ref: 9fdd0b708e0068d6c0be75b7e3df7bbdb7d1d236
dir: /src/ext4_xattr.c/
/*
* Copyright (c) 2015 Grzegorz Kostka ([email protected])
* Copyright (c) 2015 Kaho Ng ([email protected])
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/** @addtogroup lwext4
* @{
*/
/**
* @file ext4_xattr.c
* @brief Extended Attribute manipulation.
*/
#include "ext4_config.h"
#include "ext4_types.h"
#include "ext4_misc.h"
#include "ext4_errno.h"
#include "ext4_debug.h"
#include "ext4_fs.h"
#include "ext4_trans.h"
#include "ext4_xattr.h"
#include "ext4_blockdev.h"
#include "ext4_super.h"
#include "ext4_crc32.h"
#include "ext4_block_group.h"
#include "ext4_balloc.h"
#include "ext4_inode.h"
#include <string.h>
#include <stdlib.h>
/**
* @file ext4_xattr.c
* @brief Extended Attribute Manipulation
*/
#define NAME_HASH_SHIFT 5
#define VALUE_HASH_SHIFT 16
static inline void ext4_xattr_compute_hash(struct ext4_xattr_header *header,
struct ext4_xattr_entry *entry)
{
uint32_t hash = 0;
char *name = EXT4_XATTR_NAME(entry);
int n;
for (n = 0; n < entry->e_name_len; n++) {
hash = (hash << NAME_HASH_SHIFT) ^
(hash >> (8 * sizeof(hash) - NAME_HASH_SHIFT)) ^ *name++;
}
if (entry->e_value_block == 0 && entry->e_value_size != 0) {
uint32_t *value =
(uint32_t *)((char *)header + to_le16(entry->e_value_offs));
for (n = (to_le32(entry->e_value_size) + EXT4_XATTR_ROUND) >>
EXT4_XATTR_PAD_BITS;
n; n--) {
hash = (hash << VALUE_HASH_SHIFT) ^
(hash >> (8 * sizeof(hash) - VALUE_HASH_SHIFT)) ^
to_le32(*value++);
}
}
entry->e_hash = to_le32(hash);
}
#define BLOCK_HASH_SHIFT 16
/*
* ext4_xattr_rehash()
*
* Re-compute the extended attribute hash value after an entry has changed.
*/
static void ext4_xattr_rehash(struct ext4_xattr_header *header,
struct ext4_xattr_entry *entry)
{
struct ext4_xattr_entry *here;
uint32_t hash = 0;
ext4_xattr_compute_hash(header, entry);
here = EXT4_XATTR_ENTRY(header + 1);
while (!EXT4_XATTR_IS_LAST_ENTRY(here)) {
if (!here->e_hash) {
/* Block is not shared if an entry's hash value == 0 */
hash = 0;
break;
}
hash = (hash << BLOCK_HASH_SHIFT) ^
(hash >> (8 * sizeof(hash) - BLOCK_HASH_SHIFT)) ^
to_le32(here->e_hash);
here = EXT4_XATTR_NEXT(here);
}
header->h_hash = to_le32(hash);
}
#if CONFIG_META_CSUM_ENABLE
static uint32_t
ext4_xattr_block_checksum(struct ext4_inode_ref *inode_ref,
ext4_fsblk_t blocknr,
struct ext4_xattr_header *header)
{
uint32_t checksum = 0;
uint64_t le64_blocknr = blocknr;
struct ext4_sblock *sb = &inode_ref->fs->sb;
if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM)) {
uint32_t orig_checksum;
/* Preparation: temporarily set bg checksum to 0 */
orig_checksum = header->h_checksum;
header->h_checksum = 0;
/* First calculate crc32 checksum against fs uuid */
checksum = ext4_crc32c(EXT4_CRC32_INIT, sb->uuid,
sizeof(sb->uuid));
/* Then calculate crc32 checksum block number */
