Re: [libvirt] [PATCH v2 2/3] qemu: first wait all workers finish on state cleanup

On 10/04/2016 10:27 AM, Nikolay Shirokovskiy wrote: > This fix the crash [1] > > This happens on race conditions of simultaneous exiting libvirtd and qemu process. > Let's just finish all workers that keep driver pointer before disposing > driver object or any of its members. > > [1] crash backtrace: (bt is shortened a bit): Before pushing I'll reword the above just a little bit for readability > > 0 0x00007ffff7282f2b in virClassIsDerivedFrom (klass=0xdeadbeef, parent=0x55555581d650) at util/virobject.c:169 > 1 0x00007ffff72835fd in virObjectIsClass (anyobj=0x7fffd024f580, klass=0x55555581d650) at util/virobject.c:365 > 2 0x00007ffff7283498 in virObjectLock (anyobj=0x7fffd024f580) at util/virobject.c:317 > 3 0x00007ffff722f0a3 in virCloseCallbacksUnset (closeCallbacks=0x7fffd024f580, vm=0x7fffd0194db0, > cb=0x7fffdf1af765 <qemuProcessAutoDestroy>) at util/virclosecallbacks.c:164 > 4 0x00007fffdf1afa7b in qemuProcessAutoDestroyRemove (driver=0x7fffd00f3a60, vm=0x7fffd0194db0) > at qemu/qemu_process.c:6365 > 5 0x00007fffdf1adff1 in qemuProcessStop (driver=0x7fffd00f3a60, vm=0x7fffd0194db0, > reason=VIR_DOMAIN_SHUTOFF_CRASHED, asyncJob=QEMU_ASYNC_JOB_NONE, flags=0) at qemu/qemu_process.c:5877 > 6 0x00007fffdf1f711c in processMonitorEOFEvent (driver=0x7fffd00f3a60, vm=0x7fffd0194db0) > at qemu/qemu_driver.c:4545 > 7 0x00007fffdf1f7313 in qemuProcessEventHandler (data=0x555555832710, opaque=0x7fffd00f3a60) > at qemu/qemu_driver.c:4589 > 8 0x00007ffff72a84c4 in virThreadPoolWorker (opaque=0x555555805da0) at util/virthreadpool.c:167 > > Thread 1 (Thread 0x7ffff7fb1880 (LWP 494472)): > 1 0x00007ffff72a7898 in virCondWait (c=0x7fffd01c21f8, m=0x7fffd01c21a0) at util/virthread.c:154 > 2 0x00007ffff72a8a22 in virThreadPoolFree (pool=0x7fffd01c2160) at util/virthreadpool.c:290 > 3 0x00007fffdf1edd44 in qemuStateCleanup () at qemu/qemu_driver.c:1102 > 4 0x00007ffff736570a in virStateCleanup () at libvirt.c:807 > 5 0x000055555556f991 in main (argc=1, argv=0x7fffffffe458) at libvirtd.c:1660 > --- > src/qemu/qemu_driver.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c > index 12ddbc0..58753ea 100644 > --- a/src/qemu/qemu_driver.c > +++ b/src/qemu/qemu_driver.c > @@ -1068,6 +1068,7 @@ qemuStateCleanup(void) > if (!qemu_driver) > return -1; > > + virThreadPoolFree(qemu_driver->workerPool); For this one - your thoughts on swapping the order to be NWFilterUnRegister and ThreadPoolFree(workerPool)? Nothing in the NW filter call back jumps out at me as generating a workerPool job, but since the order of Initialization is workerPool, then NWFilterCallbackRegister I figure the order to Cleanup should just be inversed.

ACK for what's here, but I'll await yours or any other feedback on swapping before pushing. John > virNWFilterUnRegisterCallbackDriver(&qemuCallbackDriver); > virObjectUnref(qemu_driver->config); > virObjectUnref(qemu_driver->hostdevMgr); > @@ -1099,7 +1100,6 @@ qemuStateCleanup(void) > virLockManagerPluginUnref(qemu_driver->lockManager); > > virMutexDestroy(&qemu_driver->lock); > - virThreadPoolFree(qemu_driver->workerPool); > VIR_FREE(qemu_driver); > > return 0; >