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