Re: [Libguestfs] [libnbd PATCH] API: Add nbd_set_opt_mode to expose NEGOTIATING state

On 8/10/20 9:09 PM, Eric Blake wrote: It helps if I add my new file before making the commit: diff --git c/lib/opt.c i/lib/opt.c new file mode 100644 index 0000000..5d74a4f --- /dev/null +++ i/lib/opt.c @@ -0,0 +1,85 @@ +/* NBD client library in userspace + * Copyright (C) 2020 Red Hat Inc. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include <config.h> + +#include <stdio.h> +#include <stdlib.h> +#include <stdbool.h> +#include <stdint.h> +#include <inttypes.h> +#include <errno.h> +#include <assert.h> +#include <limits.h> + +#include "internal.h" + +int +nbd_unlocked_set_opt_mode (struct nbd_handle *h, bool value) +{ + h->opt_mode = value; + return 0; +} + +/* NB: may_set_error = false. */ +int +nbd_unlocked_get_opt_mode (struct nbd_handle *h) +{ + return h->opt_mode; +} + +static int +wait_for_option (struct nbd_handle *h) +{ + while (nbd_internal_is_state_connecting (get_next_state (h))) { + if (nbd_unlocked_poll (h, -1) == -1) + return -1; + } + + /* Should we do further decoding, like connect.c error_unless_ready? */ + return 0; +} + +/* Issue NBD_OPT_GO (or NBD_OPT_EXPORT_NAME) and wait for the reply. */ +int +nbd_unlocked_opt_go (struct nbd_handle *h) +{ + int r; + + h->sbuf.option.option = NBD_OPT_GO; + + if (nbd_internal_run (h, cmd_issue) == -1) + debug (h, "option queued, ignoring state machine failure"); + + r = wait_for_option (h); + if (r == 0 && nbd_internal_is_state_negotiating (get_next_state (h))) + return -1; /* NBD_OPT_GO failed, but can be attempted again */ + return r; +} + +/* Issue NBD_OPT_ABORT and wait for the state change. */ +int +nbd_unlocked_opt_abort (struct nbd_handle *h) +{ + h->sbuf.option.option = NBD_OPT_ABORT; + + if (nbd_internal_run (h, cmd_issue) == -1) + debug (h, "option queued, ignoring state machine failure"); + + return wait_for_option (h); +} -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org