提交 af48b85b 编写于 作者: J Jaegeuk Kim

f2fs: add xattr and acl functionalities

This implements xattr and acl functionalities.

- F2FS uses a node page to contain use extended attributes.
Signed-off-by: NChangman Lee <cm224.lee@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>
上级 6b4ea016
/**
* 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"
#define get_inode_mode(i) ((is_inode_flag_set(F2FS_I(i), FI_ACL_MODE)) ? \
(F2FS_I(i)->i_acl_mode) : ((i)->i_mode))
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_KERNEL);
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:
acl->a_entries[i].e_id = ACL_UNDEFINED_ID;
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_KERNEL);
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);
}
struct posix_acl *f2fs_get_acl(struct inode *inode, int type)
{
struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
int name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT;
void *value = NULL;
struct posix_acl *acl;
int retval;
if (!test_opt(sbi, POSIX_ACL))
return NULL;
acl = get_cached_acl(inode, type);
if (acl != ACL_NOT_CACHED)
return acl;
if (type == ACL_TYPE_ACCESS)
name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;
retval = f2fs_getxattr(inode, name_index, "", NULL, 0);
if (retval > 0) {
value = kmalloc(retval, GFP_KERNEL);
if (!value)
return ERR_PTR(-ENOMEM);
retval = f2fs_getxattr(inode, name_index, "", value, retval);
}
if (retval < 0) {
if (retval == -ENODATA)
acl = NULL;
else
acl = ERR_PTR(retval);
} else {
acl = f2fs_acl_from_disk(value, retval);
}
kfree(value);
if (!IS_ERR(acl))
set_cached_acl(inode, type, acl);
return acl;
}
static int f2fs_set_acl(struct inode *inode, int type, struct posix_acl *acl)
{
struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
struct f2fs_inode_info *fi = F2FS_I(inode);
int name_index;
void *value = NULL;
size_t size = 0;
int error;
if (!test_opt(sbi, POSIX_ACL))
return 0;
if (S_ISLNK(inode->i_mode))
return -EOPNOTSUPP;
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)) {
cond_clear_inode_flag(fi, FI_ACL_MODE);
return (int)PTR_ERR(value);
}
}
error = f2fs_setxattr(inode, name_index, "", value, size);
kfree(value);
if (!error)
set_cached_acl(inode, type, acl);
cond_clear_inode_flag(fi, FI_ACL_MODE);
return error;
}
int f2fs_init_acl(struct inode *inode, struct inode *dir)
{
struct posix_acl *acl = NULL;
struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
int error = 0;
if (!S_ISLNK(inode->i_mode)) {
if (test_opt(sbi, POSIX_ACL)) {
acl = f2fs_get_acl(dir, ACL_TYPE_DEFAULT);
if (IS_ERR(acl))
return PTR_ERR(acl);
}
if (!acl)
inode->i_mode &= ~current_umask();
}
if (test_opt(sbi, POSIX_ACL) && acl) {
if (S_ISDIR(inode->i_mode)) {
error = f2fs_set_acl(inode, ACL_TYPE_DEFAULT, acl);
if (error)
goto cleanup;
}
error = posix_acl_create(&acl, GFP_KERNEL, &inode->i_mode);
if (error < 0)
return error;
if (error > 0)