checksum = ext4_crc32c(checksum, &le64_blocknr,
sizeof(le64_blocknr));
/* Finally calculate crc32 checksum against
* the entire xattr block */
checksum = ext4_crc32c(checksum, header,
ext4_sb_get_block_size(sb));
header->h_checksum = orig_checksum;
}
return checksum;
}
#else
#define ext4_xattr_block_checksum(...) 0
#endif
static void
ext4_xattr_set_block_checksum(struct ext4_inode_ref *inode_ref,
ext4_fsblk_t blocknr __unused,
struct ext4_xattr_header *header)
{
struct ext4_sblock *sb = &inode_ref->fs->sb;
if (!ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM))
return;
header->h_checksum =
ext4_xattr_block_checksum(inode_ref, blocknr, header);
}
static int ext4_xattr_item_cmp(struct ext4_xattr_item *a,
struct ext4_xattr_item *b)
{
int result;
if (a->is_data && !b->is_data)
return -1;
if (!a->is_data && b->is_data)
return 1;
result = a->name_index - b->name_index;
if (result)
return result;
result = a->name_len - b->name_len;
if (result)
return result;
return memcmp(a->name, b->name, a->name_len);
}
RB_GENERATE_INTERNAL(ext4_xattr_tree, ext4_xattr_item, node,
ext4_xattr_item_cmp, static inline)
static struct ext4_xattr_item *
ext4_xattr_item_alloc(uint8_t name_index, const char *name, size_t name_len)
{
struct ext4_xattr_item *item;
item = malloc(sizeof(struct ext4_xattr_item) + name_len);
if (!item)
return NULL;
item->name_index = name_index;
item->name = (char *)(item + 1);
item->name_len = name_len;
item->data = NULL;
item->data_size = 0;
item->in_inode = false;
memset(&item->node, 0, sizeof(item->node));
memcpy(item->name, name, name_len);
if (name_index == EXT4_XATTR_INDEX_SYSTEM &&
name_len == 4 &&
!memcmp(name, "data", 4))
item->is_data = true;
else
item->is_data = false;
return item;
}
static int ext4_xattr_item_alloc_data(struct ext4_xattr_item *item,
const void *orig_data, size_t data_size)
{
void *data = NULL;
ext4_assert(!item->data);
data = malloc(data_size);
if (!data)
return ENOMEM;
if (orig_data)
memcpy(data, orig_data, data_size);
item->data = data;
item->data_size = data_size;
return EOK;
}
static void ext4_xattr_item_free_data(struct ext4_xattr_item *item)
{
ext4_assert(item->data);
free(item->data);
item->data = NULL;
item->data_size = 0;
}
static int ext4_xattr_item_resize_data(struct ext4_xattr_item *item,
size_t new_data_size)
{
if (new_data_size != item->data_size) {
void *new_data;
new_data = realloc(item->data, new_data_size);
if (!new_data)
return ENOMEM;
item->data = new_data;
item->data_size = new_data_size;
}
return EOK;
}
static void ext4_xattr_item_free(struct ext4_xattr_item *item)
{
if (item->data)
ext4_xattr_item_free_data(item);
free(item);
}
static void *ext4_xattr_entry_data(struct ext4_xattr_ref *xattr_ref,
struct ext4_xattr_entry *entry,
bool in_inode)
{
char *ret;
if (in_inode) {
struct ext4_xattr_ibody_header *header;
struct ext4_xattr_entry *first_entry;
