Re: [libvirt] [PATCH] create a thread to handle MigrationParamReset to avoid deadlock

From: Li XueLei <li.xuelei1(a)zte.com.cn&gt; Libvirtd no longer receives external requests, after I do the following. Steps to reproduce: 1.Virsh tool initiates a non-p2p migrations. 2.After the phase of qemuDomainMigratePerform3 and before the phase of qemuDomainMigrateConfirm3, kill the virsh client which initiated the migration. What happens: Libvirtd will be blocked in the next call stack because it can't get the condition variables, and it will not be able to receive new requests. Thread 1 (Thread 0x7f36a7b9f8c0 (LWP 27556)): #0 0x00007f36a45799f5 in pthread_cond_wait@(a)GLIBC_2.3.2 () from /lib64/libpthread.so.0 #1 0x00007f36a6e7a97e in virCondWait () from /lib64/libvirt.so.0 #2 0x00007f3679c6a1b3 in qemuMonitorSend () from /usr/lib64/libvirt/connection-driver/libvirt_driver_qemu.so #3 0x00007f3679c837de in qemuMonitorJSONCommandWithFd () from /usr/lib64/libvirt/connection-driver/libvirt_driver_qemu.so #4 0x00007f3679c93c5a in qemuMonitorJSONSetMigrationCapabilities () from /usr/lib64/libvirt/connection-driver/libvirt_driver_qemu.so #5 0x00007f3679c786ed in qemuMonitorSetMigrationCapabilities () from /usr/lib64/libvirt/connection-driver/libvirt_driver_qemu.so #6 0x00007f3679c67857 in qemuMigrationParamsApply () from /usr/lib64/libvirt/connection-driver/libvirt_driver_qemu.so #7 0x00007f3679c67eff in qemuMigrationParamsReset () from /usr/lib64/libvirt/connection-driver/libvirt_driver_qemu.so #8 0x00007f3679c5198a in qemuMigrationSrcCleanup () from /usr/lib64/libvirt/connection-driver/libvirt_driver_qemu.so #9 0x00007f36a6dcd862 in virCloseCallbacksRun () from /lib64/libvirt.so.0 #10 0x00007f3679cc28f6 in qemuConnectClose () from /usr/lib64/libvirt/connection-driver/libvirt_driver_qemu.so #11 0x00007f36a70a0870 in virConnectDispose () from /lib64/libvirt.so.0 #12 0x00007f36a6e3f43b in virObjectUnref () from /lib64/libvirt.so.0 #13 0x00007f36a70a55c4 in virConnectClose () from /lib64/libvirt.so.0 #14 0x000056058a206f92 in remoteClientFree () #15 0x00007f36a6fa49a0 in virNetServerClientDispose () from /lib64/libvirt.so.0 #16 0x00007f36a6e3f43b in virObjectUnref () from /lib64/libvirt.so.0 #17 0x00007f36a6e3fd21 in virObjectFreeCallback () from /lib64/libvirt.so.0 #18 0x00007f36a6f9942e in virNetSocketEventFree () from /lib64/libvirt.so.0 #19 0x00007f36a6de8439 in virEventPollCleanupHandles () from /lib64/libvirt.so.0 #20 0x00007f36a6de9ab6 in virEventPollRunOnce () from /lib64/libvirt.so.0 #21 0x00007f36a6de817a in virEventRunDefaultImpl () from /lib64/libvirt.so.0 #22 0x00007f36a6faadb5 in virNetDaemonRun () from /lib64/libvirt.so.0 #23 0x000056058a1c5cc1 in main ()