error = f2fs_set_acl(inode, ACL_TYPE_ACCESS, acl);
}
cleanup:
posix_acl_release(acl);
return error;
}
int f2fs_acl_chmod(struct inode *inode)
{
struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
struct posix_acl *acl;
int error;
mode_t mode = get_inode_mode(inode);
if (!test_opt(sbi, POSIX_ACL))
return 0;
if (S_ISLNK(mode))
return -EOPNOTSUPP;
acl = f2fs_get_acl(inode, ACL_TYPE_ACCESS);
if (IS_ERR(acl) || !acl)
return PTR_ERR(acl);
error = posix_acl_chmod(&acl, GFP_KERNEL, mode);
if (error)
return error;
error = f2fs_set_acl(inode, ACL_TYPE_ACCESS, acl);
posix_acl_release(acl);
return error;
}
static size_t f2fs_xattr_list_acl(struct dentry *dentry, char *list,
size_t list_size, const char *name, size_t name_len, int type)
{
struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
const char *xname = POSIX_ACL_XATTR_DEFAULT;
size_t size;
if (!test_opt(sbi, POSIX_ACL))
return 0;
if (type == ACL_TYPE_ACCESS)
xname = POSIX_ACL_XATTR_ACCESS;
size = strlen(xname) + 1;
if (list && size <= list_size)
memcpy(list, xname, size);
return size;
}
static int f2fs_xattr_get_acl(struct dentry *dentry, const char *name,
void *buffer, size_t size, int type)
{
struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
struct posix_acl *acl;
int error;
if (strcmp(name, "") != 0)
return -EINVAL;
if (!test_opt(sbi, POSIX_ACL))
return -EOPNOTSUPP;
acl = f2fs_get_acl(dentry->d_inode, type);
if (IS_ERR(acl))
return PTR_ERR(acl);
if (!acl)
return -ENODATA;
error = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
posix_acl_release(acl);
return error;
}
static int f2fs_xattr_set_acl(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);
struct inode *inode = dentry->d_inode;
struct posix_acl *acl = NULL;
int error;
if (strcmp(name, "") != 0)
return -EINVAL;
if (!test_opt(sbi, 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);
if (acl) {
error = posix_acl_valid(acl);
if (error)
goto release_and_out;
}
} else {
acl = NULL;
}
error = f2fs_set_acl(inode, type, acl);
release_and_out:
posix_acl_release(acl);
return error;
}
const struct xattr_handler f2fs_xattr_acl_default_handler = {
.prefix = POSIX_ACL_XATTR_DEFAULT,
.flags = ACL_TYPE_DEFAULT,
.list = f2fs_xattr_list_acl,
.get = f2fs_xattr_get_acl,
.set = f2fs_xattr_set_acl,
};
const struct xattr_handler f2fs_xattr_acl_access_handler = {
.prefix = POSIX_ACL_XATTR_ACCESS,
.flags = ACL_TYPE_ACCESS,
.list = f2fs_xattr_list_acl,
.get = f2fs_xattr_get_acl,
.set = f2fs_xattr_set_acl,
};
static size_t f2fs_xattr_advise_list(struct dentry *dentry, char *list,
size_t list_size, const char *name, size_t name_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;
}
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,
};
/**
* fs/f2fs/acl.h
*
* Copyright (c) 2012 Samsung Electronics Co., Ltd.
* http://www.samsung.com/
*
* Portions of this code from linux/fs/ext2/acl.h
*
* 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.
