This is really simple in tmpfs since the VFS already takes care of
shuffling the dentries.  Just adjust nlink on parent directories and touch
c & mtimes.
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
Acked-by: NHugh Dickins <hughd@google.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>