[PATCH 2/4] block: Add protocol-specific image info

[Hanna Reitz <hreitz@redhat.com>]

The ImageInfo object currently only contains (optional) format-specific
image information.  However, perhaps the protocol node can provide some
additional information, so add a new field presenting it.

Signed-off-by: Hanna Reitz <hreitz@redhat.com>
---
 qapi/block-core.json |  6 +++++-
 block/qapi.c         | 19 +++++++++++++++++++
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/qapi/block-core.json b/qapi/block-core.json
index beeb91952a..e7d6c2e0cc 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -236,6 +236,9 @@
 # @format-specific: structure supplying additional format-specific
 #                   information (since 1.7)
 #
+# @protocol-specific: structure supplying additional protocol-specific
+#                     information (since 7.1)
+#
 # Since: 1.3
 #
 ##
@@ -246,7 +249,8 @@
            '*backing-filename': 'str', '*full-backing-filename': 'str',
            '*backing-filename-format': 'str', '*snapshots': ['SnapshotInfo'],
            '*backing-image': 'ImageInfo',
-           '*format-specific': 'ImageInfoSpecific' } }
+           '*format-specific': 'ImageInfoSpecific',
+           '*protocol-specific': 'ImageInfoSpecific' } }
 
 ##
 # @ImageCheck:
diff --git a/block/qapi.c b/block/qapi.c
index 51202b470a..293983cf82 100644
--- a/block/qapi.c
+++ b/block/qapi.c
@@ -262,6 +262,7 @@ void bdrv_query_image_info(BlockDriverState *bs,
     int64_t size;
     const char *backing_filename;
     BlockDriverInfo bdi;
+    BlockDriverState *protocol_bs;
     int ret;
     Error *err = NULL;
     ImageInfo *info;
@@ -303,6 +304,24 @@ void bdrv_query_image_info(BlockDriverState *bs,
     }
     info->has_format_specific = info->format_specific != NULL;
 
+    /* Try to look for an unambiguous protocol node */
+    protocol_bs = bs;
+    while (protocol_bs && !QLIST_EMPTY(&protocol_bs->children)) {
+        protocol_bs = bdrv_primary_bs(protocol_bs);
+    }
+    if (protocol_bs) {
+        /* Assert that this is a protocol node */
+        assert(QLIST_EMPTY(&protocol_bs->children));
+
+        info->protocol_specific = bdrv_get_specific_info(protocol_bs, &err);
+        if (err) {
+            error_propagate(errp, err);
+            qapi_free_ImageInfo(info);
+            goto out;
+        }
+        info->has_protocol_specific = info->protocol_specific != NULL;
+    }
+
     backing_filename = bs->backing_file;
     if (backing_filename[0] != '\0') {
         char *backing_filename2;
-- 
2.35.1