- 根目录:
- fs
- f2fs
- xattr.c
/*
* fs/f2fs/xattr.c
*
* Copyright (c) 2012 Samsung Electronics Co., Ltd.
* http://www.samsung.com/
*
* Portions of this code from linux/fs/ext2/xattr.c
*
* Copyright (C) 2001-2003 Andreas Gruenbacher <agruen@suse.de>
*
* Fix by Harrison Xing <harrison@mountainviewdata.com>.
* Extended attributes for symlinks and special files added per
* suggestion of Luka Renko <luka.renko@hermes.si>.
* xattr consolidation Copyright (c) 2004 James Morris <jmorris@redhat.com>,
* Red Hat Inc.
*
* 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/rwsem.h>
#include <linux/f2fs_fs.h>
#include <linux/security.h>
#include <linux/posix_acl_xattr.h>
#include "f2fs.h"
#include "xattr.h"
static size_t f2fs_xattr_generic_list(struct dentry *dentry, char *list,
size_t list_size, const char *name, size_t len, int type)
{
struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
int total_len, prefix_len = 0;
const char *prefix = NULL;
switch (type) {
case F2FS_XATTR_INDEX_USER:
if (!test_opt(sbi, XATTR_USER))
return -EOPNOTSUPP;
prefix = XATTR_USER_PREFIX;
prefix_len = XATTR_USER_PREFIX_LEN;
break;
case F2FS_XATTR_INDEX_TRUSTED:
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
prefix = XATTR_TRUSTED_PREFIX;
prefix_len = XATTR_TRUSTED_PREFIX_LEN;
break;
case F2FS_XATTR_INDEX_SECURITY:
prefix = XATTR_SECURITY_PREFIX;
prefix_len = XATTR_SECURITY_PREFIX_LEN;
break;
default:
return -EINVAL;
}
total_len = prefix_len + len + 1;
if (list && total_len <= list_size) {
memcpy(list, prefix, prefix_len);
memcpy(list + prefix_len, name, len);
list[prefix_len + len] = '\0';
}
return total_len;
}
static int f2fs_xattr_generic_get(struct dentry *dentry, const char *name,
void *buffer, size_t size, int type)
{
struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
switch (type) {
case F2FS_XATTR_INDEX_USER:
if (!test_opt(sbi, XATTR_USER))
return -EOPNOTSUPP;
break;
case F2FS_XATTR_INDEX_TRUSTED:
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
break;
case F2FS_XATTR_INDEX_SECURITY:
break;
default:
return -EINVAL;
}
if (strcmp(name, "") == 0)
return -EINVAL;
return f2fs_getxattr(dentry->d_inode, type, name, buffer, size);
}
static int f2fs_xattr_generic_set(struct dentry *dentry, const char *name,
const void *value, size_t size, int flags, int type)
{
struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
switch (type) {
case F2FS_XATTR_INDEX_USER:
if (!test_opt(sbi, XATTR_USER))
return -EOPNOTSUPP;
break;
case F2FS_XATTR_INDEX_TRUSTED:
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
break;
case F2FS_XATTR_INDEX_SECURITY:
break;
default:
return -EINVAL;
}
if (strcmp(name, "") == 0)
return -EINVAL;
return f2fs_setxattr(dentry->d_inode, type, name,
value, size, NULL, flags);
}
static size_t f2fs_xattr_advise_list(struct dentry *dentry, char *list,
size_t list_size, const char *name, size_t len, int type)
{
const char *xname = F2FS_SYSTEM_ADVISE_PREFIX;
size_t size;
if (type != F2FS_XATTR_INDEX_ADVISE)
return 0;
size = strlen(xname) + 1;
if (list && size <= list_size)
memcpy(list, xname, size);
return size;
}
static int f2fs_xattr_advise_get(struct dentry *dentry, const char *name,
void *buffer, size_t size, int type)
{
struct inode *inode = dentry->d_inode;
if (strcmp(name, "") != 0)
return -EINVAL;
*((char *)buffer) = F2FS_I(inode)->i_advise;
return sizeof(char);
}
static int f2fs_xattr_advise_set(struct dentry *dentry, const char *name,
const void *value, size_t size, int flags, int type)
{
struct inode *inode = dentry->d_inode;
if (strcmp(name, "") != 0)
