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 X-Spam-Level: X-Spam-Status: No, score=-5.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 6BB53C4338F for ; Mon, 26 Jul 2021 16:38:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5579660C41 for ; Mon, 26 Jul 2021 16:38:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239809AbhGZP6M (ORCPT ); Mon, 26 Jul 2021 11:58:12 -0400 Received: from mail-pj1-f44.google.com ([209.85.216.44]:52798 "EHLO mail-pj1-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238716AbhGZPqY (ORCPT ); Mon, 26 Jul 2021 11:46:24 -0400 Received: by mail-pj1-f44.google.com with SMTP id m1so13621651pjv.2 for ; Mon, 26 Jul 2021 09:26:52 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; 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=zI7plmiWGse2X1CHO4VHp6XbSpQzNDfX1o+rPvqEzrE=; b=ZEzXSYX+jberFKDSCcpcGq/lo6PFyARUytfcUB+yg5YLSWAkQkl6f4HkFstJDawEjI /55yqSFfoDBK23fdXGv0F2WtbgpHlqI3dQ9pV4tQ5mX+wWcoa15lMw8Oyr/qP77brORY wGyNI3w/g2bbDs2ycFqWeZbr9W+IQ6bbP714wgeJcu/8UO1qq3g1Me7jYNNquccPl4MX LK5AR6UYk13oSD6t/eYmRnlxdzC/DFm6BcM6mLGQpq6JePs0dL4ivEPCD2lB3sBZ1V6X p6yddCZBeTAN/j0GFwyGltVfixw7D8QH4wd16+kaLldEwBwAvU16H1N1VA5fW3f3tt6I p85g== X-Gm-Message-State: AOAM532FMTFZ1609dcRVUf/L0EPOIkEJiopibMPCnIosXFMIz5jCXk+j CoCPN7QrWFoToohNbk7DgNY= X-Google-Smtp-Source: ABdhPJxQyThOh7PjfsGEo+L9anS/AcjVQ+uwjyh8iLAOS29SWlLr3tIa5bo8hKBw6l9sHStWguy/yg== X-Received: by 2002:a62:b413:0:b029:327:75dd:c8da with SMTP id h19-20020a62b4130000b029032775ddc8damr18790616pfn.34.1627316811761; Mon, 26 Jul 2021 09:26:51 -0700 (PDT) Received: from bvanassche-linux.mtv.corp.google.com ([2620:15c:211:1:7d43:3766:10c6:c3cb]) by smtp.gmail.com with ESMTPSA id bj15sm121481pjb.6.2021.07.26.09.26.50 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 26 Jul 2021 09:26:50 -0700 (PDT) Subject: Re: [PATCH 2/4] configfs: Fix writing at a non-zero offset To: Bodo Stroesser , Christoph Hellwig Cc: Joel Becker , linux-kernel@vger.kernel.org, "Martin K . Petersen" , Yanko Kaneti , Brendan Higgins References: <20210723212353.896343-1-bvanassche@acm.org> <20210723212353.896343-3-bvanassche@acm.org> <7bee65ce-f5f1-a525-c72d-221b5d23cf3e@gmail.com> From: Bart Van Assche Message-ID: Date: Mon, 26 Jul 2021 09:26:49 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <7bee65ce-f5f1-a525-c72d-221b5d23cf3e@gmail.com> 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 7/26/21 7:58 AM, Bodo Stroesser wrote: > On 23.07.21 23:23, Bart Van Assche wrote: > Let's say user writes 5 times to configfs file while keeping it open. > On every write() call it writes 1 character only, e.g. first "A", then > "B", ... > > The original code before the changes 5 times called flush_write_buffer > for the > strings "A\0", "B\0", ... (with the '\0' not included in the count > parameter, > so count is 1 always, which is the length of the last write). Isn't that behavior a severe violation of how POSIX specifies that the write() system call should be implemented? Thanks, Bart.