==== run-regress-async-mount ====
vnconfig -u $(<vnd) 2>/dev/null || true
/bin/sh: vnd: No such file or directory
umount -f /mnt/regress-vnd 2>/dev/null || true
mkdir -p /mnt/regress-vnd
mount_mfs -s1M -oasync swap /mnt/regress-vnd
dd if=/dev/zero of=/mnt/regress-vnd/disk.img count=1024
1024+0 records in
1024+0 records out
524288 bytes transferred in 0.010 secs (50229039 bytes/sec)
vnconfig /mnt/regress-vnd/disk.img >vnd
fdisk -iy -b "960@64:0c" $(<vnd)
Writing MBR at offset 0.
newfs -t msdos $(<vnd)i
/dev/rvnd0i: 920 sectors in 115 FAT12 clusters (4096 bytes/cluster)
bps=512 spc=8 res=1 nft=2 rde=512 sec=960 mid=0xf8 spf=1 spt=63 hds=1 hid=64

==== cleanup ====
vnconfig -u $(<vnd) 2>/dev/null || true
umount -f /mnt/regress-vnd 2>/dev/null || true
rmdir /mnt/regress-vnd 2>/dev/null || true