K 10
svn:author
V 3
sef
K 8
svn:date
V 27
2019-09-23T04:28:07.724183Z
K 7
svn:log
V 589
Add two options to allow mount to avoid covering up existing mount points.
The two options are

* nocover/cover:  Prevent/allow mounting over an existing root mountpoint.
E.g., "mount -t ufs -o nocover /dev/sd1a /usr/local" will fail if /usr/local
is already a mountpoint.
* emptydir/noemptydir:  Prevent/allow mounting on a non-empty directory.
E.g., "mount -t ufs -o emptydir /dev/sd1a /usr" will fail.

Neither of these options is intended to be a default, for historical and
compatibility reasons.

Reviewed by:	allanjude, kib
Differential Revision:	https://reviews.freebsd.org/D21458

END