From patchwork Sun Apr 27 16:14:48 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Aneesh Kumar K.V" X-Patchwork-Id: 4072111 Return-Path: X-Original-To: patchwork-linux-nfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 97003C0ACC for ; Sun, 27 Apr 2014 16:22:39 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 9A92920270 for ; Sun, 27 Apr 2014 16:22:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9C92A2026D for ; Sun, 27 Apr 2014 16:22:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753937AbaD0QQp (ORCPT ); Sun, 27 Apr 2014 12:16:45 -0400 Received: from e23smtp02.au.ibm.com ([202.81.31.144]:55917 "EHLO e23smtp02.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753520AbaD0QQH (ORCPT ); Sun, 27 Apr 2014 12:16:07 -0400 Received: from /spool/local by e23smtp02.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Mon, 28 Apr 2014 02:16:02 +1000 Received: from d23relay04.au.ibm.com (d23relay04.au.ibm.com [9.190.234.120]) by d23dlp03.au.ibm.com (Postfix) with ESMTP id 3FB2A3578048; Mon, 28 Apr 2014 02:16:02 +1000 (EST) Received: from d23av02.au.ibm.com (d23av02.au.ibm.com [9.190.235.138]) by d23relay04.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id s3RFt4vH29163740; Mon, 28 Apr 2014 01:55:04 +1000 Received: from d23av02.au.ibm.com (localhost [127.0.0.1]) by d23av02.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id s3RGG05j032619; Mon, 28 Apr 2014 02:16:01 +1000 Received: from skywalker.in.ibm.com ([9.79.196.205]) by d23av02.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id s3RGF2CW031555; Mon, 28 Apr 2014 02:15:58 +1000 From: "Aneesh Kumar K.V" To: agruen@kernel.org, bfields@fieldses.org, akpm@linux-foundation.org, viro@zeniv.linux.org.uk, dhowells@redhat.com Cc: aneesh.kumar@linux.vnet.ibm.com, linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH -V1 17/22] richacl: Automatic Inheritance Date: Sun, 27 Apr 2014 21:44:48 +0530 Message-Id: <1398615293-22931-18-git-send-email-aneesh.kumar@linux.vnet.ibm.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1398615293-22931-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> References: <1398615293-22931-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14042716-5490-0000-0000-00000583EEF4 Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org X-Spam-Status: No, score=-7.5 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Andreas Gruenbacher Automatic Inheritance (AI) allows changes to the acl of a directory to recursively propagate down to files and directories in the directory. To implement this, the kernel keeps track of which permissions have been inherited, and makes sure that permission propagation is turned off when the file permission bits of a file are changed (upon create or chmod). The actual permission propagation is implemented in user space. AI works as follows: - When the ACL4_AUTO_INHERIT flag in the acl of a file is cleared, the file is not affected by AI. - When the ACL4_AUTO_INHERIT flag in the acl of a directory is set and a file or subdirectory is created in that directory, files created in the directory will have the ACL4_AUTO_INHERIT flag set, and all inherited aces will have the ACE4_INHERITED_ACE flag set. This allows user space to distinguish between aces which have been inherited, and aces which have been explicitly added. - When the ACL4_PROTECTED acl flag in the acl of a file is set, AI will not modify the acl of the file. This does not affect propagation of permissions from the file to its children (if the file is a directory). Linux does not have a way of creating files without setting the file permission bits, so all files created inside a directory with ACL4_AUTO_INHERIT set will also have the ACL4_PROTECTED flag set. This effectively disables AI. Protocols which support