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 B6D19C47073 for ; Thu, 4 Jan 2024 06:23:38 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 15B628D006F; Thu, 4 Jan 2024 01:23:38 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 10C2A8D006C; Thu, 4 Jan 2024 01:23:38 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id F3DE18D006F; Thu, 4 Jan 2024 01:23:37 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id E102B8D006C for ; Thu, 4 Jan 2024 01:23:37 -0500 (EST) Received: from smtpin27.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id A9E1F1C0FB9 for ; Thu, 4 Jan 2024 06:23:37 +0000 (UTC) X-FDA: 81640637274.27.2C33160 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by imf17.hostedemail.com (Postfix) with ESMTP id EEE3F40009 for ; Thu, 4 Jan 2024 06:23:35 +0000 (UTC) Authentication-Results: imf17.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf17.hostedemail.com: domain of hch@lst.de designates 213.95.11.211 as permitted sender) smtp.mailfrom=hch@lst.de ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1704349416; 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: in-reply-to:in-reply-to:references:references; bh=Rv8vAyJdMcL+ww6N19acUOfpv+e/u43oWUj/kvuZhYs=; b=Wwf6CH0lxpf/qP+pIPRuyxl54VEtzbHvMf+fOU0PsewKeJ6kWDWuiwYHX/cBIiDp2ndX8I wJ5KE4KQ4Vdl8KmJiMBXMcY9Ducp3O7nU4MFF9XqZT/q5Shr3hlJ9rpGVDODnnv5EdoNMb LGDe+YuUQAtrnvbueU2uXNZua3w44uk= ARC-Authentication-Results: i=1; imf17.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf17.hostedemail.com: domain of hch@lst.de designates 213.95.11.211 as permitted sender) smtp.mailfrom=hch@lst.de ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1704349416; a=rsa-sha256; cv=none; b=agvBxiTvq190fpqVR/EgRWKcnSBr4eJ2RsyJrlWey9DStFIuBm5XvRF6XezKk6DnC3fisZ wK/f7Yt7aPvGjbg5GXVoiO5n4pWViZcQRYOoyGjqSW3X530Z2YBxOx7cDq3PiaMkOUOckL Tc3NnfpLy0W8uEze9JWTapkyhwhHuRI= Received: by verein.lst.de (Postfix, from userid 2407) id 3D58068AFE; Thu, 4 Jan 2024 07:23:32 +0100 (CET) Date: Thu, 4 Jan 2024 07:23:31 +0100 From: Christoph Hellwig To: "Darrick J. Wong" Cc: Christoph Hellwig , Chandan Babu R , Hugh Dickins , Andrew Morton , linux-xfs@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 08/15] xfs: don't modify file and inode flags for shmem files Message-ID: <20240104062331.GB29215@lst.de> References: <20240103084126.513354-1-hch@lst.de> <20240103084126.513354-9-hch@lst.de> <20240104000145.GB361584@frogsfrogsfrogs> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240104000145.GB361584@frogsfrogsfrogs> User-Agent: Mutt/1.5.17 (2007-11-01) X-Rspamd-Queue-Id: EEE3F40009 X-Rspam-User: X-Rspamd-Server: rspam04 X-Stat-Signature: 8idupc3ira58jppp3cwurkawb9c8jrft X-HE-Tag: 1704349415-443543 X-HE-Meta: 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 wdmvDvne 5s1eM7N1bI+syOb6WKotzSAKBEF+RcW+Ulp7s1boQYiPJeJZHeXjvnT0Qxb3snkTDZnh1BfjcOO9WDgbV4uwMtcgvKQ== 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, Jan 03, 2024 at 04:01:45PM -0800, Darrick J. Wong wrote: > I actually want S_PRIVATE here to avoid interference from all the > security hooks and whatnot when scrub is using an xfile to stash a > large amount of data. Shouldn't this patch change xfile_create to call > shmem_kernel_file_setup instead? Yes, and it used to do that before I reshuffled it.. > > - inode->i_mode &= ~0177; > > - inode->i_uid = GLOBAL_ROOT_UID; > > - inode->i_gid = GLOBAL_ROOT_GID; > > Also, I don't know if it matters that the default uid/gid are now going > to be whatever the defaults would be for a new file instead of root > only. That seems like it could invite problems, but otoh xfiles are > never installed in the fd table so userspace should never get access > anyway. In-kernel shm files are created on shm_mnt, which is owned by the global root, so this will do the right thing.