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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,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 0F089C433E2 for ; Wed, 2 Sep 2020 17:55:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C7CF020758 for ; Wed, 2 Sep 2020 17:55:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20150623.gappssmtp.com header.i=@kernel-dk.20150623.gappssmtp.com header.b="QZwigp9r" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726794AbgIBRzT (ORCPT ); Wed, 2 Sep 2020 13:55:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44236 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726293AbgIBRzS (ORCPT ); Wed, 2 Sep 2020 13:55:18 -0400 Received: from mail-io1-xd41.google.com (mail-io1-xd41.google.com [IPv6:2607:f8b0:4864:20::d41]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8EB42C061244 for ; Wed, 2 Sep 2020 10:55:18 -0700 (PDT) Received: by mail-io1-xd41.google.com with SMTP id d190so6748917iof.3 for ; Wed, 02 Sep 2020 10:55:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=lF4pWhsByTOqyLOv5Bpsnjv77SPv18a7OvunkXhgK6g=; b=QZwigp9rDr7WwPU/I1qts5FEAk31WkqDNDl8N+DvmtO2nQx96vJeTzuFumkhiOBQkd WKdGpg1Q/loZr6Kd20KwOSbKfa09huVjkEz+HjFtFxdkd7vP/XhEY3mAMCT+4hgEaMNU fQ05n1cD9A/6dqL5TCY4CIWdCXrKB33hP9ys1eguvw5U4QzsPatrjXO+hRQ+/IKI6wnC xbRTWOuga0s9JGaGms7n7S+GRWQKjvWmasMgqRlBSg9iP47FORwWJJKUTdRkvs6hjap7 jIhKiR2GVHEGY9YvGhgDJ7nNADwhMV1IUdI1oRNMcU1NUTBpL92rqpJIegcI1c91483A WzfQ== 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=lF4pWhsByTOqyLOv5Bpsnjv77SPv18a7OvunkXhgK6g=; b=gM2igndPNod21eHVADeOEwepRMGcqjm3x6JSsOFnZWhKIuE8dV/4YjFcGnuA3/bHru DoaXIXfr+ybe57j3Ul1QpvWmkXmiV/zGEGzpuA+/cLmqvaXYG0HQpj6J8vlilxAxchDv Zgn83zqqgtvdzIRw0pyEbpCw7N/WXROAbWzvSIxec4wl3zDlayoiJE5/6efx4cr5IVzB BkZW5GOkEcAw/nZgijP0hEq2lctlxB6Yq2DlNelTa0zfU8Xf/e3bBxur4jwCh+FNWeyS biWvPxtUxn34ZWQRiFwtPdmmBgx3IkdxzvwtnREG57sGVMX54vaWK2Nc/Sl7x1aZXhaK sz4w== X-Gm-Message-State: AOAM531FjMtheiDGNx+b/ChSsIxGlxdhZjHc3Y8O1fEizfvXWYfw5IvM wOF4d7z60gDVd5JKQZYVZ/KPdg== X-Google-Smtp-Source: ABdhPJypzj6dCXiSRVbMCqcI0gl9vjF/pJGbjYaoT1JJlIicw1aUuWkEtaw2iUzf3mJ52pOGevMZTA== X-Received: by 2002:a05:6638:69d:: with SMTP id i29mr4340471jab.138.1599069317884; Wed, 02 Sep 2020 10:55:17 -0700 (PDT) Received: from [192.168.1.57] ([65.144.74.34]) by smtp.gmail.com with ESMTPSA id p124sm126225iof.19.2020.09.02.10.55.16 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 02 Sep 2020 10:55:17 -0700 (PDT) Subject: Re: [PATCH V2] block: allow for_each_bvec to support zero len bvec To: Ming Lei Cc: linux-block@vger.kernel.org, syzbot , Tetsuo Handa , Al Viro , Matthew Wilcox , stable@vger.kernel.org References: <20200817100055.2495905-1-ming.lei@redhat.com> From: Jens Axboe Message-ID: Date: Wed, 2 Sep 2020 11:55:16 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20200817100055.2495905-1-ming.lei@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 8/17/20 4:00 AM, Ming Lei wrote: > Block layer usually doesn't support or allow zero-length bvec. Since > commit 1bdc76aea115 ("iov_iter: use bvec iterator to implement > iterate_bvec()"), iterate_bvec() switches to bvec iterator. However, > Al mentioned that 'Zero-length segments are not disallowed' in iov_iter. > > Fixes for_each_bvec() so that it can move on after seeing one zero > length bvec. Applied, thanks. -- Jens Axboe