nbd/common.c

   1 /*
   2  *  Copyright (C) 2005  Anthony Liguori <anthony@codemonkey.ws>
   3  *
   4  *  Network Block Device Common Code
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; under version 2 of the License.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include "qemu/osdep.h"
  20 #include "qapi/error.h"
  21 #include "nbd-internal.h"
  22
  23 /* nbd_wr_syncv
  24  * The function may be called from coroutine or from non-coroutine context.
  25  * When called from non-coroutine context @ioc must be in blocking mode.
  26  */
  27 ssize_t nbd_wr_syncv(QIOChannel *ioc,
  28                      struct iovec *iov,
  29                      size_t niov,
  30                      size_t length,
  31                      bool do_read,
  32                      Error **errp)
  33 {
  34     ssize_t done = 0;
  35     struct iovec *local_iov = g_new(struct iovec, niov);
  36     struct iovec *local_iov_head = local_iov;
  37     unsigned int nlocal_iov = niov;
  38
  39     nlocal_iov = iov_copy(local_iov, nlocal_iov, iov, niov, 0, length);
  40
  41     while (nlocal_iov > 0) {
  42         ssize_t len;
  43         if (do_read) {
  44             len = qio_channel_readv(ioc, local_iov, nlocal_iov, errp);
  45         } else {
  46             len = qio_channel_writev(ioc, local_iov, nlocal_iov, errp);
  47         }
  48         if (len == QIO_CHANNEL_ERR_BLOCK) {
  49             /* errp should not be set */
  50             assert(qemu_in_coroutine());
  51             qio_channel_yield(ioc, do_read ? G_IO_IN : G_IO_OUT);
  52             continue;
  53         }
  54         if (len < 0) {
  55             done = -EIO;
  56             goto cleanup;
  57         }
  58
  59         if (do_read && len == 0) {
  60             break;
  61         }
  62
  63         iov_discard_front(&local_iov, &nlocal_iov, len);
  64         done += len;
  65     }
  66
  67  cleanup:
  68     g_free(local_iov_head);
  69     return done;
  70 }
  71
  72
  73 void nbd_tls_handshake(QIOTask *task,
  74                        void *opaque)
  75 {
  76     struct NBDTLSHandshakeData *data = opaque;
  77
  78     if (qio_task_propagate_error(task, &data->error)) {
  79         TRACE("TLS failed %s", error_get_pretty(data->error));
  80     }
  81     data->complete = true;
  82     g_main_loop_quit(data->loop);
  83 }