return -EINVAL;
if (!inode_owner_or_capable(inode))
return -EPERM;
if (value == NULL)
return -EINVAL;
F2FS_I(inode)->i_advise |= *(char *)value;
return 0;
}
#ifdef CONFIG_F2FS_FS_SECURITY
static int f2fs_initxattrs(struct inode *inode, const struct xattr *xattr_array,
void *page)
{
const struct xattr *xattr;
int err = 0;
for (xattr = xattr_array; xattr->name != NULL; xattr++) {
err = f2fs_setxattr(inode, F2FS_XATTR_INDEX_SECURITY,
xattr->name, xattr->value,
xattr->value_len, (struct page *)page, 0);
if (err < 0)
break;
}
return err;
}
int f2fs_init_security(struct inode *inode, struct inode *dir,
const struct qstr *qstr, struct page *ipage)
{
return security_inode_init_security(inode, dir, qstr,
&f2fs_initxattrs, ipage);
}
#endif
const struct xattr_handler f2fs_xattr_user_handler = {
.prefix = XATTR_USER_PREFIX,
.flags = F2FS_XATTR_INDEX_USER,
.list = f2fs_xattr_generic_list,
.get = f2fs_xattr_generic_get,
.set = f2fs_xattr_generic_set,
};
const struct xattr_handler f2fs_xattr_trusted_handler = {
.prefix = XATTR_TRUSTED_PREFIX,
.flags = F2FS_XATTR_INDEX_TRUSTED,
.list = f2fs_xattr_generic_list,
.get = f2fs_xattr_generic_get,
.set = f2fs_xattr_generic_set,
};
const struct xattr_handler f2fs_xattr_advise_handler = {
.prefix = F2FS_SYSTEM_ADVISE_PREFIX,
.flags = F2FS_XATTR_INDEX_ADVISE,
.list = f2fs_xattr_advise_list,
.get = f2fs_xattr_advise_get,
.set = f2fs_xattr_advise_set,
};
const struct xattr_handler f2fs_xattr_security_handler = {
.prefix = XATTR_SECURITY_PREFIX,
.flags = F2FS_XATTR_INDEX_SECURITY,
.list = f2fs_xattr_generic_list,
.get = f2fs_xattr_generic_get,
.set = f2fs_xattr_generic_set,
};
static const struct xattr_handler *f2fs_xattr_handler_map[] = {
[F2FS_XATTR_INDEX_USER] = &f2fs_xattr_user_handler,
#ifdef CONFIG_F2FS_FS_POSIX_ACL
[F2FS_XATTR_INDEX_POSIX_ACL_ACCESS] = &posix_acl_access_xattr_handler,
[F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT] = &posix_acl_default_xattr_handler,
#endif
[F2FS_XATTR_INDEX_TRUSTED] = &f2fs_xattr_trusted_handler,
#ifdef CONFIG_F2FS_FS_SECURITY
[F2FS_XATTR_INDEX_SECURITY] = &f2fs_xattr_security_handler,
#endif
[F2FS_XATTR_INDEX_ADVISE] = &f2fs_xattr_advise_handler,
};
const struct xattr_handler *f2fs_xattr_handlers[] = {
&f2fs_xattr_user_handler,
#ifdef CONFIG_F2FS_FS_POSIX_ACL
&posix_acl_access_xattr_handler,
&posix_acl_default_xattr_handler,
#endif
&f2fs_xattr_trusted_handler,
#ifdef CONFIG_F2FS_FS_SECURITY
&f2fs_xattr_security_handler,
#endif
&f2fs_xattr_advise_handler,
NULL,
};
static inline const struct xattr_handler *f2fs_xattr_handler(int index)
{
const struct xattr_handler *handler = NULL;
if (index > 0 && index < ARRAY_SIZE(f2fs_xattr_handler_map))
handler = f2fs_xattr_handler_map[index];
return handler;
}
static struct f2fs_xattr_entry *__find_xattr(void *base_addr, int index,
size_t len, const char *name)
{
struct f2fs_xattr_entry *entry;
list_for_each_xattr(entry, base_addr) {
if (entry->e_name_index != index)
continue;
if (entry->e_name_len != len)
continue;
if (!memcmp(entry->e_name, name, len))
break;
}
return entry;
}
static void *read_all_xattrs(struct inode *inode, struct page *ipage)
{
struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
struct f2fs_xattr_header *header;
size_t size = PAGE_SIZE, inline_size = 0;
void *txattr_addr;
inline_size = inline_xattr_size(inode);
txattr_addr = kzalloc(inline_size + size, GFP_F2FS_ZERO);
if (!txattr_addr)
return NULL;
/* read from inline xattr */
if (inline_size) {
struct page *page = NULL;
void *inline_addr;
if (ipage) {
