b4efea53e0
moea_pvo_remove() might remove the last mapping of a page, in which case it is clearly no longer writeable. This can happen via pmap_remove(), or when a CoW fault removes the last mapping of the old page. Reported and tested by: bdragon Reviewed by: alc, bdragon, kib MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D22044