2 * Serving QEMU block devices via NBD
4 * Copyright (c) 2012 Red Hat, Inc.
6 * Author: Paolo Bonzini <pbonzini@redhat.com>
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.
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"
19 #include "block/nbd.h"
20 #include "qemu/sockets.h"
22 static int server_fd
= -1;
24 static void nbd_accept(void *opaque
)
26 struct sockaddr_in addr
;
27 socklen_t addr_len
= sizeof(addr
);
29 int fd
= accept(server_fd
, (struct sockaddr
*)&addr
, &addr_len
);
31 nbd_client_new(NULL
, fd
, nbd_client_put
);
35 void qmp_nbd_server_start(SocketAddress
*addr
, Error
**errp
)
37 if (server_fd
!= -1) {
38 error_setg(errp
, "NBD server already running");
42 server_fd
= socket_listen(addr
, errp
);
43 if (server_fd
!= -1) {
44 qemu_set_fd_handler2(server_fd
, NULL
, nbd_accept
, NULL
, NULL
);
48 /* Hook into the BlockDriverState notifiers to close the export when
51 typedef struct NBDCloseNotifier
{
54 QTAILQ_ENTRY(NBDCloseNotifier
) next
;
57 static QTAILQ_HEAD(, NBDCloseNotifier
) close_notifiers
=
58 QTAILQ_HEAD_INITIALIZER(close_notifiers
);
60 static void nbd_close_notifier(Notifier
*n
, void *data
)
62 NBDCloseNotifier
*cn
= DO_UPCAST(NBDCloseNotifier
, n
, n
);
64 notifier_remove(&cn
->n
);
65 QTAILQ_REMOVE(&close_notifiers
, cn
, next
);
67 nbd_export_close(cn
->exp
);
68 nbd_export_put(cn
->exp
);
72 void qmp_nbd_server_add(const char *device
, bool has_writable
, bool writable
,
79 if (server_fd
== -1) {
80 error_setg(errp
, "NBD server not running");
84 if (nbd_export_find(device
)) {
85 error_setg(errp
, "NBD server already exporting device '%s'", device
);
89 bs
= bdrv_find(device
);
91 error_set(errp
, QERR_DEVICE_NOT_FOUND
, device
);
98 if (bdrv_is_read_only(bs
)) {
102 exp
= nbd_export_new(bs
, 0, -1, writable
? 0 : NBD_FLAG_READ_ONLY
, NULL
);
104 nbd_export_set_name(exp
, device
);
106 n
= g_malloc0(sizeof(NBDCloseNotifier
));
107 n
->n
.notify
= nbd_close_notifier
;
109 bdrv_add_close_notifier(bs
, &n
->n
);
110 QTAILQ_INSERT_TAIL(&close_notifiers
, n
, next
);
113 void qmp_nbd_server_stop(Error
**errp
)
115 while (!QTAILQ_EMPTY(&close_notifiers
)) {
116 NBDCloseNotifier
*cn
= QTAILQ_FIRST(&close_notifiers
);
117 nbd_close_notifier(&cn
->n
, nbd_export_get_blockdev(cn
->exp
));
120 if (server_fd
!= -1) {
121 qemu_set_fd_handler2(server_fd
, NULL
, NULL
, NULL
, NULL
);