[PATCH 4/5] block: bdrv_insert_node(): don't use bdrv_open()

[Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>]

Use bdrv_new_open_driver_opts() instead of complicated bdrv_open().

Among other extra things bdrv_open() also check for white-listed
formats, which we don't want for internal node creation: currently
backup doesn't work when copy-before-write filter is not white-listed.
As well block-stream doesn't work when copy-on-read is not
white-listed.

Fixes: 751cec7a261adaf1145dc7adf6de7c9c084e5a0b
Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=2004812
Reported-by: Yanan Fu
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 block.c | 32 +++++++++++++++++++++++++++-----
 1 file changed, 27 insertions(+), 5 deletions(-)

diff --git a/block.c b/block.c
index 3a90407b83..a174801785 100644
--- a/block.c
+++ b/block.c
@@ -5134,11 +5134,29 @@ BlockDriverState *bdrv_insert_node(BlockDriverState *bs, QDict *options,
     ERRP_GUARD();
     int ret;
     BlockDriverState *new_node_bs;
+    const char *drvname, *node_name;
+    BlockDriver *drv;
+
+    drvname = qdict_get_try_str(options, "driver");
+    if (!drvname) {
+        error_setg(errp, "driver is not specified");
+        goto fail;
+    }
+
+    drv = bdrv_find_format(drvname);
+    if (!drv) {
+        error_setg(errp, "Unknown driver: '%s'", drvname);
+        goto fail;
+    }
 
-    new_node_bs = bdrv_open(NULL, NULL, options, flags, errp);
-    if (new_node_bs == NULL) {
+    node_name = qdict_get_try_str(options, "node-name");
+
+    new_node_bs = bdrv_new_open_driver_opts(drv, node_name, options, flags,
+                                            errp);
+    options = NULL; /* bdrv_new_open_driver() eats options */
+    if (!new_node_bs) {
         error_prepend(errp, "Could not create node: ");
-        return NULL;
+        goto fail;
     }
 
     bdrv_drained_begin(bs);
@@ -5147,11 +5165,15 @@ BlockDriverState *bdrv_insert_node(BlockDriverState *bs, QDict *options,
 
     if (ret < 0) {
         error_prepend(errp, "Could not replace node: ");
-        bdrv_unref(new_node_bs);
-        return NULL;
+        goto fail;
     }
 
     return new_node_bs;
+
+fail:
+    qobject_unref(options);
+    bdrv_unref(new_node_bs);
+    return NULL;
 }
 
 /*
-- 
2.29.2