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authorYang Zhang <yang.z.zhang@intel.com>2015-08-28 09:58:54 +0800
committerYang Zhang <yang.z.zhang@intel.com>2015-09-01 12:44:00 +0800
commite44e3482bdb4d0ebde2d8b41830ac2cdb07948fb (patch)
tree66b09f592c55df2878107a468a91d21506104d3f /qemu/blockdev-nbd.c
parent9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (diff)
Add qemu 2.4.0
Change-Id: Ic99cbad4b61f8b127b7dc74d04576c0bcbaaf4f5 Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>
Diffstat (limited to 'qemu/blockdev-nbd.c')
-rw-r--r--qemu/blockdev-nbd.c136
1 files changed, 136 insertions, 0 deletions
diff --git a/qemu/blockdev-nbd.c b/qemu/blockdev-nbd.c
new file mode 100644
index 000000000..bcdd18b3f
--- /dev/null
+++ b/qemu/blockdev-nbd.c
@@ -0,0 +1,136 @@
+/*
+ * 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 "sysemu/block-backend.h"
+#include "hw/block/block.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)) {
+ shutdown(fd, 2);
+ 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_handler(server_fd, nbd_accept, NULL, NULL);
+ }
+}
+
+/*
+ * Hook into the BlockBackend notifiers to close the export when the
+ * backend 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)
+{
+ BlockBackend *blk;
+ 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;
+ }
+
+ blk = blk_by_name(device);
+ if (!blk) {
+ error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
+ "Device '%s' not found", device);
+ return;
+ }
+ if (!blk_is_inserted(blk)) {
+ error_setg(errp, QERR_DEVICE_HAS_NO_MEDIUM, device);
+ return;
+ }
+
+ if (!has_writable) {
+ writable = false;
+ }
+ if (blk_is_read_only(blk)) {
+ writable = false;
+ }
+
+ exp = nbd_export_new(blk, 0, -1, writable ? 0 : NBD_FLAG_READ_ONLY, NULL,
+ errp);
+ if (!exp) {
+ return;
+ }
+
+ nbd_export_set_name(exp, device);
+
+ n = g_new0(NBDCloseNotifier, 1);
+ n->n.notify = nbd_close_notifier;
+ n->exp = exp;
+ blk_add_close_notifier(blk, &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_handler(server_fd, NULL, NULL, NULL);
+ close(server_fd);
+ server_fd = -1;
+ }
+}