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linux/fs/ocfs2/acl.c
Joseph Qi 3d94ea51c1 ocfs2: clean up dead code in ocfs2_acl_from_xattr() 
In ocfs2_acl_from_xattr(), if size is less than sizeof(struct
posix_acl_entry), it returns ERR_PTR(-EINVAL) directly.  Then assign (size
/ sizeof(struct posix_acl_entry)) to count which will be at least 1, that
means the following branch (count < 0) and (count == 0) will never be
true.

Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Acked-by: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11 15:56:39 -07:00

534 lines
12 KiB
C
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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/slab.h>
#include <linux/string.h>
#include <cluster/masklog.h>
#include "ocfs2.h"
#include "alloc.h"
#include "dlmglue.h"
#include "file.h"
#include "inode.h"
#include "journal.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);
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);
switch(acl->a_entries[n].e_tag) {
case ACL_USER:
acl->a_entries[n].e_uid =
make_kuid(&init_user_ns,
le32_to_cpu(entry->e_id));
break;
case ACL_GROUP:
acl->a_entries[n].e_gid =
make_kgid(&init_user_ns,
le32_to_cpu(entry->e_id));
break;
default:
break;
}
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);
switch(acl->a_entries[n].e_tag) {
case ACL_USER:
entry->e_id = cpu_to_le32(
from_kuid(&init_user_ns,
acl->a_entries[n].e_uid));
break;
case ACL_GROUP:
entry->e_id = cpu_to_le32(
from_kgid(&init_user_ns,
acl->a_entries[n].e_gid));
break;
default:
entry->e_id = cpu_to_le32(ACL_UNDEFINED_ID);
break;
}
}
return ocfs2_acl;
}
static struct posix_acl *ocfs2_get_acl_nolock(struct inode *inode,
int type,
struct buffer_head *di_bh)
{
int name_index;
char *value = NULL;
struct posix_acl *acl;
int retval;
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;
}
/*
* Helper function to set i_mode in memory and disk. Some call paths
* will not have di_bh or a journal handle to pass, in which case it
* will create it's own.
*/
static int ocfs2_acl_set_mode(struct inode *inode, struct buffer_head *di_bh,
handle_t *handle, umode_t new_mode)
{
int ret, commit_handle = 0;
struct ocfs2_dinode *di;
if (di_bh == NULL) {
ret = ocfs2_read_inode_block(inode, &di_bh);
if (ret) {
mlog_errno(ret);
goto out;
}
} else
get_bh(di_bh);
if (handle == NULL) {
handle = ocfs2_start_trans(OCFS2_SB(inode->i_sb),
OCFS2_INODE_UPDATE_CREDITS);
if (IS_ERR(handle)) {
ret = PTR_ERR(handle);
mlog_errno(ret);
goto out_brelse;
}
commit_handle = 1;
}
di = (struct ocfs2_dinode *)di_bh->b_data;
ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
OCFS2_JOURNAL_ACCESS_WRITE);
if (ret) {
mlog_errno(ret);
goto out_commit;
}
inode->i_mode = new_mode;
inode->i_ctime = CURRENT_TIME;
di->i_mode = cpu_to_le16(inode->i_mode);
di->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
di->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
ocfs2_journal_dirty(handle, di_bh);
out_commit:
if (commit_handle)
ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
out_brelse:
brelse(di_bh);
out:
return ret;
}
/*
* 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) {
umode_t mode = inode->i_mode;
ret = posix_acl_equiv_mode(acl, &mode);
if (ret < 0)
return ret;
else {
if (ret == 0)
acl = NULL;
ret = ocfs2_acl_set_mode(inode, di_bh,
handle, mode);
if (ret)
return ret;
}
}
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;
}
struct posix_acl *ocfs2_iop_get_acl(struct inode *inode, int type)
{
struct ocfs2_super *osb;
struct buffer_head *di_bh = NULL;
struct posix_acl *acl;
int ret = -EAGAIN;
osb = OCFS2_SB(inode->i_sb);
if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
return NULL;
ret = ocfs2_read_inode_block(inode, &di_bh);
if (ret < 0)
return ERR_PTR(ret);
acl = ocfs2_get_acl_nolock(inode, type, di_bh);
brelse(di_bh);
return acl;
}
int ocfs2_acl_chmod(struct inode *inode)
{
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
struct posix_acl *acl;
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);
ret = posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
if (ret)
return ret;
ret = ocfs2_set_acl(NULL, inode, NULL, ACL_TYPE_ACCESS,
acl, NULL, NULL);
posix_acl_release(acl);
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, ret2;
umode_t mode;
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) {
mode = inode->i_mode & ~current_umask();
ret = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
if (ret) {
mlog_errno(ret);
goto cleanup;
}
}
}
if ((osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) && acl) {
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;
}
mode = inode->i_mode;
ret = posix_acl_create(&acl, GFP_NOFS, &mode);
if (ret < 0)
return ret;
ret2 = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
if (ret2) {
mlog_errno(ret2);
ret = ret2;
goto cleanup;
}
if (ret > 0) {
ret = ocfs2_set_acl(handle, inode,
di_bh, ACL_TYPE_ACCESS,
acl, meta_ac, data_ac);
}
}
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(&init_user_ns, 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 (!inode_owner_or_capable(inode))
return -EPERM;
if (value) {
acl = posix_acl_from_xattr(&init_user_ns, 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;
}
const 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,
};
const 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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