diff options
| -rw-r--r-- | block.c | 24 |
1 files changed, 15 insertions, 9 deletions
@@ -84,14 +84,6 @@ static BlockDriverState *bdrv_open_inherit(const char *filename, static void bdrv_replace_child_noperm(BdrvChild *child, BlockDriverState *new_bs); -static int bdrv_attach_child_noperm(BlockDriverState *parent_bs, - BlockDriverState *child_bs, - const char *child_name, - const BdrvChildClass *child_class, - BdrvChildRole child_role, - BdrvChild **child, - Transaction *tran, - Error **errp); static void bdrv_remove_filter_or_cow_child(BlockDriverState *bs, Transaction *tran); @@ -2759,6 +2751,12 @@ static TransactionActionDrv bdrv_attach_child_common_drv = { /* * Common part of attaching bdrv child to bs or to blk or to job + * + * Resulting new child is returned through @child. + * At start *@child must be NULL. + * @child is saved to a new entry of @tran, so that *@child could be reverted to + * NULL on abort(). So referenced variable must live at least until transaction + * end. */ static int bdrv_attach_child_common(BlockDriverState *child_bs, const char *child_name, @@ -2833,6 +2831,10 @@ static int bdrv_attach_child_common(BlockDriverState *child_bs, return 0; } +/* + * Variable referenced by @child must live at least until transaction end. + * (see bdrv_attach_child_common() doc for details) + */ static int bdrv_attach_child_noperm(BlockDriverState *parent_bs, BlockDriverState *child_bs, const char *child_name, @@ -2915,7 +2917,6 @@ BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs, child_role, perm, shared_perm, opaque, &child, tran, errp); if (ret < 0) { - assert(child == NULL); goto out; } @@ -2923,6 +2924,9 @@ BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs, out: tran_finalize(tran, ret); + /* child is unset on failure by bdrv_attach_child_common_abort() */ + assert((ret < 0) == !child); + bdrv_unref(child_bs); return child; } @@ -2962,6 +2966,8 @@ BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs, out: tran_finalize(tran, ret); + /* child is unset on failure by bdrv_attach_child_common_abort() */ + assert((ret < 0) == !child); bdrv_unref(child_bs); |