diff -r 2e80cd715047 tools/examples/block
--- a/tools/examples/block	Thu Feb 01 11:42:50 2007 +0000
+++ b/tools/examples/block	Thu Feb 01 11:58:38 2007 -0500
@@ -367,7 +367,13 @@ mount it read-write in a guest domain."
           fatal 'Failed to find an unused loop device'
         fi
 
-        do_or_die losetup "$loopdev" "$file"
+        cmode=`canonicalise_mode $mode`
+        if [ "$cmode" == 'r' ]
+        then
+          do_or_die losetup -r "$loopdev" "$file"
+        else
+          do_or_die losetup "$loopdev" "$file"
+        fi
         xenstore_write "$XENBUS_PATH/node" "$loopdev"
         write_dev "$loopdev"
         release_lock "block"