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