Re: [libvirt] [PATCH v2] qemu_agent: Ignore expected EOFs

https://bugzilla.redhat.com/show_bug.cgi?id=892079 One of my previous patches (f2a4e5f176c408) tried to fix crashing libvirtd on domain detroy. However, we need to copy pattern from qemuProcessHandleMonitorEOF() instead of decrementing reference counter. The rationale for this is, if qemu process is dying due to domain being destroyed, we obtain EOF on both the monitor and agent sockets. However, if the exit is expected, qemuProcessStop is called, which cleans both agent and monitor sockets up. We want qemuAgentClose() to be called iff the EOF is not expected, so we don't leak an FD and memory. --- diff to v1: -handle race with qemuProcessHandleMonitorEOF correctly src/qemu/qemu_process.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c index 2f08215..013b2ca 100644 --- a/src/qemu/qemu_process.c +++ b/src/qemu/qemu_process.c @@ -133,14 +133,30 @@ qemuProcessHandleAgentEOF(qemuAgentPtr agent, virObjectLock(vm); priv = vm->privateData; - if (priv->agent == agent && - !virObjectUnref(priv->agent)) + + if (!priv->agent) { + VIR_DEBUG("Agent freed already"); + goto unlock; + }

+ + if (priv->beingDestroyed) { + VIR_DEBUG("Domain is being destroyed, agent EOF is expected"); + goto unlock; + } + + if (priv->agent == agent) priv->agent = NULL;

virObjectUnlock(vm); qemuDriverUnlock(driver); qemuAgentClose(agent); + return; + +unlock: + virObjectUnlock(vm); + qemuDriverUnlock(driver); + return; }