A technique for accelerating the creation of a hyperclone of a virtual
file system. A hyperclone inode is copied from the base inode. Each
indirect and direct block referenced by the base inode is also copied and
the block pointers within the base inode are set to reference the copied
direct data blocks. A CTW bit is set within each copied block that alerts
the file system that the reference indirect or direct block is not to be
deallocated.