A number of bugs conspired together to cause some nasty problems when
a QEMU vm failed to start
- vm->monitor was not initialized to -1, so when a VM failed to start
the vm->monitor was just '0', and thus we closed FD 0 (libvirtd's stdin)
- The next client to connect got FD 0 as its socket
- The first bug struck again, causing the client to be closed even
though libvirt thought it was still open
- libvirtd now polle on FD=0, which gave back POLLNVAL because it was
closed
- event.c was not looking for POLLNVAL so it span 100% cpu when this
happened, instead of invoking the callback with an error code
- virsh was not cleaning up the priv->watiDispatch call upon I/O errors,
so virsh then hung when doing virConenctClose
This patch does 3 things
- Treats POLLNVAL as VIR_EVENT_HANDLE_ERROR, so the callback gets
to see the error & de-registers the client from the event loop
- Add the missing initialization of vm->monitor
- Fix remote_internal.c handling of I/O errors
Daniel
Index: qemud/event.c
===================================================================
RCS file: /data/cvs/libvirt/qemud/event.c,v
retrieving revision 1.17
diff -u -p -u -p -r1.17 event.c
--- qemud/event.c 22 Dec 2008 12:55:47 -0000 1.17
+++ qemud/event.c 5 Feb 2009 17:12:51 -0000
@@ -653,6 +653,8 @@ virPollEventToEventHandleType(int events
ret |= VIR_EVENT_HANDLE_WRITABLE;
if(events & POLLERR)
ret |= VIR_EVENT_HANDLE_ERROR;
+ if(events & POLLNVAL) /* Treat NVAL as error, since libvirt doesn't distinguish */
+ ret |= VIR_EVENT_HANDLE_ERROR;
if(events & POLLHUP)
ret |= VIR_EVENT_HANDLE_HANGUP;
return ret;
Index: src/domain_conf.c
===================================================================
RCS file: /data/cvs/libvirt/src/domain_conf.c,v
retrieving revision 1.64
diff -u -p -u -p -r1.64 domain_conf.c
--- src/domain_conf.c 30 Jan 2009 21:52:22 -0000 1.64
+++ src/domain_conf.c 5 Feb 2009 17:12:51 -0000
@@ -504,6 +504,7 @@ virDomainObjPtr virDomainAssignDef(virCo
domain->state = VIR_DOMAIN_SHUTOFF;
domain->def = def;
domain->monitor_watch = -1;
+ domain->monitor = -1;
if (VIR_REALLOC_N(doms->objs, doms->count + 1) < 0) {
virReportOOMError(conn);
Index: src/remote_internal.c
===================================================================
RCS file: /data/cvs/libvirt/src/remote_internal.c,v
retrieving revision 1.136
diff -u -p -u -p -r1.136 remote_internal.c
--- src/remote_internal.c 3 Feb 2009 13:08:07 -0000 1.136
+++ src/remote_internal.c 5 Feb 2009 17:12:52 -0000
@@ -6192,17 +6192,17 @@ processCalls(virConnectPtr conn,
continue;
virReportSystemError(in_open ? NULL : conn, errno,
"%s", _("poll on socket failed"));
- return -1;
+ goto error;
}
if (fds[0].revents & POLLOUT) {
if (processCallSend(conn, priv, in_open) < 0)
- return -1;
+ goto error;
}
if (fds[0].revents & POLLIN) {
if (processCallRecv(conn, priv, in_open) < 0)
- return -1;
+ goto error;
}
/* Iterate through waiting threads and if
@@ -6253,9 +6253,21 @@ processCalls(virConnectPtr conn,
if (fds[0].revents & (POLLHUP | POLLERR)) {
errorf(in_open ? NULL : conn, VIR_ERR_INTERNAL_ERROR,
"%s", _("received hangup / error event on socket"));
- return -1;
+ goto error;
}
}
+
+
+error:
+ priv->waitDispatch = thiscall->next;
+ DEBUG("Giving up the buck due to I/O error %d %p %p", thiscall->proc_nr, thiscall, priv->waitDispatch);
+ /* See if someone else is still waiting
+ * and if so, then pass the buck ! */
+ if (priv->waitDispatch) {
+ DEBUG("Passing the buck to %d %p", priv->waitDispatch->proc_nr, priv->waitDispatch);
+ virCondSignal(&priv->waitDispatch->cond);
+ }
+ return -1;
}
/*
--
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|: http://libvirt.org -o- http://virt-manager.org -o- http://ovirt.org :|
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