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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4418FC71157 for ; Wed, 18 Jun 2025 12:17:09 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id AA40C6B0088; Wed, 18 Jun 2025 08:17:08 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A542C6B0089; Wed, 18 Jun 2025 08:17:08 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 943106B008A; Wed, 18 Jun 2025 08:17:08 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 85B716B0088 for ; Wed, 18 Jun 2025 08:17:08 -0400 (EDT) Received: from smtpin05.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 36ED0BF1A6 for ; Wed, 18 Jun 2025 12:17:08 +0000 (UTC) X-FDA: 83568420936.05.7D3A47C Received: from nyc.source.kernel.org (nyc.source.kernel.org [147.75.193.91]) by imf15.hostedemail.com (Postfix) with ESMTP id 62C39A000D for ; Wed, 18 Jun 2025 12:17:06 +0000 (UTC) Authentication-Results: imf15.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=YXUTunyo; spf=pass (imf15.hostedemail.com: domain of jlayton@kernel.org designates 147.75.193.91 as permitted sender) smtp.mailfrom=jlayton@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1750249026; a=rsa-sha256; cv=none; b=SMWB9rcIYHA74+Jy4MhtKrUS0xICu7KxCmWiystwCIh92/X0GM42WdAofvwDVqTYq/1rwD jx28EaCgekg8dI2McDH9SPXVt4d3O9yKcV3c9kwAaKaEcoo+qQCPqbwWv6UJJlT0Ypmn2l wMYKTSRN5EiVYUfMdShVtt0taLcTAl4= ARC-Authentication-Results: i=1; imf15.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=YXUTunyo; spf=pass (imf15.hostedemail.com: domain of jlayton@kernel.org designates 147.75.193.91 as permitted sender) smtp.mailfrom=jlayton@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1750249026; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=fP+qbmU1fRGKbqe5AgskcEzGxrF9TJe21i4eCRh/hfc=; b=nKRWgJvif3ytNn2clFMJjwbyL2/UgpuzIvtFiGMiRiIG0E9NuJvfqcMDk3ZRJggsy698PY yOZt9W9HZHCYCs2BjV8QBqrTa1OJNdxjhPUR/LW02r7F9ejvtGFUIGRdmy6tCCzoWDv+Lr DjCBTQ6Akyg+AmYCwV4EOPbrd/mv/ew= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by nyc.source.kernel.org (Postfix) with ESMTP id A4487A525B6; Wed, 18 Jun 2025 12:17:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 61E0DC4CEE7; Wed, 18 Jun 2025 12:17:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1750249025; bh=JDWuucTS1lkJ7vrfyUZEIdmL3rzVzzcaXJRO2vPbEiU=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=YXUTunyosf60QYIIAP6SLmts7vPmnOWrvdgkSGWmDYY5OJmdRBfahFOTsTAjzSJZq