From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-427704-1527095533-2-4194198840458709610 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-charsets: plain='us-ascii' X-Resolved-to: linux@kroah.com X-Delivered-to: linux@kroah.com X-Mail-from: linux-fsdevel-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=fm2; t= 1527095533; b=cwhzbJOL0dBzFXMahz9lqrJOdb695kz5N8ji1zescGepkPmSmz 7Xr6N/+d4RlYVvINeHwiZg6LICDCGefe78PeVt+EYs68T4Pgkq1SNCURPqKlgGOk AWLgxnLQBxCoH24EIZKXKAIFHn+6BuAUVyxrySNVVB9eavzgn80e9xmy95cxWoQV riAj0H0fRcDnntwZ90kpDdq8RgHAsL1+8rnbjU5WIOlZaMBnF5oyD/rvCw7+QbT0 PlYSvcJo+D6CwWL9ifTYJcMHNCYW5MJqCsis1T2NOv0uuP6o0sDPwZsZCqi3AFKA RasU3bl9BdkD9RQfJwHbXPD6ZE2k8UYYmldA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=date:from:to:cc:subject:message-id :references:mime-version:content-type:in-reply-to:sender :list-id; s=fm2; t=1527095533; bh=OzN6a3DkweSgfwbppktyMXQhsxjzou M2wZbcPpLYIyw=; b=SGmz1VVlpnpRJB4jjrccV8PSCr13Mt8ehP0+7esN02IS2K dSLiJRwk5oQKggbtCTa6oEHcRFpsxLHEQV367HHuxc3m/Tvw10bpKp5W3YnVF4BH jpvt1g1keb3KNEHpveYcWEiTGAg/dMNa3FEsoA7pLxp34rEnfXd8II/wrWUOb/YD FXVGtPgbxdRsQGj32WSV/feq6O2/UI9IF2KjtJNSwFZiOVrFmfyuH1syLyZzd/Bm jLVHc/DwbBXYow5K50nHslZQI6A+ZoaM87edygEds/JBQS7jb4FOKsAjU2r6RJ+c jLGpCnCRnoAzeFVWsl7dwhVpkSkFF3nHNx8wzxUQ== ARC-Authentication-Results: i=1; mx3.messagingengine.com; arc=none (no signatures found); dkim=pass (2048-bit rsa key sha256) header.d=gmail.com header.i=@gmail.com header.b=G9A1fLdz x-bits=2048 x-keytype=rsa x-algorithm=sha256 x-selector=20161025; dmarc=pass (p=none,has-list-id=yes,d=none) header.from=gmail.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=linux-fsdevel-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-cm=none score=0; x-google-dkim=pass (2048-bit rsa key) header.d=1e100.net header.i=@1e100.net header.b=YaqkOxWv; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=gmail.com header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 Authentication-Results: mx3.messagingengine.com; arc=none (no signatures found); dkim=pass (2048-bit rsa key sha256) header.d=gmail.com header.i=@gmail.com header.b=G9A1fLdz x-bits=2048 x-keytype=rsa x-algorithm=sha256 x-selector=20161025; dmarc=pass (p=none,has-list-id=yes,d=none) header.from=gmail.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=linux-fsdevel-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-cm=none score=0; x-google-dkim=pass (2048-bit rsa key) header.d=1e100.net header.i=@1e100.net header.b=YaqkOxWv; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=gmail.com header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 X-ME-VSCategory: clean X-CM-Envelope: MS4wfJXnb3109EdxCJX0vlWFLP75FridxQwBpJwZzXBYq72N+FAYN/kuTvthVIR6eN/wcUafT31o0QXXWKj6gOZ2JXcnwDi4qOOF9FgG978pDQUk6PkbvYUa C85MiHtJ9C0/iV5w33kdqxtpcqID5x7A6jdNv86ngbsWxXUhuHQipxsTyd573yczRuoM3aNDXnUJMoUPEOXPVMsRMrSTLa51AI+wAniAHomfqoNGTqkOBl7H X-CM-Analysis: v=2.3 cv=Tq3Iegfh c=1 sm=1 tr=0 a=UK1r566ZdBxH71SXbqIOeA==:117 a=UK1r566ZdBxH71SXbqIOeA==:17 a=kj9zAlcOel0A:10 a=x7bEGLp0ZPQA:10 a=X4QjQfKnsHYA:10 a=VUJBJC2UJ8kA:10 a=O6gDU49s6lMXWFxsZvsA:9 a=CjuIK1q_8ugA:10 X-ME-CMScore: 0 X-ME-CMCategory: none Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933609AbeEWRMJ (ORCPT ); Wed, 23 May 2018 13:12:09 -0400 Received: from mail-qk0-f194.google.com ([209.85.220.194]:42335 "EHLO mail-qk0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932667AbeEWRMI (ORCPT ); Wed, 23 May 2018 13:12:08 -0400 X-Google-Smtp-Source: ADUXVKKdOTu47rJWeSwY18IG8MV8IAQjRd1rBue+73PSCbrG6eJTPQ1kEvSTw7yCiTxpwRaXqb+uLw== Date: Wed, 23 May 2018 13:12:04 -0400 From: Kent Overstreet To: Christoph Hellwig Cc: Matthew Wilcox , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Andrew Morton , Dave Chinner , darrick.wong@oracle.com, tytso@mit.edu, linux-btrfs@vger.kernel.org, clm@fb.com, jbacik@fb.com, viro@zeniv.linux.org.uk, peterz@infradead.org Subject: Re: [PATCH 01/10] mm: pagecache add lock Message-ID: <20180523171204.GA20772@kmo-pixel> References: <20180518074918.13816-1-kent.overstreet@gmail.com> <20180518074918.13816-3-kent.overstreet@gmail.com> <20180518131305.GA6361@bombadil.infradead.org> <20180518155330.GA16931@infradead.org> <20180520224524.GC11495@kmo-pixel> <20180523152239.GA2425@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180523152239.GA2425@infradead.org> User-Agent: Mutt/1.9.5 (2018-04-13) Sender: linux-fsdevel-owner@vger.kernel.org X-Mailing-List: linux-fsdevel@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Wed, May 23, 2018 at 08:22:39AM -0700, Christoph Hellwig wrote: > On Sun, May 20, 2018 at 06:45:24PM -0400, Kent Overstreet wrote: > > > > > > Honestly I think this probably should be in the core. But IFF we move > > > it to the core the existing users of per-fs locks need to be moved > > > over first. E.g. XFS as the very first one, and at least ext4 and f2fs > > > that copied the approach, and probably more if you audit deep enough. > > > > I'm not going to go and redo locking in XFS and ext4 as a prerequisite to > > merging bcachefs. Sorry, but that's a bit crazy. > > It isn't crazy at all. In general we expect people to do their fair > share of core work to get their pet feature in. How much is acceptable > is a difficult question and not black and white. > > But if you want to grow a critical core structure you better take a stab > at converting existing users. Without that the tradeoff of growing > that core structure is simply not given. > > Or to put it in words for this exact feature: unless your new field > is also used by mainstream file systems it is not going to be added. Christoph, I'm really not someone you can accuse of avoiding my share of core work and refactoring and you know it. When are you going to get around to converting existing users of fs/direct-io.c to iomap so it can be deleted? The kernel is carrying around two dio implementations right now thanks to you. Not a good situation, is it?