MFC r230249:

MFC r230249:

Make sure all intermediate variables holding mount flags (mnt_flag)
and that all internal kernel calls passing mount flags are declared
as uint64_t so that flags in the top 32-bits are not lost.

MFC r230250:

There are several bugs/hangs when trying to take a snapshot on a UFS/FFS
filesystem running with journaled soft updates. Until these problems
have been tracked down, return ENOTSUPP when an attempt is made to
take a snapshot on a filesystem running with journaled soft updates.

git-svn-id: svn://svn.freebsd.org/base/stable/9@230725 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f