"loopback mount" via vnd feature request

["Toru Nishimura" <locore64%alkyltechnology.com@localhost>]

Hi,

NetBSD can do mount regular files just like L*, however,
the way to practice it is awkward.  I include my own
(incomplete) shell scripts to ease the daily ISO image
(re-)mounting burden at the bottom.

The issue here is that our vnconfig (vnode-config) is
unable to show off which file is bound with vnd device alive.
The addition of -l option is not optimal since showing inode
number is no better than debug'ng feature.  It'd nice to
provide a straight-and-easy-to-use way for loopback mounting.
Possible implementations would vary, I suppose.

/// mount-iso ///
#!/bin/ksh

any="vnd0 vnd1 vnd2 vnd3"
mnt=${2-/removal}

if [ ! -f $1 ]
then
       echo 2>&1 "Usage: mount-iso <iso_image> [<mntdir>]"
       exit 1
fi
if /sbin/mount | egrep "vnd[0-9]a on $mnt type"
then
       echo 2>&1 "$mnt is in use"
       exit 1
fi

for i in $any
do
       /usr/sbin/vnconfig -c $i $1 2>/dev/null
       [ $? -ne 0 ] && continue

       /sbin/mount_cd9660 -o ro /dev/${i}a $mnt
       /sbin/mount | egrep "$mnt type"
       exit $?
done
echo 2>&1 "All of $any in use"
exit 1

/// umount-iso ///
#!/bin/ksh

mnt=${1-/removal}

/sbin/mount | egrep "vnd[0-9]a on $mnt type"
if [ $? -ne 0 ]
then
       echo 2>&1 "$mnt is not in use"
       exit 1
fi

dev=$(/sbin/mount | awk '$3 == "'$mnt'" { print $1 }')
dev=${dev##/dev/}
dev=${dev%a}

/sbin/umount $mnt && /usr/sbin/vnconfig -u $dev

---

Toru Nishimura / ALKYL Technology