/*
* Read ntfs dir like stream of attr_indexentry, not like btree of them.
* This is done by scanning $BITMAP:$I30 for busy clusters and reading them.
* Of course $INDEX_ROOT:$I30 is read before. Last read values are stored in
* fnode, so we can skip toward record number num almost immediately.
* Anyway this is rather slow routine. The problem is that we don't know
* how many records are there in $INDEX_ALLOCATION:$I30 block.
*/