[Qemu-devel] [PATCH V4 05/13] block: add image info query function bdrv_query_image_info()

[Wenchao Xia <xiawenc@linux.vnet.ibm.com>]

  This patch add function bdrv_query_image_info(), which will return
image info in qmp object format. The implementation code are mostly
copied from qemu-img.c, but use block layer function to get snapshot
info.
  A check with bdrv_can_read_snapshot(), was done before collecting
snapshot info.

Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 block.c               |   73 +++++++++++++++++++++++++++++++++++++++++++++++++
 include/block/block.h |    1 +
 2 files changed, 74 insertions(+), 0 deletions(-)

diff --git a/block.c b/block.c
index fba1be4..245a082 100644
--- a/block.c
+++ b/block.c
@@ -2888,6 +2888,79 @@ SnapshotInfoList *bdrv_query_snapshot_infolist(BlockDriverState *bs,
     return head;
 }
 
+/* collect all internal snapshot info in a image for ImageInfo */
+static void collect_snapshots_info(BlockDriverState *bs,
+                                   ImageInfo *info,
+                                   Error **errp)
+{
+    SnapshotInfoList *info_list;
+
+    if (!bdrv_can_read_snapshot(bs)) {
+        return;
+    }
+    info_list = bdrv_query_snapshot_infolist(bs, NULL, NULL, errp);
+    if (info_list != NULL) {
+        info->has_snapshots = true;
+        info->snapshots = info_list;
+    }
+}
+
+static void collect_image_info(BlockDriverState *bs,
+                               ImageInfo *info)
+{
+    uint64_t total_sectors;
+    char backing_filename[1024];
+    char backing_filename2[1024];
+    BlockDriverInfo bdi;
+    const char *filename;
+
+    filename = bdrv_get_filename(bs);
+    bdrv_get_geometry(bs, &total_sectors);
+
+    info->filename        = g_strdup(filename);
+    info->format          = g_strdup(bdrv_get_format_name(bs));
+    info->virtual_size    = total_sectors * 512;
+    info->actual_size     = bdrv_get_allocated_file_size(bs);
+    info->has_actual_size = info->actual_size >= 0;
+    if (bdrv_is_encrypted(bs)) {
+        info->encrypted = true;
+        info->has_encrypted = true;
+    }
+    if (bdrv_get_info(bs, &bdi) >= 0) {
+        if (bdi.cluster_size != 0) {
+            info->cluster_size = bdi.cluster_size;
+            info->has_cluster_size = true;
+        }
+        info->dirty_flag = bdi.is_dirty;
+        info->has_dirty_flag = true;
+    }
+    bdrv_get_backing_filename(bs, backing_filename, sizeof(backing_filename));
+    if (backing_filename[0] != '\0') {
+        info->backing_filename = g_strdup(backing_filename);
+        info->has_backing_filename = true;
+        bdrv_get_full_backing_filename(bs, backing_filename2,
+                                       sizeof(backing_filename2));
+
+        if (strcmp(backing_filename, backing_filename2) != 0) {
+            info->full_backing_filename = g_strdup(backing_filename2);
+            info->has_full_backing_filename = true;
+        }
+
+        if (bs->backing_format[0]) {
+            info->backing_filename_format = g_strdup(bs->backing_format);
+            info->has_backing_filename_format = true;
+        }
+    }
+}
+
+ImageInfo *bdrv_query_image_info(BlockDriverState *bs, Error **errp)
+{
+    ImageInfo *info = g_new0(ImageInfo, 1);
+    collect_image_info(bs, info);
+    collect_snapshots_info(bs, info, errp);
+    return info;
+}
+
 BlockInfo *bdrv_query_info(BlockDriverState *bs)
 {
     BlockInfo *info = g_malloc0(sizeof(*info));
diff --git a/include/block/block.h b/include/block/block.h
index ce18d4b..b6f80c3 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -323,6 +323,7 @@ SnapshotInfoList *bdrv_query_snapshot_infolist(BlockDriverState *bs,
                                                SnapshotFilterFunc filter,
                                                void *opaque,
                                                Error **errp);
+ImageInfo *bdrv_query_image_info(BlockDriverState *bs, Error **errp);
 BlockInfo *bdrv_query_info(BlockDriverState *s);
 BlockStats *bdrv_query_stats(const BlockDriverState *bs);
 int bdrv_can_read_snapshot(BlockDriverState *bs);
-- 
1.7.1