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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 CED1DC43603 for ; Tue, 10 Dec 2019 17:45:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AEA2E207FF for ; Tue, 10 Dec 2019 17:45:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727597AbfLJRpU (ORCPT ); Tue, 10 Dec 2019 12:45:20 -0500 Received: from mx2.suse.de ([195.135.220.15]:33226 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727527AbfLJRpU (ORCPT ); Tue, 10 Dec 2019 12:45:20 -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 0F733AC2F; Tue, 10 Dec 2019 17:45:19 +0000 (UTC) Received: by ds.suse.cz (Postfix, from userid 10065) id 8703EDA727; Tue, 10 Dec 2019 18:45:19 +0100 (CET) Date: Tue, 10 Dec 2019 18:45:18 +0100 From: David Sterba To: Omar Sandoval Cc: linux-btrfs@vger.kernel.org, kernel-team@fb.com Subject: Re: [PATCH 6/9] btrfs: remove redundant i_size check in __extent_writepage_io() Message-ID: <20191210174518.GE3929@twin.jikos.cz> Reply-To: dsterba@suse.cz Mail-Followup-To: dsterba@suse.cz, Omar Sandoval , linux-btrfs@vger.kernel.org, kernel-team@fb.com References: <365cd6fdadd6a91c22ccf61fcb1deb688763a176.1575336816.git.osandov@fb.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <365cd6fdadd6a91c22ccf61fcb1deb688763a176.1575336816.git.osandov@fb.com> User-Agent: Mutt/1.5.23.1-rc1 (2014-03-12) Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Mon, Dec 02, 2019 at 05:34:22PM -0800, Omar Sandoval wrote: > From: Omar Sandoval > > In __extent_writepage_io(), we check whether > i_size <= page_offset(page). > > Note that if i_size < page_offset(page), then > i_size >> PAGE_SHIFT < page->index. If i_size == page_offset(page), then > i_size >> PAGE_SHIFT == page->index && offset_in_page(i_size) == 0. > > __extent_writepage() already has a check for these cases that > returns without calling __extent_writepage_io(): > > end_index = i_size >> PAGE_SHIFT > pg_offset = offset_in_page(i_size); > if (page->index > end_index || > (page->index == end_index && !pg_offset)) { > page->mapping->a_ops->invalidatepage(page, 0, PAGE_SIZE); > unlock_page(page); > return 0; > } > > Get rid of the one in __extent_writepage_io(), which was obsoleted in > 211c17f51f46 ("Fix corners in writepage and btrfs_truncate_page"). > > Signed-off-by: Omar Sandoval Reviewed-by: David Sterba