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