kxPnPlS6slT5+GRGnHwkT/BB5KQAq686YOct4fZLZq/2VusQzUQCyBW8f5oGn9wF5n rhpq7JLUCEDL71/Yr4fsEURn1kDJoeoH/NrlhM+Nz1ey3/ZGIqLYavjzbMChr99etm I03eMKHZVUgqKaSIefZqj3zNpEsR1NxcT3YZhDAH0wt3H7D+c3VRK4IOZDGODxAoRC EZV+6yJ4GLvlSRhEBJ+U7js3yX0He04EoqdPri5i+2xvYlFis8Zx4NZQdEAbExHEX6 q7pndEGZggWRQ== Message-ID: Subject: Re: [PATCH v1 5/8] iomap: add iomap_writeback_dirty_folio() From: Jeff Layton To: Matthew Wilcox , Christoph Hellwig Cc: "Darrick J. Wong" , Joanne Koong , miklos@szeredi.hu, brauner@kernel.org, linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org, bernd.schubert@fastmail.fm, kernel-team@meta.com, linux-mm@kvack.org, linux-nfs@vger.kernel.org Date: Wed, 18 Jun 2025 08:17:03 -0400 In-Reply-To: References: <20250606233803.1421259-1-joannelkoong@gmail.com> <20250606233803.1421259-6-joannelkoong@gmail.com> <20250609171444.GL6156@frogsfrogsfrogs> Autocrypt: addr=jlayton@kernel.org; prefer-encrypt=mutual; keydata=mQINBE6V0TwBEADXhJg7s8wFDwBMEvn0qyhAnzFLTOCHooMZyx7XO7dAiIhDSi7G1NPxw n8jdFUQMCR/GlpozMFlSFiZXiObE7sef9rTtM68ukUyZM4pJ9l0KjQNgDJ6Fr342Htkjxu/kFV1Wv egyjnSsFt7EGoDjdKqr1TS9syJYFjagYtvWk/UfHlW09X+jOh4vYtfX7iYSx/NfqV3W1D7EDi0PqV T2h6v8i8YqsATFPwO4nuiTmL6I40ZofxVd+9wdRI4Db8yUNA4ZSP2nqLcLtFjClYRBoJvRWvsv4lm 0OX6MYPtv76hka8lW4mnRmZqqx3UtfHX/hF/zH24Gj7A6sYKYLCU3YrI2Ogiu7/ksKcl7goQjpvtV YrOOI5VGLHge0awt7bhMCTM9KAfPc+xL/ZxAMVWd3NCk5SamL2cE99UWgtvNOIYU8m6EjTLhsj8sn VluJH0/RcxEeFbnSaswVChNSGa7mXJrTR22lRL6ZPjdMgS2Km90haWPRc8Wolcz07Y2se0xpGVLEQ cDEsvv5IMmeMe1/qLZ6NaVkNuL3WOXvxaVT9USW1+/SGipO2IpKJjeDZfehlB/kpfF24+RrK+seQf CBYyUE8QJpvTZyfUHNYldXlrjO6n5MdOempLqWpfOmcGkwnyNRBR46g/jf8KnPRwXs509yAqDB6sE LZH+yWr9LQZEwARAQABtCVKZWZmIExheXRvbiA8amxheXRvbkBwb29jaGllcmVkcy5uZXQ+iQI7BB MBAgAlAhsDBgsJCAcDAgYVCAIJCgsEFgIDAQIeAQIXgAUCTpXWPAIZAQAKCRAADmhBGVaCFc65D/4 gBLNMHopQYgG/9RIM3kgFCCQV0pLv0hcg1cjr+bPI5f1PzJoOVi9s0wBDHwp8+vtHgYhM54yt43uI 7Htij0RHFL5eFqoVT4TSfAg2qlvNemJEOY0e4daljjmZM7UtmpGs9NN0r9r50W82eb5Kw5bc/r0km R/arUS2st+ecRsCnwAOj6HiURwIgfDMHGPtSkoPpu3DDp/cjcYUg3HaOJuTjtGHFH963B+f+hyQ2B rQZBBE76ErgTDJ2Db9Ey0kw7VEZ4I2nnVUY9B5dE2pJFVO5HJBMp30fUGKvwaKqYCU2iAKxdmJXRI ONb7dSde8LqZahuunPDMZyMA5+mkQl7kpIpR6kVDIiqmxzRuPeiMP7O2FCUlS2DnJnRVrHmCljLkZ Wf7ZUA22wJpepBligemtSRSbqCyZ3B48zJ8g5B8xLEntPo/NknSJaYRvfEQqGxgk5kkNWMIMDkfQO lDSXZvoxqU9wFH/9jTv1/6p8dHeGM0BsbBLMqQaqnWiVt5mG92E1zkOW69LnoozE6Le+12DsNW7Rj