From patchwork Mon Sep 26 14:08:18 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Brauner X-Patchwork-Id: 12988921 X-Patchwork-Delegate: paul@paul-moore.com 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3A2EDC6FA86 for ; Mon, 26 Sep 2022 15:24:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236344AbiIZPYi (ORCPT ); Mon, 26 Sep 2022 11:24:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49366 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236655AbiIZPX6 (ORCPT ); Mon, 26 Sep 2022 11:23:58 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1993B5F83; Mon, 26 Sep 2022 07:09:37 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id E659C60DCB; Mon, 26 Sep 2022 14:09:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8AFBAC43140; Mon, 26 Sep 2022 14:09:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1664201376; bh=Gyihsl0k0ltjTYjFDm6RLihDBzJuOn7TKfd2vlboYAs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Av7BKs1xbpAdmYWfWRfCyCZqnSpA+CYLUIIy80zQ+ofgFUq+moYS+uI6kZQ3ATjcO JJsksMPV+wR+/ChjYeTkW35gWBnxHt+fG7uJuSbaaigQJ/keMoJYtQVL3OUDOYt+GN Eg2il6hATIQGZX7BjsbOmtiXuUj4wOrQkLQ92Z779o1L4RH5cOM2dXABATHWdsKSHP tWDeTR2MHrspeeqdUNmTcE7lF9VWJHBszcqlITHL8oGE8wPtZBLkAhbpnxnDwl389g HtYyN6vDRQxIcAJQsPXm7nMUGfbSO6QYZwT54ci3GuFeTNZX4E0ciMcsvMPsPs5Wv+ UWzpYDBMmJGzw== From: Christian Brauner To: linux-fsdevel@vger.kernel.org Cc: Christian Brauner , Seth Forshee , Christoph Hellwig , Al Viro , Tyler Hicks , ecryptfs@vger.kernel.org, linux-security-module@vger.kernel.org Subject: [PATCH v2 21/30] ecryptfs: implement set acl method Date: Mon, 26 Sep 2022 16:08:18 +0200 Message-Id: <20220926140827.142806-22-brauner@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220926140827.142806-1-brauner@kernel.org> References: <20220926140827.142806-1-brauner@kernel.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2926; i=brauner@kernel.org; h=from:subject; bh=Gyihsl0k0ltjTYjFDm6RLihDBzJuOn7TKfd2vlboYAs=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMSQbbnLkz/VImufPL3xY7tfZCImm3nN3F/yp7rq/Z8db7/fc 9/2ndZSyMIhxMciKKbI4tJuEyy3nqdhslKkBM4eVCWQIAxenAEwkRZqRYdWC87Yrb60zEZhwNVNzt8 smuVIrd6l2xS3Tn++9lzDz2FRGhmea7trfuOO9P9w7dtUj86Qfy5el+rbzN8/S8UxZzOWczgoA X-Developer-Key: i=brauner@kernel.org; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 Precedence: bulk List-ID: The current way of setting and getting posix acls through the generic xattr interface is error prone and type unsafe. The vfs needs to interpret and fixup posix acls before storing or reporting it to userspace. Various hacks exist to make this work. The code is hard to understand and difficult to maintain in it's current form. Instead of making this work by hacking posix acls through xattr handlers we are building a dedicated posix acl api around the get and set inode operations. This removes a lot of hackiness and makes the codepaths easier to maintain. A lot of background can be found in [1]. In order to build a type safe posix api around get and set acl we need all filesystem to implement get and set acl. So far ecryptfs didn't implement get and set acl inode operations because it wanted easy access to the dentry. Now that we extended the set acl inode operation to take a dentry argument and added a new get acl inode operation that takes a dentry argument we can let ecryptfs implement get and set acl inode operations. Note, until the vfs has been switched to the new posix acl api this patch is a non-functional change. Link: https://lore.kernel.org/all/20220801145520.1532837-1-brauner@kernel.org [1] Signed-off-by: Christian Brauner (Microsoft) --- Notes: /* v2 */ unchanged fs/ecryptfs/inode.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c index 740312986388..c3d1ae688a19 100644 --- a/fs/ecryptfs/inode.c +++ b/fs/ecryptfs/inode.c @@ -1129,6 +1129,21 @@ static struct posix_acl *ecryptfs_get_acl(struct user_namespace *mnt_userns, posix_acl_xattr_name(type)); } +static int ecryptfs_set_acl(struct user_namespace *mnt_userns, + struct dentry *dentry, struct posix_acl *acl, + int type) +{ + int rc; + struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry); + struct inode *lower_inode = d_inode(lower_dentry); + + rc = vfs_set_acl(&init_user_ns, lower_dentry, + posix_acl_xattr_name(type), acl); + if (!rc) + fsstack_copy_attr_all(d_inode(dentry), lower_inode); + return rc; +} + const struct inode_operations ecryptfs_symlink_iops = { .get_link = ecryptfs_get_link, .permission = ecryptfs_permission, @@ -1153,6 +1168,7 @@ const struct inode_operations ecryptfs_dir_iops = { .fileattr_get = ecryptfs_fileattr_get, .fileattr_set = ecryptfs_fileattr_set, .get_acl = ecryptfs_get_acl, + .set_acl = ecryptfs_set_acl, }; const struct inode_operations ecryptfs_main_iops = { @@ -1163,6 +1179,7 @@ const struct inode_operations ecryptfs_main_iops = { .fileattr_get = ecryptfs_fileattr_get, .fileattr_set = ecryptfs_fileattr_set, .get_acl = ecryptfs_get_acl, + .set_acl = ecryptfs_set_acl, }; static int ecryptfs_xattr_get(const struct xattr_handler *handler,