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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 915ACC433E0 for ; Mon, 4 Jan 2021 16:20:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5FB7020578 for ; Mon, 4 Jan 2021 16:20:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728170AbhADQUE (ORCPT ); Mon, 4 Jan 2021 11:20:04 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48518 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728314AbhADQSF (ORCPT ); Mon, 4 Jan 2021 11:18:05 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 196B0C061574; Mon, 4 Jan 2021 08:17:25 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=lnGlZ07Br4iRlx3cevTIbdW4ub6R6dieT0l2rpJ6lwI=; b=tSSZE3lQD79SAw8vs/wFUAst7H O8JnawGM5RJ95pzH6VVKUk5k/G6vG2uvRkxUb4BrwOmdDgtrnK8dNeAYrGrTdLH9cP+IuPNBM3cnR 28sZSFUYzCYPrxI2ICJmlVxdNm1ZDu+LQdG/wzRNoEoV4UeQ/Bi7myY4XRTqGHyawqxRO5rbhvtdo QLEfCz880D7kiNBodvZqjfMCm27sTho9JnenONQ3rmEsC4+1E9j1LwAiZ/n8SLo2YjygUQWNFykUS df3uHHIM+TUoLvtjY0AsX9OmjMudZ0m7KjDgemglOb2X0xpYprEGOj4pECSwL4ziQQxl1/CM+UIln f2D7oESA==; Received: from hch by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1kwSXk-000HuD-Qz; Mon, 04 Jan 2021 16:17:17 +0000 Date: Mon, 4 Jan 2021 16:17:16 +0000 From: Christoph Hellwig To: Pavel Begunkov Cc: linux-block@vger.kernel.org, Jens Axboe , Christoph Hellwig , Matthew Wilcox , Ming Lei , Johannes Weiner , Alexander Viro , "Darrick J . Wong" , "Martin K . Petersen" , Jonathan Corbet , linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, io-uring@vger.kernel.org, linux-kernel@vger.kernel.org, target-devel@vger.kernel.org, linux-scsi@vger.kernel.org, linux-doc@vger.kernel.org Subject: Re: [PATCH v2 1/7] splice: don't generate zero-len segement bvecs Message-ID: <20210104161716.GA68600@infradead.org> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Jan 02, 2021 at 03:17:33PM +0000, Pavel Begunkov wrote: > iter_file_splice_write() may spawn bvec segments with zero-length. In > preparation for prohibiting them, filter out by hand at splice level. > > Signed-off-by: Pavel Begunkov > --- > fs/splice.c | 9 +++++---- > 1 file changed, 5 insertions(+), 4 deletions(-) > > diff --git a/fs/splice.c b/fs/splice.c > index 866d5c2367b2..7299330c3270 100644 > --- a/fs/splice.c > +++ b/fs/splice.c > @@ -644,7 +644,6 @@ iter_file_splice_write(struct pipe_inode_info *pipe, struct file *out, > ret = splice_from_pipe_next(pipe, &sd); > if (ret <= 0) > break; > - Spurious empty line removal.. > + if (!this_len) > + continue; Maybe throw in a comment on why we skip empty segments here? Otherwise looks good: Reviewed-by: Christoph Hellwig