int16_t inode_size =
ext4_get16(&xattr_ref->fs->sb, inode_size);
header = EXT4_XATTR_IHDR(&xattr_ref->fs->sb,
xattr_ref->inode_ref->inode);
first_entry = EXT4_XATTR_IFIRST(header);
ret = ((char *)first_entry + to_le16(entry->e_value_offs));
if (ret + EXT4_XATTR_SIZE(to_le32(entry->e_value_size)) -
(char *)xattr_ref->inode_ref->inode > inode_size)
ret = NULL;
return ret;
}
int32_t block_size = ext4_sb_get_block_size(&xattr_ref->fs->sb);
ret = ((char *)xattr_ref->block.data + to_le16(entry->e_value_offs));
if (ret + EXT4_XATTR_SIZE(to_le32(entry->e_value_size)) -
(char *)xattr_ref->block.data > block_size)
ret = NULL;
return ret;
}
static int ext4_xattr_block_fetch(struct ext4_xattr_ref *xattr_ref)
{
int ret = EOK;
size_t size_rem;
void *data;
struct ext4_xattr_entry *entry = NULL;
ext4_assert(xattr_ref->block.data);
entry = EXT4_XATTR_BFIRST(&xattr_ref->block);
size_rem = ext4_sb_get_block_size(&xattr_ref->fs->sb);
for (; size_rem > 0 && !EXT4_XATTR_IS_LAST_ENTRY(entry);
entry = EXT4_XATTR_NEXT(entry),
size_rem -= EXT4_XATTR_LEN(entry->e_name_len)) {
struct ext4_xattr_item *item;
char *e_name = EXT4_XATTR_NAME(entry);
data = ext4_xattr_entry_data(xattr_ref, entry, false);
if (!data) {
ret = EIO;
goto Finish;
}
item = ext4_xattr_item_alloc(entry->e_name_index, e_name,
(size_t)entry->e_name_len);
if (!item) {
ret = ENOMEM;
goto Finish;
}
if (ext4_xattr_item_alloc_data(
item, data, to_le32(entry->e_value_size)) != EOK) {
ext4_xattr_item_free(item);
ret = ENOMEM;
goto Finish;
}
RB_INSERT(ext4_xattr_tree, &xattr_ref->root, item);
xattr_ref->block_size_rem -=
EXT4_XATTR_SIZE(item->data_size) +
EXT4_XATTR_LEN(item->name_len);
xattr_ref->ea_size += EXT4_XATTR_SIZE(item->data_size) +
EXT4_XATTR_LEN(item->name_len);
}
Finish:
return ret;
}
static int ext4_xattr_inode_fetch(struct ext4_xattr_ref *xattr_ref)
{
void *data;
size_t size_rem;
int ret = EOK;
struct ext4_xattr_ibody_header *header = NULL;
struct ext4_xattr_entry *entry = NULL;
uint16_t inode_size = ext4_get16(&xattr_ref->fs->sb, inode_size);
uint16_t extra_isize = ext4_inode_get_extra_isize(&xattr_ref->fs->sb,
xattr_ref->inode_ref->inode);
header = EXT4_XATTR_IHDR(&xattr_ref->fs->sb,
xattr_ref->inode_ref->inode);
entry = EXT4_XATTR_IFIRST(header);
size_rem = inode_size - EXT4_GOOD_OLD_INODE_SIZE -
extra_isize;
for (; size_rem > 0 && !EXT4_XATTR_IS_LAST_ENTRY(entry);
entry = EXT4_XATTR_NEXT(entry),
size_rem -= EXT4_XATTR_LEN(entry->e_name_len)) {
struct ext4_xattr_item *item;
char *e_name = EXT4_XATTR_NAME(entry);
data = ext4_xattr_entry_data(xattr_ref, entry, true);
if (!data) {
ret = EIO;
goto Finish;
}
item = ext4_xattr_item_alloc(entry->e_name_index, e_name,
(size_t)entry->e_name_len);
if (!item) {
ret = ENOMEM;
goto Finish;
}
if (ext4_xattr_item_alloc_data(
item, data, to_le32(entry->e_value_size)) != EOK) {
ext4_xattr_item_free(item);
ret = ENOMEM;
