[libvirt] [PATCH] fix bug libvirt daemon deadlock when another force console break down an existed console client when this deadlock hanppened, libvirtd backtrace as follow, a typical ABBA deadlock circumstance:
(gdb) thread 23
[Switching to thread 23 (Thread 0x7fbb54810700 (LWP 296966))]
(gdb) bt
at rpc/virnetserverclient.c:1503
client=client@entry=0x5641d20e20a0, msg=0x7fbb08003ab0,
rerr=rerr@entry=0x7fbb5480f7b0, procedure=201,
type=type@entry=3, serial=9) at rpc/virnetserverprogram.c:173
msg=<optimized out>, rerr=rerr@entry=0x7fbb5480f7b0, procedure=<optimized
out>, serial=<optimized out>)
at rpc/virnetserverprogram.c:222
opaque=opaque@entry=0x5641d20e20a0) at stream.c:246
force=force@entry=true) at conf/virchrdev.c:386
at qemu/qemu_driver.c:16188
st=st@entry=0x7fbb08008fc0, flags=1) at libvirt-domain.c:9363
rerr=0x7fbb5480fc10, msg=<optimized out>, client=0x5641d20e4e80) at
remote_dispatch.h:8540
rerr=0x7fbb5480fc10, args=0x7fbb08005eb0, ret=<optimized out>) at
remote_dispatch.h:8505
server=0x5641d20be420, prog=0x5641d20da580) at rpc/virnetserverprogram.c:437
msg=0x5641d20e9a20) at rpc/virnetserverprogram.c:307
srv=0x5641d20be420) at rpc/virnetserver.c:148
---Type <return> to continue, or q <return> to quit---
(gdb) thread 26
[Switching to thread 26 (Thread 0x7fbb87a378c0 (LWP 295636))]
(gdb) bt
at stream.c:286
at rpc/virnetserverclient.c:1247
at rpc/virnetserverclient.c:1457
at util/vireventpoll.c:508
Signed-off-by: LanceLiu <liu.lance.89(a)gmail.com>
---
src/remote/remote_daemon_stream.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/src/remote/remote_daemon_stream.c b/src/remote/remote_daemon_stream.c
index 1f6e783..b27348f 100644
--- a/src/remote/remote_daemon_stream.c
+++ b/src/remote/remote_daemon_stream.c
@@ -284,14 +284,16 @@ daemonStreamEvent(virStreamPtr st, int events, void *opaque)
* -1 on fatal client error
*/
static int
-daemonStreamFilter(virNetServerClientPtr client ATTRIBUTE_UNUSED,
+daemonStreamFilter(virNetServerClientPtr client,
virNetMessagePtr msg,
void *opaque)
{
daemonClientStream *stream = opaque;
int ret = 0;
+ virObjectUnlock(client);
virMutexLock(&stream->priv->lock);
+ virObjectLock(client);
if (msg->header.type != VIR_NET_STREAM &&
msg->header.type != VIR_NET_STREAM_HOLE)
--
1.8.3.1