mirror of https://gitee.com/openkylin/qemu.git
106 lines
2.5 KiB
C
106 lines
2.5 KiB
C
/*
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* Serving QEMU block devices via NBD
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*
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* Copyright (c) 2012 Red Hat, Inc.
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*
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* Author: Paolo Bonzini <pbonzini@redhat.com>
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*
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* This work is licensed under the terms of the GNU GPL, version 2 or
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* later. See the COPYING file in the top-level directory.
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*/
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#include "sysemu/blockdev.h"
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#include "sysemu/block-backend.h"
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#include "hw/block/block.h"
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#include "qapi/qmp/qerror.h"
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#include "sysemu/sysemu.h"
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#include "qmp-commands.h"
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#include "trace.h"
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#include "block/nbd.h"
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#include "qemu/sockets.h"
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static int server_fd = -1;
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static void nbd_accept(void *opaque)
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{
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struct sockaddr_in addr;
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socklen_t addr_len = sizeof(addr);
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int fd = accept(server_fd, (struct sockaddr *)&addr, &addr_len);
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if (fd >= 0) {
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nbd_client_new(NULL, fd, nbd_client_put);
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}
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}
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void qmp_nbd_server_start(SocketAddress *addr, Error **errp)
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{
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if (server_fd != -1) {
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error_setg(errp, "NBD server already running");
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return;
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}
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server_fd = socket_listen(addr, errp);
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if (server_fd != -1) {
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qemu_set_fd_handler(server_fd, nbd_accept, NULL, NULL);
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}
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}
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void qmp_nbd_server_add(const char *device, bool has_writable, bool writable,
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Error **errp)
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{
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BlockBackend *blk;
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NBDExport *exp;
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if (server_fd == -1) {
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error_setg(errp, "NBD server not running");
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return;
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}
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if (nbd_export_find(device)) {
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error_setg(errp, "NBD server already exporting device '%s'", device);
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return;
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}
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blk = blk_by_name(device);
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if (!blk) {
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error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
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"Device '%s' not found", device);
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return;
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}
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if (!blk_is_inserted(blk)) {
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error_setg(errp, QERR_DEVICE_HAS_NO_MEDIUM, device);
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return;
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}
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if (!has_writable) {
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writable = false;
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}
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if (blk_is_read_only(blk)) {
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writable = false;
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}
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exp = nbd_export_new(blk, 0, -1, writable ? 0 : NBD_FLAG_READ_ONLY, NULL,
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errp);
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if (!exp) {
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return;
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}
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nbd_export_set_name(exp, device);
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/* The list of named exports has a strong reference to this export now and
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* our only way of accessing it is through nbd_export_find(), so we can drop
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* the strong reference that is @exp. */
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nbd_export_put(exp);
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}
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void qmp_nbd_server_stop(Error **errp)
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{
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nbd_export_close_all();
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if (server_fd != -1) {
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qemu_set_fd_handler(server_fd, NULL, NULL, NULL);
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close(server_fd);
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server_fd = -1;
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}
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}
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