From patchwork Thu Oct 5 18:44:55 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Blake X-Patchwork-Id: 13410628 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id AA470E92728 for ; Thu, 5 Oct 2023 18:47:11 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qoTME-0001UX-Vn; Thu, 05 Oct 2023 14:45:59 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qoTLu-0000h3-76 for qemu-devel@nongnu.org; Thu, 05 Oct 2023 14:45:39 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qoTLq-00061C-Db for qemu-devel@nongnu.org; Thu, 05 Oct 2023 14:45:37 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1696531533; 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=knjRuugyxW0IGIk8PR29yIdyGDbClxs1Mfu992OLjEM=; b=Ho6DLbHzAk0q7KDGwNf+soIG4CI8OCQBUtccBOmYHL2TeBT4mOMc+6KgmHDwDK7q8Vs6Wj kK0bvm32SA+OYwr0nWVZbsYxbANoUQExSzFW7LMWfGDtOzwkfHIIdOz1zsG3Nkrr/B5Cv1 rjTyaecjdaHD4c8iQwGrok7/Jkmb2V4= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-190-rhP_MOIFOoS0tyOOfM6luw-1; Thu, 05 Oct 2023 14:45:29 -0400 X-MC-Unique: rhP_MOIFOoS0tyOOfM6luw-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 8989A29AA2DD; Thu, 5 Oct 2023 18:45:29 +0000 (UTC) Received: from green.redhat.com (unknown [10.2.16.63]) by smtp.corp.redhat.com (Postfix) with ESMTP id 371DD2156711; Thu, 5 Oct 2023 18:45:29 +0000 (UTC) From: Eric Blake To: qemu-devel@nongnu.org Cc: Vladimir Sementsov-Ogievskiy , qemu-block@nongnu.org (open list:Network Block Dev...) Subject: [PULL 08/15] nbd/server: Enable initial support for extended headers Date: Thu, 5 Oct 2023 13:44:55 -0500 Message-ID: <20231005184447.682556-25-eblake@redhat.com> In-Reply-To: <20231005184447.682556-17-eblake@redhat.com> References: <20231005184447.682556-17-eblake@redhat.com> MIME-Version: 1.0 Content-type: text/plain X-Scanned-By: MIMEDefang 3.1 on 10.11.54.6 Received-SPF: pass client-ip=170.10.133.124; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, 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=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Time to start supporting clients that request extended headers. Now we can finally reach the code added across several previous patches. Even though the NBD spec has been altered to allow us to accept NBD_CMD_READ larger than the max payload size (provided our response is a hole or broken up over more than one data chunk), we are not planning to take advantage of that, and continue to cap NBD_CMD_READ to 32M regardless of header size. For NBD_CMD_WRITE_ZEROES and NBD_CMD_TRIM, the block layer already supports 64-bit operations without any effort on our part. For NBD_CMD_BLOCK_STATUS, the client's length is a hint, and the previous patch took care of implementing the required NBD_REPLY_TYPE_BLOCK_STATUS_EXT. We do not yet support clients that want to do request payload filtering of NBD_CMD_BLOCK_STATUS; that will be added in later patches, but is not essential for qemu as a client since qemu only requests the single context base:allocation. Signed-off-by: Eric Blake Reviewed-by: Vladimir Sementsov-Ogievskiy Message-ID: <20230925192229.3186470-19-eblake@redhat.com> --- docs/interop/nbd.txt | 1 + nbd/server.c | 21 +++++++++++++++++++++ 2 files changed, 22 insertions(+) diff --git a/docs/interop/nbd.txt b/docs/interop/nbd.txt index f5ca25174a6..9aae5e1f294 100644 --- a/docs/interop/nbd.txt +++ b/docs/interop/nbd.txt @@ -69,3 +69,4 @@ NBD_CMD_BLOCK_STATUS for "qemu:dirty-bitmap:", NBD_CMD_CACHE NBD_CMD_FLAG_FAST_ZERO * 5.2: NBD_CMD_BLOCK_STATUS for "qemu:allocation-depth" * 7.1: NBD_FLAG_CAN_MULTI_CONN for shareable writable exports +* 8.2: NBD_OPT_EXTENDED_HEADERS diff --git a/nbd/server.c b/nbd/server.c index 183efe27bf8..d3eed6535bf 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -482,6 +482,10 @@ static int nbd_negotiate_handle_export_name(NBDClient *client, bool no_zeroes, [10 .. 133] reserved (0) [unless no_zeroes] */ trace_nbd_negotiate_handle_export_name(); + if (client->mode >= NBD_MODE_EXTENDED) { + error_setg(errp, "Extended headers already negotiated"); + return -EINVAL; + } if (client->optlen > NBD_MAX_STRING_SIZE) { error_setg(errp, "Bad length received"); return -EINVAL; @@ -1264,6 +1268,10 @@ static int nbd_negotiate_options(NBDClient *client, Error **errp) case NBD_OPT_STRUCTURED_REPLY: if (length) { ret = nbd_reject_length(client, false, errp); + } else if (client->mode >= NBD_MODE_EXTENDED) { + ret = nbd_negotiate_send_rep_err( + client, NBD_REP_ERR_EXT_HEADER_REQD, errp, + "extended headers already negotiated"); } else if (client->mode >= NBD_MODE_STRUCTURED) { ret = nbd_negotiate_send_rep_err( client, NBD_REP_ERR_INVALID, errp, @@ -1280,6 +1288,19 @@ static int nbd_negotiate_options(NBDClient *client, Error **errp) errp); break; + case NBD_OPT_EXTENDED_HEADERS: + if (length) { + ret = nbd_reject_length(client, false, errp); + } else if (client->mode >= NBD_MODE_EXTENDED) { + ret = nbd_negotiate_send_rep_err( + client, NBD_REP_ERR_INVALID, errp, + "extended headers already negotiated"); + } else { + ret = nbd_negotiate_send_rep(client, NBD_REP_ACK, errp); + client->mode = NBD_MODE_EXTENDED; + } + break; + default: ret = nbd_opt_drop(client, NBD_REP_ERR_UNSUP, errp, "Unsupported option %" PRIu32 " (%s)",