ROOT_DEV usage in hostfs

[Christoph Hellwig <hch@lst.de>]

Could someone explain why hosts does thnings like:

	if((ino->i_sb->s_dev == ROOT_DEV) && (ino->i_uid == getuid()))
		ino->i_uid = 0;

(in fs/hostfs/hostfs_kern.c:read_name())

and

	if(attr->ia_valid & ATTR_UID){
		if((dentry->d_inode->i_sb->s_dev == ROOT_DEV) &&
		   (attr->ia_uid == 0))
			attr->ia_uid = getuid();
		attrs.ia_valid |= HOSTFS_ATTR_UID;
		attrs.ia_uid = attr->ia_uid;
	}
	if(attr->ia_valid & ATTR_GID){
		if((dentry->d_inode->i_sb->s_dev == ROOT_DEV) &&
		   (attr->ia_gid == 0))
			attr->ia_gid = getuid();
		attrs.ia_valid |= HOSTFS_ATTR_GID;
		attrs.ia_gid = attr->ia_gid;
	}

(hostfs_getattr)

A filesystems shouldn't have special casing for the rootfs, and
chowning files from root to the current user sounds like an extremly
bad idea to me aswell.

It's also the last thing preventing us from exporting ROOT_DEV