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,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 19D8AC48BD1 for ; Fri, 11 Jun 2021 20:48:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F2A65613CA for ; Fri, 11 Jun 2021 20:48:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230233AbhFKUui (ORCPT ); Fri, 11 Jun 2021 16:50:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53916 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230298AbhFKUuf (ORCPT ); Fri, 11 Jun 2021 16:50:35 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 52B09C0617AF; Fri, 11 Jun 2021 13:48:36 -0700 (PDT) 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=PEdTCh+3iQ9aG3ty3r/97MIrJQbDTmwMwReez7sMv4o=; b=KYF6CaumPuQU2GTJfQ9sWJZiLO VSV+jNcwIUqBGNrabM4XoIO84fIz/hGxFl6Xxo3iqLsaxvpLMg8P1GgQT6mmgI3oweSzliuwOz4CC S5trjg6xjamxKjdbQ/npHNd5bjkHbR0qeY8Y+Gq1cP2wkqyypDkWOmrt2Y4+V/421oBbJpLjSz/7u cxGp2WbHBezt29x+8Dgn6iHdd1P/XWCxFLoaML45vIeM9XneB1SukbVt9WmOvs9mdsCrx+KdGserT hugNtOHYWr4JGC4mPUPWWqM9zsH8f5wR+Kw0Xbvfpr7ueK+TcGYXeDQDqA4DT164MfyV9ainWlarv hVjEXjyQ==; Received: from willy by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1lro4h-0037lR-Jd; Fri, 11 Jun 2021 20:48:23 +0000 Date: Fri, 11 Jun 2021 21:48:19 +0100 From: Matthew Wilcox To: Jeff Layton Cc: ceph-devel@vger.kernel.org, linux-cachefs@redhat.com, pfmeec@rit.edu, dhowells@redhat.com, idryomov@gmail.com, stable@vger.kernel.org, Andrew W Elble Subject: Re: [PATCH] ceph: fix write_begin optimization when write is beyond EOF Message-ID: References: <20210611195904.160416-1-jlayton@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210611195904.160416-1-jlayton@kernel.org> Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Fri, Jun 11, 2021 at 03:59:04PM -0400, Jeff Layton wrote: > if ((pos_in_page == 0 && len == PAGE_SIZE) || > - (pos >= i_size_read(inode)) || > + (index > (i_size_read(inode) / PAGE_SIZE)) || I think that wants to be ((i_size_read(inode) - 1) / PAGE_SIZE) If your file is 4096 bytes long, that means bytes 0-4095 contain data. Except that i_size can be 0, so ... if ((offset == 0 && len == PAGE_SIZE) || i_size == 0 || (index > (i_size - 1) / PAGE_SIZE) || (offset == 0 && pos + len >= i_size)) zero_user_segments(page, 0, pos_in_page, pos_in_page + len, PAGE_SIZE);