LXR linux/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#include <linux/bug.h>
  18
  19/*
  20 * fsnotify_d_instantiate - instantiate a dentry for inode
  21 */
  22static 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. */
  29static 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 */
  38static inline int fsnotify_perm(struct file *file, int mask)
  39{
  40        struct path *path = &file->f_path;
  41        struct inode *inode = file_inode(file);
  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 */
  66static inline void fsnotify_d_move(struct dentry *dentry)
  67{
  68        /*
  69         * On move we need to update dentry->d_flags to indicate if the new parent
  70         * cares about events from this dentry.
  71         */
  72        __fsnotify_update_dcache_flags(dentry);
  73}
  74
  75/*
  76 * fsnotify_link_count - inode's link count changed
  77 */
  78static inline void fsnotify_link_count(struct inode *inode)
  79{
  80        fsnotify(inode, FS_ATTRIB, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
  81}
  82
  83/*
  84 * fsnotify_move - file old_name at old_dir was moved to new_name at new_dir
  85 */
  86static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir,
  87                                 const unsigned char *old_name,
  88                                 int isdir, struct inode *target, struct dentry *moved)
  89{
  90        struct inode *source = moved->d_inode;
  91        u32 fs_cookie = fsnotify_get_cookie();
  92        __u32 old_dir_mask = (FS_EVENT_ON_CHILD | FS_MOVED_FROM);
  93        __u32 new_dir_mask = (FS_EVENT_ON_CHILD | FS_MOVED_TO);
  94        const unsigned char *new_name = moved->d_name.name;
  95
  96        if (old_dir == new_dir)
  97                old_dir_mask |= FS_DN_RENAME;
  98
  99        if (isdir) {
 100                old_dir_mask |= FS_ISDIR;
 101                new_dir_mask |= FS_ISDIR;
 102        }
 103
 104        fsnotify(old_dir, old_dir_mask, source, FSNOTIFY_EVENT_INODE, old_name,
 105                 fs_cookie);
 106        fsnotify(new_dir, new_dir_mask, source, FSNOTIFY_EVENT_INODE, new_name,
 107                 fs_cookie);
 108
 109        if (target)
 110                fsnotify_link_count(target);
 111
 112        if (source)
 113                fsnotify(source, FS_MOVE_SELF, moved->d_inode, FSNOTIFY_EVENT_INODE, NULL, 0);
 114        audit_inode_child(new_dir, moved, AUDIT_TYPE_CHILD_CREATE);
 115}
 116
 117/*
 118 * fsnotify_inode_delete - and inode is being evicted from cache, clean up is needed
 119 */
 120static inline void fsnotify_inode_delete(struct inode *inode)
 121{
 122        __fsnotify_inode_delete(inode);
 123}
 124
 125/*
 126 * fsnotify_vfsmount_delete - a vfsmount is being destroyed, clean up is needed
 127 */
 128static inline void fsnotify_vfsmount_delete(struct vfsmount *mnt)
 129{
 130        __fsnotify_vfsmount_delete(mnt);
 131}
 132
 133/*
 134 * fsnotify_nameremove - a filename was removed from a directory
 135 */
 136static inline void fsnotify_nameremove(struct dentry *dentry, int isdir)
 137{
 138        __u32 mask = FS_DELETE;
 139
 140        if (isdir)
 141                mask |= FS_ISDIR;
 142
 143        fsnotify_parent(NULL, dentry, mask);
 144}
 145
 146/*
 147 * fsnotify_inoderemove - an inode is going away
 148 */
 149static inline void fsnotify_inoderemove(struct inode *inode)
 150{
 151        fsnotify(inode, FS_DELETE_SELF, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
 152        __fsnotify_inode_delete(inode);
 153}
 154
 155/*
 156 * fsnotify_create - 'name' was linked in
 157 */
 158static inline void fsnotify_create(struct inode *inode, struct dentry *dentry)
 159{
 160        audit_inode_child(inode, dentry, AUDIT_TYPE_CHILD_CREATE);
 161
 162        fsnotify(inode, FS_CREATE, dentry->d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name, 0);
 163}
 164
 165/*
 166 * fsnotify_link - new hardlink in 'inode' directory
 167 * Note: We have to pass also the linked inode ptr as some filesystems leave
 168 *   new_dentry->d_inode NULL and instantiate inode pointer later
 169 */
 170static inline void fsnotify_link(struct inode *dir, struct inode *inode, struct dentry *new_dentry)
 171{
 172        fsnotify_link_count(inode);
 173        audit_inode_child(dir, new_dentry, AUDIT_TYPE_CHILD_CREATE);
 174
 175        fsnotify(dir, FS_CREATE, inode, FSNOTIFY_EVENT_INODE, new_dentry->d_name.name, 0);
 176}
 177
 178/*
 179 * fsnotify_mkdir - directory 'name' was created
 180 */
 181static inline void fsnotify_mkdir(struct inode *inode, struct dentry *dentry)
 182{
 183        __u32 mask = (FS_CREATE | FS_ISDIR);
 184        struct inode *d_inode = dentry->d_inode;
 185
 186        audit_inode_child(inode, dentry, AUDIT_TYPE_CHILD_CREATE);
 187
