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=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,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 66FB4C4BA15 for ; Wed, 26 Feb 2020 16:17:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3E67B2084E for ; Wed, 26 Feb 2020 16:17:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="zCYArvRa" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726971AbgBZQR6 (ORCPT ); Wed, 26 Feb 2020 11:17:58 -0500 Received: from aserp2120.oracle.com ([141.146.126.78]:42252 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726148AbgBZQR6 (ORCPT ); Wed, 26 Feb 2020 11:17:58 -0500 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 01QFvf0S033348; Wed, 26 Feb 2020 16:17:46 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : references : mime-version : content-type : in-reply-to; s=corp-2020-01-29; bh=WKDZDiIYwkHJ2rTuDV4wlnpR6BBfh5Fu3+ipePDTfXQ=; b=zCYArvRaXJmqXBidy/Q5qenDhKRVmcVzrktrvGTdPBebl7sI5xagcFXYUgC2ZTho07tX 8THf6oPBRBGDEimP3iO3azzyM8eFBSqhsmbQck3Xo9cvFeTLs8rxZH5Gs7qCs2bqBwep kDW0tlB18T7ZAWetfkGwd8DjYJE/ODI8GfgyauamE+0ynyOly7JgozmFqhfZYTLu8Voi ZhCEe385XKiZTK+ckxaYG3+QLbPUNsejpIf5y/VwD+yqAsgQdcIAiygRRlOkipSVLX47 d+GvnJFJeLM5RBiaNxuCxHgL2QL6lTNHVcaDMdu8B9C8eH8Gfs9Irt/KJGDjeL68Z09I Pg== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by aserp2120.oracle.com with ESMTP id 2ydcsrmqqg-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 26 Feb 2020 16:17:46 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 01QGELGG110521; Wed, 26 Feb 2020 16:17:45 GMT Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by userp3030.oracle.com with ESMTP id 2ydcs2fs6w-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 26 Feb 2020 16:17:45 +0000 Received: from abhmp0012.oracle.com (abhmp0012.oracle.com [141.146.116.18]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 01QGHiaR030245; Wed, 26 Feb 2020 16:17:44 GMT Received: from localhost (/67.169.218.210) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 26 Feb 2020 08:17:43 -0800 Date: Wed, 26 Feb 2020 08:17:42 -0800 From: "Darrick J. Wong" To: Matthew Wilcox Cc: Ritesh Harjani , jack@suse.cz, tytso@mit.edu, linux-ext4@vger.kernel.org, adilger.kernel@dilger.ca, linux-fsdevel@vger.kernel.org, hch@infradead.org, cmaiolino@redhat.com Subject: Re: [PATCHv3 6/6] Documentation: Correct the description of FIEMAP_EXTENT_LAST Message-ID: <20200226161742.GB8036@magnolia> References: <279638c6939b1f6ef3ab32912cb51da1a967cf8e.1582702694.git.riteshh@linux.ibm.com> <20200226130503.GY24185@bombadil.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200226130503.GY24185@bombadil.infradead.org> User-Agent: Mutt/1.9.4 (2018-02-28) X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9543 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 bulkscore=0 malwarescore=0 mlxlogscore=999 mlxscore=0 phishscore=0 suspectscore=0 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2001150001 definitions=main-2002260111 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9543 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxscore=0 adultscore=0 suspectscore=0 bulkscore=0 malwarescore=0 spamscore=0 impostorscore=0 clxscore=1015 lowpriorityscore=0 mlxlogscore=999 phishscore=0 priorityscore=1501 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2001150001 definitions=main-2002260111 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Wed, Feb 26, 2020 at 05:05:03AM -0800, Matthew Wilcox wrote: > On Wed, Feb 26, 2020 at 03:27:08PM +0530, Ritesh Harjani wrote: > > Currently FIEMAP_EXTENT_LAST is not working consistently across > > different filesystem's fiemap implementations and thus this feature > > may be broken. So fix the documentation about this flag to meet the > > right expectations. > > Are you saying filesystems have both false positives and false negatives? > I can understand how a filesystem might fail to set FIEMAP_EXTENT_LAST, > but not how a filesystem might set it when there's actually another > extent beyond this one. > > > * FIEMAP_EXTENT_LAST > > -This is the last extent in the file. A mapping attempt past this > > -extent will return nothing. > > +This is generally the last extent in the file. A mapping attempt past this > > +extent may return nothing. But the user must still confirm by trying to map > > +past this extent, since different filesystems implement this differently. "This flag means nothing and can be set arbitrarily by the fs for the lulz." Yuck. I was really hoping for "This is set on the last extent record in the dataset generated by the query parameters", particularly becaue that's how e2fsprogs utilties interpret that flag. --D