[PATCH 2/4] Avoid bogus I/O event errors when closing the QEMU monitor

["Daniel P. Berrange" <berrange@xxxxxxxxxx>]

From: "Daniel P. Berrange" <berrange@xxxxxxxxxx>

After calling qemuMonitorClose(), it is still possible for
the QEMU monitor I/O event callback to get invoked. This
will trigger an error message because mon->fd has been set
to -1 at this point. Silently ignore the case where mon->fd
is -1, likewise for mon->watch being zero.

Signed-off-by: Daniel P. Berrange <berrange@xxxxxxxxxx>
---
 src/qemu/qemu_monitor.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c
index cb121e8..6c3f09e 100644
--- a/src/qemu/qemu_monitor.c
+++ b/src/qemu/qemu_monitor.c
@@ -538,6 +538,9 @@ static void qemuMonitorUpdateWatch(qemuMonitorPtr mon)
         VIR_EVENT_HANDLE_HANGUP |
         VIR_EVENT_HANDLE_ERROR;
 
+    if (!mon->watch)
+        return;
+
     if (mon->lastError.code == VIR_ERR_OK) {
         events |= VIR_EVENT_HANDLE_READABLE;
 
@@ -563,6 +566,11 @@ qemuMonitorIO(int watch, int fd, int events, void *opaque) {
 #if DEBUG_IO
     VIR_DEBUG("Monitor %p I/O on watch %d fd %d events %d", mon, watch, fd, events);
 #endif
+    if (mon->fd == -1 || mon->watch == 0) {
+        qemuMonitorUnlock(mon);
+        virObjectUnref(mon);
+        return;
+    }
 
     if (mon->fd != fd || mon->watch != watch) {
         if (events & (VIR_EVENT_HANDLE_HANGUP | VIR_EVENT_HANDLE_ERROR))
@@ -830,9 +838,12 @@ void qemuMonitorClose(qemuMonitorPtr mon)
           "mon=%p refs=%d", mon, mon->object.refs);
 
     if (mon->fd >= 0) {
-        if (mon->watch)
+        if (mon->watch) {
             virEventRemoveHandle(mon->watch);
+            mon->watch = 0;
+        }
         VIR_FORCE_CLOSE(mon->fd);
+        fprintf(stderr, "Closing monitr\n");
     }
 
     /* In case another thread is waiting for its monitor command to be
-- 
1.7.11.4

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