1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
|
/*
* Serving QEMU block devices via NBD
*
* Copyright (c) 2012 Red Hat, Inc.
*
* Author: Paolo Bonzini <pbonzini@redhat.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or
* later. See the COPYING file in the top-level directory.
*/
#include "sysemu/blockdev.h"
#include "hw/block/block.h"
#include "monitor/monitor.h"
#include "qapi/qmp/qerror.h"
#include "sysemu/sysemu.h"
#include "qmp-commands.h"
#include "trace.h"
#include "block/nbd.h"
#include "qemu/sockets.h"
static int server_fd = -1;
static void nbd_accept(void *opaque)
{
struct sockaddr_in addr;
socklen_t addr_len = sizeof(addr);
int fd = accept(server_fd, (struct sockaddr *)&addr, &addr_len);
if (fd >= 0) {
nbd_client_new(NULL, fd, nbd_client_put);
}
}
void qmp_nbd_server_start(SocketAddress *addr, Error **errp)
{
if (server_fd != -1) {
error_setg(errp, "NBD server already running");
return;
}
server_fd = socket_listen(addr, errp);
if (server_fd != -1) {
qemu_set_fd_handler2(server_fd, NULL, nbd_accept, NULL, NULL);
}
}
/* Hook into the BlockDriverState notifiers to close the export when
* the file is closed.
*/
typedef struct NBDCloseNotifier {
Notifier n;
NBDExport *exp;
QTAILQ_ENTRY(NBDCloseNotifier) next;
} NBDCloseNotifier;
static QTAILQ_HEAD(, NBDCloseNotifier) close_notifiers =
QTAILQ_HEAD_INITIALIZER(close_notifiers);
static void nbd_close_notifier(Notifier *n, void *data)
{
NBDCloseNotifier *cn = DO_UPCAST(NBDCloseNotifier, n, n);
notifier_remove(&cn->n);
QTAILQ_REMOVE(&close_notifiers, cn, next);
nbd_export_close(cn->exp);
nbd_export_put(cn->exp);
g_free(cn);
}
static void nbd_server_put_ref(NBDExport *exp)
{
BlockDriverState *bs = nbd_export_get_blockdev(exp);
drive_put_ref(drive_get_by_blockdev(bs));
}
void qmp_nbd_server_add(const char *device, bool has_writable, bool writable,
Error **errp)
{
BlockDriverState *bs;
NBDExport *exp;
NBDCloseNotifier *n;
if (server_fd == -1) {
error_setg(errp, "NBD server not running");
return;
}
if (nbd_export_find(device)) {
error_setg(errp, "NBD server already exporting device '%s'", device);
return;
}
bs = bdrv_find(device);
if (!bs) {
error_set(errp, QERR_DEVICE_NOT_FOUND, device);
return;
}
if (!has_writable) {
writable = false;
}
if (bdrv_is_read_only(bs)) {
writable = false;
}
exp = nbd_export_new(bs, 0, -1, writable ? 0 : NBD_FLAG_READ_ONLY,
nbd_server_put_ref);
nbd_export_set_name(exp, device);
drive_get_ref(drive_get_by_blockdev(bs));
n = g_malloc0(sizeof(NBDCloseNotifier));
n->n.notify = nbd_close_notifier;
n->exp = exp;
bdrv_add_close_notifier(bs, &n->n);
QTAILQ_INSERT_TAIL(&close_notifiers, n, next);
}
void qmp_nbd_server_stop(Error **errp)
{
while (!QTAILQ_EMPTY(&close_notifiers)) {
NBDCloseNotifier *cn = QTAILQ_FIRST(&close_notifiers);
nbd_close_notifier(&cn->n, nbd_export_get_blockdev(cn->exp));
}
if (server_fd != -1) {
qemu_set_fd_handler2(server_fd, NULL, NULL, NULL, NULL);
close(server_fd);
server_fd = -1;
}
}
|
