block: Allow reference for bdrv_file_open()

Allow specifying a reference to an existing block device (by name) for
bdrv_file_open() instead of a filename and/or options.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/qemu-io.c b/qemu-io.c
index fdc46a97e8..bfb773e70f 100644
--- a/qemu-io.c
+++ b/qemu-io.c
@@ -59,7 +59,7 @@ static int openfile(char *name, int flags, int growable, QDict *opts)
     }
 
     if (growable) {
-        if (bdrv_file_open(&qemuio_bs, name, opts, flags, &local_err)) {
+        if (bdrv_file_open(&qemuio_bs, name, NULL, opts, flags, &local_err)) {
             fprintf(stderr, "%s: can't open device %s: %s\n", progname, name,
                     error_get_pretty(local_err));
             error_free(local_err);