fs/reiser4/plugin/dir/seekable_dir.c

   1 /* Copyright 2005 by Hans Reiser, licensing governed by
   2  * reiser4/README */
   3
   4 #include "../../inode.h"
   5
   6 /* this is implementation of build_entry_key method of dir
   7    plugin for SEEKABLE_HASHED_DIR_PLUGIN_ID
   8    This is for directories where we want repeatable and restartable readdir()
   9    even in case 32bit user level struct dirent (readdir(3)).
  10 */
  11 void
  12 build_entry_key_seekable(const struct inode *dir, const struct qstr *name,
  13                          reiser4_key * result)
  14 {
  15         oid_t objectid;
  16
  17         assert("nikita-2283", dir != NULL);
  18         assert("nikita-2284", name != NULL);
  19         assert("nikita-2285", name->name != NULL);
  20         assert("nikita-2286", result != NULL);
  21
  22         reiser4_key_init(result);
  23         /* locality of directory entry's key is objectid of parent
  24            directory */
  25         set_key_locality(result, get_inode_oid(dir));
  26         /* minor packing locality is constant */
  27         set_key_type(result, KEY_FILE_NAME_MINOR);
  28         /* dot is special case---we always want it to be first entry in
  29            a directory. Actually, we just want to have smallest
  30            directory entry.
  31          */
  32         if ((name->len == 1) && (name->name[0] == '.'))
  33                 return;
  34
  35         /* objectid of key is 31 lowest bits of hash. */
  36         objectid =
  37             inode_hash_plugin(dir)->hash(name->name,
  38                                          (int)name->len) & 0x7fffffff;
  39
  40         assert("nikita-2303", !(objectid & ~KEY_OBJECTID_MASK));
  41         set_key_objectid(result, objectid);
  42
  43         /* offset is always 0. */
  44         set_key_offset(result, (__u64) 0);
  45         return;
  46 }