K 10
svn:author
V 3
kib
K 8
svn:date
V 27
2019-04-08T15:20:05.826508Z
K 7
svn:log
V 300
Handle races when remounting UFS volume from ro to rw.

In particular, ensure that writers are not unleashed before SU
structures are initialized.  Also, correctly handle MNT_ASYNC before
this.

Reported and tested by:	pho
Reviewed by:	mckusick
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week

END