goto Finish;
}
item->in_inode = true;
RB_INSERT(ext4_xattr_tree, &xattr_ref->root, item);
xattr_ref->inode_size_rem -=
EXT4_XATTR_SIZE(item->data_size) +
EXT4_XATTR_LEN(item->name_len);
xattr_ref->ea_size += EXT4_XATTR_SIZE(item->data_size) +
EXT4_XATTR_LEN(item->name_len);
}
Finish:
return ret;
}
static size_t ext4_xattr_inode_space(struct ext4_xattr_ref *xattr_ref)
{
uint16_t inode_size = ext4_get16(&xattr_ref->fs->sb, inode_size);
uint16_t extra_isize = ext4_inode_get_extra_isize(&xattr_ref->fs->sb,
xattr_ref->inode_ref->inode);
uint16_t size_rem = inode_size - EXT4_GOOD_OLD_INODE_SIZE -
extra_isize;
return size_rem;
}
static size_t ext4_xattr_block_space(struct ext4_xattr_ref *xattr_ref)
{
return ext4_sb_get_block_size(&xattr_ref->fs->sb);
}
static int ext4_xattr_fetch(struct ext4_xattr_ref *xattr_ref)
{
int ret = EOK;
uint16_t inode_size = ext4_get16(&xattr_ref->fs->sb, inode_size);
if (inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
ret = ext4_xattr_inode_fetch(xattr_ref);
if (ret != EOK)
return ret;
}
if (xattr_ref->block_loaded)
ret = ext4_xattr_block_fetch(xattr_ref);
xattr_ref->dirty = false;
return ret;
}
static struct ext4_xattr_item *
ext4_xattr_lookup_item(struct ext4_xattr_ref *xattr_ref, uint8_t name_index,
const char *name, size_t name_len)
{
struct ext4_xattr_item tmp = {
.name_index = name_index,
.name = (char *)name, /*RB_FIND - won't touch this string*/
.name_len = name_len,
};
if (name_index == EXT4_XATTR_INDEX_SYSTEM &&
name_len == 4 &&
!memcmp(name, "data", 4))
tmp.is_data = true;
return RB_FIND(ext4_xattr_tree, &xattr_ref->root, &tmp);
}
static struct ext4_xattr_item *
ext4_xattr_insert_item(struct ext4_xattr_ref *xattr_ref, uint8_t name_index,
const char *name, size_t name_len, const void *data,
size_t data_size)
{
struct ext4_xattr_item *item;
item = ext4_xattr_item_alloc(name_index, name, name_len);
if (!item)
return NULL;
if ((xattr_ref->ea_size + EXT4_XATTR_SIZE(data_size) +
EXT4_XATTR_LEN(item->name_len)
>
ext4_xattr_inode_space(xattr_ref) -
sizeof(struct ext4_xattr_ibody_header))
&&
(xattr_ref->ea_size + EXT4_XATTR_SIZE(data_size) +
EXT4_XATTR_LEN(item->name_len) >
ext4_xattr_block_space(xattr_ref) -
sizeof(struct ext4_xattr_header))) {
ext4_xattr_item_free(item);
return NULL;
}
item->in_inode = true;
if (xattr_ref->inode_size_rem -
(int32_t)EXT4_XATTR_SIZE(data_size) -
(int32_t)EXT4_XATTR_LEN(item->name_len) < 0) {
if (xattr_ref->block_size_rem -
(int32_t)EXT4_XATTR_SIZE(data_size) -
(int32_t)EXT4_XATTR_LEN(item->name_len) < 0)
return NULL;
item->in_inode = false;
}
if (ext4_xattr_item_alloc_data(item, data, data_size) != EOK) {
ext4_xattr_item_free(item);
return NULL;
}
RB_INSERT(ext4_xattr_tree, &xattr_ref->root, item);
xattr_ref->ea_size +=
EXT4_XATTR_SIZE(item->data_size) + EXT4_XATTR_LEN(item->name_len);
if (item->in_inode) {
xattr_ref->inode_size_rem -=
