xref: /openbmc/qemu/nbd/common.c (revision 7ef295ea)
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 "nbd-internal.h"
21 
22 ssize_t nbd_wr_syncv(QIOChannel *ioc,
23                      struct iovec *iov,
24                      size_t niov,
25                      size_t offset,
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,
36                           iov, niov,
37                           offset, length);
38 
39     while (nlocal_iov > 0) {
40         ssize_t len;
41         if (do_read) {
42             len = qio_channel_readv(ioc, local_iov, nlocal_iov, &local_err);
43         } else {
44             len = qio_channel_writev(ioc, local_iov, nlocal_iov, &local_err);
45         }
46         if (len == QIO_CHANNEL_ERR_BLOCK) {
47             if (qemu_in_coroutine()) {
48                 /* XXX figure out if we can create a variant on
49                  * qio_channel_yield() that works with AIO contexts
50                  * and consider using that in this branch */
51                 qemu_coroutine_yield();
52             } else {
53                 qio_channel_wait(ioc,
54                                  do_read ? G_IO_IN : G_IO_OUT);
55             }
56             continue;
57         }
58         if (len < 0) {
59             TRACE("I/O error: %s", error_get_pretty(local_err));
60             error_free(local_err);
61             /* XXX handle Error objects */
62             done = -EIO;
63             goto cleanup;
64         }
65 
66         if (do_read && len == 0) {
67             break;
68         }
69 
70         iov_discard_front(&local_iov, &nlocal_iov, len);
71         done += len;
72     }
73 
74  cleanup:
75     g_free(local_iov_head);
76     return done;
77 }
78 
79 
80 void nbd_tls_handshake(Object *src,
81                        Error *err,
82                        void *opaque)
83 {
84     struct NBDTLSHandshakeData *data = opaque;
85 
86     if (err) {
87         TRACE("TLS failed %s", error_get_pretty(err));
88         data->error = error_copy(err);
89     }
90     data->complete = true;
91     g_main_loop_quit(data->loop);
92 }
93