The NBD server already used to send a FUA flag when the writethrough mode was set. This code was a remnant from the times where protocol drivers actually had to implement writethrough modes. Since nowadays the block layer sends flushes in writethrough mode and non-root nodes are always writeback, this was mostly dead code - only mostly because if NBD was configured to be used without a format, we sent _both_ FUA and an explicit flush afterwards, which makes the code not technically dead, but useless overhead. This patch changes the code so that the block layer's FUA flag is recognised and translated into a NBD FUA flag. The additional flush is avoided now. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
540 lines
16 KiB
C
540 lines
16 KiB
C
/*
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* QEMU Block driver for NBD
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*
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* Copyright (C) 2008 Bull S.A.S.
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* Author: Laurent Vivier <Laurent.Vivier@bull.net>
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*
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* Some parts:
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* Copyright (C) 2007 Anthony Liguori <anthony@codemonkey.ws>
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include "qemu/osdep.h"
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#include "block/nbd-client.h"
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#include "qapi/error.h"
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#include "qemu/uri.h"
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#include "block/block_int.h"
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#include "qemu/module.h"
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#include "qapi/qmp/qdict.h"
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#include "qapi/qmp/qjson.h"
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#include "qapi/qmp/qint.h"
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#include "qapi/qmp/qstring.h"
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#include "qemu/cutils.h"
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#define EN_OPTSTR ":exportname="
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typedef struct BDRVNBDState {
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NbdClientSession client;
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} BDRVNBDState;
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static int nbd_parse_uri(const char *filename, QDict *options)
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{
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URI *uri;
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const char *p;
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QueryParams *qp = NULL;
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int ret = 0;
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bool is_unix;
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uri = uri_parse(filename);
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if (!uri) {
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return -EINVAL;
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}
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/* transport */
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if (!strcmp(uri->scheme, "nbd")) {
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is_unix = false;
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} else if (!strcmp(uri->scheme, "nbd+tcp")) {
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is_unix = false;
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} else if (!strcmp(uri->scheme, "nbd+unix")) {
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is_unix = true;
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} else {
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ret = -EINVAL;
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goto out;
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}
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p = uri->path ? uri->path : "/";
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p += strspn(p, "/");
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if (p[0]) {
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qdict_put(options, "export", qstring_from_str(p));
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}
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qp = query_params_parse(uri->query);
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if (qp->n > 1 || (is_unix && !qp->n) || (!is_unix && qp->n)) {
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ret = -EINVAL;
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goto out;
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}
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if (is_unix) {
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/* nbd+unix:///export?socket=path */
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if (uri->server || uri->port || strcmp(qp->p[0].name, "socket")) {
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ret = -EINVAL;
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goto out;
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}
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qdict_put(options, "path", qstring_from_str(qp->p[0].value));
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} else {
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QString *host;
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/* nbd[+tcp]://host[:port]/export */
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if (!uri->server) {
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ret = -EINVAL;
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goto out;
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}
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/* strip braces from literal IPv6 address */
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if (uri->server[0] == '[') {
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host = qstring_from_substr(uri->server, 1,
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strlen(uri->server) - 2);
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} else {
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host = qstring_from_str(uri->server);
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}
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qdict_put(options, "host", host);
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if (uri->port) {
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char* port_str = g_strdup_printf("%d", uri->port);
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qdict_put(options, "port", qstring_from_str(port_str));
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g_free(port_str);
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}
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}
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out:
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if (qp) {
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query_params_free(qp);
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}
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uri_free(uri);
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return ret;
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}
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static void nbd_parse_filename(const char *filename, QDict *options,
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Error **errp)
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{
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char *file;
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char *export_name;
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const char *host_spec;
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const char *unixpath;
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if (qdict_haskey(options, "host")
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|| qdict_haskey(options, "port")
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|| qdict_haskey(options, "path"))
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{
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error_setg(errp, "host/port/path and a file name may not be specified "
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"at the same time");
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return;
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}
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if (strstr(filename, "://")) {
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int ret = nbd_parse_uri(filename, options);
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if (ret < 0) {
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error_setg(errp, "No valid URL specified");
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}
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return;
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}
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file = g_strdup(filename);
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export_name = strstr(file, EN_OPTSTR);
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if (export_name) {
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if (export_name[strlen(EN_OPTSTR)] == 0) {
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goto out;
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}
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export_name[0] = 0; /* truncate 'file' */
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export_name += strlen(EN_OPTSTR);
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qdict_put(options, "export", qstring_from_str(export_name));
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}
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/* extract the host_spec - fail if it's not nbd:... */
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if (!strstart(file, "nbd:", &host_spec)) {
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error_setg(errp, "File name string for NBD must start with 'nbd:'");
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goto out;
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}
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if (!*host_spec) {
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goto out;
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}