*/
#ifndef __F2FS_ACL_H__
#define __F2FS_ACL_H__
#include <linux/posix_acl_xattr.h>
#define F2FS_ACL_VERSION 0x0001
struct f2fs_acl_entry {
__le16 e_tag;
__le16 e_perm;
__le32 e_id;
};
struct f2fs_acl_entry_short {
__le16 e_tag;
__le16 e_perm;
};
struct f2fs_acl_header {
__le32 a_version;
};
#ifdef CONFIG_F2FS_FS_POSIX_ACL
extern struct posix_acl *f2fs_get_acl(struct inode *inode, int type);
extern int f2fs_acl_chmod(struct inode *inode);
extern int f2fs_init_acl(struct inode *inode, struct inode *dir);
#else
#define f2fs_check_acl NULL
#define f2fs_get_acl NULL
#define f2fs_set_acl NULL
static inline int f2fs_acl_chmod(struct inode *inode)
{
return 0;
}
static inline int f2fs_init_acl(struct inode *inode, struct inode *dir)
{
return 0;
}
#endif
#endif /* __F2FS_ACL_H__ */
/**
* 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 "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 name_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;
default:
return -EINVAL;
}
total_len = prefix_len + name_len + 1;
if (list && total_len <= list_size) {
memcpy(list, prefix, prefix_len);
memcpy(list+prefix_len, name, name_len);
list[prefix_len + name_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;
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;
default:
return -EINVAL;
}
if (strcmp(name, "") == 0)
return -EINVAL;
return f2fs_setxattr(dentry->d_inode, type, name, value, size);
}
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,
};
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] = &f2fs_xattr_acl_access_handler,
[F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT] = &f2fs_xattr_acl_default_handler,
#endif
[F2FS_XATTR_INDEX_TRUSTED] = &f2fs_xattr_trusted_handler,
[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
&f2fs_xattr_acl_access_handler,
&f2fs_xattr_acl_default_handler,
#endif
&f2fs_xattr_trusted_handler,
&f2fs_xattr_advise_handler,
NULL,
};
static inline const struct xattr_handler *f2fs_xattr_handler(int name_index)
{
const struct xattr_handler *handler = NULL;
if (name_index > 0 && name_index < ARRAY_SIZE(f2fs_xattr_handler_map))
handler = f2fs_xattr_handler_map[name_index];
return handler;
}
int f2fs_getxattr(struct inode *inode, int name_index, const char *name,
void *buffer, size_t buffer_size)
{
struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
struct f2fs_inode_info *fi = F2FS_I(inode);
struct f2fs_xattr_entry *entry;
struct page *page;
void *base_addr;
int error = 0, found = 0;
int value_len, name_len;
if (name == NULL)
return -EINVAL;
name_len = strlen(name);
if (!fi->i_xattr_nid)
return -ENODATA;
page = get_node_page(sbi, fi->i_xattr_nid);
base_addr = page_address(page);
list_for_each_xattr(entry, base_addr) {
if (entry->e_name_index != name_index)
continue;
if (entry->e_name_len != name_len)
continue;
if (!memcmp(entry->e_name, name, name_len)) {
found = 1;
break;
}
}
if (!found) {
error = -ENODATA;
goto cleanup;
}
value_len = le16_to_cpu(entry->e_value_size);
if (buffer && value_len > buffer_size) {
error = -ERANGE;
goto cleanup;
}
if (buffer) {
char *pval = entry->e_name + entry->e_name_len;
memcpy(buffer, pval, value_len);
}
error = value_len;
cleanup:
f2fs_put_page(page, 1);
return error;
}
ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
{
struct inode *inode = dentry->d_inode;
struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
struct f2fs_inode_info *fi = F2FS_I(inode);
struct f2fs_xattr_entry *entry;
struct page *page;
void *base_addr;
