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]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 98897D2D10F for ; Tue, 13 Jan 2026 14:27:27 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 06FA66B008A; Tue, 13 Jan 2026 09:27:27 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 01D206B0092; Tue, 13 Jan 2026 09:27:26 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E0D396B0093; Tue, 13 Jan 2026 09:27:26 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id C9DF76B008A for ; Tue, 13 Jan 2026 09:27:26 -0500 (EST) Received: from smtpin02.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 796171A9423 for ; Tue, 13 Jan 2026 14:27:26 +0000 (UTC) X-FDA: 84327168492.02.1CC5BC9 Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf03.hostedemail.com (Postfix) with ESMTP id 9273B20002 for ; Tue, 13 Jan 2026 14:27:24 +0000 (UTC) Authentication-Results: imf03.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=UKOKD7zq; spf=pass (imf03.hostedemail.com: domain of jlayton@kernel.org designates 172.234.252.31 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=1768314444; 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=voYb0DywiBp6FZyvGWnVpLV+F3/B5O4eT1B8kp+Veyg=; b=pmwYbUsR+N4yLDFsd02eekCrMn1R/1sL8Tyu1CK9Kz/GbbLxrgqlMNFC1Rf4MtIdacP1wn 7NeM53wCIF6dT1VGxwMV+MVun97yAwhXBmsQfOZXBfbVAlMvVgGInRbV8yut1LxwxEdE/U uI0zIm6mWP63FBwmJl1k6WLkE4pofU8= ARC-Authentication-Results: i=1; imf03.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=UKOKD7zq; spf=pass (imf03.hostedemail.com: domain of jlayton@kernel.org designates 172.234.252.31 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=1768314444; a=rsa-sha256; cv=none; b=RCZza/uS2vzTrUtvBUZ8mCJhmoXtaOIT0BSZyBrl0wAySqUeLXRbFnc4wxzfDytuudzn+V L19eo52f9STm6dw2f0f8b0Y5+Imnuuglies/TcZ6b1A+dW8wdB4DdRA3Z91lHs/Ec1zhat ctJPmBfVYnnx7fEfN5Nd6hHO/YWMRdg= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 2DF6B4385A; Tue, 13 Jan 2026 14:27:23 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A6C53C116C6; Tue, 13 Jan 2026 14:27:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1768314443; bh=voYb0DywiBp6FZyvGWnVpLV+F3/B5O4eT1B8kp+Veyg=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=UKOKD7zq7ZENrVufNp/hM9Mf0esyBXwtSb1sraVHk7Kuw5JckEtlSzd4ownbobJ2a Z6hXRiwc+r9lFFNguJyyzRISM+lnaXmTVbRwnM+g/OMPuuuDDH3+MLb2waHm+/zlZI XGM8HcLNIcpQWROLZPkoKCcaAsdOF0maoXn+pjHKao6g/ryZpSURBrh8k3+NHno34A Rhcj8av4r26P7UQZS7Ipu+vsshBmFzpjCfOuQPdiXfjb6dSx6DN201oYh/kJPONRvB VM4kvbs0zqDEJqHusQNNJjr4AmHBhYOcEZfs5aY4qhISBIwfaX17P5qjKtI5qLJSn6 qFu6bkPuVOV8g== Message-ID: <594043c04e431992f6585d7430b39cff2b770655.camel@kernel.org> Subject: Re: [PATCH 00/24] vfs: require filesystems to explicitly opt-in to lease support From: Jeff Layton To: Chuck Lever , Christian Brauner , Amir Goldstein Cc: Jan Kara , Luis de Bethencourt , Salah Triki , Nicolas Pitre , Christoph Hellwig , Anders Larsen , Alexander Viro , David Sterba , Chris Mason , Gao Xiang , Chao Yu , Yue Hu , Jeffle Xu , Sandeep Dhavale , Hongbo Li , Chunhai Guo , Jan Kara , Theodore Ts'o , Andreas Dilger , Jaegeuk Kim , OGAWA Hirofumi , David Woodhouse , Richard Weinberger , Dave Kleikamp , Ryusuke Konishi , Viacheslav Dubeyko , Konstantin Komarov , Mark Fasheh , Joel Becker , Joseph Qi , Mike Marshall , Martin Brandenburg , Miklos Szeredi , Phillip Lougher , Carlos Maiolino , Hugh Dickins , Baolin Wang , Andrew Morton , Namjae Jeon , Sungjong Seo , Yuezhang Mo , Alexander Aring , Andreas Gruenbacher , Jonathan Corbet , "Matthew Wilcox (Oracle)" , Eric Van Hensbergen , Latchesar Ionkov , Dominique Martinet , Christian Schoenebeck , Xiubo Li , Ilya Dryomov , Trond Myklebust , Anna Schumaker , Steve French , Paulo Alcantara , Ronnie Sahlberg , Shyam Prasad N , Tom Talpey , Bharath SM , Hans de Goede , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-erofs@lists.ozlabs.