Subject: modify default read/write flag in bdrv_init.
Signed-off by Chunyan Liu <cyliu@novell.com>

Index: xen-4.2.0-testing/tools/qemu-xen-traditional-dir-remote/vl.c
===================================================================
--- xen-4.2.0-testing.orig/tools/qemu-xen-traditional-dir-remote/vl.c
+++ xen-4.2.0-testing/tools/qemu-xen-traditional-dir-remote/vl.c
@@ -2627,6 +2627,8 @@ int drive_init(struct drive_opt *arg, in
     strncpy(drives_table[nb_drives].serial, serial, sizeof(serial));
     nb_drives++;
 
+    bdrv_flags = BDRV_O_RDWR;
+
     switch(type) {
     case IF_IDE:
     case IF_XEN:
@@ -2640,6 +2642,7 @@ int drive_init(struct drive_opt *arg, in
 	    break;
 	case MEDIA_CDROM:
             bdrv_set_type_hint(bdrv, BDRV_TYPE_CDROM);
+            bdrv_flags &= ~BDRV_O_RDWR;
 	    break;
 	}
         break;
@@ -2660,7 +2663,6 @@ int drive_init(struct drive_opt *arg, in
     }
     if (!file[0])
         return -2;
-    bdrv_flags = 0;
     if (snapshot) {
         bdrv_flags |= BDRV_O_SNAPSHOT;
         cache = 2; /* always use write-back with snapshot */