xref: /openbmc/qemu/nbd/common.c (revision d9d3aaea)
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 }
97