Re: [uml-devel] NFS root

[Jeff D. <jd...@ka...>]

ch...@ch... said:
> There are a few issues that prevent NFS root from working. 

Not any more.

> 1) initcall: inet_init occurs before uml_net_init preventing us from
> registering our netdevice in time for ipconfig.

I'm not sure what the dependency there was, but it's no longer a problem.
I did add a bit of code to make sure that uml_net_init processes any IP 
addresses that had already been assigned to the UML interfaces.  

> 2) tap_open_common demands the initial open of the device to also
> specify an interface address.

This works a lot better now.  I set the interface up with dhcp from the
nfs server (another UML communicating over uml_switch).

> 3) [net/ipv4/]ipconfig.c busy waits either side of the device open
> calls but jiffies remain frozen.

It turns out there was a period of time during the boot when the timer
wasn't ticking.  This is fixed.

After this (and making sure that dhcp/bootp work), I can nfs boot one UML
off another.  The one thing I didn't figure out is what to stick in fstab
or wherever else to get a clean boot.  I ended up putting

	192.168.0.253:/nfs      /                               nfs defaults 0 0

which pursuaded fsck to ignore it, but it was mounted readonly, which screwed
the rest of the boot.

				Jeff