We were basing the advertisement of maximum discard and transfer length off of UINT32_MAX, but since the rest of the block layer has signed int limits on a transaction, nothing could ever reach that maximum, and we risk overflowing an int once things are converted to byte-based rather than sector-based limits. What's more, we DO have a much smaller limit: both the current kernel and qemu-nbd have a hard limit of 32M on a read or write transaction, and while they may also permit up to a full 32 bits on a discard transaction, the upstream NBD protocol is proposing wording that without any explicit advertisement otherwise, clients should limit ALL requests to the same limits as read and write, even though the other requests do not actually require as many bytes across the wire. So the better limit to tell the block layer is 32M for both values. Behavior doesn't actually change with this patch (the block layer is currently ignoring the max_transfer advertisements); but when that problem is fixed in a later series, this patch will prevent the exposure of a latent bug. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
509 lines
15 KiB
C
509 lines
15 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_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 = NBD_MAX_SECTORS;
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bs->bl.max_transfer_length = NBD_MAX_SECTORS;
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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_flags = nbd_client_co_writev,
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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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};
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static BlockDriver bdrv_nbd_tcp = {
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.format_name = "nbd",
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.protocol_name = "nbd+tcp",
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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_flags = nbd_client_co_writev,
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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,
|
|
.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_flags = nbd_client_co_writev,
|
|
.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);
|