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-mtd@lists.infradead.org, jfs-discussion@lists.sourceforge.net, linux-nilfs@vger.kernel.org, ntfs3@lists.linux.dev, ocfs2-devel@lists.linux.dev, devel@lists.orangefs.org, linux-unionfs@vger.kernel.org, linux-xfs@vger.kernel.org, linux-mm@kvack.org, gfs2@lists.linux.dev, linux-doc@vger.kernel.org, v9fs@lists.linux.dev, ceph-devel@vger.kernel.org, linux-nfs@vger.kernel.org, linux-cifs@vger.kernel.org, samba-technical@lists.samba.org Date: Tue, 13 Jan 2026 09:27:14 -0500 In-Reply-To: <5809690c-bc87-4e66-9604-3f3ee58e2902@oracle.com> References: <20260108-setlease-6-20-v1-0-ea4dec9b67fa@kernel.org> <8af369636c32b868f83669c49aea708ca3b894ac.camel@kernel.org> <20260113-mondlicht-raven-82fc4eb70e9d@brauner> <4a38de737a64e9b32092ea1f8a25a61b33705034.camel@kernel.org> <5809690c-bc87-4e66-9604-3f3ee58e2902@oracle.com> 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 3.58.2 (3.58.2-1.fc43) MIME-Version: 1.0 X-Rspamd-Queue-Id: 9273B20002 X-Stat-Signature: uh8xy18esa5ioaam9xi7h53jsxh9w1g4 X-Rspam-User: X-Rspamd-Server: rspam05 X-HE-Tag: 1768314444-142704 X-HE-Meta: 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 vv9PT8/C +AF8mtSrR8LGD8WmuqSU3+TZpAxVwH2V7aJ3ROht+92f/o0gL7LXN2tW1WrHrc5TrSjQlpa0FBld8fhIxwTcidVWtpSTaVA4Dlqw6KTmRukgiWToIieVa65NcvGRznyGxyk9aL9hJfwzB5EhPHTFjoimZRxAOIchLDzkzAGfgtQpolXoEGwJo9gaGUZyxk+/osaCU8N6aiixpV+JIDMlCY2JQQ8zmXxGGjBmSf/akNk9+UjBnFTy7TrGxjntzkUpDHb3nTeoh9CPbSCi6yQtWKnxg+MUJCal5wnB2lX64jAsa2zG6hlr3mOmPMg== 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 Tue, 2026-01-13 at 09:03 -0500, Chuck Lever wrote: > On 1/13/26 6:45 AM, Jeff Layton wrote: > > On Tue, 2026-01-13 at 09:54 +0100, Christian Brauner wrote: > > > On Mon, Jan 12, 2026 at 09:50:20AM -0500, Jeff Layton wrote: > > > > On Mon, 2026-01-12 at 09:31 -0500, Chuck Lever wrote: > > > > > On 1/12/26 8:34 AM, Jeff Layton wrote: > > > > > > On Fri, 2026-01-09 at 19:52 +0100, Amir Goldstein wrote: > > > > > > > On Thu, Jan 8, 2026 at 7:57=E2=80=AFPM Jeff Layton wrote: > > > > > > > >=20 > > > > > > > > On Thu, 2026-01-08 at 18:40 +0100, Jan Kara wrote: > > > > > > > > > On Thu 08-01-26 12:12:55, Jeff Layton wrote: > > > > > > > > > > Yesterday, I sent patches to fix how directory delegati= on support is > > > > > > > > > > handled on filesystems where the should be disabled [1]= . That set is > > > > > > > > > > appropriate for v6.19. For v7.0, I want to make lease s= upport be more > > > > > > > > > > opt-in, rather than opt-out: > > > > > > > > > >=20 > > > > > > > > > > For historical reasons, when ->setlease() file_operatio= n is set to NULL, > > > > > > > > > > the default is to use the kernel-internal lease impleme= ntation. This > > > > > > > > > > means that if you want to disable them, you need to exp= licitly set the > > > > > > > > > > ->setlease() file_operation to simple_nosetlease() or t= he equivalent. > > > > > > > > > >=20 > > > > > > > > > > This