EXT4_XATTR_SIZE(item->data_size) +
EXT4_XATTR_LEN(item->name_len);
} else {
xattr_ref->block_size_rem -=
EXT4_XATTR_SIZE(item->data_size) +
EXT4_XATTR_LEN(item->name_len);
}
xattr_ref->dirty = true;
return item;
}
static int ext4_xattr_remove_item(struct ext4_xattr_ref *xattr_ref,
uint8_t name_index, const char *name,
size_t name_len)
{
int ret = ENOENT;
struct ext4_xattr_item *item =
ext4_xattr_lookup_item(xattr_ref, name_index, name, name_len);
if (item) {
if (item == xattr_ref->iter_from)
xattr_ref->iter_from =
RB_NEXT(ext4_xattr_tree, &xattr_ref->root, item);
xattr_ref->ea_size -= EXT4_XATTR_SIZE(item->data_size) +
EXT4_XATTR_LEN(item->name_len);
if (item->in_inode) {
xattr_ref->inode_size_rem +=
EXT4_XATTR_SIZE(item->data_size) +
EXT4_XATTR_LEN(item->name_len);
} else {
xattr_ref->block_size_rem +=
EXT4_XATTR_SIZE(item->data_size) +
EXT4_XATTR_LEN(item->name_len);
}
RB_REMOVE(ext4_xattr_tree, &xattr_ref->root, item);
ext4_xattr_item_free(item);
xattr_ref->dirty = true;
ret = EOK;
}
return ret;
}
static int ext4_xattr_resize_item(struct ext4_xattr_ref *xattr_ref,
struct ext4_xattr_item *item,
size_t new_data_size)
{
int ret = EOK;
bool to_inode = false, to_block = false;
size_t old_data_size = item->data_size;
int32_t orig_room_size = item->in_inode ?
xattr_ref->inode_size_rem :
xattr_ref->block_size_rem;
/*
* Check if we can hold this entry in both in-inode and
* on-block form
*/
if ((xattr_ref->ea_size - EXT4_XATTR_SIZE(old_data_size) +
EXT4_XATTR_SIZE(new_data_size)
>
ext4_xattr_inode_space(xattr_ref) -
sizeof(struct ext4_xattr_ibody_header))
&&
(xattr_ref->ea_size - EXT4_XATTR_SIZE(old_data_size) +
EXT4_XATTR_SIZE(new_data_size)
>
ext4_xattr_block_space(xattr_ref) -
sizeof(struct ext4_xattr_header))) {
return ENOSPC;
}
/*
* More complicated case: we do not allow entries stucking in
* the middle between in-inode space and on-block space, so
* the entry has to stay in either inode space or block space.
*/
if (item->in_inode) {
if (xattr_ref->inode_size_rem +
(int32_t)EXT4_XATTR_SIZE(old_data_size) -
(int32_t)EXT4_XATTR_SIZE(new_data_size) < 0) {
if (xattr_ref->block_size_rem -
(int32_t)EXT4_XATTR_SIZE(new_data_size) -
(int32_t)EXT4_XATTR_LEN(item->name_len) < 0)
return ENOSPC;
to_block = true;
}
} else {
if (xattr_ref->block_size_rem +
(int32_t)EXT4_XATTR_SIZE(old_data_size) -
(int32_t)EXT4_XATTR_SIZE(new_data_size) < 0) {
if (xattr_ref->inode_size_rem -
(int32_t)EXT4_XATTR_SIZE(new_data_size) -
(int32_t)EXT4_XATTR_LEN(item->name_len) < 0)
return ENOSPC;
to_inode = true;
}
}
ret = ext4_xattr_item_resize_data(item, new_data_size);
if (ret != EOK)
return ret;
xattr_ref->ea_size =
xattr_ref->ea_size -
EXT4_XATTR_SIZE(old_data_size) +
EXT4_XATTR_SIZE(new_data_size);
/*
* This entry may originally lie in inode space or block space,
* and it is going to be transferred to another place.