iR5K+27MObjXEYIW7FIvNN/TQ6U1EOsdxwB8o//Yfc3p2QqPr5uS93SDDan5ehH59BnHpguTc27Xi QQZ9EGiieCUx6Zh2ze3X2UW9YNzE15uKwkkuEIj60NvQRmEDfweYfOfPVOueC+iFifbQgSmVmZiBM YXl0b24gPGpsYXl0b25AcmVkaGF0LmNvbT6JAjgEEwECACIFAk6V0q0CGwMGCwkIBwMCBhUIAgkKC wQWAgMBAh4BAheAAAoJEAAOaEEZVoIViKUQALpvsacTMWWOd7SlPFzIYy2/fjvKlfB/Xs4YdNcf9q LqF+lk2RBUHdR/dGwZpvw/OLmnZ8TryDo2zXVJNWEEUFNc7wQpl3i78r6UU/GUY/RQmOgPhs3epQC 3PMJj4xFx+VuVcf/MXgDDdBUHaCTT793hyBeDbQuciARDJAW24Q1RCmjcwWIV/pgrlFa4lAXsmhoa c8UPc82Ijrs6ivlTweFf16VBc4nSLX5FB3ls7S5noRhm5/Zsd4PGPgIHgCZcPgkAnU1S/A/rSqf3F LpU+CbVBDvlVAnOq9gfNF+QiTlOHdZVIe4gEYAU3CUjbleywQqV02BKxPVM0C5/oVjMVx3bri75n1 TkBYGmqAXy9usCkHIsG5CBHmphv9MHmqMZQVsxvCzfnI5IO1+7MoloeeW/lxuyd0pU88dZsV/riHw 87i2GJUJtVlMl5IGBNFpqoNUoqmvRfEMeXhy/kUX4Xc03I1coZIgmwLmCSXwx9MaCPFzV/dOOrju2 xjO+2sYyB5BNtxRqUEyXglpujFZqJxxau7E0eXoYgoY9gtFGsspzFkVNntamVXEWVVgzJJr/EWW0y +jNd54MfPRqH+eCGuqlnNLktSAVz1MvVRY1dxUltSlDZT7P2bUoMorIPu8p7ZCg9dyX1+9T6Muc5d Hxf/BBP/ir+3e8JTFQBFOiLNdFtB9KZWZmIExheXRvbiA8amxheXRvbkBzYW1iYS5vcmc+iQI4BBM BAgAiBQJOldK9AhsDBgsJCAcDAgYVCAIJCgsEFgIDAQIeAQIXgAAKCRAADmhBGVaCFWgWD/0ZRi4h N9FK2BdQs9RwNnFZUr7JidAWfCrs37XrA/56olQl3ojn0fQtrP4DbTmCuh0SfMijB24psy1GnkPep naQ6VRf7Dxg/Y8muZELSOtsv2CKt3/02J1BBitrkkqmHyni5fLLYYg6fub0T/8Kwo1qGPdu1hx2BQ RERYtQ/S5d/T0cACdlzi6w8rs5f09hU9Tu4qV1JLKmBTgUWKN969HPRkxiojLQziHVyM/weR5Reu6 FZVNuVBGqBD+sfk/c98VJHjsQhYJijcsmgMb1NohAzwrBKcSGKOWJToGEO/1RkIN8tqGnYNp2G+aR 685D0chgTl1WzPRM6mFG1+n2b2RR95DxumKVpwBwdLPoCkI24JkeDJ7lXSe3uFWISstFGt0HL8Eew P8RuGC8s5h7Ct91HMNQTbjgA+Vi1foWUVXpEintAKgoywaIDlJfTZIl6Ew8ETN/7DLy8bXYgq0Xzh aKg3CnOUuGQV5/nl4OAX/3jocT5Cz/OtAiNYj5mLPeL5z2ZszjoCAH6caqsF2oLyAnLqRgDgR+wTQ T6gMhr2IRsl+cp8gPHBwQ4uZMb+X00c/Amm9VfviT+BI7B66cnC7Zv6Gvmtu2rEjWDGWPqUgccB7h dMKnKDthkA227/82tYoFiFMb/NwtgGrn5n2vwJyKN6SEoygGrNt0SI84y6hEVbQlSmVmZiBMYXl0b 24gPGpsYXl0b25AcHJpbWFyeWRhdGEuY29tPokCOQQTAQIAIwUCU4xmKQIbAwcLCQgHAwIBBhUIAg kKCwQWAgMBAh4BAheAAAoJEAAOaEEZVoIV1H0P/j4OUTwFd7BBbpoSp695qb6HqCzWMuExsp8nZjr uymMaeZbGr3OWMNEXRI1FWNHMtcMHWLP/RaDqCJil28proO+PQ/yPhsr2QqJcW4nr91tBrv/MqItu AXLYlsgXqp4BxLP67bzRJ1Bd2x0bWXurpEXY//VBOLnODqThGEcL7jouwjmnRh9FTKZfBDpFRaEfD FOXIfAkMKBa/c9TQwRpx2DPsl3eFWVCNuNGKeGsirLqCxUg5kWTxEorROppz9oU4HPicL6rRH22Ce 6nOAON2vHvhkUuO3GbffhrcsPD4DaYup4ic+DxWm+DaSSRJ+e1yJvwi6NmQ9P9UAuLG93S2MdNNbo sZ9P8k2mTOVKMc+GooI9Ve/vH8unwitwo7ORMVXhJeU6Q0X7zf3SjwDq2lBhn1DSuTsn2DbsNTiDv qrAaCvbsTsw+SZRwF85eG67eAwouYk+dnKmp1q57LDKMyzysij2oDKbcBlwB/TeX16p8+LxECv51a