Re: Rebooting domu fails in nfs share exported from another domu on the same dom0

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Fri, Jul 18, 2014 at 03:31:43PM -0400, annie li wrote:
> 
> On 2014/7/18 14:53, Konrad Rzeszutek Wilk wrote:
> >On Thu, Jul 17, 2014 at 12:56:12PM -0400, annie li wrote:
> >>On 2014/7/17 11:49, Roger Pau Monné wrote:
> >>>On 16/07/14 22:36, annie li wrote:
> >>>>Hi
> >>>>
> >>>>I hit a problem in such scenario: vm1 is running and export nfs service,
> >>>>dom0 mount this nfs, and vm2 is booted in this nfs location. vm1 and vm2
> >>>>are running on the same dom0.
> >>>>
> >>>>When this bug happens, the data flow is:  vm2 blkfront-> vm2 blkback->
> >I am a bit confused here. 'vm2 blkfront -> vm2 blkback'? Did you
> >mean 'dom0 blkback'?
> 
> Yes, Dom0 blkback.
> 
> >
> >
> >>>>loop -> nfs file -> nfs client -> bridge priv1 -> vm1 vif -> vm1 netback
> >>>>-> vm1 netfront.
> >So both netback and netfront run in the same guest? I think you
> >want these two swapped around (netfront -> netback).
> 
> No, the netfront in above routine means the one in guest vm1, and this is
> network RX path in vm1.

OK, so 'dom0 netback' then. As the netback thread is running in the
initial domain?

So a revised view is:

  vm2 blkfront -> dom0 blkback -> loop -> nfs file -> nfs client
	-> bridge priv1 -> vm1 vif -> dom0 netback -> vm1 netfront

So with the grant map (blkfront -> blkback) the source is dom0
and the destination is vm1. For the grant copy, the source is
dom0 and the destinatation is vm2 right? (or did I get my src
and dst confused?).