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kernel-ark/fs/ocfs2/acl.c
Christoph Hellwig 431547b3c4 sanitize xattr handler prototypes 
Add a flags argument to struct xattr_handler and pass it to all xattr
handler methods.  This allows using the same methods for multiple
handlers, e.g. for the ACL methods which perform exactly the same action
for the access and default ACLs, just using a different underlying
attribute.  With a little more groundwork it'll also allow sharing the
methods for the regular user/trusted/secure handlers in extN, ocfs2 and
jffs2 like it's already done for xfs in this patch.

Also change the inode argument to the handlers to a dentry to allow
using the handlers mechnism for filesystems that require it later,
e.g. cifs.

[with GFS2 bits updated by Steven Whitehouse <swhiteho@redhat.com>]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Morris <jmorris@namei.org>
Acked-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-12-16 12:16:49 -05:00

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/* -*- mode: c; c-basic-offset: 8; -*-
* vim: noexpandtab sw=8 ts=8 sts=0:
*
* acl.c
*
* Copyright (C) 2004, 2008 Oracle. All rights reserved.
*
* CREDITS:
* Lots of code in this file is copy from linux/fs/ext3/acl.c.
* Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License version 2 as published by the Free Software Foundation.
*
* 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 <linux/init.h>
#include <linux/module.h>
#include <linux/string.h>
#define MLOG_MASK_PREFIX ML_INODE
#include <cluster/masklog.h>
#include "ocfs2.h"
#include "alloc.h"
#include "dlmglue.h"
#include "file.h"
#include "ocfs2_fs.h"
#include "xattr.h"
#include "acl.h"
/*
* Convert from xattr value to acl struct.
*/
static struct posix_acl *ocfs2_acl_from_xattr(const void *value, size_t size)
{
int n, count;
struct posix_acl *acl;
if (!value)
return NULL;
if (size < sizeof(struct posix_acl_entry))
return ERR_PTR(-EINVAL);
count = size / sizeof(struct posix_acl_entry);
if (count < 0)
return ERR_PTR(-EINVAL);
if (count == 0)
return NULL;
acl = posix_acl_alloc(count, GFP_NOFS);
if (!acl)
return ERR_PTR(-ENOMEM);
for (n = 0; n < count; n++) {
struct ocfs2_acl_entry *entry =
(struct ocfs2_acl_entry *)value;
acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag);
acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
acl->a_entries[n].e_id = le32_to_cpu(entry->e_id);
value += sizeof(struct posix_acl_entry);
}
return acl;
}
/*
* Convert acl struct to xattr value.
*/
static void *ocfs2_acl_to_xattr(const struct posix_acl *acl, size_t *size)
{
struct ocfs2_acl_entry *entry = NULL;
char *ocfs2_acl;
size_t n;
*size = acl->a_count * sizeof(struct posix_acl_entry);
ocfs2_acl = kmalloc(*size, GFP_NOFS);
if (!ocfs2_acl)
return ERR_PTR(-ENOMEM);
entry = (struct ocfs2_acl_entry *)ocfs2_acl;
for (n = 0; n < acl->a_count; n++, entry++) {
entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag);
entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
entry->e_id = cpu_to_le32(acl->a_entries[n].e_id);
}
return ocfs2_acl;
}
static struct posix_acl *ocfs2_get_acl_nolock(struct inode *inode,
int type,
struct buffer_head *di_bh)
{
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
int name_index;
char *value = NULL;
struct posix_acl *acl;
int retval;
if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
return NULL;
switch (type) {
case ACL_TYPE_ACCESS:
name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
break;
case ACL_TYPE_DEFAULT:
name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
break;
default:
return ERR_PTR(-EINVAL);
}
retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index, "", NULL, 0);
if (retval > 0) {
value = kmalloc(retval, GFP_NOFS);
if (!value)
return ERR_PTR(-ENOMEM);
retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index,
"", value, retval);
}
if (retval > 0)
acl = ocfs2_acl_from_xattr(value, retval);
else if (retval == -ENODATA || retval == 0)
acl = NULL;
else
acl = ERR_PTR(retval);
kfree(value);
return acl;
}
/*
* Get posix acl.
*/
static struct posix_acl *ocfs2_get_acl(struct inode *inode, int type)
{
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
struct buffer_head *di_bh = NULL;
struct posix_acl *acl;
int ret;
if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
return NULL;
ret = ocfs2_inode_lock(inode, &di_bh, 0);
if (ret < 0) {
mlog_errno(ret);
acl = ERR_PTR(ret);
return acl;
}
acl = ocfs2_get_acl_nolock(inode, type, di_bh);
ocfs2_inode_unlock(inode, 0);
brelse(di_bh);
return acl;
}
/*
* Set the access or default ACL of an inode.
*/
static int ocfs2_set_acl(handle_t *handle,
struct inode *inode,
struct buffer_head *di_bh,
int type,
struct posix_acl *acl,
struct ocfs2_alloc_context *meta_ac,
struct ocfs2_alloc_context *data_ac)
{
int name_index;
void *value = NULL;
size_t size = 0;
int ret;
if (S_ISLNK(inode->i_mode))
return -EOPNOTSUPP;
switch (type) {
case ACL_TYPE_ACCESS:
name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
if (acl) {
mode_t mode = inode->i_mode;
ret = posix_acl_equiv_mode(acl, &mode);
if (ret < 0)
return ret;
else {
inode->i_mode = mode;
if (ret == 0)
