block: Use bdrv_get_backing_file_depth()

Use the dedicated counting function in qmp_query_block in order to
propagate the backing file depth to HMP and add backing_file_depth
to qmp-commands.hx

Signed-off-by: Benoit Canet <benoit@irqsave.net>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/block.c b/block.c
index 1206bba..24323c1 100644
--- a/block.c
+++ b/block.c
@@ -2450,6 +2450,9 @@ BlockInfoList *qmp_query_block(Error **errp)
                 info->value->inserted->backing_file = g_strdup(bs->backing_file);
             }
 
+            info->value->inserted->backing_file_depth =
+                bdrv_get_backing_file_depth(bs);
+
             if (bs->io_limits_enabled) {
                 info->value->inserted->bps =
                                bs->io_limits.bps[BLOCK_IO_LIMIT_TOTAL];