sjS9TInnipssssUDrHIvoTTXWcz7Y5wIngxDFwT8rPY3EggzLGfK5Zx2Q5S/N0FfmADmKknG/D8qG IcJE574D956tiUDKN4I+/g125ORR1v7bP+OIaayAvq17RP+qcAqkxc0x8iCYVCYDouDyNvWPGRhbL UO7mlBpjW9jK9e2fvZY9iw3QzIPGKtClKZWZmIExheXRvbiA8amVmZi5sYXl0b25AcHJpbWFyeWRh dGEuY29tPokCOQQTAQIAIwUCU4xmUAIbAwcLCQgHAwIBBhUIAgkKCwQWAgMBAh4BAheAAAoJEAAOa EEZVoIVzJoQALFCS6n/FHQS+hIzHIb56JbokhK0AFqoLVzLKzrnaeXhE5isWcVg0eoV2oTScIwUSU apy94if69tnUo4Q7YNt8/6yFM6hwZAxFjOXR0ciGE3Q+Z1zi49Ox51yjGMQGxlakV9ep4sV/d5a50 M+LFTmYSAFp6HY23JN9PkjVJC4PUv5DYRbOZ6Y1+TfXKBAewMVqtwT1Y+LPlfmI8dbbbuUX/kKZ5d dhV2736fgyfpslvJKYl0YifUOVy4D1G/oSycyHkJG78OvX4JKcf2kKzVvg7/Rnv+AueCfFQ6nGwPn 0P91I7TEOC4XfZ6a1K3uTp4fPPs1Wn75X7K8lzJP/p8lme40uqwAyBjk+IA5VGd+CVRiyJTpGZwA0 jwSYLyXboX+Dqm9pSYzmC9+/AE7lIgpWj+3iNisp1SWtHc4pdtQ5EU2SEz8yKvDbD0lNDbv4ljI7e flPsvN6vOrxz24mCliEco5DwhpaaSnzWnbAPXhQDWb/lUgs/JNk8dtwmvWnqCwRqElMLVisAbJmC0 BhZ/Ab4sph3EaiZfdXKhiQqSGdK4La3OTJOJYZphPdGgnkvDV9Pl1QZ0ijXQrVIy3zd6VCNaKYq7B AKidn5g/2Q8oio9Tf4XfdZ9dtwcB+bwDJFgvvDYaZ5bI3ln4V3EyW5i2NfXazz/GA/I/ZtbsigCFc 8ftCBKZWZmIExheXRvbiA8amxheXRvbkBrZXJuZWwub3JnPokCOAQTAQIAIgUCWe8u6AIbAwYLCQg HAwIGFQgCCQoLBBYCAwECHgECF4AACgkQAA5oQRlWghUuCg/+Lb/xGxZD2Q1oJVAE37uW308UpVSD 2tAMJUvFTdDbfe3zKlPDTuVsyNsALBGclPLagJ5ZTP+Vp2irAN9uwBuacBOTtmOdz4ZN2tdvNgozz uxp4CHBDVzAslUi2idy+xpsp47DWPxYFIRP3M8QG/aNW052LaPc0cedYxp8+9eiVUNpxF4SiU4i9J DfX/sn9XcfoVZIxMpCRE750zvJvcCUz9HojsrMQ1NFc7MFT1z3MOW2/RlzPcog7xvR5ENPH19ojRD CHqumUHRry+RF0lH00clzX/W8OrQJZtoBPXv9ahka/Vp7kEulcBJr1cH5Wz/WprhsIM7U9pse1f1g Yy9YbXtWctUz8uvDR7shsQxAhX3qO7DilMtuGo1v97I/Kx4gXQ52syh/w6EBny71CZrOgD6kJwPVV AaM1LRC28muq91WCFhs/nzHozpbzcheyGtMUI2Ao4K6mnY+3zIuXPygZMFr9KXE6fF7HzKxKuZMJO aEZCiDOq0anx6FmOzs5E6Jqdpo/mtI8beK+BE7Va6ni7YrQlnT0i3vaTVMTiCThbqsB20VrbMjlhp f8lfK1XVNbRq/R7GZ9zHESlsa35ha60yd/j3pu5hT2xyy8krV8vGhHvnJ1XRMJBAB/UYb6FyC7S+m QZIQXVeAA+smfTT0tDrisj1U5x6ZB9b3nBg65kc= Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.56.2 (3.56.2-1.fc42) MIME-Version: 1.0 X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 62C39A000D X-Stat-Signature: q8wehr85ubxfou6n8hjwcgq9zdjt65x5 X-Rspam-User: X-HE-Tag: 1750249026-154938 X-HE-Meta: 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 gthTN9Ul PSPnXtGbgXGnAVQ48tK7zXKRmS2OpFZbQ1/Ay1YcEenXxnc+N8NZ7fzEfpO3YfXK1aOKaiiKFd2hLCr4NP+ZukrRd76vYiNyPcl3mY5EatbCLMSaD4dqj+6HGBQfuFSUqaZCxvXpk7MIlZS0SVcZkyh3epwE3jKf9IyWyulLApotbUhmADcnhigW9iaqFm0ZkjvWyGnhFXS+BEGq+HFgHdBFYfA7zRGQ+0lio+I5fwaMxudKzC9eG2Jusq9tBAUPfRHFJJitX6XMHqeET5ZLZau9+2yMDQgm3xPu2 