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/* are we a UNIX or TCP socket? */
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if (strstart(host_spec, "unix:", &unixpath)) {
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qdict_put(options, "path", qstring_from_str(unixpath));
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} else {
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InetSocketAddress *addr = NULL;
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addr = inet_parse(host_spec, errp);
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if (!addr) {
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goto out;
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}
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qdict_put(options, "host", qstring_from_str(addr->host));
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qdict_put(options, "port", qstring_from_str(addr->port));
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qapi_free_InetSocketAddress(addr);
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}
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out:
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g_free(file);
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}
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static SocketAddress *nbd_config(BDRVNBDState *s, QDict *options, char **export,
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Error **errp)
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{
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SocketAddress *saddr;
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if (qdict_haskey(options, "path") == qdict_haskey(options, "host")) {
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if (qdict_haskey(options, "path")) {
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error_setg(errp, "path and host may not be used at the same time.");
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} else {
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error_setg(errp, "one of path and host must be specified.");
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}
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return NULL;
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}
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saddr = g_new0(SocketAddress, 1);
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if (qdict_haskey(options, "path")) {
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UnixSocketAddress *q_unix;
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saddr->type = SOCKET_ADDRESS_KIND_UNIX;
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q_unix = saddr->u.q_unix.data = g_new0(UnixSocketAddress, 1);
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q_unix->path = g_strdup(qdict_get_str(options, "path"));
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qdict_del(options, "path");
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} else {
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InetSocketAddress *inet;
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saddr->type = SOCKET_ADDRESS_KIND_INET;
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inet = saddr->u.inet.data = g_new0(InetSocketAddress, 1);
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inet->host = g_strdup(qdict_get_str(options, "host"));
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if (!qdict_get_try_str(options, "port")) {
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inet->port = g_strdup_printf("%d", NBD_DEFAULT_PORT);
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} else {
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inet->port = g_strdup(qdict_get_str(options, "port"));
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}
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qdict_del(options, "host");
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qdict_del(options, "port");
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}
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s->client.is_unix = saddr->type == SOCKET_ADDRESS_KIND_UNIX;
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*export = g_strdup(qdict_get_try_str(options, "export"));
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if (*export) {
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qdict_del(options, "export");
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}
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return saddr;
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}
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NbdClientSession *nbd_get_client_session(BlockDriverState *bs)
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{
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BDRVNBDState *s = bs->opaque;
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return &s->client;
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}
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static QIOChannelSocket *nbd_establish_connection(SocketAddress *saddr,
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Error **errp)
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{
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QIOChannelSocket *sioc;
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Error *local_err = NULL;
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sioc = qio_channel_socket_new();
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qio_channel_socket_connect_sync(sioc,
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saddr,
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&local_err);
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if (local_err) {
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error_propagate(errp, local_err);
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return NULL;
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}
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qio_channel_set_delay(QIO_CHANNEL(sioc), false);
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return sioc;
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}
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static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp)
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{
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Object *obj;
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QCryptoTLSCreds *creds;
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obj = object_resolve_path_component(
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object_get_objects_root(), id);
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if (!obj) {
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error_setg(errp, "No TLS credentials with id '%s'",
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id);
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return NULL;
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}
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creds = (QCryptoTLSCreds *)
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object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS);
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if (!creds) {
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error_setg(errp, "Object with id '%s' is not TLS credentials",
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id);
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return NULL;
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}
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if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT) {
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error_setg(errp,
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"Expecting TLS credentials with a client endpoint");
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return NULL;
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}
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object_ref(obj);
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return creds;
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}
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static int nbd_open(BlockDriverState *bs, QDict *options, int flags,
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Error **errp)
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{
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BDRVNBDState *s = bs->opaque;
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char *export = NULL;
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QIOChannelSocket *sioc = NULL;
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SocketAddress *saddr;
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const char *tlscredsid;
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QCryptoTLSCreds *tlscreds = NULL;
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const char *hostname = NULL;
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int ret = -EINVAL;
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/* Pop the config into our state object. Exit if invalid. */
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saddr = nbd_config(s, options, &export, errp);
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if (!saddr) {
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goto error;
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}
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tlscredsid = g_strdup(qdict_get_try_str(options, "tls-creds"));
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if (tlscredsid) {
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qdict_del(options, "tls-creds");
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tlscreds = nbd_get_tls_creds(tlscredsid, errp);
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if (!tlscreds) {
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goto error;
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}
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if (saddr->type != SOCKET_ADDRESS_KIND_INET) {
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error_setg(errp, "TLS only supported over IP sockets");
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goto error;
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}
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hostname = saddr->u.inet.data->host;
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}
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/* establish TCP connection, return error if it fails
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* TODO: Configurable retry-until-timeout behaviour.
