[PVFB][TOOLS] Terminate backend when frontend vanishes early

Ensure the backend terminates when the frontend vanishes before the
connection is established.  This happens when the guest doesn't have
the devices.

Signed-off-by: Markus Armbruster <armbru@redhat.com>

diff --git a/tools/xenfb/xenfb.c b/tools/xenfb/xenfb.c
index a692f8fd8607302cc50b6bb6029c89c6e37036cc..eb46de1c92fe8451d3eea4ff0e6bc00ef33a45b6 100644 (file)
--- a/tools/xenfb/xenfb.c
+++ b/tools/xenfb/xenfb.c
@@ -245,11 +245,10 @@ static int xenfb_wait_for_state(struct xs_handle *xsh, const char *dir,
        unsigned state, dummy;
        char **vec;
 
+       awaited |= 1 << XenbusStateUnknown;
+
        for (;;) {
                state = xenfb_read_state(xsh, dir);
-               if (state < 0)
-                       return -1;
-
                if ((1 << state) & awaited)
                        return state;