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, 2025-06-11 at 05:34 +0100, Matthew Wilcox wrote: > On Mon, Jun 09, 2025 at 08:59:53PM -0700, Christoph Hellwig wrote: > > On Mon, Jun 09, 2025 at 10:14:44AM -0700, Darrick J. Wong wrote: > > > > Where "folio laundering" means calling ->launder_folio, right? > > >=20 > > > What does fuse use folio laundering for, anyway? It looks to me like > > > the primary users are invalidate_inode_pages*. Either the caller car= es > > > about flushing dirty data and has called filemap_write_and_wait_range= ; > > > or it doesn't and wants to tear down the pagecache ahead of some othe= r > > > operation that's going to change the file contents and doesn't care. > > >=20 > > > I suppose it could be useful as a last-chance operation on a dirty fo= lio > > > that was dirtied after a filemap_write_and_wait_range but before > > > invalidate_inode_pages*? Though for xfs we just return EBUSY and let > > > the caller try again (or not). Is there a subtlety to fuse here that= I > > > don't know about? > >=20 > > My memory might be betraying me, but I think willy once launched an > > attempt to see if we can kill launder_folio. Adding him, and the > > mm and nfs lists to check if I have a point :) >=20 > I ... got distracted with everything else. >=20 > Looking at the original addition of ->launder_page (e3db7691e9f3), I > don't understand why we need it. invalidate_inode_pages2() isn't > supposed to invalidate dirty pages, so I don't understand why nfs > found it necessary to do writeback from ->releasepage() instead > of just returning false like iomap does. >=20 > There's now a new question of what the hell btrfs is up to with > ->launder_folio, which they just added recently. IIRC... The problem was a race where a task could could dirty a page in a mmap'ed file after it had been written back but before it was unmapped from the pagecache. Bear in mind that the NFS client may need write back and then invalidate the pagecache for a file that is still in use if it discovers that the inode's attributes have changed on the server. Trond's solution was to write the page out while holding the page lock in this situation. I think we'd all welcome a way to avoid this race that didn't require launder_folio(). --=20 Jeff Layton