creating files without specifying permissions can explicitly clear the ACL4_PROTECTED flag after creating a file (and reset the file masks to "undo" applying the create mode; see richacl_compute_max_masks()). This is a workaround; a per-create or per-process flag indicating to ignore the create mode when AI is in effect would fix this problem. Signed-off-by: Andreas Gruenbacher Signed-off-by: Aneesh Kumar K.V --- fs/richacl_base.c | 10 +++++++++- fs/richacl_inode.c | 7 ++++++- include/linux/richacl.h | 23 ++++++++++++++++++++++- 3 files changed, 37 insertions(+), 3 deletions(-) diff --git a/fs/richacl_base.c b/fs/richacl_base.c index 5d777f6b8a61..d3beaacf6b9b 100644 --- a/fs/richacl_base.c +++ b/fs/richacl_base.c @@ -336,7 +336,8 @@ richacl_chmod(struct richacl *acl, mode_t mode) if (acl->a_owner_mask == owner_mask && acl->a_group_mask == group_mask && acl->a_other_mask == other_mask && - (acl->a_flags & ACL4_MASKED)) + (acl->a_flags & ACL4_MASKED) && + (!richacl_is_auto_inherit(acl) || richacl_is_protected(acl))) return acl; clone = richacl_clone(acl); @@ -348,6 +349,8 @@ richacl_chmod(struct richacl *acl, mode_t mode) clone->a_owner_mask = owner_mask; clone->a_group_mask = group_mask; clone->a_other_mask = other_mask; + if (richacl_is_auto_inherit(clone)) + clone->a_flags |= ACL4_PROTECTED; return clone; } @@ -520,6 +523,11 @@ richacl_inherit(const struct richacl *dir_acl, int isdir) ace++; } } + if (richacl_is_auto_inherit(dir_acl)) { + acl->a_flags = ACL4_AUTO_INHERIT; + richacl_for_each_entry(ace, acl) + ace->e_flags |= ACE4_INHERITED_ACE; + } return acl; } diff --git a/fs/richacl_inode.c b/fs/richacl_inode.c index f590fb526812..c1297ad909dc 100644 --- a/fs/richacl_inode.c +++ b/fs/richacl_inode.c @@ -37,9 +37,14 @@ richacl_inherit_inode(const struct richacl *dir_acl, struct inode *inode) acl = richacl_inherit(dir_acl, S_ISDIR(inode->i_mode)); if (acl) { + /* + * We need to set ACL4_PROTECTED because we are + * doing an implicit chmod + */ + if (richacl_is_auto_inherit(acl)) + acl->a_flags |= ACL4_PROTECTED; richacl_compute_max_masks(acl); - /* * Ensure that the acl will not grant any permissions beyond * the create mode. diff --git a/include/linux/richacl.h b/include/linux/richacl.h index 7ac6587cb166..88f95d78b897 100644 --- a/include/linux/richacl.h +++ b/include/linux/richacl.h @@ -48,10 +48,16 @@ struct richacl { _ace != _acl->a_entries - 1; \ _ace--) +/* a_flags values */ +#define ACL4_AUTO_INHERIT 0x01 +#define ACL4_PROTECTED 0x02 +/* #define ACL4_DEFAULTED 0x04 */ /* Flag values defined by rich-acl */ #define ACL4_MASKED 0x80 #define ACL4_VALID_FLAGS ( \ + ACL4_AUTO_INHERIT | \ + ACL4_PROTECTED | \ ACL4_MASKED) /* e_type values */ @@ -68,6 +74,7 @@ struct richacl { /*#define ACE4_SUCCESSFUL_ACCESS_ACE_FLAG 0x0010*/ /*#define ACE4_FAILED_ACCESS_ACE_FLAG 0x0020*/ #define ACE4_IDENTIFIER_GROUP 0x0040 +#define ACE4_INHERITED_ACE 0x0080 /* richacl specific flag values */ #define ACE4_SPECIAL_WHO 0x4000 @@ -77,6 +84,7 @@ struct richacl { ACE4_NO_PROPAGATE_INHERIT_ACE | \ ACE4_INHERIT_ONLY_ACE | \ ACE4_IDENTIFIER_GROUP | \ + ACE4_INHERITED_ACE | \ ACE4_SPECIAL_WHO) /* e_mask bitflags */ @@ -183,6 +191,18 @@ richacl_put(struct richacl *acl) kfree(acl); } +static inline int +richacl_is_auto_inherit(const struct richacl *acl) +{ + return acl->a_flags & ACL4_AUTO_INHERIT; +} + +static inline int +richacl_is_protected(const struct richacl *acl) +{ + return acl->a_flags & ACL4_PROTECTED; +} + /** * richace_is_owner - check if @ace is an OWNER@ entry */ @@ -253,7 +273,8 @@ richace_clear_inheritance_flags(struct richace *ace) ace->e_flags &= ~(ACE4_FILE_INHERIT_ACE | ACE4_DIRECTORY_INHERIT_ACE | ACE4_NO_PROPAGATE_INHERIT_ACE | - ACE4_INHERIT_ONLY_ACE); + ACE4_INHERIT_ONLY_ACE | + ACE4_INHERITED_ACE); } /**