*/
if (to_block) {
xattr_ref->inode_size_rem +=
EXT4_XATTR_SIZE(old_data_size) +
EXT4_XATTR_LEN(item->name_len);
xattr_ref->block_size_rem -=
EXT4_XATTR_SIZE(new_data_size) +
EXT4_XATTR_LEN(item->name_len);
item->in_inode = false;
} else if (to_inode) {
xattr_ref->block_size_rem +=
EXT4_XATTR_SIZE(old_data_size) +
EXT4_XATTR_LEN(item->name_len);
xattr_ref->inode_size_rem -=
EXT4_XATTR_SIZE(new_data_size) +
EXT4_XATTR_LEN(item->name_len);
item->in_inode = true;
} else {
/*
* No need to transfer as there is enough space for the entry
* to stay in inode space or block space it used to be.
*/
orig_room_size +=
EXT4_XATTR_SIZE(old_data_size);
orig_room_size -=
EXT4_XATTR_SIZE(new_data_size);
if (item->in_inode)
xattr_ref->inode_size_rem = orig_room_size;
else
xattr_ref->block_size_rem = orig_room_size;
}
xattr_ref->dirty = true;
return ret;
}
static void ext4_xattr_purge_items(struct ext4_xattr_ref *xattr_ref)
{
struct ext4_xattr_item *item, *save_item;
RB_FOREACH_SAFE(item, ext4_xattr_tree, &xattr_ref->root, save_item) {
RB_REMOVE(ext4_xattr_tree, &xattr_ref->root, item);
ext4_xattr_item_free(item);
}
xattr_ref->ea_size = 0;
xattr_ref->inode_size_rem = ext4_xattr_inode_space(xattr_ref) -
sizeof(struct ext4_xattr_ibody_header);
if (xattr_ref->inode_size_rem < 0)
xattr_ref->inode_size_rem = 0;
xattr_ref->block_size_rem = ext4_xattr_block_space(xattr_ref) -
sizeof(struct ext4_xattr_header);
}
static int ext4_xattr_try_alloc_block(struct ext4_xattr_ref *xattr_ref)
{
int ret = EOK;
ext4_fsblk_t xattr_block = 0;
xattr_block = ext4_inode_get_file_acl(xattr_ref->inode_ref->inode,
&xattr_ref->fs->sb);
if (!xattr_block) {
ext4_fsblk_t goal =
ext4_fs_inode_to_goal_block(xattr_ref->inode_ref);
ret = ext4_balloc_alloc_block(xattr_ref->inode_ref,
goal,
&xattr_block);
if (ret != EOK)
goto Finish;
ret = ext4_trans_block_get(xattr_ref->fs->bdev, &xattr_ref->block,
xattr_block);
if (ret != EOK) {
ext4_balloc_free_block(xattr_ref->inode_ref,
xattr_block);
goto Finish;
}
ext4_inode_set_file_acl(xattr_ref->inode_ref->inode,
&xattr_ref->fs->sb, xattr_block);
xattr_ref->inode_ref->dirty = true;
xattr_ref->block_loaded = true;
}
Finish:
return ret;
}
static void ext4_xattr_try_free_block(struct ext4_xattr_ref *xattr_ref)
{
ext4_fsblk_t xattr_block;
xattr_block = ext4_inode_get_file_acl(xattr_ref->inode_ref->inode,
&xattr_ref->fs->sb);
ext4_inode_set_file_acl(xattr_ref->inode_ref->inode, &xattr_ref->fs->sb,
0);
ext4_block_set(xattr_ref->fs->bdev, &xattr_ref->block);
ext4_balloc_free_block(xattr_ref->inode_ref, xattr_block);
xattr_ref->inode_ref->dirty = true;
xattr_ref->block_loaded = false;
}
static void ext4_xattr_set_block_header(struct ext4_xattr_ref *xattr_ref)
{
struct ext4_xattr_header *block_header = NULL;
block_header = EXT4_XATTR_BHDR(&xattr_ref->block);
