From patchwork Mon Sep 7 18:19:50 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 274337 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 61BC3C433E2 for ; Mon, 7 Sep 2020 18:25:11 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C8EFE20732 for ; Mon, 7 Sep 2020 18:25:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="d7AUnfy3" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C8EFE20732 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:52802 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kFLpF-0005LI-S9 for qemu-devel@archiver.kernel.org; Mon, 07 Sep 2020 14:25:09 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:42366) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kFLl2-00056M-Rq for qemu-devel@nongnu.org; Mon, 07 Sep 2020 14:20:48 -0400 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:39011) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kFLku-0004T3-9e for qemu-devel@nongnu.org; Mon, 07 Sep 2020 14:20:48 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1599502839; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=wc/jSdAq1lcmwuEkAonnR0I9E6LeqecdKUJZ4lvzsDo=; b=d7AUnfy3Sq4GNB+vWwl2WOp0it5wxQuSjHGgQl57Jv6phRM62bbjdFTrp/kcXOvgm72Dhn fxFVpIojZYtpPXGIfwHnAp+8ap8mgCCozxuUJpY3QqVh9aUgfTWMqFloDoPJwuBjSXoanf 6tMj0X9DGUTrFIJNNJOB6nZwIPzuz3Q= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-6-QFoqFs1HNZCEuXXiTxHMFQ-1; Mon, 07 Sep 2020 14:20:37 -0400 X-MC-Unique: QFoqFs1HNZCEuXXiTxHMFQ-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 16EC1807335; Mon, 7 Sep 2020 18:20:36 +0000 (UTC) Received: from linux.fritz.box.com (ovpn-114-154.ams2.redhat.com [10.36.114.154]) by smtp.corp.redhat.com (Postfix) with ESMTP id EC34A60C0F; Mon, 7 Sep 2020 18:20:34 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Subject: [PATCH 08/29] nbd: Add max-connections to nbd-server-start Date: Mon, 7 Sep 2020 20:19:50 +0200 Message-Id: <20200907182011.521007-9-kwolf@redhat.com> In-Reply-To: <20200907182011.521007-1-kwolf@redhat.com> References: <20200907182011.521007-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=kwolf@redhat.com X-Mimecast-Spam-Score: 0.001 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=205.139.110.61; envelope-from=kwolf@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/09/07 03:05:01 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.1, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, qemu-devel@nongnu.org, mreitz@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" This is a QMP equivalent of qemu-nbd's --shared option, limiting the maximum number of clients that can attach at the same time. Signed-off-by: Kevin Wolf Reviewed-by: Max Reitz Reviewed-by: Eric Blake --- qapi/block-export.json | 10 +++++++-- include/block/nbd.h | 3 ++- block/monitor/block-hmp-cmds.c | 2 +- blockdev-nbd.c | 33 ++++++++++++++++++++++------ storage-daemon/qemu-storage-daemon.c | 4 ++-- 5 files changed, 39 insertions(+), 13 deletions(-) diff --git a/qapi/block-export.json b/qapi/block-export.json index afb1af048d..7dedd893ab 100644 --- a/qapi/block-export.json +++ b/qapi/block-export.json @@ -17,6 +17,8 @@ # is only resolved at time of use, so can be deleted and # recreated on the fly while the NBD server is active. # If missing, it will default to denying access (since 4.0). +# @max-connections: The maximum number of connections to allow at the same +# time, 0 for unlimited. (since 5.2; default: 0) # # Keep this type consistent with the nbd-server-start arguments. The only # intended difference is using SocketAddress instead of SocketAddressLegacy. @@ -26,7 +28,8 @@ { 'struct': 'NbdServerOptions', 'data': { 'addr': 'SocketAddress', '*tls-creds': 'str', - '*tls-authz': 'str'} } + '*tls-authz': 'str', + '*max-connections': 'uint32' } } ## # @nbd-server-start: @@ -43,6 +46,8 @@ # is only resolved at time of use, so can be deleted and # recreated on the fly while the NBD server is active. # If missing, it will default to denying access (since 4.0). +# @max-connections: The maximum number of connections to allow at the same +# time, 0 for unlimited. (since 5.2; default: 0) # # Returns: error if the server is already running. # @@ -54,7 +59,8 @@ { 'command': 'nbd-server-start', 'data': { 'addr': 'SocketAddressLegacy', '*tls-creds': 'str', - '*tls-authz': 'str'} } + '*tls-authz': 'str', + '*max-connections': 'uint32' } } ## # @BlockExportOptionsNbd: diff --git a/include/block/nbd.h b/include/block/nbd.h