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=-6.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 A3FBCC63697 for ; Tue, 17 Nov 2020 18:36:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3CA07221FD for ; Tue, 17 Nov 2020 18:36:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="TDkYXN8C" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730011AbgKQSgJ (ORCPT ); Tue, 17 Nov 2020 13:36:09 -0500 Received: from mail.kernel.org ([198.145.29.99]:38728 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727007AbgKQSgJ (ORCPT ); Tue, 17 Nov 2020 13:36:09 -0500 Received: from sol.localdomain (172-10-235-113.lightspeed.sntcca.sbcglobal.net [172.10.235.113]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id AA74F223C7; Tue, 17 Nov 2020 18:36:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1605638168; bh=XFTKnyksOQF5hI0TvFTXOnV3KR3hpWlZi6TBqSIlN+o=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=TDkYXN8CuXva+9OJ9b39gOkV0069pK+fKDahpqGUjsGcqRpFilPNA9fKO0pC028pt IoJRLdqRMCA9DRRLjwr7kUg0oPUfUKs6w/Tw2vuqqcgbZTDTUEyH/IIqd8BM2F1iwh QjPFKNx/xoX0SEq3VPRzU472078pyjJ1hcwl1m/U= Date: Tue, 17 Nov 2020 10:36:06 -0800 From: Eric Biggers To: Daniel Rosenberg Cc: kernel-team@android.com, "Theodore Y . Ts'o" , Richard Weinberger , linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-fscrypt@vger.kernel.org, Andreas Dilger , Alexander Viro , linux-mtd@lists.infradead.org, linux-fsdevel@vger.kernel.org, Jaegeuk Kim , linux-ext4@vger.kernel.org, Gabriel Krisman Bertazi Subject: Re: [f2fs-dev] [PATCH v2 1/3] libfs: Add generic function for setting dentry_ops Message-ID: References: <20201117040315.28548-1-drosen@google.com> <20201117040315.28548-2-drosen@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org On Tue, Nov 17, 2020 at 10:16:49AM -0800, Eric Biggers wrote: > > Here's a suggestion which I think explains it a lot better. It's still possible > I'm misunderstanding something, though, so please check it carefully: > > /** > * generic_set_encrypted_ci_d_ops - helper for setting d_ops for given dentry > * @dentry: dentry to set ops on > * > * Casefolded directories need d_hash and d_compare set, so that the dentries > * contained in them are handled case-insensitively. Note that these operations > * are needed on the parent directory rather than on the dentries in it, and the > * casefolding flag can be enabled on an empty directory later but the > * dentry_operations can't be changed later. As a result, if the filesystem has > * casefolding support enabled at all, we have to give all dentries the > * casefolding operations even if their inode doesn't have the casefolding flag > * currently (and thus the casefolding ops would be no-ops for now). > * > * Encryption works differently in that the only dentry operation it needs is > * d_revalidate, which it only needs on dentries that have the no-key name flag. > * The no-key flag can't be set "later", so we don't have to worry about that. > * > * Finally, to maximize compatibility with overlayfs (which isn't compatible > * with certain dentry operations) and to avoid taking an unnecessary > * performance hit, we use custom dentry_operations for each possible > * combination rather always installing all operations. > */ Last line in my suggestion has a typo: "rather" => "rather than". - Eric