[libvirt] [PATCH] create a thread to handle MigrationParamReset to avoid deadlock
From: Li XueLei <li.xuelei1(a)zte.com.cn>
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 ()
Here's a patch to solve this bug, that is to create a thread to do
MigrationParamReset.
Signed-off-by: Li XueLei <li.xuelei1(a)zte.com.cn>
Signed-off-by: Yi Wang <wang.yi59(a)zte.com.cn>
---
src/remote/remote_daemon_dispatch.c | 16 +++++++++++++---
1 file changed, 13 insertions(+), 3 deletions(-)
diff --git a/src/remote/remote_daemon_dispatch.c b/src/remote/remote_daemon_dispatch.c
index 76c676c..3962ee3 100644
--- a/src/remote/remote_daemon_dispatch.c
+++ b/src/remote/remote_daemon_dispatch.c
@@ -1741,9 +1741,10 @@ remoteClientFreePrivateCallbacks(struct daemonClientPrivate *priv)
* We keep the libvirt connection open until any async
* jobs have finished, then clean it up elsewhere
*/
-void remoteClientFree(void *data)
+
+static void remoteClientFreeFun(void *opaque)
{
- struct daemonClientPrivate *priv = data;
+ struct daemonClientPrivate *priv = opaque;
if (priv->conn)
virConnectClose(priv->conn);
@@ -1760,7 +1761,16 @@ void remoteClientFree(void *data)
if (priv->storageConn)
virConnectClose(priv->storageConn);
- VIR_FREE(priv);
+ VIR_FREE(priv);
+}
+
+void remoteClientFree(void *data)
+{
+ virThread thread;
+
+ if (virThreadCreate(&thread, false, remoteClientFreeFun, data) < 0) {
+ VIR_ERROR("Unable to create remoteClientFreeFun thread");
+ }
}
--
1.8.3.1