acl = NULL;
}
}
break;
case ACL_TYPE_DEFAULT:
name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
if (!S_ISDIR(inode->i_mode))
return acl ? -EACCES : 0;
break;
default:
return -EINVAL;
}
if (acl) {
value = ocfs2_acl_to_xattr(acl, &size);
if (IS_ERR(value))
return (int)PTR_ERR(value);
}
if (handle)
ret = ocfs2_xattr_set_handle(handle, inode, di_bh, name_index,
"", value, size, 0,
meta_ac, data_ac);
else
ret = ocfs2_xattr_set(inode, name_index, "", value, size, 0);
kfree(value);
return ret;
}
int ocfs2_check_acl(struct inode *inode, int mask)
{
struct posix_acl *acl = ocfs2_get_acl(inode, ACL_TYPE_ACCESS);
if (IS_ERR(acl))
return PTR_ERR(acl);
if (acl) {
int ret = posix_acl_permission(inode, acl, mask);
posix_acl_release(acl);
return ret;
}
return -EAGAIN;
}
int ocfs2_acl_chmod(struct inode *inode)
{
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
struct posix_acl *acl, *clone;
int ret;
if (S_ISLNK(inode->i_mode))
return -EOPNOTSUPP;
if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
return 0;
acl = ocfs2_get_acl(inode, ACL_TYPE_ACCESS);
if (IS_ERR(acl) || !acl)
return PTR_ERR(acl);
clone = posix_acl_clone(acl, GFP_KERNEL);
posix_acl_release(acl);
if (!clone)
return -ENOMEM;
ret = posix_acl_chmod_masq(clone, inode->i_mode);
if (!ret)
ret = ocfs2_set_acl(NULL, inode, NULL, ACL_TYPE_ACCESS,
clone, NULL, NULL);
posix_acl_release(clone);
return ret;
}
/*
* Initialize the ACLs of a new inode. If parent directory has default ACL,
* then clone to new inode. Called from ocfs2_mknod.
*/
int ocfs2_init_acl(handle_t *handle,
struct inode *inode,
struct inode *dir,
struct buffer_head *di_bh,
struct buffer_head *dir_bh,
struct ocfs2_alloc_context *meta_ac,
struct ocfs2_alloc_context *data_ac)
{
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
struct posix_acl *acl = NULL;
int ret = 0;
if (!S_ISLNK(inode->i_mode)) {
if (osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) {
acl = ocfs2_get_acl_nolock(dir, ACL_TYPE_DEFAULT,
dir_bh);
if (IS_ERR(acl))
return PTR_ERR(acl);
}
if (!acl)
inode->i_mode &= ~current_umask();
}
if ((osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) && acl) {
struct posix_acl *clone;
mode_t mode;
if (S_ISDIR(inode->i_mode)) {
ret = ocfs2_set_acl(handle, inode, di_bh,
ACL_TYPE_DEFAULT, acl,
meta_ac, data_ac);
if (ret)
goto cleanup;
}
clone = posix_acl_clone(acl, GFP_NOFS);
ret = -ENOMEM;
if (!clone)
goto cleanup;
mode = inode->i_mode;
ret = posix_acl_create_masq(clone, &mode);
if (ret >= 0) {
inode->i_mode = mode;
if (ret > 0) {
ret = ocfs2_set_acl(handle, inode,
di_bh, ACL_TYPE_ACCESS,
clone, meta_ac, data_ac);
}
}
posix_acl_release(clone);
}
cleanup:
posix_acl_release(acl);
return ret;
}
static size_t ocfs2_xattr_list_acl_access(struct dentry *dentry,
char *list,
size_t list_len,
const char *name,
size_t name_len,
int type)
{
struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);
if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
return 0;
if (list && size <= list_len)
memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
return size;
}
static size_t ocfs2_xattr_list_acl_default(struct dentry *dentry,
char *list,
size_t list_len,
const char *name,
size_t name_len,
int type)
{
struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);
if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
return 0;
if (list && size <= list_len)
memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
return size;
}
static int ocfs2_xattr_get_acl(struct dentry *dentry, const char *name,
void *buffer, size_t size, int type)
{
struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
struct posix_acl *acl;
int ret;
if (strcmp(name, "") != 0)
return -EINVAL;
if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
return -EOPNOTSUPP;
acl = ocfs2_get_acl(dentry->d_inode, type);
if (IS_ERR(acl))
return PTR_ERR(acl);
if (acl == NULL)
return -ENODATA;
ret = posix_acl_to_xattr(acl, buffer, size);
posix_acl_release(acl);
return ret;
}
static int ocfs2_xattr_set_acl(struct dentry *dentry, const char *name,
const void *value, size_t size, int flags, int type)
{
struct inode *inode = dentry->d_inode;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
struct posix_acl *acl;
int ret = 0;
if (strcmp(name, "") != 0)
return -EINVAL;
if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
return -EOPNOTSUPP;
if (!is_owner_or_cap(inode))
return -EPERM;
if (value) {
acl = posix_acl_from_xattr(value, size);
if (IS_ERR(acl))
return PTR_ERR(acl);
else if (acl) {
ret = posix_acl_valid(acl);
if (ret)
goto cleanup;
}
} else
acl = NULL;
ret = ocfs2_set_acl(NULL, inode, NULL, type, acl, NULL, NULL);
cleanup:
posix_acl_release(acl);
return ret;
}
struct xattr_handler ocfs2_xattr_acl_access_handler = {
.prefix = POSIX_ACL_XATTR_ACCESS,
.flags = ACL_TYPE_ACCESS,
.list = ocfs2_xattr_list_acl_access,
.get = ocfs2_xattr_get_acl,
.set = ocfs2_xattr_set_acl,
};
struct xattr_handler ocfs2_xattr_acl_default_handler = {
.prefix = POSIX_ACL_XATTR_DEFAULT,
.flags = ACL_TYPE_DEFAULT,
.list = ocfs2_xattr_list_acl_default,
.get = ocfs2_xattr_get_acl,
.set = ocfs2_xattr_set_acl,
};
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