From 0044e3848b02ef6edba5961d1f4b6297d137d207 Mon Sep 17 00:00:00 2001

From: Hanna Reitz <hreitz@redhat.com>

Date: Mon, 20 Jun 2022 18:26:59 +0200

Subject: [PATCH 12/20] block/qapi: Introduce BlockGraphInfo

RH-Author: Hanna Czenczek <hreitz@redhat.com>

RH-MergeRequest: 145: Show protocol-level information in qemu-img info

RH-Bugzilla: 1860292

RH-Acked-by: Kevin Wolf <kwolf@redhat.com>

RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

RH-Acked-by: Stefano Garzarella <sgarzare@redhat.com>

RH-Commit: [7/12] de47bac372cd552b812c774a2f35f95923af74ff (hreitz/qemu-kvm-c-9-s)

Introduce a new QAPI type BlockGraphInfo and an associated

bdrv_query_block_graph_info() function that recursively gathers

BlockNodeInfo objects through a block graph.

A follow-up patch is going to make "qemu-img info" use this to print

information about all nodes that are (usually implicitly) opened for a

given image file.

Signed-off-by: Hanna Reitz <hreitz@redhat.com>

Message-Id: <20220620162704.80987-8-hreitz@redhat.com>

Reviewed-by: Kevin Wolf <kwolf@redhat.com>

Signed-off-by: Kevin Wolf <kwolf@redhat.com>

(cherry picked from commit 6cab33997b91eb86e82a6a2ae58a24f835249d4a)

Signed-off-by: Hanna Czenczek <hreitz@redhat.com>

---

 block/qapi.c         | 48 ++++++++++++++++++++++++++++++++++++++++++++

 include/block/qapi.h |  3 +++

 qapi/block-core.json | 35 ++++++++++++++++++++++++++++++++

 3 files changed, 86 insertions(+)

diff --git a/block/qapi.c b/block/qapi.c

index 5d0a8d2ce3..f208c21ccf 100644

--- a/block/qapi.c

+++ b/block/qapi.c

@@ -411,6 +411,54 @@ fail:

     qapi_free_ImageInfo(info);

 }

+/**

+ * bdrv_query_block_graph_info:

+ * @bs: root node to start from

+ * @p_info: location to store image information

+ * @errp: location to store error information

+ *

+ * Store image information about the graph starting from @bs in @p_info.

+ *

+ * @p_info will be set only on success. On error, store error in @errp.

+ */

+void bdrv_query_block_graph_info(BlockDriverState *bs,

+                                 BlockGraphInfo **p_info,

+                                 Error **errp)

+{

+    BlockGraphInfo *info;

+    BlockChildInfoList **children_list_tail;

+    BdrvChild *c;

+    ERRP_GUARD();

+

+    info = g_new0(BlockGraphInfo, 1);

+    bdrv_do_query_node_info(bs, qapi_BlockGraphInfo_base(info), errp);

+    if (*errp) {

+        goto fail;

+    }

+

+    children_list_tail = &info->children;

+

+    QLIST_FOREACH(c, &bs->children, next) {

+        BlockChildInfo *c_info;

+

+        c_info = g_new0(BlockChildInfo, 1);

+        QAPI_LIST_APPEND(children_list_tail, c_info);

+

+        c_info->name = g_strdup(c->name);

+        bdrv_query_block_graph_info(c->bs, &c_info->info, errp);

+        if (*errp) {

+            goto fail;

+        }

+    }

+

+    *p_info = info;

+    return;

+

+fail:

+    assert(*errp != NULL);

+    qapi_free_BlockGraphInfo(info);

+}

+

 /* @p_info will be set only on success. */

 static void bdrv_query_info(BlockBackend *blk, BlockInfo **p_info,

                             Error **errp)

diff --git a/include/block/qapi.h b/include/block/qapi.h

index 2174bf8fa2..196436020e 100644

--- a/include/block/qapi.h

+++ b/include/block/qapi.h

@@ -43,6 +43,9 @@ void bdrv_query_image_info(BlockDriverState *bs,

                            bool flat,

                            bool skip_implicit_filters,

                            Error **errp);

+void bdrv_query_block_graph_info(BlockDriverState *bs,

+                                 BlockGraphInfo **p_info,

+                                 Error **errp);

 void bdrv_snapshot_dump(QEMUSnapshotInfo *sn);

 void bdrv_image_info_specific_dump(ImageInfoSpecific *info_spec,

diff --git a/qapi/block-core.json b/qapi/block-core.json

index 4cf2deeb6c..d703e0fb16 100644

--- a/qapi/block-core.json

+++ b/qapi/block-core.json

@@ -307,6 +307,41 @@

       '*backing-image': 'ImageInfo'

   } }

+##

+# @BlockChildInfo:

+#

+# Information about all nodes in the block graph starting at some node,

+# annotated with information about that node in relation to its parent.

+#

+# @name: Child name of the root node in the BlockGraphInfo struct, in its role

+#        as the child of some undescribed parent node

+#

+# @info: Block graph information starting at this node

+#

+# Since: 8.0

+##

+{ 'struct': 'BlockChildInfo',

+  'data': {

+      'name': 'str',

+      'info': 'BlockGraphInfo'

+  } }

+

+##

+# @BlockGraphInfo:

+#

+# Information about all nodes in a block (sub)graph in the form of BlockNodeInfo

+# data.

+# The base BlockNodeInfo struct contains the information for the (sub)graph's

+# root node.

+#

+# @children: Array of links to this node's child nodes' information

+#

+# Since: 8.0

+##

+{ 'struct': 'BlockGraphInfo',

+  'base': 'BlockNodeInfo',

+  'data': { 'children': ['BlockChildInfo'] } }

+

 ##

 # @ImageCheck:

 #

-- 

2.31.1