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