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, 0 insertions, 3 deletions

diff --git a/migration/migration.c b/migration/migration.c
index 04af71988d..a5ade23e24 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -341,9 +341,6 @@ static void process_incoming_migration_bh(void *opaque)
     /* Make sure all file formats flush their mutable metadata.
      * If we get an error here, just don't restart the VM yet. */
     bdrv_invalidate_cache_all(&local_err);
-    if (!local_err) {
-        blk_resume_after_migration(&local_err);
-    }
     if (local_err) {
         error_report_err(local_err);
         local_err = NULL;