qemu-char: fix MISSING_COMMA
[qemu.git] / blockdev-nbd.c
1 /*
2 * Serving QEMU block devices via NBD
3 *
4 * Copyright (c) 2012 Red Hat, Inc.
5 *
6 * Author: Paolo Bonzini <pbonzini@redhat.com>
7 *
8 * This work is licensed under the terms of the GNU GPL, version 2 or
9 * later. See the COPYING file in the top-level directory.
10 */
11
12 #include "sysemu/blockdev.h"
13 #include "hw/block/block.h"
14 #include "monitor/monitor.h"
15 #include "qapi/qmp/qerror.h"
16 #include "sysemu/sysemu.h"
17 #include "qmp-commands.h"
18 #include "trace.h"
19 #include "block/nbd.h"
20 #include "qemu/sockets.h"
21
22 static int server_fd = -1;
23
24 static void nbd_accept(void *opaque)
25 {
26 struct sockaddr_in addr;
27 socklen_t addr_len = sizeof(addr);
28
29 int fd = accept(server_fd, (struct sockaddr *)&addr, &addr_len);
30 if (fd >= 0 && !nbd_client_new(NULL, fd, nbd_client_put)) {
31 shutdown(fd, 2);
32 close(fd);
33 }
34 }
35
36 void qmp_nbd_server_start(SocketAddress *addr, Error **errp)
37 {
38 if (server_fd != -1) {
39 error_setg(errp, "NBD server already running");
40 return;
41 }
42
43 server_fd = socket_listen(addr, errp);
44 if (server_fd != -1) {
45 qemu_set_fd_handler2(server_fd, NULL, nbd_accept, NULL, NULL);
46 }
47 }
48
49 /* Hook into the BlockDriverState notifiers to close the export when
50 * the file is closed.
51 */
52 typedef struct NBDCloseNotifier {
53 Notifier n;
54 NBDExport *exp;
55 QTAILQ_ENTRY(NBDCloseNotifier) next;
56 } NBDCloseNotifier;
57
58 static QTAILQ_HEAD(, NBDCloseNotifier) close_notifiers =
59 QTAILQ_HEAD_INITIALIZER(close_notifiers);
60
61 static void nbd_close_notifier(Notifier *n, void *data)
62 {
63 NBDCloseNotifier *cn = DO_UPCAST(NBDCloseNotifier, n, n);
64
65 notifier_remove(&cn->n);
66 QTAILQ_REMOVE(&close_notifiers, cn, next);
67
68 nbd_export_close(cn->exp);
69 nbd_export_put(cn->exp);
70 g_free(cn);
71 }
72
73 void qmp_nbd_server_add(const char *device, bool has_writable, bool writable,
74 Error **errp)
75 {
76 BlockDriverState *bs;
77 NBDExport *exp;
78 NBDCloseNotifier *n;
79
80 if (server_fd == -1) {
81 error_setg(errp, "NBD server not running");
82 return;
83 }
84
85 if (nbd_export_find(device)) {
86 error_setg(errp, "NBD server already exporting device '%s'", device);
87 return;
88 }
89
90 bs = bdrv_find(device);
91 if (!bs) {
92 error_set(errp, QERR_DEVICE_NOT_FOUND, device);
93 return;
94 }
95 if (!bdrv_is_inserted(bs)) {
96 error_set(errp, QERR_DEVICE_HAS_NO_MEDIUM, device);
97 return;
98 }
99
100 if (!has_writable) {
101 writable = false;
102 }
103 if (bdrv_is_read_only(bs)) {
104 writable = false;
105 }
106
107 exp = nbd_export_new(bs, 0, -1, writable ? 0 : NBD_FLAG_READ_ONLY, NULL);
108
109 nbd_export_set_name(exp, device);
110
111 n = g_new0(NBDCloseNotifier, 1);
112 n->n.notify = nbd_close_notifier;
113 n->exp = exp;
114 bdrv_add_close_notifier(bs, &n->n);
115 QTAILQ_INSERT_TAIL(&close_notifiers, n, next);
116 }
117
118 void qmp_nbd_server_stop(Error **errp)
119 {
120 while (!QTAILQ_EMPTY(&close_notifiers)) {
121 NBDCloseNotifier *cn = QTAILQ_FIRST(&close_notifiers);
122 nbd_close_notifier(&cn->n, nbd_export_get_blockdev(cn->exp));
123 }
124
125 if (server_fd != -1) {
126 qemu_set_fd_handler2(server_fd, NULL, NULL, NULL, NULL);
127 close(server_fd);
128 server_fd = -1;
129 }
130 }