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*/
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sioc = nbd_establish_connection(saddr, errp);
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if (!sioc) {
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ret = -ECONNREFUSED;
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goto error;
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}
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/* NBD handshake */
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ret = nbd_client_init(bs, sioc, export,
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tlscreds, hostname, errp);
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error:
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if (sioc) {
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object_unref(OBJECT(sioc));
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}
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if (tlscreds) {
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object_unref(OBJECT(tlscreds));
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}
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qapi_free_SocketAddress(saddr);
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g_free(export);
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return ret;
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}
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static int nbd_co_readv(BlockDriverState *bs, int64_t sector_num,
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int nb_sectors, QEMUIOVector *qiov)
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{
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return nbd_client_co_readv(bs, sector_num, nb_sectors, qiov);
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}
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static int nbd_co_writev_flags(BlockDriverState *bs, int64_t sector_num,
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int nb_sectors, QEMUIOVector *qiov, int flags)
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{
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int ret;
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ret = nbd_client_co_writev(bs, sector_num, nb_sectors, qiov, &flags);
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if (ret < 0) {
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return ret;
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}
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/* The flag wasn't sent to the server, so we need to emulate it with an
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* explicit flush */
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if (flags & BDRV_REQ_FUA) {
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ret = nbd_client_co_flush(bs);
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}
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return ret;
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}
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static int nbd_co_writev(BlockDriverState *bs, int64_t sector_num,
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int nb_sectors, QEMUIOVector *qiov)
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{
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return nbd_co_writev_flags(bs, sector_num, nb_sectors, qiov, 0);
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}
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static int nbd_co_flush(BlockDriverState *bs)
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{
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return nbd_client_co_flush(bs);
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}
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static void nbd_refresh_limits(BlockDriverState *bs, Error **errp)
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{
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bs->bl.max_discard = UINT32_MAX >> BDRV_SECTOR_BITS;
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bs->bl.max_transfer_length = UINT32_MAX >> BDRV_SECTOR_BITS;
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}
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static int nbd_co_discard(BlockDriverState *bs, int64_t sector_num,
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int nb_sectors)
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{
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return nbd_client_co_discard(bs, sector_num, nb_sectors);
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}
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static void nbd_close(BlockDriverState *bs)
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{
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nbd_client_close(bs);
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}
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static int64_t nbd_getlength(BlockDriverState *bs)
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{
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BDRVNBDState *s = bs->opaque;
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return s->client.size;
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}
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static void nbd_detach_aio_context(BlockDriverState *bs)
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{
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nbd_client_detach_aio_context(bs);
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}
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static void nbd_attach_aio_context(BlockDriverState *bs,
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AioContext *new_context)
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{
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nbd_client_attach_aio_context(bs, new_context);
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}
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static void nbd_refresh_filename(BlockDriverState *bs, QDict *options)
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{
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QDict *opts = qdict_new();
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const char *path = qdict_get_try_str(options, "path");
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const char *host = qdict_get_try_str(options, "host");
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const char *port = qdict_get_try_str(options, "port");
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const char *export = qdict_get_try_str(options, "export");
