From patchwork Fri Mar 10 20:15:23 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Blake X-Patchwork-Id: 13170033 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1F724C74A4B for ; Fri, 10 Mar 2023 20:16:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231446AbjCJUQd (ORCPT ); Fri, 10 Mar 2023 15:16:33 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40144 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231421AbjCJUQ2 (ORCPT ); Fri, 10 Mar 2023 15:16:28 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C6C6312DDD7 for ; Fri, 10 Mar 2023 12:15:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1678479333; 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=ySNF9VklMnLNMFFSlXUm9DSmVb0PMck6UAVDHRxOWTI=; b=UBVApivxgnLPK00WUs95ReAGLQuV3oNNaC/IEkddxYtvMpn7sNg1N7THRwVqlxpiYY1v8Y Oa2rTGUSEvRKftDLi3zzIMCISGG10LhtpVNYe28C8xSKMvFK0xoOUk6vskIyd7W8B1WC8H eOZ2pOdoavFVhEovy83qgQHeOjhgmF4= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-67-l6gRyfhQNuOgRsi4_uQD8A-1; Fri, 10 Mar 2023 15:15:28 -0500 X-MC-Unique: l6gRyfhQNuOgRsi4_uQD8A-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id D3A5E858F09; Fri, 10 Mar 2023 20:15:27 +0000 (UTC) Received: from green.redhat.com (unknown [10.2.16.147]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1EA8C4014CF3; Fri, 10 Mar 2023 20:15:27 +0000 (UTC) From: Eric Blake To: josef@toxicpanda.com, linux-block@vger.kernel.org, nbd@other.debian.org Cc: philipp.reisner@linbit.com, lars.ellenberg@linbit.com, christoph.boehmwalder@linbit.com, corbet@lwn.net, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/3] uapi nbd: improve doc links to userspace spec Date: Fri, 10 Mar 2023 14:15:23 -0600 Message-Id: <20230310201525.2615385-2-eblake@redhat.com> In-Reply-To: <20230310201525.2615385-1-eblake@redhat.com> References: <20230310201525.2615385-1-eblake@redhat.com> MIME-Version: 1.0 Content-type: text/plain X-Scanned-By: MIMEDefang 3.1 on 10.11.54.2 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org The uapi header intentionally documents only the NBD server features that the kernel module will utilize as a client. But while it already had one mention of skipped bits due to userspace extensions, it did not actually direct the reader to the canonical source to learn about those extensions. While touching comments, fix an outdated reference that listed only READ and WRITE as commands. The documentation file also had a stale link to sourceforge; nbd ditched that several years ago in favor of github. Signed-off-by: Eric Blake Reviewed-by: Ming Lei --- Documentation/admin-guide/blockdev/nbd.rst | 2 +- include/uapi/linux/nbd.h | 15 ++++++++++++--- 2 files changed, 13 insertions(+), 4 deletions(-) diff --git a/Documentation/admin-guide/blockdev/nbd.rst b/Documentation/admin-guide/blockdev/nbd.rst index d78dfe559dcf..faf2ac4b1509 100644 --- a/Documentation/admin-guide/blockdev/nbd.rst +++ b/Documentation/admin-guide/blockdev/nbd.rst @@ -14,7 +14,7 @@ to borrow disk space from another computer. Unlike NFS, it is possible to put any filesystem on it, etc. For more information, or to download the nbd-client and nbd-server -tools, go to http://nbd.sf.net/. +tools, go to https://github.com/NetworkBlockDevice/nbd. The nbd kernel module need only be installed on the client system, as the nbd-server is completely in userspace. In fact, diff --git a/include/uapi/linux/nbd.h b/include/uapi/linux/nbd.h index 20d6cc91435d..8797387caaf7 100644 --- a/include/uapi/linux/nbd.h +++ b/include/uapi/linux/nbd.h @@ -11,6 +11,8 @@ * Cleanup PARANOIA usage & code. * 2004/02/19 Paul Clements * Removed PARANOIA, plus various cleanup and comments + * 2023 Copyright Red Hat + * Link to userspace extensions. */ #ifndef _UAPILINUX_NBD_H @@ -30,12 +32,18 @@ #define NBD_SET_TIMEOUT _IO( 0xab, 9 ) #define NBD_SET_FLAGS _IO( 0xab, 10) +/* + * See also https://github.com/NetworkBlockDevice/nbd/blob/master/doc/proto.md + * for additional userspace extensions not yet utilized in the kernel module. + */ + enum { NBD_CMD_READ = 0, NBD_CMD_WRITE = 1, NBD_CMD_DISC = 2, NBD_CMD_FLUSH = 3, NBD_CMD_TRIM = 4 + /* userspace defines additional extension commands */ }; /* values for flags field, these are server interaction specific. */ @@ -64,14 +72,15 @@ enum { #define NBD_REQUEST_MAGIC 0x25609513 #define NBD_REPLY_MAGIC 0x67446698 /* Do *not* use magics: 0x12560953 0x96744668. */ +/* magic 0x668e33ef for structured reply not supported by kernel yet */ /* * This is the packet used for communication between client and * server. All data are in network byte order. */ struct nbd_request { - __be32 magic; - __be32 type; /* == READ || == WRITE */ + __be32 magic; /* NBD_REQUEST_MAGIC */ + __be32 type; /* See NBD_CMD_* */ char handle[8]; __be64 from; __be32 len; @@ -82,7 +91,7 @@ struct nbd_request { * it has completed an I/O request (or an error occurs). */ struct nbd_reply { - __be32 magic; + __be32 magic; /* NBD_REPLY_MAGIC */ __be32 error; /* 0 = ok, else error */ char handle[8]; /* handle you got from request */ };