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 ssize_t nbd_wr_syncv(QIOChannel *ioc,
  24                      struct iovec *iov,
  25                      size_t niov,
  26                      size_t length,
  27                      bool do_read)
  28 {
  29     ssize_t done = 0;
  30     Error *local_err = NULL;
  31     struct iovec *local_iov = g_new(struct iovec, niov);
  32     struct iovec *local_iov_head = local_iov;
  33     unsigned int nlocal_iov = niov;
  34
  35     nlocal_iov = iov_copy(local_iov, nlocal_iov, iov, niov, 0, length);
  36
  37     while (nlocal_iov > 0) {
  38         ssize_t len;
  39         if (do_read) {
  40             len = qio_channel_readv(ioc, local_iov, nlocal_iov, &local_err);
  41         } else {
  42             len = qio_channel_writev(ioc, local_iov, nlocal_iov, &local_err);
  43         }
  44         if (len == QIO_CHANNEL_ERR_BLOCK) {
  45             if (qemu_in_coroutine()) {
  46                 /* XXX figure out if we can create a variant on
  47                  * qio_channel_yield() that works with AIO contexts
  48                  * and consider using that in this branch */
  49                 qemu_coroutine_yield();
  50             } else if (done) {
  51                 /* XXX this is needed by nbd_reply_ready.  */
  52                 qio_channel_wait(ioc,
  53                                  do_read ? G_IO_IN : G_IO_OUT);
  54             } else {
  55                 return -EAGAIN;
  56             }
  57             continue;
  58         }
  59         if (len < 0) {
  60             TRACE("I/O error: %s", error_get_pretty(local_err));
  61             error_free(local_err);
  62             /* XXX handle Error objects */
  63             done = -EIO;
  64             goto cleanup;
  65         }
  66
  67         if (do_read && len == 0) {
  68             break;
  69         }
  70
  71         iov_discard_front(&local_iov, &nlocal_iov, len);
  72         done += len;
  73     }
  74
  75  cleanup:
  76     g_free(local_iov_head);
  77     return done;
  78 }
  79
  80
  81 void nbd_tls_handshake(QIOTask *task,
  82                        void *opaque)
  83 {
  84     struct NBDTLSHandshakeData *data = opaque;
  85
  86     if (qio_task_propagate_error(task, &data->error)) {
  87         TRACE("TLS failed %s", error_get_pretty(data->error));
  88     }
  89     data->complete = true;
  90     g_main_loop_quit(data->loop);
  91 }