On 03/10/2017 03:50 PM, Martin Kletzander wrote: > On Fri, Mar 10, 2017 at 01:41:23PM +0100, Michal Privoznik wrote: >> https://bugzilla.redhat.com/show_bug.cgi?id=1430634 >> >> If a qemu process has died, we get EOF on its monitor. At this >> point, since qemu process was the only one running in the >> namespace kernel has already cleaned the namespace up. Any >> attempt of ours to enter it has to fail. >> >> This really happened in the bug linked above. We've tried to >> attach a disk to qemu and while we were in the monitor talking to >> qemu it just died. Therefore our code tried to do some roll back >> (e.g. deny the device in cgroups again, restore labels, etc.). >> However, during the roll back (esp. when restoring labels) we >> still thought that domain has a namespace. So we used secdriver's >> transactions. This failed as there is no namespace to enter. >> >> Signed-off-by: Michal Privoznik <mprivozn@xxxxxxxxxx> >> --- >> src/qemu/qemu_domain.c | 25 +++++++++++++++++++++++++ >> src/qemu/qemu_domain.h | 3 +++ >> src/qemu/qemu_process.c | 4 ++++ >> 3 files changed, 32 insertions(+) >> >> diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c >> index 1a42fcf1b..d5833b026 100644 >> --- a/src/qemu/qemu_domain.c >> +++ b/src/qemu/qemu_domain.c >> @@ -201,6 +201,22 @@ qemuDomainEnableNamespace(virDomainObjPtr vm, >> } >> >> >> +static void >> +qemuDomainDisableNamespace(virDomainObjPtr vm, >> + qemuDomainNamespace ns) >> +{ >> + qemuDomainObjPrivatePtr priv = vm->privateData; >> + >> + if (priv->namespaces) { >> + ignore_value(virBitmapClearBit(priv->namespaces, ns)); >> + if (virBitmapIsAllClear(priv->namespaces)) { >> + virBitmapFree(priv->namespaces); >> + priv->namespaces = NULL; >> + } >> + } >> +} >> + > > This function is written in a way that... > >> @@ -7805,6 +7821,15 @@ qemuDomainCreateNamespace(virQEMUDriverPtr driver, >> } >> >> >> +void >> +qemuDomainDestroyNamespace(virQEMUDriverPtr driver ATTRIBUTE_UNUSED, >> + virDomainObjPtr vm) >> +{ >> + if (qemuDomainNamespaceEnabled(vm, QEMU_DOMAIN_NS_MOUNT)) >> + qemuDomainDisableNamespace(vm, QEMU_DOMAIN_NS_MOUNT); >> +} >> + > > ...this wrapper over it is kinda useless. But your call on whether to > keep it (I get there are some "consistency" and "naming" reasons). Yeah, I'd like to keep it for consistency reasons. I'll push this as is and if somebody disagree I'm happy to review their patch. > > ACK to this, although I feel like commit 3e6839d4e801 should be > reverted, but that's up for a discussion. It does not make *any* > difference now, but I just feel like it's cleaner that way. I was thinking about this too and I'm torn. I mean, on one side it would be great from consistency POV. On the other we would be effectively adding dead code. So I guess for now lets stick with status quo and not revert it. Michal -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list