has caused a number of problems over the years as = some filesystems > > > > > > > > > > have inadvertantly allowed leases to be acquired simply= by having left > > > > > > > > > > it set to NULL. It would be better if filesystems had t= o opt-in to lease > > > > > > > > > > support, particularly with the advent of directory dele= gations. > > > > > > > > > >=20 > > > > > > > > > > This series has sets the ->setlease() operation in a pi= le of existing > > > > > > > > > > local filesystems to generic_setlease() and then change= s > > > > > > > > > > kernel_setlease() to return -EINVAL when the setlease()= operation is not > > > > > > > > > > set. > > > > > > > > > >=20 > > > > > > > > > > With this change, new filesystems will need to explicit= ly set the > > > > > > > > > > ->setlease() operations in order to provide lease and d= elegation > > > > > > > > > > support. > > > > > > > > > >=20 > > > > > > > > > > I mainly focused on filesystems that are NFS exportable= , since NFS and > > > > > > > > > > SMB are the main users of file leases, and they tend to= end up exporting > > > > > > > > > > the same filesystem types. Let me know if I've missed a= ny. > > > > > > > > >=20 > > > > > > > > > So, what about kernfs and fuse? They seem to be exportabl= e and don't have > > > > > > > > > .setlease set... > > > > > > > > >=20 > > > > > > > >=20 > > > > > > > > Yes, FUSE needs this too. I'll add a patch for that. > > > > > > > >=20 > > > > > > > > As far as kernfs goes: AIUI, that's basically what sysfs an= d resctrl > > > > > > > > are built on. Do we really expect people to set leases ther= e? > > > > > > > >=20 > > > > > > > > I guess it's technically a regression since you could set t= hem on those > > > > > > > > sorts of files earlier, but people don't usually export ker= nfs based > > > > > > > > filesystems via NFS or SMB, and that seems like something t= hat could be > > > > > > > > used to make mischief. > > > > > > > >=20 > > > > > > > > AFAICT, kernfs_export_ops is mostly to support open_by_hand= le_at(). See > > > > > > > > commit aa8188253474 ("kernfs: add exportfs operations"). > > > > > > > >=20 > > > > > > > > One idea: we could add a wrapper around generic_setlease() = for > > > > > > > > filesystems like this that will do a WARN_ONCE() and then c= all > > > > > > > > generic_setlease(). That would keep leases working on them = but we might > > > > > > > > get some reports that would tell us who's setting leases on= these files > > > > > > > > and why. > > > > > > >=20 > > > > > > > IMO, you are being too cautious, but whatever. > > > > > > >=20 > > > > > > > It is not accurate that kernfs filesystems are NFS exportable= in general. > > > > > > > Only cgroupfs has KERNFS_ROOT_SUPPORT_EXPORTOP. > > > > > > >=20 > > > > > > > If any application is using leases on cgroup files, it must b= e some > > > > > > > very advanced runtime (i.e. systemd), so we should know about= the > > > > > > > regression sooner rather than later. > > > > > > >=20 > > > > > >=20 > > > > > > I think so too. For now, I think I'll not bother with the WARN_= ONCE(). > > > > > > Let's just leave kernfs out of the set until someone presents a= real > > > > > > use-case. > > > > > >=20 > > > > > > > There are also the recently added nsfs and pidfs export_opera= tions. > > > > > > >=20 > > > > > > > I have a recollection about wanting to be explicit