Re: [libvirt] [PATCH 1/2] qemu: don't kill qemu process on restart if networkNotify fails
On 04/25/2017 12:33 PM, Laine Stump wrote:
Nothing that could happen during networkNotifyActualDevice() could
justify unceremoniously killing the qemu process, but that's what we
were doing.
So that galaxy in far far away land circa commit id '04711a0f' when all
this was added -
In particular, new code added in commit 85bcc022 (first appearred in
appeared
libvirt-3.2.0) attempts to reattach tap devices to their assigned
bridge devices when libvirtd restarts (to make it easier to recover
from a restart of a libvirt network). But if the network has been
stopped and *not* restarted, the bridge device won't exist and
networkNotifyActualDevice() will fail.
This patch changes qemuProcessNotifyNets() to return void, so that
qemuProcessReconnect() will soldier on regardless of what happens (any
errors will still be logged, but we won't terminate the guest).
Partially resolves: https://bugzilla.redhat.com/1442700
---
NB: there are many other things that might fail during reconnection of
a qemu process that shouldn't lead to killing the qemu
process. qemuProcessReconnect() could use a good audit to change what
happens when certain items fail.
Nose game, not me ;-)
src/qemu/qemu_process.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index 53170d7..fcb5763 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -2825,7 +2825,7 @@ int qemuProcessStopCPUs(virQEMUDriverPtr driver,
-static int
+static void
qemuProcessNotifyNets(virDomainDefPtr def)
{
size_t i;
@@ -2840,10 +2840,8 @@ qemuProcessNotifyNets(virDomainDefPtr def)
if (virDomainNetGetActualType(net) == VIR_DOMAIN_NET_TYPE_DIRECT)
ignore_value(virNetDevMacVLanReserveName(net->ifname, false));
- if (networkNotifyActualDevice(def, net) < 0)
- return -1;
+ networkNotifyActualDevice(def, net);
Seems like networkNotifyActualDevice should then return a void too?
And have it's comments/content changed...
IIUC thought, essentially if the network goes away, the domain isn't
necessarily shut down - it gets notified somehow that the network isn't
there any more and soldiers on. So from that aspect I can certain agree
that just because we discover an error when libvirtd restarts doesn't
mean we should now kill the domain.
I think the concept behind the patch is fine - it's the "how much more"
should be done... (and yes with the eye on keeping backports to a
minimum, yep understood).
John
}
- return 0;
}
static int
@@ -3480,8 +3478,7 @@ qemuProcessReconnect(void *opaque)
if (qemuSecurityReserveLabel(driver->securityManager, obj->def, obj->pid)
< 0)
goto error;
- if (qemuProcessNotifyNets(obj->def) < 0)
- goto error;
+ qemuProcessNotifyNets(obj->def);
if (qemuProcessFiltersInstantiate(obj->def))
goto error;