blob: 4320ffab3495bbadb6c9b176e98241904bc51ecb [file] [log] [blame]
/*
* fs/f2fs/acl.c
*
* Copyright (c) 2012 Samsung Electronics Co., Ltd.
* http://www.samsung.com/
*
* Portions of this code from linux/fs/ext2/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.
*/
#include <linux/f2fs_fs.h>
#include "f2fs.h"
#include "xattr.h"
#include "acl.h"
static inline size_t f2fs_acl_size(int count)
{
if (count <= 4) {
return sizeof(struct f2fs_acl_header) +
count * sizeof(struct f2fs_acl_entry_short);
} else {
return sizeof(struct f2fs_acl_header) +
4 * sizeof(struct f2fs_acl_entry_short) +
(count - 4) * sizeof(struct f2fs_acl_entry);
}
}
static inline int f2fs_acl_count(size_t size)
{
ssize_t s;
size -= sizeof(struct f2fs_acl_header);
s = size - 4 * sizeof(struct f2fs_acl_entry_short);
if (s < 0) {
if (size % sizeof(struct f2fs_acl_entry_short))
return -1;
return size / sizeof(struct f2fs_acl_entry_short);
} else {
if (s % sizeof(struct f2fs_acl_entry))
return -1;
return s / sizeof(struct f2fs_acl_entry) + 4;
}
}
static struct posix_acl *f2fs_acl_from_disk(const char *value, size_t size)
{
int i, count;
struct posix_acl *acl;
struct f2fs_acl_header *hdr = (struct f2fs_acl_header *)value;
struct f2fs_acl_entry *entry = (struct f2fs_acl_entry *)(hdr + 1);
const char *end = value + size;
if (hdr->a_version != cpu_to_le32(F2FS_ACL_VERSION))
return ERR_PTR(-EINVAL);
count = f2fs_acl_count(size);
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 (i = 0; i < count; i++) {
if ((char *)entry > end)
goto fail;
acl->a_entries[i].e_tag = le16_to_cpu(entry->e_tag);
acl->a_entries[i].e_perm = le16_to_cpu(entry->e_perm);
switch (acl->a_entries[i].e_tag) {
case ACL_USER_OBJ:
case ACL_GROUP_OBJ:
case ACL_MASK:
case ACL_OTHER:
entry = (struct f2fs_acl_entry *)((char *)entry +
sizeof(struct f2fs_acl_entry_short));
break;
case ACL_USER:
acl->a_entries[i].e_uid =
make_kuid(&init_user_ns,
le32_to_cpu(entry->e_id));
entry = (struct f2fs_acl_entry *)((char *)entry +
sizeof(struct f2fs_acl_entry));
break;
case ACL_GROUP:
acl->a_entries[i].e_gid =
make_kgid(&init_user_ns,
le32_to_cpu(entry->e_id));
entry = (struct f2fs_acl_entry *)((char *)entry +
sizeof(struct f2fs_acl_entry));
break;
default:
goto fail;
}
}
if ((char *)entry != end)
goto fail;
return acl;
fail:
posix_acl_release(acl);
return ERR_PTR(-EINVAL);
}
static void *f2fs_acl_to_disk(const struct posix_acl *acl, size_t *size)
{
struct f2fs_acl_header *f2fs_acl;
struct f2fs_acl_entry *entry;
int i;
f2fs_acl = kmalloc(sizeof(struct f2fs_acl_header) + acl->a_count *
sizeof(struct f2fs_acl_entry), GFP_NOFS);
if (!f2fs_acl)
return ERR_PTR(-ENOMEM);
f2fs_acl->a_version = cpu_to_le32(F2FS_ACL_VERSION);
entry = (struct f2fs_acl_entry *)(f2fs_acl + 1);
for (i = 0; i < acl->a_count; i++) {
entry->e_tag = cpu_to_le16(acl->a_entries[i].e_tag);
entry->e_perm = cpu_to_le16(acl->a_entries[i].e_perm);
switch (acl->a_entries[i].e_tag) {
case ACL_USER:
entry->e_id = cpu_to_le32(
from_kuid(&init_user_ns,
acl->a_entries[i].e_uid));
entry = (struct f2fs_acl_entry *)((char *)entry +
sizeof(struct f2fs_acl_entry));
break;
case ACL_GROUP:
entry->e_id = cpu_to_le32(
from_kgid(&init_user_ns,
acl->a_entries[i].e_gid));
entry = (struct f2fs_acl_entry *)((char *)entry +
sizeof(struct f2fs_acl_entry));
break;
case ACL_USER_OBJ:
case ACL_GROUP_OBJ:
case ACL_MASK:
case ACL_OTHER:
entry = (struct f2fs_acl_entry *)((char *)entry +
sizeof(struct f2fs_acl_entry_short));
break;
default:
goto fail;
}
}
*size = f2fs_acl_size(acl->a_count);
return (void *)f2fs_acl;
fail:
kfree(f2fs_acl);
return ERR_PTR(-EINVAL);
}
static struct posix_acl *__f2fs_get_acl(struct inode *inode, int type,
struct page *dpage)
{
int name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT;
void *value = NULL;
struct posix_acl *acl;
int retval;
if (type == ACL_TYPE_ACCESS)
name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;
retval = f2fs_getxattr(inode, name_index, "", NULL, 0, dpage);
if (retval > 0) {
value = kmalloc(retval, GFP_F2FS_ZERO);
if (!value)
return ERR_PTR(-ENOMEM);
retval = f2fs_getxattr(inode, name_index, "", value,
retval, dpage);
}
if (retval > 0)
