From patchwork Mon Apr 10 18:06:08 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Blake X-Patchwork-Id: 13206556 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 B5F82C77B6F for ; Mon, 10 Apr 2023 18:07:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230430AbjDJSHT (ORCPT ); Mon, 10 Apr 2023 14:07:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48312 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230410AbjDJSHR (ORCPT ); Mon, 10 Apr 2023 14:07:17 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6BF032718 for ; Mon, 10 Apr 2023 11:06:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1681149982; 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=ISj7vJEBaH0Ok4XCxrHU0Yfhlf+Ohg61blivylaRcYI=; b=d2T2Tcp5OmgO1h13B7K4CZdIhN3+Ur4a6MnmI2t8BnMDHbicEbCfx9bIQi50FI1dimAAN3 d5hb8klphsM3LSC2vAK7oa/ByPID4zv4fQCKkY1C9kezLtGWntH+VYMoZT5Q95bFf8QR55 /Z8pZDDyl0y+VkVYEXI1c9PsWV9mdJc= 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-372-hcSii8A9PcyeTamlHWGCyw-1; Mon, 10 Apr 2023 14:06:17 -0400 X-MC-Unique: hcSii8A9PcyeTamlHWGCyw-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 845F4858F09; Mon, 10 Apr 2023 18:06:16 +0000 (UTC) Received: from green.redhat.com (unknown [10.2.16.95]) by smtp.corp.redhat.com (Postfix) with ESMTP id B2858492C13; Mon, 10 Apr 2023 18:06:15 +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, Ming Lei Subject: [PATCH v3 1/4] uapi nbd: improve doc links to userspace spec Date: Mon, 10 Apr 2023 13:06:08 -0500 Message-Id: <20230410180611.1051618-2-eblake@redhat.com> In-Reply-To: <20230410180611.1051618-1-eblake@redhat.com> References: <20230410180611.1051618-1-eblake@redhat.com> MIME-Version: 1.0 Content-type: text/plain X-Scanned-By: MIMEDefang 3.1 on 10.11.54.9 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. Signed-off-by: Eric Blake Reviewed-by: Ming Lei Reviewed-by: Josef Bacik --- v2: Split change to sourceforge link to separate patch v3: Add R-b --- include/uapi/linux/nbd.h | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) 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 */ };