inline_addr = inline_xattr_addr(ipage);
} else {
page = get_node_page(sbi, inode->i_ino);
if (IS_ERR(page))
goto fail;
inline_addr = inline_xattr_addr(page);
}
memcpy(txattr_addr, inline_addr, inline_size);
f2fs_put_page(page, 1);
}
/* read from xattr node block */
if (F2FS_I(inode)->i_xattr_nid) {
struct page *xpage;
void *xattr_addr;
/* The inode already has an extended attribute block. */
xpage = get_node_page(sbi, F2FS_I(inode)->i_xattr_nid);
if (IS_ERR(xpage))
goto fail;
xattr_addr = page_address(xpage);
memcpy(txattr_addr + inline_size, xattr_addr, PAGE_SIZE);
f2fs_put_page(xpage, 1);
}
header = XATTR_HDR(txattr_addr);
/* never been allocated xattrs */
if (le32_to_cpu(header->h_magic) != F2FS_XATTR_MAGIC) {
header->h_magic = cpu_to_le32(F2FS_XATTR_MAGIC);
header->h_refcount = cpu_to_le32(1);
}
return txattr_addr;
fail:
kzfree(txattr_addr);
return NULL;
}
static inline int write_all_xattrs(struct inode *inode, __u32 hsize,
void *txattr_addr, struct page *ipage)
{
struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
size_t inline_size = 0;
void *xattr_addr;
struct page *xpage;
nid_t new_nid = 0;
int err;
inline_size = inline_xattr_size(inode);
if (hsize > inline_size && !F2FS_I(inode)->i_xattr_nid)
if (!alloc_nid(sbi, &new_nid))
return -ENOSPC;
/* write to inline xattr */
if (inline_size) {
struct page *page = NULL;
void *inline_addr;
if (ipage) {
inline_addr = inline_xattr_addr(ipage);
f2fs_wait_on_page_writeback(ipage, NODE);
} else {
page = get_node_page(sbi, inode->i_ino);
if (IS_ERR(page)) {
alloc_nid_failed(sbi, new_nid);
return PTR_ERR(page);
}
inline_addr = inline_xattr_addr(page);
f2fs_wait_on_page_writeback(page, NODE);
}
memcpy(inline_addr, txattr_addr, inline_size);
f2fs_put_page(page, 1);
/* no need to use xattr node block */
if (hsize <= inline_size) {
err = truncate_xattr_node(inode, ipage);
alloc_nid_failed(sbi, new_nid);
return err;
}
}
/* write to xattr node block */
if (F2FS_I(inode)->i_xattr_nid) {
xpage = get_node_page(sbi, F2FS_I(inode)->i_xattr_nid);
if (IS_ERR(xpage)) {
alloc_nid_failed(sbi, new_nid);
return PTR_ERR(xpage);
}
f2fs_bug_on(sbi, new_nid);
f2fs_wait_on_page_writeback(xpage, NODE);
} else {
struct dnode_of_data dn;
set_new_dnode(&dn, inode, NULL, NULL, new_nid);
xpage = new_node_page(&dn, XATTR_NODE_OFFSET, ipage);
if (IS_ERR(xpage)) {
alloc_nid_failed(sbi, new_nid);
return PTR_ERR(xpage);
}
alloc_nid_done(sbi, new_nid);
}
xattr_addr = page_address(xpage);
memcpy(xattr_addr, txattr_addr + inline_size, PAGE_SIZE -
sizeof(struct node_footer));
set_page_dirty(xpage);
f2fs_put_page(xpage, 1);
/* need to checkpoint during fsync */
F2FS_I(inode)->xattr_ver = cur_cp_version(F2FS_CKPT(sbi));
return 0;
}
int f2fs_getxattr(struct inode *inode, int index, const char *name,
void *buffer, size_t buffer_size)
{
struct f2fs_xattr_entry *entry;
void *base_addr;
int error = 0;
size_t size, len;
if (name == NULL)
return -EINVAL;
len = strlen(name);
if (len > F2FS_NAME_LEN)
return -ERANGE;
base_addr = read_all_xattrs(inode, NULL);
if (!base_addr)
return -ENOMEM;
entry = __find_xattr(base_addr, index, len, name);
if (IS_XATTR_LAST_ENTRY(entry)) {
error = -ENODATA;
goto cleanup;
}
size = le16_to_cpu(entry->e_value_size);
if (buffer && size > buffer_size) {
error = -ERANGE;
goto cleanup;
}
if (buffer) {
char *pval = entry->e_name + entry->e_name_len;
memcpy(buffer, pval, size);
}
error = size;
cleanup:
kzfree(base_addr);
return error;
}
ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
{
struct inode *inode = dentry->d_inode;
