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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6CF5CC43334 for ; Tue, 19 Jul 2022 14:23:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238132AbiGSOXR (ORCPT ); Tue, 19 Jul 2022 10:23:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40290 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238340AbiGSOW7 (ORCPT ); Tue, 19 Jul 2022 10:22:59 -0400 Received: from outgoing.mit.edu (outgoing-auth-1.mit.edu [18.9.28.11]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 980FB48C94; Tue, 19 Jul 2022 07:06:32 -0700 (PDT) Received: from cwcc.thunk.org (pool-173-48-118-63.bstnma.fios.verizon.net [173.48.118.63]) (authenticated bits=0) (User authenticated as tytso@ATHENA.MIT.EDU) by outgoing.mit.edu (8.14.7/8.12.4) with ESMTP id 26JE64Hc032665 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 19 Jul 2022 10:06:05 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mit.edu; s=outgoing; t=1658239567; bh=pFRhtD0UYXegEYar/cYUoYiQFDVavLLZf/TJ5SxzjKk=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=pyGsb0Tfd4JJA+w/5eG0B95/9hfD4SG6u4KsBEoSxCrMF0ybcPQrYIlylp7JLQlYv nP09zeoD07k7y4ujU+gT4zDxYrZV1IKtksbIsKMLv4J4tU5fabUfLQ8sU0BVlYw/sV O1sUlDX3YQkCcrRw/3ijBTgaZJSMRemagBBWv+6WE+iSYQwAs1/96nmr6V6Fk/wT2t XAZ5g7SaN+/h5WNxMFrzGebpflAFrD1nkxO7ghfHUQpp74Nw6TFtpJ4tXaPIHjCkxH LSRSYPAoou8dJ1SqJOSiVyLm3/PWASj7OxHp/CqegeG3nlc93wQHxAuSz13m3GXF5o CiaLe4ypKE2mw== Received: by cwcc.thunk.org (Postfix, from userid 15806) id 7BEB815C00E4; Tue, 19 Jul 2022 10:06:04 -0400 (EDT) Date: Tue, 19 Jul 2022 10:06:04 -0400 From: "Theodore Ts'o" To: Greg KH Cc: Baokun Li , stable@vger.kernel.org, linux-ext4@vger.kernel.org, adilger.kernel@dilger.ca, jack@suse.cz, ritesh.list@gmail.com, lczerner@redhat.com, enwlinux@gmail.com, linux-kernel@vger.kernel.org, yi.zhang@huawei.com, yebin10@huawei.com, yukuai3@huawei.com, Hulk Robot Subject: Re: [PATCH 4.19] ext4: fix race condition between ext4_ioctl_setflags and ext4_fiemap Message-ID: References: <20220715023928.2701166-1-libaokun1@huawei.com> <425ab528-7d9a-975a-7f4c-5f903cedd8bc@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 19, 2022 at 01:26:57PM +0200, Greg KH wrote: > On Sat, Jul 16, 2022 at 10:33:30AM +0800, Baokun Li wrote: > > This problem persists until the patch d3b6f23f7167("ext4: move ext4_fiemap > > to use iomap framework") is incorporated in v5.7-rc1. > > Then why not ask for that change to be added instead? Switching over to use the iomap framework is a quite invasive change, which is fraught with danager and potential performance regressions. So it's really not something that would be considered safe for an LTS kernel. As an upstream developer I'd ask why are people trying to use a kernel as old as 4.19, but RHEL has done more insane things than that. Also, I know what the answer is, and it's just too depressing for a nice summer day like this. :-) - Ted