On Wed, Mar 16, 2011 at 02:54:28PM +0800, Wen Congyang wrote:
Steps to reproduce this bug: # virsh qemu-monitor-command domain 'cpu_set 2 online' --hmp The domain has 2 cpus, and we try to set the third cpu online. The qemu crashes, and this command will hang.
The reason is that the refs is not 1 when we unwatch the monitor. We lock the monitor, but we do not unlock it. So virCondWait() will be blocked.
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
--- src/qemu/qemu_monitor.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c index da38096..dc08594 100644 --- a/src/qemu/qemu_monitor.c +++ b/src/qemu/qemu_monitor.c @@ -239,7 +239,8 @@ qemuMonitorUnwatch(void *monitor) qemuMonitorPtr mon = monitor;
qemuMonitorLock(mon); - qemuMonitorUnref(mon); + if (qemuMonitorUnref(mon) > 0) + qemuMonitorUnlock(mon); }
ACK We should probably annotate qemuMonitorUnref() (and similar functions) with ATTRIBUTE_RETURN_CHECK too Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|