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=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, 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 A9C96CA9EBB for ; Fri, 25 Oct 2019 01:15:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7752321D71 for ; Fri, 25 Oct 2019 01:15:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=plexistor-com.20150623.gappssmtp.com header.i=@plexistor-com.20150623.gappssmtp.com header.b="F7CvUN1n" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388560AbfJYBPt (ORCPT ); Thu, 24 Oct 2019 21:15:49 -0400 Received: from mail-ed1-f66.google.com ([209.85.208.66]:39911 "EHLO mail-ed1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388530AbfJYBPs (ORCPT ); Thu, 24 Oct 2019 21:15:48 -0400 Received: by mail-ed1-f66.google.com with SMTP id l25so505173edt.6 for ; Thu, 24 Oct 2019 18:15:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=plexistor-com.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=H1GaUvponGzx8dfabBhKW2OqVVQdC3N0IbNOHN+GfyA=; b=F7CvUN1nPbeQ3ofUpTfw3ik8aSK5aNiLPnsPsnj56b2FzDgopyq8dS+4OdywSY3cRK Eb7pBK79RZCAqa7dMaDNiALdZ1Q3F4Qp1fNImEMnjWIyz47c4BHaKK+WCMwcPVNBfHiN xknjfj8h/cTsqLjN1CpurQu9NYku85BMGiwf+6d9S5cE50PlssibV/Qo7E4k6g+D1o7G BXtMdHwxSZDmgNJWJzqGOPCg0ZODwFjbIvuczE7ACnosAFZZhRB0n7cefeG6+aipnjAf ijbC86raCT7G6EcIKb+iSX/posRmH1Oq7/anIPBl3mwLVo+v+cMt72aXJqlVakb/ePHY pyYw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=H1GaUvponGzx8dfabBhKW2OqVVQdC3N0IbNOHN+GfyA=; b=ln5JF4QaRak84pDVshpRKbYvXpaoRBNGjAkNbBLaBs8IIxRwnXgxYxIREsjLzHm53S LwGA96GL2DnJppc3VxY9lBGMZJg7IGbFpibnL3vELHyet7pS5lr5IaFz+xb1qquE50Wp //aSPPxmKXSUhSuMs01PfcsLZ8WxbR+A85qAKbw4P5DPQ9HQF+u+aAsPhrXE9EAmSvin 16NxpoxwmohiXHW2MT0hlvYbSDflLrfkQ3zcAcGOa+X4q5cFt6GghvFQNR0upS+9rnJv dY4NZeQZqxZiS1SnGD2FTaXcxWu7C9Q2896L9p6+8LVK+kPYpxMb4IT+eQW04jzXXLfo r7rw== X-Gm-Message-State: APjAAAVxcm96nCVtO1o6fqPNWwSWQf5YtOzKitPcj19JOsiSYjB7YWOu V/xABY1p7JBmYHw46cwCnFsmyQ== X-Google-Smtp-Source: APXvYqz6czjRAMv/BeSl0ugHesI8gzA5oRUMvzQQRtKwlS9OjlmuA9FEFIHOOZH28oxILnBJQbs9HQ== X-Received: by 2002:a50:cbc2:: with SMTP id l2mr1201839edi.304.1571966147286; Thu, 24 Oct 2019 18:15:47 -0700 (PDT) Received: from [10.68.217.182] ([217.70.210.43]) by smtp.googlemail.com with ESMTPSA id gj14sm1695ejb.62.2019.10.24.18.15.45 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 24 Oct 2019 18:15:46 -0700 (PDT) Subject: Re: [PATCH 0/5] Enable per-file/directory DAX operations To: Dave Chinner , Boaz Harrosh Cc: ira.weiny@intel.com, linux-kernel@vger.kernel.org, Alexander Viro , "Darrick J. Wong" , Dan Williams , Christoph Hellwig , "Theodore Y. Ts'o" , Jan Kara , linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org References: <20191020155935.12297-1-ira.weiny@intel.com> <20191023221332.GE2044@dread.disaster.area> <20191024073446.GA4614@dread.disaster.area> <20191024213508.GB4614@dread.disaster.area> <20191025003603.GE4614@dread.disaster.area> From: Boaz Harrosh Message-ID: <9ffbc2a5-c85b-3633-1ad5-a9a3fe33cd2e@plexistor.com> Date: Fri, 25 Oct 2019 04:15:44 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.1.0 MIME-Version: 1.0 In-Reply-To: <20191025003603.GE4614@dread.disaster.area> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 25/10/2019 03:36, Dave Chinner wrote: > On Fri, Oct 25, 2019 at 02:29:04AM +0300, Boaz Harrosh wrote: <> >> Perhaps we always go by the directory. And then do an mv dir_DAX/foo dir_NODAX/foo > > The inode is instatiated before the rename is run, so it's set up > with it's old dir config, not the new one. So this ends up with the > same problem of haivng to change the S_DAX flag and aops vector > dynamically on rename. Same problem, not a solution. > Yes Admin needs a inode-drop_caches after the mv if she/he wants an effective change. >> to have an effective change. In hard links the first one at iget time before populating >> the inode cache takes affect. > > If something like a find or backup program brings the inode into > cache, the app may not even get the behaviour it wants, and it can't > change it until the inode is evicted from cache, which may be never. inode-drop-caches. (echo 2 > /proc/sys/vm/drop_caches) > Nobody wants implicit/random/uncontrollable/unchangeable behaviour > like this. > You mean in the case of hard links between different mode directories? I agree it is not so good. I do not like it too. <> > We went over all this ground when we disabled the flag in the first > place. We disabled the flag because we couldn't come up with a sane > way to flip the ops vector short of tracking the number of aops > calls in progress at any given time. i.e. reference counting the > aops structure, but that's hard to do with a const ops structure, > and so it got disabled rather than allowing users to crash > kernels.... > Do you mean dropping this patchset all together? I missed that. Current patchset with the i_size == 0 thing is really bad I think. Its the same has dropping the direct change all together and only supporting inheritance from parent. [Which again for me is really not interesting] > Cheers, > -Dave. Lets sleep on it. Please remind me if xfs supports clone + DAX Thanks Dave Boaz