int error = 0;
size_t rest = buffer_size;
if (!fi->i_xattr_nid)
return 0;
page = get_node_page(sbi, fi->i_xattr_nid);
base_addr = page_address(page);
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:
f2fs_put_page(page, 1);
return error;
}
int f2fs_setxattr(struct inode *inode, int name_index, const char *name,
const void *value, size_t value_len)
{
struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
struct f2fs_inode_info *fi = F2FS_I(inode);
struct f2fs_xattr_header *header = NULL;
struct f2fs_xattr_entry *here, *last;
struct page *page;
void *base_addr;
int error, found, free, name_len, newsize;
char *pval;
if (name == NULL)
return -EINVAL;
name_len = strlen(name);
if (value == NULL)
value_len = 0;
if (name_len > 255 || value_len > MAX_VALUE_LEN)
return -ERANGE;
mutex_lock_op(sbi, NODE_NEW);
if (!fi->i_xattr_nid) {
/* Allocate new attribute block */
struct dnode_of_data dn;
if (!alloc_nid(sbi, &fi->i_xattr_nid)) {
mutex_unlock_op(sbi, NODE_NEW);
return -ENOSPC;
}
set_new_dnode(&dn, inode, NULL, NULL, fi->i_xattr_nid);
mark_inode_dirty(inode);
page = new_node_page(&dn, XATTR_NODE_OFFSET);
if (IS_ERR(page)) {
alloc_nid_failed(sbi, fi->i_xattr_nid);
fi->i_xattr_nid = 0;
mutex_unlock_op(sbi, NODE_NEW);
return PTR_ERR(page);
}
alloc_nid_done(sbi, fi->i_xattr_nid);
base_addr = page_address(page);
header = XATTR_HDR(base_addr);
header->h_magic = cpu_to_le32(F2FS_XATTR_MAGIC);
header->h_refcount = cpu_to_le32(1);
} else {
/* The inode already has an extended attribute block. */
page = get_node_page(sbi, fi->i_xattr_nid);
if (IS_ERR(page)) {
mutex_unlock_op(sbi, NODE_NEW);
return PTR_ERR(page);
}
base_addr = page_address(page);
header = XATTR_HDR(base_addr);
}
if (le32_to_cpu(header->h_magic) != F2FS_XATTR_MAGIC) {
error = -EIO;
goto cleanup;
}
/* find entry with wanted name. */
found = 0;
list_for_each_xattr(here, base_addr) {
if (here->e_name_index != name_index)
continue;
if (here->e_name_len != name_len)
continue;
if (!memcmp(here->e_name, name, name_len)) {
found = 1;
break;
}
}
last = here;
while (!IS_XATTR_LAST_ENTRY(last))
last = XATTR_NEXT_ENTRY(last);
newsize = XATTR_ALIGN(sizeof(struct f2fs_xattr_entry) +
name_len + value_len);
/* 1. Check space */
if (value) {
/* If value is NULL, it is remove operation.
* In case of update operation, we caculate free.
*/
free = MIN_OFFSET - ((char *)last - (char *)header);
if (found)
free = free - ENTRY_SIZE(here);
if (free < newsize) {
error = -ENOSPC;
goto cleanup;
}
}
/* 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);
}
/* 3. Write new entry */
if (value) {
/* Before we come here, old entry is removed.
* We just write new entry. */
memset(last, 0, newsize);
last->e_name_index = name_index;
last->e_name_len = name_len;
memcpy(last->e_name, name, name_len);
pval = last->e_name + name_len;
memcpy(pval, value, value_len);
last->e_value_size = cpu_to_le16(value_len);
}
set_page_dirty(page);
f2fs_put_page(page, 1);
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);
}
f2fs_write_inode(inode, NULL);
mutex_unlock_op(sbi, NODE_NEW);
return 0;
cleanup:
f2fs_put_page(page, 1);
mutex_unlock_op(sbi, NODE_NEW);
return error;
}
/**
* fs/f2fs/xattr.h
*
* Copyright (c) 2012 Samsung Electronics Co., Ltd.
* http://www.samsung.com/
*
* Portions of this code from linux/fs/ext2/xattr.h
*
* On-disk format of extended attributes for the ext2 filesystem.
*
* (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
*
* 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.