memset(block_header, 0, sizeof(struct ext4_xattr_header));
block_header->h_magic = EXT4_XATTR_MAGIC;
block_header->h_refcount = to_le32(1);
block_header->h_blocks = to_le32(1);
}
static void
ext4_xattr_set_inode_entry(struct ext4_xattr_item *item,
struct ext4_xattr_ibody_header *ibody_header,
struct ext4_xattr_entry *entry, void *ibody_data_ptr)
{
entry->e_name_len = (uint8_t)item->name_len;
entry->e_name_index = item->name_index;
entry->e_value_offs =
to_le16((char *)ibody_data_ptr - (char *)EXT4_XATTR_IFIRST(ibody_header));
entry->e_value_block = 0;
entry->e_value_size = to_le32(item->data_size);
}
static void ext4_xattr_set_block_entry(struct ext4_xattr_item *item,
struct ext4_xattr_header *block_header,
struct ext4_xattr_entry *block_entry,
void *block_data_ptr)
{
block_entry->e_name_len = (uint8_t)item->name_len;
block_entry->e_name_index = item->name_index;
block_entry->e_value_offs =
to_le16((char *)block_data_ptr - (char *)block_header);
block_entry->e_value_block = 0;
block_entry->e_value_size = to_le32(item->data_size);
}
static int ext4_xattr_write_to_disk(struct ext4_xattr_ref *xattr_ref)
{
int ret = EOK;
bool block_modified = false;
void *ibody_data = NULL;
void *block_data = NULL;
struct ext4_xattr_item *item, *save_item;
size_t inode_size_rem, block_size_rem;
struct ext4_xattr_ibody_header *ibody_header = NULL;
struct ext4_xattr_header *block_header = NULL;
struct ext4_xattr_entry *entry = NULL;
struct ext4_xattr_entry *block_entry = NULL;
inode_size_rem = ext4_xattr_inode_space(xattr_ref);
block_size_rem = ext4_xattr_block_space(xattr_ref);
if (inode_size_rem > sizeof(struct ext4_xattr_ibody_header)) {
ibody_header = EXT4_XATTR_IHDR(&xattr_ref->fs->sb,
xattr_ref->inode_ref->inode);
entry = EXT4_XATTR_IFIRST(ibody_header);
}
if (!xattr_ref->dirty)
goto Finish;
/* If there are enough spaces in the ibody EA table.*/
if (inode_size_rem > sizeof(struct ext4_xattr_ibody_header)) {
memset(ibody_header, 0, inode_size_rem);
ibody_header->h_magic = EXT4_XATTR_MAGIC;
ibody_data = (char *)ibody_header + inode_size_rem;
inode_size_rem -= sizeof(struct ext4_xattr_ibody_header);
xattr_ref->inode_ref->dirty = true;
}
/* If we need an extra block to hold the EA entries*/
if (xattr_ref->ea_size > inode_size_rem) {
if (!xattr_ref->block_loaded) {
ret = ext4_xattr_try_alloc_block(xattr_ref);
if (ret != EOK)
goto Finish;
}
memset(xattr_ref->block.data, 0,
ext4_sb_get_block_size(&xattr_ref->fs->sb));
block_header = EXT4_XATTR_BHDR(&xattr_ref->block);
block_entry = EXT4_XATTR_BFIRST(&xattr_ref->block);
ext4_xattr_set_block_header(xattr_ref);
block_data = (char *)block_header + block_size_rem;
block_size_rem -= sizeof(struct ext4_xattr_header);
ext4_trans_set_block_dirty(xattr_ref->block.buf);