struct f2fs_xattr_entry *entry;
void *base_addr;
int error = 0;
size_t rest = buffer_size;
base_addr = read_all_xattrs(inode, NULL);
if (!base_addr)
return -ENOMEM;
list_for_each_xattr(entry, base_addr) {
const struct xattr_handler *handler =
f2fs_xattr_handler(entry->e_name_index);
size_t size;
if (!handler)
continue;
size = handler->list(dentry, buffer, rest, entry->e_name,
entry->e_name_len, handler->flags);
if (buffer && size > rest) {
error = -ERANGE;
goto cleanup;
}
if (buffer)
buffer += size;
rest -= size;
}
error = buffer_size - rest;
cleanup:
kzfree(base_addr);
return error;
}
static int __f2fs_setxattr(struct inode *inode, int index,
const char *name, const void *value, size_t size,
struct page *ipage, int flags)
{
struct f2fs_inode_info *fi = F2FS_I(inode);
struct f2fs_xattr_entry *here, *last;
void *base_addr;
int found, newsize;
size_t len;
__u32 new_hsize;
int error = -ENOMEM;
if (name == NULL)
return -EINVAL;
if (value == NULL)
size = 0;
len = strlen(name);
if (len > F2FS_NAME_LEN || size > MAX_VALUE_LEN(inode))
return -ERANGE;
base_addr = read_all_xattrs(inode, ipage);
if (!base_addr)
goto exit;
/* find entry with wanted name. */
here = __find_xattr(base_addr, index, len, name);
found = IS_XATTR_LAST_ENTRY(here) ? 0 : 1;
if ((flags & XATTR_REPLACE) && !found) {
error = -ENODATA;
goto exit;
} else if ((flags & XATTR_CREATE) && found) {
error = -EEXIST;
goto exit;
}
last = here;
while (!IS_XATTR_LAST_ENTRY(last))
last = XATTR_NEXT_ENTRY(last);
newsize = XATTR_ALIGN(sizeof(struct f2fs_xattr_entry) + len + size);
/* 1. Check space */
if (value) {
int free;
/*
* If value is NULL, it is remove operation.
* In case of update operation, we calculate free.
*/
free = MIN_OFFSET(inode) - ((char *)last - (char *)base_addr);
if (found)
free = free + ENTRY_SIZE(here);
if (unlikely(free < newsize)) {
error = -ENOSPC;
goto exit;
}
}
/* 2. Remove old entry */
if (found) {
/*
* If entry is found, remove old entry.
* If not found, remove operation is not needed.
*/
struct f2fs_xattr_entry *next = XATTR_NEXT_ENTRY(here);
int oldsize = ENTRY_SIZE(here);
memmove(here, next, (char *)last - (char *)next);
last = (struct f2fs_xattr_entry *)((char *)last - oldsize);
memset(last, 0, oldsize);
}
new_hsize = (char *)last - (char *)base_addr;
/* 3. Write new entry */
if (value) {
char *pval;
/*
* Before we come here, old entry is removed.
* We just write new entry.
*/
memset(last, 0, newsize);
last->e_name_index = index;
last->e_name_len = len;
memcpy(last->e_name, name, len);
pval = last->e_name + len;
memcpy(pval, value, size);
last->e_value_size = cpu_to_le16(size);
new_hsize += newsize;
}
error = write_all_xattrs(inode, new_hsize, base_addr, ipage);
if (error)
goto exit;
if (is_inode_flag_set(fi, FI_ACL_MODE)) {
inode->i_mode = fi->i_acl_mode;
inode->i_ctime = CURRENT_TIME;
clear_inode_flag(fi, FI_ACL_MODE);
}
if (ipage)
update_inode(inode, ipage);
else
update_inode_page(inode);
exit:
kzfree(base_addr);
return error;
}
int f2fs_setxattr(struct inode *inode, int index, const char *name,
const void *value, size_t size,
struct page *ipage, int flags)
{
struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
int err;
/* this case is only from init_inode_metadata */
if (ipage)
return __f2fs_setxattr(inode, index, name, value,
size, ipage, flags);
f2fs_balance_fs(sbi);
f2fs_lock_op(sbi);
/* protect xattr_ver */
down_write(&F2FS_I(inode)->i_sem);
err = __f2fs_setxattr(inode, index, name, value, size, ipage, flags);
up_write(&F2FS_I(inode)->i_sem);
f2fs_unlock_op(sbi);
return err;
}