acl = f2fs_acl_from_disk(value, retval);
else if (retval == -ENODATA)
acl = NULL;
else
acl = ERR_PTR(retval);
kfree(value);
if (!IS_ERR(acl))
set_cached_acl(inode, type, acl);
return acl;
}
struct posix_acl *f2fs_get_acl(struct inode *inode, int type)
{
return __f2fs_get_acl(inode, type, NULL);
}
static int __f2fs_set_acl(struct inode *inode, int type,
struct posix_acl *acl, struct page *ipage)
{
struct f2fs_inode_info *fi = F2FS_I(inode);
int name_index;
void *value = NULL;
size_t size = 0;
int error;
switch (type) {
case ACL_TYPE_ACCESS:
name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;
if (acl) {
error = posix_acl_equiv_mode(acl, &inode->i_mode);
if (error < 0)
return error;
set_acl_inode(fi, inode->i_mode);
if (error == 0)
acl = NULL;
}
break;
case ACL_TYPE_DEFAULT:
name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT;
if (!S_ISDIR(inode->i_mode))
return acl ? -EACCES : 0;
break;
default:
return -EINVAL;
}
if (acl) {
value = f2fs_acl_to_disk(acl, &size);
if (IS_ERR(value)) {
clear_inode_flag(fi, FI_ACL_MODE);
return (int)PTR_ERR(value);
}
}
error = f2fs_setxattr(inode, name_index, "", value, size, ipage, 0);
kfree(value);
if (!error)
set_cached_acl(inode, type, acl);
clear_inode_flag(fi, FI_ACL_MODE);
return error;
}
int f2fs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
{
return __f2fs_set_acl(inode, type, acl, NULL);
}
/*
* Most part of f2fs_acl_clone, f2fs_acl_create_masq, f2fs_acl_create
* are copied from posix_acl.c
*/
static struct posix_acl *f2fs_acl_clone(const struct posix_acl *acl,
gfp_t flags)
{
struct posix_acl *clone = NULL;
if (acl) {
int size = sizeof(struct posix_acl) + acl->a_count *
sizeof(struct posix_acl_entry);
clone = kmemdup(acl, size, flags);
if (clone)
atomic_set(&clone->a_refcount, 1);
}
return clone;
}
static int f2fs_acl_create_masq(struct posix_acl *acl, umode_t *mode_p)
{
struct posix_acl_entry *pa, *pe;
struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL;
umode_t mode = *mode_p;
int not_equiv = 0;
/* assert(atomic_read(acl->a_refcount) == 1); */
FOREACH_ACL_ENTRY(pa, acl, pe) {
switch(pa->e_tag) {
case ACL_USER_OBJ:
pa->e_perm &= (mode >> 6) | ~S_IRWXO;
mode &= (pa->e_perm << 6) | ~S_IRWXU;
break;
case ACL_USER:
case ACL_GROUP:
not_equiv = 1;
break;
case ACL_GROUP_OBJ:
group_obj = pa;
break;
case ACL_OTHER:
pa->e_perm &= mode | ~S_IRWXO;
mode &= pa->e_perm | ~S_IRWXO;
break;
case ACL_MASK:
mask_obj = pa;
not_equiv = 1;
break;
default:
return -EIO;
}
}
if (mask_obj) {
mask_obj->e_perm &= (mode >> 3) | ~S_IRWXO;
mode &= (mask_obj->e_perm << 3) | ~S_IRWXG;
} else {
if (!group_obj)
return -EIO;
group_obj->e_perm &= (mode >> 3) | ~S_IRWXO;
mode &= (group_obj->e_perm << 3) | ~S_IRWXG;
}
*mode_p = (*mode_p & ~S_IRWXUGO) | mode;
return not_equiv;
}
static int f2fs_acl_create(struct inode *dir, umode_t *mode,
struct posix_acl **default_acl, struct posix_acl **acl,
struct page *dpage)
{
struct posix_acl *p;
int ret;
if (S_ISLNK(*mode) || !IS_POSIXACL(dir))
goto no_acl;
p = __f2fs_get_acl(dir, ACL_TYPE_DEFAULT, dpage);
if (IS_ERR(p)) {
if (p == ERR_PTR(-EOPNOTSUPP))
goto apply_umask;
return PTR_ERR(p);
}
if (!p)
goto apply_umask;
*acl = f2fs_acl_clone(p, GFP_NOFS);
if (!*acl)
goto no_mem;
ret = f2fs_acl_create_masq(*acl, mode);
if (ret < 0)
goto no_mem_clone;
if (ret == 0) {
posix_acl_release(*acl);
*acl = NULL;
}
if (!S_ISDIR(*mode)) {
posix_acl_release(p);
*default_acl = NULL;
} else {
*default_acl = p;
}
return 0;
apply_umask:
*mode &= ~current_umask();
no_acl:
*default_acl = NULL;
*acl = NULL;
return 0;
no_mem_clone:
posix_acl_release(*acl);
no_mem:
posix_acl_release(p);
return -ENOMEM;
}
int f2fs_init_acl(struct inode *inode, struct inode *dir, struct page *ipage,
struct page *dpage)
{
struct posix_acl *default_acl = NULL, *acl = NULL;
int error = 0;
error = f2fs_acl_create(dir, &inode->i_mode, &default_acl, &acl, dpage);
if (error)
return error;
if (default_acl) {
error = __f2fs_set_acl(inode, ACL_TYPE_DEFAULT, default_acl,
ipage);
posix_acl_release(default_acl);
}
if (acl) {
if (!error)
error = __f2fs_set_acl(inode, ACL_TYPE_ACCESS, acl,
ipage);
posix_acl_release(acl);
}
return error;
}