*/
#ifndef __F2FS_XATTR_H__
#define __F2FS_XATTR_H__
#include <linux/init.h>
#include <linux/xattr.h>
/* Magic value in attribute blocks */
#define F2FS_XATTR_MAGIC 0xF2F52011
/* Maximum number of references to one attribute block */
#define F2FS_XATTR_REFCOUNT_MAX 1024
/* Name indexes */
#define F2FS_SYSTEM_ADVISE_PREFIX "system.advise"
#define F2FS_XATTR_INDEX_USER 1
#define F2FS_XATTR_INDEX_POSIX_ACL_ACCESS 2
#define F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT 3
#define F2FS_XATTR_INDEX_TRUSTED 4
#define F2FS_XATTR_INDEX_LUSTRE 5
#define F2FS_XATTR_INDEX_SECURITY 6
#define F2FS_XATTR_INDEX_ADVISE 7
struct f2fs_xattr_header {
__le32 h_magic; /* magic number for identification */
__le32 h_refcount; /* reference count */
__u32 h_reserved[4]; /* zero right now */
};
struct f2fs_xattr_entry {
__u8 e_name_index;
__u8 e_name_len;
__le16 e_value_size; /* size of attribute value */
char e_name[0]; /* attribute name */
};
#define XATTR_HDR(ptr) ((struct f2fs_xattr_header *)(ptr))
#define XATTR_ENTRY(ptr) ((struct f2fs_xattr_entry *)(ptr))
#define XATTR_FIRST_ENTRY(ptr) (XATTR_ENTRY(XATTR_HDR(ptr)+1))
#define XATTR_ROUND (3)
#define XATTR_ALIGN(size) ((size + XATTR_ROUND) & ~XATTR_ROUND)
#define ENTRY_SIZE(entry) (XATTR_ALIGN(sizeof(struct f2fs_xattr_entry) + \
entry->e_name_len + le16_to_cpu(entry->e_value_size)))
#define XATTR_NEXT_ENTRY(entry) ((struct f2fs_xattr_entry *)((char *)(entry) +\
ENTRY_SIZE(entry)))
#define IS_XATTR_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)
#define list_for_each_xattr(entry, addr) \
for (entry = XATTR_FIRST_ENTRY(addr);\
!IS_XATTR_LAST_ENTRY(entry);\
entry = XATTR_NEXT_ENTRY(entry))
#define MIN_OFFSET XATTR_ALIGN(PAGE_SIZE - \
sizeof(struct node_footer) - \
sizeof(__u32))
#define MAX_VALUE_LEN (MIN_OFFSET - sizeof(struct f2fs_xattr_header) - \
sizeof(struct f2fs_xattr_entry))
/**
* On-disk structure of f2fs_xattr
* We use only 1 block for xattr.
*
* +--------------------+
* | f2fs_xattr_header |
* | |
* +--------------------+
* | f2fs_xattr_entry |
* | .e_name_index = 1 |
* | .e_name_len = 3 |
* | .e_value_size = 14 |
* | .e_name = "foo" |
* | "value_of_xattr" |<- value_offs = e_name + e_name_len
* +--------------------+
* | f2fs_xattr_entry |
* | .e_name_index = 4 |
* | .e_name = "bar" |
* +--------------------+
* | |
* | Free |
* | |
* +--------------------+<- MIN_OFFSET
* | node_footer |
* | (nid, ino, offset) |
* +--------------------+
*
**/
#ifdef CONFIG_F2FS_FS_XATTR
extern const struct xattr_handler f2fs_xattr_user_handler;
extern const struct xattr_handler f2fs_xattr_trusted_handler;
extern const struct xattr_handler f2fs_xattr_acl_access_handler;
extern const struct xattr_handler f2fs_xattr_acl_default_handler;
extern const struct xattr_handler f2fs_xattr_advise_handler;
extern const struct xattr_handler *f2fs_xattr_handlers[];
extern int f2fs_setxattr(struct inode *inode, int name_index, const char *name,
const void *value, size_t value_len);
extern int f2fs_getxattr(struct inode *inode, int name_index, const char *name,
void *buffer, size_t buffer_size);
extern ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer,
size_t buffer_size);
#else
#define f2fs_xattr_handlers NULL
static inline int f2fs_setxattr(struct inode *inode, int name_index,
const char *name, const void *value, size_t value_len)
{
return -EOPNOTSUPP;
}
static inline int f2fs_getxattr(struct inode *inode, int name_index,
const char *name, void *buffer, size_t buffer_size)
{
return -EOPNOTSUPP;
}
static inline ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer,
size_t buffer_size)
{
return -EOPNOTSUPP;
}
#endif
#endif /* __F2FS_XATTR_H__ */
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