The Linux VFS will never allow a filesystem which is in use to
be unmounted. This behavior differs from other platforms like
FreeBSD which allow a filesystem to be force unmounted. This
will result in errors being returned to applications actively
using the filesystem.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Mariusz Zaborski <oshogbo@vexillium.org>
Closes#10013
89adffb7bc