fs/9p: Implement POSIX ACL permission checking function (85ff872d) · Commits · e / devices / android_kernel_fairphone_FP5

fs/9p/Kconfig

+13 −0

Original line number	Diff line number	Diff line
		@@ -17,3 +17,16 @@ config 9P_FSCACHE
		Choose Y here to enable persistent, read-only local
		caching support for 9p clients using FS-Cache


		config 9P_FS_POSIX_ACL
		bool "9P POSIX Access Control Lists"
		depends on 9P_FS
		select FS_POSIX_ACL
		help
		POSIX Access Control Lists (ACLs) support permissions for users and
		groups beyond the owner/group/world scheme.

		To learn more about Access Control Lists, visit the POSIX ACLs for
		Linux website <http://acl.bestbits.at/>.

		If you don't know what Access Control Lists are, say N

fs/9p/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -13,3 +13,4 @@ obj-$(CONFIG_9P_FS) := 9p.o
		xattr_user.o

		9p-$(CONFIG_9P_FSCACHE) += cache.o
		9p-$(CONFIG_9P_FS_POSIX_ACL) += acl.o

fs/9p/acl.c

0 → 100644

+96 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright IBM Corporation, 2010
		* Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
		*
		* This program is free software; you can redistribute it and/or modify it
		* under the terms of version 2.1 of the GNU Lesser General Public License
		* as published by the Free Software Foundation.
		*
		* This program is distributed in the hope that it would be useful, but
		* WITHOUT ANY WARRANTY; without even the implied warranty of
		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
		*
		*/

		#include <linux/module.h>
		#include <linux/fs.h>
		#include <net/9p/9p.h>
		#include <net/9p/client.h>
		#include <linux/slab.h>
		#include <linux/posix_acl_xattr.h>
		#include "xattr.h"
		#include "acl.h"

		static struct posix_acl __v9fs_get_acl(struct p9_fid fid, char *name)
		{
		ssize_t size;
		void *value = NULL;
		struct posix_acl *acl = NULL;;

		size = v9fs_fid_xattr_get(fid, name, NULL, 0);
		if (size > 0) {
		value = kzalloc(size, GFP_NOFS);
		if (!value)
		return ERR_PTR(-ENOMEM);
		size = v9fs_fid_xattr_get(fid, name, value, size);
		if (size > 0) {
		acl = posix_acl_from_xattr(value, size);
		if (IS_ERR(acl))
		goto err_out;
		}
		} else if (size == -ENODATA \|\| size == 0 \|\|
		size == -ENOSYS \|\| size == -EOPNOTSUPP) {
		acl = NULL;
		} else
		acl = ERR_PTR(-EIO);

		err_out:
		kfree(value);
		return acl;
		}

		int v9fs_get_acl(struct inode inode, struct p9_fid fid)
		{
		int retval = 0;
		struct posix_acl pacl, dacl;

		/* get the default/access acl values and cache them */
		dacl = __v9fs_get_acl(fid, POSIX_ACL_XATTR_DEFAULT);
		pacl = __v9fs_get_acl(fid, POSIX_ACL_XATTR_ACCESS);

		if (!IS_ERR(dacl) && !IS_ERR(pacl)) {
		set_cached_acl(inode, ACL_TYPE_DEFAULT, dacl);
		set_cached_acl(inode, ACL_TYPE_ACCESS, pacl);
		posix_acl_release(dacl);
		posix_acl_release(pacl);
		} else
		retval = -EIO;

		return retval;
		}

		static struct posix_acl v9fs_get_cached_acl(struct inode inode, int type)
		{
		struct posix_acl *acl;
		/*
		* 9p Always cache the acl value when
		* instantiating the inode (v9fs_inode_from_fid)
		*/
		acl = get_cached_acl(inode, type);
		BUG_ON(acl == ACL_NOT_CACHED);
		return acl;
		}

		int v9fs_check_acl(struct inode *inode, int mask)
		{
		struct posix_acl *acl = v9fs_get_cached_acl(inode, ACL_TYPE_ACCESS);

		if (IS_ERR(acl))
		return PTR_ERR(acl);
		if (acl) {
		int error = posix_acl_permission(inode, acl, mask);
		posix_acl_release(acl);
		return error;
		}
		return -EAGAIN;
		}

fs/9p/acl.h

0 → 100644

+27 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright IBM Corporation, 2010
		* Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
		*
		* This program is free software; you can redistribute it and/or modify it
		* under the terms of version 2.1 of the GNU Lesser General Public License
		* as published by the Free Software Foundation.
		*
		* This program is distributed in the hope that it would be useful, but
		* WITHOUT ANY WARRANTY; without even the implied warranty of
		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
		*
		*/
		#ifndef FS_9P_ACL_H
		#define FS_9P_ACL_H

		#ifdef CONFIG_9P_FS_POSIX_ACL
		extern int v9fs_get_acl(struct inode , struct p9_fid );
		extern int v9fs_check_acl(struct inode *inode, int mask);
		#else
		#define v9fs_check_acl NULL
		static inline int v9fs_get_acl(struct inode inode, struct p9_fid fid)
		{
		return 0;
		}
		#endif
		#endif /* FS_9P_XATTR_H */

fs/9p/vfs_inode.c

+9 −1

Original line number	Diff line number	Diff line
		@@ -36,6 +36,7 @@
		#include <linux/sched.h>
		#include <linux/slab.h>
		#include <linux/xattr.h>
		#include <linux/posix_acl.h>
		#include <net/9p/9p.h>
		#include <net/9p/client.h>

		@@ -44,6 +45,7 @@
		#include "fid.h"
		#include "cache.h"
		#include "xattr.h"
		#include "acl.h"

		static const struct inode_operations v9fs_dir_inode_operations;
		static const struct inode_operations v9fs_dir_inode_operations_dotu;
		@@ -500,6 +502,11 @@ v9fs_inode_dotl(struct v9fs_session_info v9ses, struct p9_fid fid,
		v9fs_vcookie_set_qid(ret, &st->qid);
		v9fs_cache_inode_get_cookie(ret);
		#endif
		err = v9fs_get_acl(ret, fid);
		if (err) {
		iput(ret);
		goto error;
		}
		kfree(st);
		return ret;
		error:
		@@ -1959,7 +1966,7 @@ static const struct inode_operations v9fs_dir_inode_operations_dotl = {
		.getxattr = generic_getxattr,
		.removexattr = generic_removexattr,
		.listxattr = v9fs_listxattr,

		.check_acl = v9fs_check_acl,
		};

		static const struct inode_operations v9fs_dir_inode_operations = {
		@@ -1986,6 +1993,7 @@ static const struct inode_operations v9fs_file_inode_operations_dotl = {
		.getxattr = generic_getxattr,
		.removexattr = generic_removexattr,
		.listxattr = v9fs_listxattr,
		.check_acl = v9fs_check_acl,
		};

		static const struct inode_operations v9fs_symlink_inode_operations = {