void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason)

{

    BdrvOpBlocker *blocker;

    assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX);



    blocker = g_malloc0(sizeof(BdrvOpBlocker));

    blocker->reason = reason;

    QLIST_INSERT_HEAD(&bs->op_blockers[op], blocker, list);

}
