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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 BC138C1747C for ; Tue, 5 Nov 2019 13:59:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 96ED221928 for ; Tue, 5 Nov 2019 13:59:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389294AbfKEN7e (ORCPT ); Tue, 5 Nov 2019 08:59:34 -0500 Received: from mx2.suse.de ([195.135.220.15]:41568 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2388209AbfKEN7e (ORCPT ); Tue, 5 Nov 2019 08:59:34 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id E376FAC44; Tue, 5 Nov 2019 13:59:32 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id 3C9EC1E47E5; Tue, 5 Nov 2019 14:59:32 +0100 (CET) Date: Tue, 5 Nov 2019 14:59:32 +0100 From: Jan Kara To: Matthew Bobrowski Cc: tytso@mit.edu, jack@suse.cz, adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, riteshh@linux.ibm.com Subject: Re: [PATCH v7 11/11] ext4: introduce direct I/O write using iomap infrastructure Message-ID: <20191105135932.GN22379@quack2.suse.cz> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org On Tue 05-11-19 23:02:39, Matthew Bobrowski wrote: > + if (ret >= 0 && iov_iter_count(from)) { > + ssize_t err; > + loff_t endbyte; > + > + offset = iocb->ki_pos; > + err = ext4_buffered_write_iter(iocb, from); > + if (err < 0) > + return err; > + > + /* > + * We need to ensure that the pages within the page cache for > + * the range covered by this I/O are written to disk and > + * invalidated. This is in attempt to preserve the expected > + * direct I/O semantics in the case we fallback to buffered I/O > + * to complete off the I/O request. > + */ > + ret += err; > + endbyte = offset + ret - 1; ^^ err here? Otherwise you would write out and invalidate too much AFAICT - the 'offset' is position just before we fall back to buffered IO. Otherwise this hunk looks good to me. > + err = filemap_write_and_wait_range(iocb->ki_filp->f_mapping, > + offset, endbyte); > + if (!err) > + invalidate_mapping_pages(iocb->ki_filp->f_mapping, > + offset >> PAGE_SHIFT, > + endbyte >> PAGE_SHIFT); > + } > + > + return ret; > +} > + Honza -- Jan Kara SUSE Labs, CR