[arch-general] iniitcpio root device check

[Dwight Schauer]

I have an arch linux install running in qemu using a 9p virtual root
filesystem (root filesystem is just a sub directory on the host).

This is the line I use to launch it:

qemu-system-x86_64 -enable-kvm -virtfs
local,path=$(pwd)/wn-root,security_model=mapped,mount_tag=wn-root -smp
2 -m 1024 -kernel ./wn-root/boot/vmlinuz26 -append 'rootfstype=9p
rootflags="trans=virtio,version=9p2000.L" root=wn-root ro
rootdelay=10' --initrd ./wn-root/boot/kernel26-fallback.img -net vde
-net nic,vlan=0,macaddr=52:54:00:00:EE:03

Immediately after "::Running Hook [resume]" though I get:

Root device 'wn-root' does'nt exist. Attempting to create it.
ERROR: Unable to determine major/minor number of root device 'wn-root'.

At that point I'm dropped into the recovery shell, I exit that, it
complains, but continues to boot fine as it the existence in /dev/ of
a 9p filesystem source is not needed.

I did not find anything in mkinitcpio.conf to disable this check,
which in this case is not needed, as the root filesystem is mounted
without any problem.

Using 9p for a kvm root filesystem is useful for cases where something
like Linux containers (LXC) is not sufficient to accomplish some task.

For the most part this is working fine, still have some 9p filesystem
oddities to work through. For instance, syslog-ng won't start and
using makepkg on some packages results in "cat: -: No such file or
directory" (that error does not occur when that arch install is
chrooted into and build run from inside the chroot). The 9p issues are
not relevant to the initcpio workaround I'm looking for though.

Dwight