block: New BdrvChildRole.activate() for blk_resume_after_migration()

Instead of manually calling blk_resume_after_migration() in migration
code after doing bdrv_invalidate_cache_all(), integrate the BlockBackend
activation with cache invalidation into a single function. This is
achieved with a new callback in BdrvChildRole that is called by
bdrv_invalidate_cache_all().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>

1 files changed, 11 insertions, 1 deletions

diff --git a/block.c b/block.c
index 1e00e313c3..c8e6de29f0 100644
--- a/block.c
+++ b/block.c
@@ -3949,7 +3949,7 @@ void bdrv_init_with_whitelist(void)
 
 void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp)
 {
-    BdrvChild *child;
+    BdrvChild *child, *parent;
     Error *local_err = NULL;
     int ret;
 
@@ -3985,6 +3985,16 @@ void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp)
         error_setg_errno(errp, -ret, "Could not refresh total sector count");
         return;
     }
+
+    QLIST_FOREACH(parent, &bs->parents, next_parent) {
+        if (parent->role->activate) {
+            parent->role->activate(parent, &local_err);
+            if (local_err) {
+                error_propagate(errp, local_err);
+                return;
+            }
+        }
+    }
 }
 
 void bdrv_invalidate_cache_all(Error **errp)