36af599417
Otherwise, the nbd client may hang waiting for the server response. Signed-off-by: Hani Benhabiles <hani@linux.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
126 lines
3.0 KiB
C
126 lines
3.0 KiB
C
/*
|
|
* 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)) {
|
|
close(fd);
|
|
}
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
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, NULL);
|
|
|
|
nbd_export_set_name(exp, device);
|
|
|
|
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;
|
|
}
|
|
}
|