[CONSOLED] Shouldn't call domain_create_ring() for a domU which is shutting down.

There is a race condition between domain_create_ring() and the removal
of the domU entry from xenstore. If the removal of the domU entry from xenstore
comes later than the first xs_gather() call in domain_create_ring(), it will go
on and bind the evtchn port to the dying domU, which will cause below error
message: (XEN) (file=event_channel.c, line=144) EVTCHNOP failure: domain 0, error -22, line 144

Signed-off-by: Max Zhen <max.zhen@sun.com>

diff --git a/tools/console/daemon/io.c b/tools/console/daemon/io.c
index 93f96b101d08a475371d4800bd5c7c09b73c3319..8bb18cafab7dba31ea6152da62463a148dbf6752 100644 (file)
--- a/tools/console/daemon/io.c
+++ b/tools/console/daemon/io.c
@@ -293,12 +293,14 @@ static bool watch_domain(struct domain *dom, bool watch)
        bool success;
 
        sprintf(domid_str, "dom%u", dom->domid);
-       if (watch)
+       if (watch) {
                success = xs_watch(xs, dom->conspath, domid_str);
-       else
+               if (success)
+                       domain_create_ring(dom);
+       } else {
                success = xs_unwatch(xs, dom->conspath, domid_str);
-       if (success)
-               domain_create_ring(dom);
+       }
+
        return success;
 }