about not = allowing > > > > > > > those to be exportable to NFS (nsfs specifically), but I can'= t see where > > > > > > > and if that restriction was done. > > > > > > >=20 > > > > > > > Christian? Do you remember? > > > > > > >=20 > > > > > >=20 > > > > > > (cc'ing Chuck) > > > > > >=20 > > > > > > FWIW, you can currently export and mount /sys/fs/cgroup via NFS= . The > > > > > > directory doesn't show up when you try to get to it via NFSv4, = but you > > > > > > can mount it using v3 and READDIR works. The files are all empt= y when > > > > > > you try to read them. I didn't try to do any writes. > > > > > >=20 > > > > > > Should we add a mechanism to prevent exporting these sorts of > > > > > > filesystems? > > > > > >=20 > > > > > > Even better would be to make nfsd exporting explicitly opt-in. = What if > > > > > > we were to add a EXPORT_OP_NFSD flag that explicitly allows fil= esystems > > > > > > to opt-in to NFS exporting, and check for that in __fh_verify()= ? We'd > > > > > > have to add it to a bunch of existing filesystems, but that's f= airly > > > > > > simple to do with an LLM. > > > > >=20 > > > > > What's the active harm in exporting /sys/fs/cgroup ? It has to be= done > > > > > explicitly via /etc/exports, so this is under the NFS server admi= n's > > > > > control. Is it an attack surface? > > > > >=20 > > > >=20 > > > > Potentially? > > > >=20 > > > > I don't see any active harm with exporting cgroupfs. It doesn't wor= k > > > > right via nfsd, but it's not crashing the box or anything. > > > >=20 > > > > At one time, those were only defined by filesystems that wanted to > > > > allow NFS export. Now we've grown them on filesystems that just wan= t to > > > > provide filehandles for open_by_handle_at() and the like. nfsd does= n't > > > > care though: if the fs has export operations, it'll happily use the= m. > > > >=20 > > > > Having an explicit "I want to allow nfsd" flag see ms like it might > > > > save us some headaches in the future when other filesystems add exp= ort > > > > ops for this sort of filehandle use. > > >=20 > > > So we are re-hashing a discussion we had a few months ago (Amir was > > > involved at least). > > >=20 > >=20 > > Yep, I was lurking on it, but didn't have a lot of input at the time. > >=20 > > > I don't think we want to expose cgroupfs via NFS that's super weird. > > > It's like remote partial resource management and it would be very > > > strange if a remote process suddenly would be able to move things aro= und > > > in the cgroup tree. So I would prefer to not do this. > > >=20 > > > So my preference would be to really sever file handles from the expor= t > > > mechanism so that we can allow stuff like pidfs and nsfs and cgroupfs= to > > > use file handles via name_to_handle_at() and open_by_handle_at() with= out > > > making them exportable. > >=20 > > Agreed. I think we want to make NFS export be a deliberate opt-in > > decision that filesystem developers make. >=20 > No objection, what about ksmbd, AFS, or Ceph? >=20 ksmbd doesn't have anything akin to an export_operations. I think it really has to rely on admins getting the share paths right when exporting. This is a bit simpler there though since SMB2 doesn't deal with filehandles. AFS and Ceph in the kernel are clients. AFS isn't reexportable via NFS, but Ceph is. We'll need to preserve that ability. --=20 Jeff Layton