qmp: add ImageInfo in BlockDeviceInfo used by query-block

Now image info will be retrieved as an embbed json object inside
BlockDeviceInfo, backing chain info and all related internal snapshot
info can be got in the enhanced recursive structure of ImageInfo. New
recursive member *backing-image is added to reflect the backing chain
status.

Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

1 files changed, 47 insertions, 3 deletions

diff --git a/block/qapi.c b/block/qapi.c
index e9d8b7433f..a4bc4113b7 100644
--- a/block/qapi.c
+++ b/block/qapi.c
@@ -94,6 +94,13 @@ int bdrv_query_snapshot_info_list(BlockDriverState *bs,
  * @p_info: location to store image information
  * @errp: location to store error information
  *
+ * Store "flat" image information in @p_info.
+ *
+ * "Flat" means it does *not* query backing image information,
+ * i.e. (*pinfo)->has_backing_image will be set to false and
+ * (*pinfo)->backing_image to NULL even when the image does in fact have
+ * a backing image.
+ *
  * @p_info will be set only on success. On error, store error in @errp.
  */
 void bdrv_query_image_info(BlockDriverState *bs,
@@ -167,9 +174,15 @@ void bdrv_query_image_info(BlockDriverState *bs,
     *p_info = info;
 }
 
-BlockInfo *bdrv_query_info(BlockDriverState *bs)
+/* @p_info will be set only on success. */
+void bdrv_query_info(BlockDriverState *bs,
+                     BlockInfo **p_info,
+                     Error **errp)
 {
     BlockInfo *info = g_malloc0(sizeof(*info));
+    BlockDriverState *bs0;
+    ImageInfo **p_image_info;
+    Error *local_err = NULL;
     info->device = g_strdup(bs->device_name);
     info->type = g_strdup("unknown");
     info->locked = bdrv_dev_is_medium_locked(bs);
@@ -223,8 +236,30 @@ BlockInfo *bdrv_query_info(BlockDriverState *bs)
             info->inserted->iops_wr =
                            bs->io_limits.iops[BLOCK_IO_LIMIT_WRITE];
         }
+
+        bs0 = bs;
+        p_image_info = &info->inserted->image;
+        while (1) {
+            bdrv_query_image_info(bs0, p_image_info, &local_err);
+            if (error_is_set(&local_err)) {
+                error_propagate(errp, local_err);
+                goto err;
+            }
+            if (bs0->drv && bs0->backing_hd) {
+                bs0 = bs0->backing_hd;
+                (*p_image_info)->has_backing_image = true;
+                p_image_info = &((*p_image_info)->backing_image);
+            } else {
+                break;
+            }
+        }
     }
-    return info;
+
+    *p_info = info;
+    return;
+
+ err:
+    qapi_free_BlockInfo(info);
 }
 
 BlockStats *bdrv_query_stats(const BlockDriverState *bs)
@@ -261,16 +296,25 @@ BlockInfoList *qmp_query_block(Error **errp)
 {
     BlockInfoList *head = NULL, **p_next = &head;
     BlockDriverState *bs = NULL;
+    Error *local_err = NULL;
 
      while ((bs = bdrv_next(bs))) {
         BlockInfoList *info = g_malloc0(sizeof(*info));
-        info->value = bdrv_query_info(bs);
+        bdrv_query_info(bs, &info->value, &local_err);
+        if (error_is_set(&local_err)) {
+            error_propagate(errp, local_err);
+            goto err;
+        }
 
         *p_next = info;
         p_next = &info->next;
     }
 
     return head;
+
+ err:
+    qapi_free_BlockInfoList(head);
+    return NULL;
 }
 
 BlockStatsList *qmp_query_blockstats(Error **errp)