From patchwork Mon Sep 5 17:25:40 2011 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: 1125182 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter2.kernel.org (8.14.4/8.14.4) with ESMTP id p85HUFia030595 for ; Mon, 5 Sep 2011 17:30:16 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752666Ab1IERaI (ORCPT ); Mon, 5 Sep 2011 13:30:08 -0400 Received: from e28smtp09.in.ibm.com ([122.248.162.9]:41013 "EHLO e28smtp09.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752094Ab1IER1j (ORCPT ); Mon, 5 Sep 2011 13:27:39 -0400 Received: from /spool/local by in.ibm.com with XMail ESMTP for from ; Mon, 5 Sep 2011 22:57:37 +0530 Received: from d28relay03.in.ibm.com ([9.184.220.60]) by in.ibm.com ([192.168.1.139]) with XMail ESMTP; Mon, 5 Sep 2011 22:57:30 +0530 Received: from d28av03.in.ibm.com (d28av03.in.ibm.com [9.184.220.65]) by d28relay03.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id p85HRTDj3956986; Mon, 5 Sep 2011 22:57:29 +0530 Received: from d28av03.in.ibm.com (loopback [127.0.0.1]) by d28av03.in.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id p85HRSVf021775; Tue, 6 Sep 2011 03:27:29 +1000 Received: from skywalker.ibm.com ([9.126.239.225]) by d28av03.in.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id p85HR6rZ021311; Tue, 6 Sep 2011 03:27:27 +1000 From: "Aneesh Kumar K.V" To: agruen@kernel.org, bfields@fieldses.org, akpm@linux-foundation.org, 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 -V6 18/26] richacl: Create-time inheritance Date: Mon, 5 Sep 2011 22:55:40 +0530 Message-Id: <1315243548-18664-19-git-send-email-aneesh.kumar@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.4.1 In-Reply-To: <1315243548-18664-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> References: <1315243548-18664-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> x-cbid: 11090517-2674-0000-0000-00000042DAF6 Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter2.kernel.org [140.211.167.43]); Mon, 05 Sep 2011 17:30:16 +0000 (UTC) From: Andreas Gruenbacher When a new file is created, it can inherit an acl from its parent directory; this is similar to how default acls work in POSIX (draft) ACLs. As with POSIX ACLs, if a file inherits an acl from its parent directory, the intersection between the create mode and the permissions granted by the inherited acl determines the file masks and file permission bits, and the umask is ignored. Signed-off-by: Andreas Gruenbacher Signed-off-by: Aneesh Kumar K.V --- fs/Makefile | 2 +- fs/richacl_base.c | 69 +++++++++++++++++++++++++++++++++++++++++++++++ fs/richacl_inode.c | 59 ++++++++++++++++++++++++++++++++++++++++ include/linux/richacl.h | 4 +++ 4 files changed, 133 insertions(+), 1 deletions(-) create mode 100644 fs/richacl_inode.c diff --git a/fs/Makefile b/fs/Makefile index 7612168..1ecf9f2 100644 --- a/fs/Makefile +++ b/fs/Makefile @@ -49,7 +49,7 @@ obj-$(CONFIG_GENERIC_ACL) += generic_acl.o obj-$(CONFIG_FHANDLE) += fhandle.o obj-$(CONFIG_FS_RICHACL) += richacl.o -richacl-y := richacl_base.o +richacl-y := richacl_base.o richacl_inode.o obj-y += quota/ diff --git a/fs/richacl_base.c b/fs/richacl_base.c index 1f885ad..b4af12c 100644 --- a/fs/richacl_base.c +++ b/fs/richacl_base.c @@ -492,3 +492,72 @@ is_everyone: return denied ? -EACCES : 0; } EXPORT_SYMBOL_GPL(richacl_permission); + +/** + * richacl_inherit - compute the inherited acl of a new file + * @dir_acl: acl of the containing direcory + * @isdir: inherit by a directory or non-directory? + * + * A directory can have acl entries which files and/or directories created + * inside the directory will inherit. This function computes the acl for such + * a new file. If there is no inheritable acl, it will return %NULL. + */ +struct richacl * +richacl_inherit(const struct richacl *dir_acl, int isdir) +{ + const struct richace *dir_ace; + struct richacl *acl = NULL; + struct richace *ace; + int count = 0; + + if (isdir) { + richacl_for_each_entry(dir_ace, dir_acl) { + if (!richace_is_inheritable(dir_ace)) + continue; + count++; + } + if (!count) + return NULL; + acl = richacl_alloc(count); + if (!acl) + return ERR_PTR(-ENOMEM); + ace = acl->a_entries; + richacl_for_each_entry(dir_ace, dir_acl) { + if (!richace_is_inheritable(dir_ace)) + continue; + memcpy(ace, dir_ace, sizeof(struct richace)); + if (dir_ace->e_flags & ACE4_NO_PROPAGATE_INHERIT_ACE) + richace_clear_inheritance_flags(ace); + if ((dir_ace->e_flags & ACE4_FILE_INHERIT_ACE) && + !(dir_ace->e_flags & ACE4_DIRECTORY_INHERIT_ACE)) + ace->e_flags |= ACE4_INHERIT_ONLY_ACE; + ace++; + } + } else { + richacl_for_each_entry(dir_ace, dir_acl) { + if (!(dir_ace->e_flags & ACE4_FILE_INHERIT_ACE)) + continue; + count++; + } + if (!count) + return NULL; + acl = richacl_alloc(count); + if (!acl) + return ERR_PTR(-ENOMEM); + ace = acl->a_entries; + richacl_for_each_entry(dir_ace, dir_acl) { + if (!(dir_ace->e_flags & ACE4_FILE_INHERIT_ACE)) + continue; + memcpy(ace, dir_ace, sizeof(struct richace)); + richace_clear_inheritance_flags(ace); + /* + * ACE4_DELETE_CHILD is meaningless for + * non-directories, so clear it. + */ + ace->e_mask &= ~ACE4_DELETE_CHILD; + ace++; + } + } + + return acl; +} diff --git a/fs/richacl_inode.c b/fs/richacl_inode.c new file mode 100644 index 0000000..a8d2beb --- /dev/null +++ b/fs/richacl_inode.c @@ -0,0 +1,59 @@ +/* + * Copyright (C) 2010 Novell, Inc. + * Written by Andreas Gruenbacher + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2, or (at your option) any + * later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + */ + +#include +#include +#include +#include + +/** + * richacl_inherit_inode - compute inherited acl and file mode + * @dir_acl: acl of the containing direcory + * @inode: inode of the new file (create mode in i_mode) + * + * The file permission bits in inode->i_mode must be set to the create mode. + * If there is an inheritable acl, the maximum permissions that the acl grants + * will be computed and permissions not granted by the acl will be removed from + * inode->i_mode. If there is no inheritable acl, the umask will be applied + * instead. + */ +struct richacl * +richacl_inherit_inode(const struct richacl *dir_acl, struct inode *inode) +{ + struct richacl *acl; + mode_t mask; + + acl = richacl_inherit(dir_acl, S_ISDIR(inode->i_mode)); + if (acl) { + + richacl_compute_max_masks(acl); + + /* + * Ensure that the acl will not grant any permissions beyond + * the create mode. + */ + acl->a_flags |= ACL4_MASKED; + acl->a_owner_mask &= richacl_mode_to_mask(inode->i_mode >> 6) | + ACE4_POSIX_OWNER_ALLOWED; + acl->a_group_mask &= richacl_mode_to_mask(inode->i_mode >> 3); + acl->a_other_mask &= richacl_mode_to_mask(inode->i_mode); + mask = ~S_IRWXUGO | richacl_masks_to_mode(acl); + } else + mask = ~current_umask(); + + inode->i_mode &= mask; + return acl; +} +EXPORT_SYMBOL_GPL(richacl_inherit_inode); diff --git a/include/linux/richacl.h b/include/linux/richacl.h index f46e797..78c35f6 100644 --- a/include/linux/richacl.h +++ b/include/linux/richacl.h @@ -291,5 +291,9 @@ extern void richacl_compute_max_masks(struct richacl *); extern struct richacl *richacl_chmod(struct richacl *, mode_t); extern int richacl_permission(struct inode *, const struct richacl *, unsigned int); +extern struct richacl *richacl_inherit(const struct richacl *, int); +/* richacl_inode.c */ +extern struct richacl *richacl_inherit_inode(const struct richacl *, + struct inode *); #endif /* __RICHACL_H */