X-Git-Url: https://git.proxmox.com/?a=blobdiff_plain;f=block.c;h=30afdcbba60eab8ffdaeffe5b2a0a168cffd040a;hb=4b028cbe7540b302d48f7d9e59a8cb860209d9fa;hp=a097772238ddbb634b3563e157b6f42a07662e17;hpb=014b99a8e41c8cd1e895137654b44dec5430122c;p=mirror_qemu.git

diff --git a/block.c b/block.c
index a097772238..30afdcbba6 100644
--- a/block.c
+++ b/block.c
@@ -1309,11 +1309,14 @@ static void bdrv_backing_detach(BdrvChild *c)
 }
 
 static int bdrv_backing_update_filename(BdrvChild *c, BlockDriverState *base,
-                                        const char *filename, Error **errp)
+                                        const char *filename,
+                                        bool backing_mask_protocol,
+                                        Error **errp)
 {
     BlockDriverState *parent = c->opaque;
     bool read_only = bdrv_is_read_only(parent);
     int ret;
+    const char *format_name;
     GLOBAL_STATE_CODE();
 
     if (read_only) {
@@ -1323,9 +1326,23 @@ static int bdrv_backing_update_filename(BdrvChild *c, BlockDriverState *base,
         }
     }
 
-    ret = bdrv_change_backing_file(parent, filename,
-                                   base->drv ? base->drv->format_name : "",
-                                   false);
+    if (base->drv) {
+        /*
+         * If the new base image doesn't have a format driver layer, which we
+         * detect by the fact that @base is a protocol driver, we record
+         * 'raw' as the format instead of putting the protocol name as the
+         * backing format
+         */
+        if (backing_mask_protocol && base->drv->protocol_name) {
+            format_name = "raw";
+        } else {
+            format_name = base->drv->format_name;
+        }
+    } else {
+        format_name = "";
+    }
+
+    ret = bdrv_change_backing_file(parent, filename, format_name, false);
     if (ret < 0) {
         error_setg_errno(errp, -ret, "Could not update backing file link");
     }
@@ -1479,10 +1496,14 @@ static void GRAPH_WRLOCK bdrv_child_cb_detach(BdrvChild *child)
 }
 
 static int bdrv_child_cb_update_filename(BdrvChild *c, BlockDriverState *base,
-                                         const char *filename, Error **errp)
+                                         const char *filename,
+                                         bool backing_mask_protocol,
+                                         Error **errp)
 {
     if (c->role & BDRV_CHILD_COW) {
-        return bdrv_backing_update_filename(c, base, filename, errp);
+        return bdrv_backing_update_filename(c, base, filename,
+                                            backing_mask_protocol,
+                                            errp);
     }
     return 0;
 }
@@ -5803,7 +5824,8 @@ void bdrv_unfreeze_backing_chain(BlockDriverState *bs, BlockDriverState *base)
  *
  */
 int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base,
-                           const char *backing_file_str)
+                           const char *backing_file_str,
+                           bool backing_mask_protocol)
 {
     BlockDriverState *explicit_top = top;
     bool update_inherits_from;
@@ -5869,6 +5891,7 @@ int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base,
 
         if (c->klass->update_filename) {
             ret = c->klass->update_filename(c, base, backing_file_str,
+                                            backing_mask_protocol,
                                             &local_err);
             if (ret < 0) {
                 /*