> -----Original Message----- > From: Greg KH [mailto:gregkh@xxxxxxxxxxxxxxxxxxx] > Sent: Thursday, March 31, 2016 1:19 PM > To: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> > Cc: KY Srinivasan <kys@xxxxxxxxxxxxx>; olaf@xxxxxxxxx; > jasowang@xxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; apw@xxxxxxxxxxxxx; > devel@xxxxxxxxxxxxxxxxxxxxxx > Subject: Re: [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@xxxxxxxxxxxxx> writes: > > > > > From: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> > > > > > > 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@xxxxxxxxxx> > > > Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx> > > > > 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? Will do. Thanks, K. Y > > thanks, > > greg k-h _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