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const char *tlscreds = qdict_get_try_str(options, "tls-creds");
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qdict_put_obj(opts, "driver", QOBJECT(qstring_from_str("nbd")));
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if (path && export) {
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snprintf(bs->exact_filename, sizeof(bs->exact_filename),
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"nbd+unix:///%s?socket=%s", export, path);
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} else if (path && !export) {
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snprintf(bs->exact_filename, sizeof(bs->exact_filename),
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"nbd+unix://?socket=%s", path);
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} else if (!path && export && port) {
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snprintf(bs->exact_filename, sizeof(bs->exact_filename),
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"nbd://%s:%s/%s", host, port, export);
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} else if (!path && export && !port) {
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snprintf(bs->exact_filename, sizeof(bs->exact_filename),
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"nbd://%s/%s", host, export);
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} else if (!path && !export && port) {
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snprintf(bs->exact_filename, sizeof(bs->exact_filename),
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"nbd://%s:%s", host, port);
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} else if (!path && !export && !port) {
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snprintf(bs->exact_filename, sizeof(bs->exact_filename),
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"nbd://%s", host);
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}
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if (path) {
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qdict_put_obj(opts, "path", QOBJECT(qstring_from_str(path)));
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} else if (port) {
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qdict_put_obj(opts, "host", QOBJECT(qstring_from_str(host)));
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qdict_put_obj(opts, "port", QOBJECT(qstring_from_str(port)));
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} else {
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qdict_put_obj(opts, "host", QOBJECT(qstring_from_str(host)));
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}
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if (export) {
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qdict_put_obj(opts, "export", QOBJECT(qstring_from_str(export)));
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}
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if (tlscreds) {
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qdict_put_obj(opts, "tls-creds", QOBJECT(qstring_from_str(tlscreds)));
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}
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bs->full_open_options = opts;
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}
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static BlockDriver bdrv_nbd = {
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.format_name = "nbd",
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.protocol_name = "nbd",
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.instance_size = sizeof(BDRVNBDState),
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.bdrv_parse_filename = nbd_parse_filename,
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.bdrv_file_open = nbd_open,
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.bdrv_co_readv = nbd_co_readv,
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.bdrv_co_writev = nbd_co_writev,
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.bdrv_co_writev_flags = nbd_co_writev_flags,
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.supported_write_flags = BDRV_REQ_FUA,
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.bdrv_close = nbd_close,
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.bdrv_co_flush_to_os = nbd_co_flush,
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.bdrv_co_discard = nbd_co_discard,
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.bdrv_refresh_limits = nbd_refresh_limits,
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.bdrv_getlength = nbd_getlength,
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.bdrv_detach_aio_context = nbd_detach_aio_context,
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.bdrv_attach_aio_context = nbd_attach_aio_context,
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.bdrv_refresh_filename = nbd_refresh_filename,
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};
|
|
|
|
static BlockDriver bdrv_nbd_tcp = {
|
|
.format_name = "nbd",
|
|
.protocol_name = "nbd+tcp",
|
|
.instance_size = sizeof(BDRVNBDState),
|
|
.bdrv_parse_filename = nbd_parse_filename,
|
|
.bdrv_file_open = nbd_open,
|
|
.bdrv_co_readv = nbd_co_readv,
|
|
.bdrv_co_writev = nbd_co_writev,
|
|
.bdrv_co_writev_flags = nbd_co_writev_flags,
|
|
.supported_write_flags = BDRV_REQ_FUA,
|
|
.bdrv_close = nbd_close,
|
|
.bdrv_co_flush_to_os = nbd_co_flush,
|
|
.bdrv_co_discard = nbd_co_discard,
|
|
.bdrv_refresh_limits = nbd_refresh_limits,
|
|
.bdrv_getlength = nbd_getlength,
|
|
.bdrv_detach_aio_context = nbd_detach_aio_context,
|
|
.bdrv_attach_aio_context = nbd_attach_aio_context,
|
|
.bdrv_refresh_filename = nbd_refresh_filename,
|
|
};
|
|
|
|
static BlockDriver bdrv_nbd_unix = {
|
|
.format_name = "nbd",
|
|
.protocol_name = "nbd+unix",
|
|
.instance_size = sizeof(BDRVNBDState),
|
|
.bdrv_parse_filename = nbd_parse_filename,
|
|
.bdrv_file_open = nbd_open,
|
|
.bdrv_co_readv = nbd_co_readv,
|
|
.bdrv_co_writev = nbd_co_writev,
|
|
.bdrv_co_writev_flags = nbd_co_writev_flags,
|
|
.supported_write_flags = BDRV_REQ_FUA,
|
|
.bdrv_close = nbd_close,
|
|
.bdrv_co_flush_to_os = nbd_co_flush,
|
|
.bdrv_co_discard = nbd_co_discard,
|
|
.bdrv_refresh_limits = nbd_refresh_limits,
|
|
.bdrv_getlength = nbd_getlength,
|
|
.bdrv_detach_aio_context = nbd_detach_aio_context,
|
|
.bdrv_attach_aio_context = nbd_attach_aio_context,
|
|
.bdrv_refresh_filename = nbd_refresh_filename,
|
|
};
|
|
|
|
static void bdrv_nbd_init(void)
|
|
{
|
|
bdrv_register(&bdrv_nbd);
|
|
bdrv_register(&bdrv_nbd_tcp);
|
|
bdrv_register(&bdrv_nbd_unix);
|
|
}
|
|
|
|
block_init(bdrv_nbd_init);
|