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 offset,
  27                      size_t length,
  28                      bool do_read)
  29 {
  30     ssize_t done = 0;
  31     Error *local_err = NULL;
  32     struct iovec *local_iov = g_new(struct iovec, niov);
  33     struct iovec *local_iov_head = local_iov;
  34     unsigned int nlocal_iov = niov;
  35
  36     nlocal_iov = iov_copy(local_iov, nlocal_iov,
  37                           iov, niov,
  38                           offset, length);
  39
  40     while (nlocal_iov > 0) {
  41         ssize_t len;
  42         if (do_read) {
  43             len = qio_channel_readv(ioc, local_iov, nlocal_iov, &local_err);
  44         } else {
  45             len = qio_channel_writev(ioc, local_iov, nlocal_iov, &local_err);
  46         }
  47         if (len == QIO_CHANNEL_ERR_BLOCK) {
  48             if (qemu_in_coroutine()) {
  49                 /* XXX figure out if we can create a variant on
  50                  * qio_channel_yield() that works with AIO contexts
  51                  * and consider using that in this branch */
  52                 qemu_coroutine_yield();
  53             } else if (done) {
  54                 /* XXX this is needed by nbd_reply_ready.  */
  55                 qio_channel_wait(ioc,
  56                                  do_read ? G_IO_IN : G_IO_OUT);
  57             } else {
  58                 return -EAGAIN;
  59             }
  60             continue;
  61         }
  62         if (len < 0) {
  63             TRACE("I/O error: %s", error_get_pretty(local_err));
  64             error_free(local_err);
  65             /* XXX handle Error objects */
  66             done = -EIO;
  67             goto cleanup;
  68         }
  69
  70         if (do_read && len == 0) {
  71             break;
  72         }
  73
  74         iov_discard_front(&local_iov, &nlocal_iov, len);
  75         done += len;
  76     }
  77
  78  cleanup:
  79     g_free(local_iov_head);
  80     return done;
  81 }
  82
  83
  84 void nbd_tls_handshake(Object *src,
  85                        Error *err,
  86                        void *opaque)
  87 {
  88     struct NBDTLSHandshakeData *data = opaque;
  89
  90     if (err) {
  91         TRACE("TLS failed %s", error_get_pretty(err));
  92         data->error = error_copy(err);
  93     }
  94     data->complete = true;
  95     g_main_loop_quit(data->loop);
  96 }