |= FS_ISDIR;
 309
 310                 fsnotify_parent(NULL, dentry, mask);
 311                 fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
 312         }
 313 }
 314
 315 #if defined(CONFIG_FSNOTIFY)    /* notify helpers */
 316
 317 /*
 318  * fsnotify_oldname_init - save off the old filename before we change it
 319  */
 320 static inline const unsigned char *fsnotify_oldname_init(const unsigned char *name)
 321 {
 322         return kstrdup(name, GFP_KERNEL);
 323 }
 324
 325 /*
 326  * fsnotify_oldname_free - free the name we got from fsnotify_oldname_init
 327  */
 328 static inline void fsnotify_oldname_free(const unsigned char *old_name)
 329 {
 330         kfree(old_name);
 331 }
 332
 333 #else   /* CONFIG_FSNOTIFY */
 334
 335 static inline const char *fsnotify_oldname_init(const unsigned char *name)
 336 {
 337         return NULL;
 338 }
 339
 340 static inline void fsnotify_oldname_free(const unsigned char *old_name)
 341 {
 342 }
 343
 344 #endif  /*  CONFIG_FSNOTIFY */
 345
 346 #endif  /* _LINUX_FS_NOTIFY_H */