index f55f5b710b..acccdb3180 100644 --- a/include/block/nbd.h +++ b/include/block/nbd.h @@ -354,7 +354,8 @@ void nbd_client_get(NBDClient *client); void nbd_client_put(NBDClient *client); void nbd_server_start(SocketAddress *addr, const char *tls_creds, - const char *tls_authz, Error **errp); + const char *tls_authz, uint32_t max_connections, + Error **errp); void nbd_server_start_options(NbdServerOptions *arg, Error **errp); /* nbd_read diff --git a/block/monitor/block-hmp-cmds.c b/block/monitor/block-hmp-cmds.c index fb632b1189..662b7f7d00 100644 --- a/block/monitor/block-hmp-cmds.c +++ b/block/monitor/block-hmp-cmds.c @@ -411,7 +411,7 @@ void hmp_nbd_server_start(Monitor *mon, const QDict *qdict) goto exit; } - nbd_server_start(addr, NULL, NULL, &local_err); + nbd_server_start(addr, NULL, NULL, 0, &local_err); qapi_free_SocketAddress(addr); if (local_err != NULL) { goto exit; diff --git a/blockdev-nbd.c b/blockdev-nbd.c index 7bcca105f9..41d5542987 100644 --- a/blockdev-nbd.c +++ b/blockdev-nbd.c @@ -23,23 +23,41 @@ typedef struct NBDServerData { QIONetListener *listener; QCryptoTLSCreds *tlscreds; char *tlsauthz; + uint32_t max_connections; + uint32_t connections; } NBDServerData; static NBDServerData *nbd_server; +static void nbd_update_server_watch(NBDServerData *s); + static void nbd_blockdev_client_closed(NBDClient *client, bool ignored) { nbd_client_put(client); + assert(nbd_server->connections > 0); + nbd_server->connections--; + nbd_update_server_watch(nbd_server); } static void nbd_accept(QIONetListener *listener, QIOChannelSocket *cioc, gpointer opaque) { + nbd_server->connections++; + nbd_update_server_watch(nbd_server); + qio_channel_set_name(QIO_CHANNEL(cioc), "nbd-server"); nbd_client_new(cioc, nbd_server->tlscreds, nbd_server->tlsauthz, nbd_blockdev_client_closed); } +static void nbd_update_server_watch(NBDServerData *s) +{ + if (!s->max_connections || s->connections < s->max_connections) { + qio_net_listener_set_client_func(s->listener, nbd_accept, NULL, NULL); + } else { + qio_net_listener_set_client_func(s->listener, NULL, NULL, NULL); + } +} static void nbd_server_free(NBDServerData *server) { @@ -88,7 +106,8 @@ static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp) void nbd_server_start(SocketAddress *addr, const char *tls_creds, - const char *tls_authz, Error **errp) + const char *tls_authz, uint32_t max_connections, + Error **errp) { if (nbd_server) { error_setg(errp, "NBD server already running"); @@ -96,6 +115,7 @@ void nbd_server_start(SocketAddress *addr, const char *tls_creds, } nbd_server = g_new0(NBDServerData, 1); + nbd_server->max_connections = max_connections; nbd_server->listener = qio_net_listener_new(); qio_net_listener_set_name(nbd_server->listener, @@ -120,10 +140,7 @@ void nbd_server_start(SocketAddress *addr, const char *tls_creds, nbd_server->tlsauthz = g_strdup(tls_authz); - qio_net_listener_set_client_func(nbd_server->listener, - nbd_accept, - NULL, - NULL); + nbd_update_server_watch(nbd_server); return; @@ -134,17 +151,19 @@ void nbd_server_start(SocketAddress *addr, const char *tls_creds, void nbd_server_start_options(NbdServerOptions *arg, Error **errp) { - nbd_server_start(arg->addr, arg->tls_creds, arg->tls_authz, errp); + nbd_server_start(arg->addr, arg->tls_creds, arg->tls_authz, + arg->max_connections, errp); } void qmp_nbd_server_start(SocketAddressLegacy *addr, bool has_tls_creds, const char *tls_creds, bool has_tls_authz, const char *tls_authz, + bool has_max_connections, uint32_t max_connections, Error **errp) { SocketAddress *addr_flat = socket_address_flatten(addr); - nbd_server_start(addr_flat, tls_creds, tls_authz, errp); + nbd_server_start(addr_flat, tls_creds, tls_authz, max_connections, errp); qapi_free_SocketAddress(addr_flat); } diff --git a/storage-daemon/qemu-storage-daemon.c b/storage-daemon/qemu-storage-daemon.c index b6f678d3ab..0fcab6ed2d 100644 --- a/storage-daemon/qemu-storage-daemon.c +++ b/storage-daemon/qemu-storage-daemon.c @@ -101,9 +101,9 @@ static void help(void) " configure a QMP monitor\n" "\n" " --nbd-server addr.type=inet,addr.host=,addr.port=\n" -" [,tls-creds=][,tls-authz=]\n" +" [,tls-creds=][,tls-authz=][,max-connections=]\n" " --nbd-server addr.type=unix,addr.path=\n" -" [,tls-creds=][,tls-authz=]\n" +" [,tls-creds=][,tls-authz=][,max-connections=]\n" " start an NBD server for exporting block nodes\n" "\n" " --object help list object types that can be added\n"