 188        fsnotify(inode, mask, d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name, 0);
 189}
 190
 191/*
 192 * fsnotify_access - file was read
 193 */
 194static inline void fsnotify_access(struct file *file)
 195{
 196        struct path *path = &file->f_path;
 197        struct inode *inode = file_inode(file);
 198        __u32 mask = FS_ACCESS;
 199
 200        if (S_ISDIR(inode->i_mode))
 201                mask |= FS_ISDIR;
 202
 203        if (!(file->f_mode & FMODE_NONOTIFY)) {
 204                fsnotify_parent(path, NULL, mask);
 205                fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
 206        }
 207}
 208
 209/*
 210 * fsnotify_modify - file was modified
 211 */
 212static inline void fsnotify_modify(struct file *file)
 213{
 214        struct path *path = &file->f_path;
 215        struct inode *inode = file_inode(file);
 216        __u32 mask = FS_MODIFY;
 217
 218        if (S_ISDIR(inode->i_mode))
 219                mask |= FS_ISDIR;
 220
 221        if (!(file->f_mode & FMODE_NONOTIFY)) {
 222                fsnotify_parent(path, NULL, mask);
 223                fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
 224        }
 225}
 226
 227/*
 228 * fsnotify_open - file was opened
 229 */
 230static inline void fsnotify_open(struct file *file)
 231{
 232        struct path *path = &file->f_path;
 233        struct inode *inode = file_inode(file);
 234        __u32 mask = FS_OPEN;
 235
 236        if (S_ISDIR(inode->i_mode))
 237                mask |= FS_ISDIR;
 238
 239        fsnotify_parent(path, NULL, mask);
 240        fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
 241}
 242
 243/*
 244 * fsnotify_close - file was closed
 245 */
 246static inline void fsnotify_close(struct file *file)
 247{
 248        struct path *path = &file->f_path;
 249        struct inode *inode = file_inode(file);
 250        fmode_t mode = file->f_mode;
 251        __u32 mask = (mode & FMODE_WRITE) ? FS_CLOSE_WRITE : FS_CLOSE_NOWRITE;
 252
 253        if (S_ISDIR(inode->i_mode))
 254                mask |= FS_ISDIR;
 255
 256        if (!(file->f_mode & FMODE_NONOTIFY)) {
 257                fsnotify_parent(path, NULL, mask);
 258                fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
 259        }
 260}
 261
 262/*
 263 * fsnotify_xattr - extended attributes were changed
 264 */
 265static inline void fsnotify_xattr(struct dentry *dentry)
 266{
 267        struct inode *inode = dentry->d_inode;
 268        __u32 mask = FS_ATTRIB;
 269
 270        if (S_ISDIR(inode->i_mode))
 271                mask |= FS_ISDIR;
 272
 273        fsnotify_parent(NULL, dentry, mask);
 274        fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
 275}
 276
 277/*
 278 * fsnotify_change - notify_change event.  file was modified and/or metadata
 279 * was changed.
 280 */
 281static inline void fsnotify_change(struct dentry *dentry, unsigned int ia_valid)
 282{
 283        struct inode *inode = dentry->d_inode;
 284        __u32 mask = 0;
 285
 286        if (ia_valid & ATTR_UID)
 287                mask |= FS_ATTRIB;
 288        if (ia_valid & ATTR_GID)
 289                mask |= FS_ATTRIB;
 290        if (ia_valid & ATTR_SIZE)
 291                mask |= FS_MODIFY;
 292
 293        /* both times implies a utime(s) call */
 294        if ((ia_valid & (ATTR_ATIME | ATTR_MTIME)) == (ATTR_ATIME | ATTR_MTIME))
 295                mask |= FS_ATTRIB;
 296        else if (ia_valid & ATTR_ATIME)
 297                mask |= FS_ACCESS;
 298        else if (ia_valid & ATTR_MTIME)
 299                mask |= FS_MODIFY;
 300
 301        if (ia_valid & ATTR_MODE)
 302                mask |= FS_ATTRIB;
 303
 304        if (mask) {
 305                if (S_ISDIR(inode->i_mode))
 306                        mask |= FS_ISDIR;
 307
 308                fsnotify_parent(NULL, dentry, mask);
 309                fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
 310        }
 311}
 312
 313#if defined(CONFIG_FSNOTIFY)    /* notify helpers */
 314
 315/*
 316 * fsnotify_oldname_init - save off the old filename before we change it
 317 */
 318static inline const unsigned char *fsnotify_oldname_init(const unsigned char *name)
 319{
 320        return kstrdup(name, GFP_KERNEL);
 321}
 322
 323/*
 324 * fsnotify_oldname_free - free the name we got from fsnotify_oldname_init
 325 */
 326static inline void fsnotify_oldname_free(const unsigned char *old_name)
 327{
 328        kfree(old_name);
 329}
 330
 331#else   /* CONFIG_FSNOTIFY */
 332
 333static inline const char *fsnotify_oldname_init(const unsigned char *name)
 334{
 335        return NULL;
 336}
 337
 338static inline void fsnotify_oldname_free(const unsigned char *old_name)
 339{
 340}
 341
 342#endif  /*  CONFIG_FSNOTIFY */
 343
 344#endif  /* _LINUX_FS_NOTIFY_H */
 345