From mboxrd@z Thu Jan 1 00:00:00 1970 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 0351EC433F5 for ; Wed, 8 Dec 2021 22:59:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240955AbhLHXCk (ORCPT ); Wed, 8 Dec 2021 18:02:40 -0500 Received: from mail-pj1-f43.google.com ([209.85.216.43]:41592 "EHLO mail-pj1-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240729AbhLHXCj (ORCPT ); Wed, 8 Dec 2021 18:02:39 -0500 Received: by mail-pj1-f43.google.com with SMTP id gx15-20020a17090b124f00b001a695f3734aso3385929pjb.0; Wed, 08 Dec 2021 14:59:07 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=upn5pCTEbLoqxAzE9pPLnLbRKo8NrWejD9fWmOQQq6A=; b=7zMqCwD7Ixt/qAdGJHw6eGNfXKeZf+LiYnjD4bS2xXr+aFtPikIbFY5zUOlRQUcJte Bl1xp4K9LOXtcVsM5+SM87h9SqoNI1sCVENx4WWbsy4ekkpZjDYNPJSOkEyuJr20C4X7 X38wTnhYBidQP5rzWbJY4WLZTeDumq+o1hSNI5cRFzTN28RDrm7pMecEm+/dgBkpUK2L 4MdB+6z1poLfhUX2+ytvZ5tgXnPkU9ggVXfYKJvVs+TcwUF0xHmi8CncMTOFJc01BMfe Cw0DHAJpfW98kTrlxtFVD9LB73XXUfakOl97FPlEo4gHRtJ9L9q6xallRJPnoBFEIPYM 31/g== X-Gm-Message-State: AOAM532i3UokRhJ6SsXw/ROgzlfnnhGPsHrG0s9gcV/l/tKw1eSHp/cK Kjijx2nXQjE/RKpJMfeXGYs= X-Google-Smtp-Source: ABdhPJzC6On7oHVJPBngf8TPLy2ERLA7zL/IiPmRnpomSCFak06QwtXDRgh7S5Y0l35e++5qLMRWfw== X-Received: by 2002:a17:902:c643:b0:141:cf6b:6999 with SMTP id s3-20020a170902c64300b00141cf6b6999mr63193988pls.80.1639004346367; Wed, 08 Dec 2021 14:59:06 -0800 (PST) Received: from ?IPv6:2620:0:1000:2514:2f89:deb4:72f3:8a11? ([2620:0:1000:2514:2f89:deb4:72f3:8a11]) by smtp.gmail.com with ESMTPSA id mz7sm7261715pjb.7.2021.12.08.14.59.04 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 08 Dec 2021 14:59:05 -0800 (PST) Subject: Re: [PATCH v2 5/8] docs: sysfs-block: document stable_writes To: Eric Biggers Cc: linux-block@vger.kernel.org, Jens Axboe , linux-doc@vger.kernel.org, Greg Kroah-Hartman , linux-kernel@vger.kernel.org, Hannes Reinecke References: <20211208005640.102814-1-ebiggers@kernel.org> <20211208005640.102814-6-ebiggers@kernel.org> <7d9f9469-5347-780a-c560-77fca6e7008b@acm.org> From: Bart Van Assche Message-ID: Date: Wed, 8 Dec 2021 14:59:03 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.14.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/8/21 2:34 PM, Eric Biggers wrote: > Yes, I meant "written out to disk" in the general sense of writeback, not in the > sense of when the data reaches its final destination. I'm not sure what the > best way to explain it is. I think it's more than just "the process of > transferring data from host memory to the device", as that is just part of a > write request, whereas stable_writes applies to whole requests. How about: > > [RW] This file will contain '1' if memory must not be modified > while it is being used in a write request to this device. When > this is the case and the kernel is performing writeback of a > page, the kernel will wait for writeback to complete before > allowing the page to be modified again, rather than allowing > immediate modification as is normally the case. This > restriction arises when the device accesses the memory multiple > times where the same data must be seen every time -- for > example, once to calculate a checksum and once to actually write > the data. If no such restriction exists, this file will contain > '0'. This file is writable for testing purposes. The above sounds good to me. Thanks, Bart.