lkml.org 
[lkml]   [2016]   [Mar]   [31]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 1/6] Drivers: hv: kvp: fix IP Failover
On Tue, Mar 29, 2016 at 02:27:16PM +0200, Vitaly Kuznetsov wrote:
> "K. Y. Srinivasan" <kys@microsoft.com> writes:
>
> > From: Vitaly Kuznetsov <vkuznets@redhat.com>
> >
> > Hyper-V VMs can be replicated to another hosts and there is a feature to
> > set different IP for replicas, it is called 'Failover TCP/IP'. When
> > such guest starts Hyper-V host sends it KVP_OP_SET_IP_INFO message as soon
> > as we finish negotiation procedure. The problem is that it can happen (and
> > it actually happens) before userspace daemon connects and we reply with
> > HV_E_FAIL to the message. As there are no repetitions we fail to set the
> > requested IP.
> >
> > Solve the issue by postponing our reply to the negotiation message till
> > userspace daemon is connected. We can't wait too long as there is a
> > host-side timeout (cca. 75 seconds) and if we fail to reply in this time
> > frame the whole KVP service will become inactive. The solution is not
> > ideal - if it takes userspace daemon more than 60 seconds to connect
> > IP Failover will still fail but I don't see a solution with our current
> > separation between kernel and userspace parts.
> >
> > Other two modules (VSS and FCOPY) don't require such delay, leave them
> > untouched.
> >
> > Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
> > Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
>
> An issue was found with this patch: we don't cancel
> kvp_host_handshake_work on module unload and if the work is still
> pending we end up crashing. As far as I can see this series didn't make
> it to char-misc tree so instead of sending a patch to this patch I'll
> send v2 for the original issue.
>
> Sorry for the inconvenience.

Ok, I'll drop this whole series. K.Y., can you resend this series after
fixing this up?

thanks,

greg k-h

\
 
 \ /
  Last update: 2016-03-31 23:21    [W:0.082 / U:0.248 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site