} else {
/* We don't need an extra block.*/
if (xattr_ref->block_loaded) {
block_header = EXT4_XATTR_BHDR(&xattr_ref->block);
block_header->h_refcount =
to_le32(to_le32(block_header->h_refcount) - 1);
if (!block_header->h_refcount) {
ext4_xattr_try_free_block(xattr_ref);
block_header = NULL;
} else {
block_entry =
EXT4_XATTR_BFIRST(&xattr_ref->block);
block_data =
(char *)block_header + block_size_rem;
block_size_rem -=
sizeof(struct ext4_xattr_header);
ext4_inode_set_file_acl(
xattr_ref->inode_ref->inode,
&xattr_ref->fs->sb, 0);
xattr_ref->inode_ref->dirty = true;
ext4_trans_set_block_dirty(xattr_ref->block.buf);
}
}
}
RB_FOREACH_SAFE(item, ext4_xattr_tree, &xattr_ref->root, save_item)
{
if (EXT4_XATTR_SIZE(item->data_size) +
EXT4_XATTR_LEN(item->name_len) <=
inode_size_rem) {
ibody_data = (char *)ibody_data -
EXT4_XATTR_SIZE(item->data_size);
ext4_xattr_set_inode_entry(item, ibody_header, entry,
ibody_data);
memcpy(EXT4_XATTR_NAME(entry), item->name,
item->name_len);
memcpy(ibody_data, item->data, item->data_size);
entry = EXT4_XATTR_NEXT(entry);
inode_size_rem -= EXT4_XATTR_SIZE(item->data_size) +
EXT4_XATTR_LEN(item->name_len);
xattr_ref->inode_ref->dirty = true;
continue;
}
if (EXT4_XATTR_SIZE(item->data_size) +
EXT4_XATTR_LEN(item->name_len) >
block_size_rem) {
ret = ENOSPC;
ext4_dbg(DEBUG_XATTR, "IMPOSSIBLE ENOSPC AS WE DID INSPECTION!\n");
ext4_assert(0);
}
block_data =
(char *)block_data - EXT4_XATTR_SIZE(item->data_size);
ext4_xattr_set_block_entry(item, block_header, block_entry,
block_data);
memcpy(EXT4_XATTR_NAME(block_entry), item->name,
item->name_len);
memcpy(block_data, item->data, item->data_size);
block_entry = EXT4_XATTR_NEXT(block_entry);
block_size_rem -= EXT4_XATTR_SIZE(item->data_size) +
EXT4_XATTR_LEN(item->name_len);
block_modified = true;
}
xattr_ref->dirty = false;
if (block_modified) {
ext4_xattr_rehash(block_header,
EXT4_XATTR_BFIRST(&xattr_ref->block));
ext4_xattr_set_block_checksum(xattr_ref->inode_ref,
xattr_ref->block.lb_id,
block_header);
ext4_trans_set_block_dirty(xattr_ref->block.buf);
}
Finish:
return ret;
}
void ext4_fs_xattr_iterate(struct ext4_xattr_ref *ref,
int (*iter)(struct ext4_xattr_ref *ref,
struct ext4_xattr_item *item))
{
struct ext4_xattr_item *item;
if (!ref->iter_from)
ref->iter_from = RB_MIN(ext4_xattr_tree, &ref->root);
RB_FOREACH_FROM(item, ext4_xattr_tree, ref->iter_from)
{
int ret = EXT4_XATTR_ITERATE_CONT;
if (iter)
iter(ref, item);
if (ret != EXT4_XATTR_ITERATE_CONT) {
if (ret == EXT4_XATTR_ITERATE_STOP)
ref->iter_from = NULL;
break;
}
}
}
void ext4_fs_xattr_iterate_reset(struct ext4_xattr_ref *ref)
{
ref->iter_from = NULL;
}
int ext4_fs_set_xattr(struct ext4_xattr_ref *ref, uint8_t name_index,
const char *name, size_t name_len, const void *data,
size_t data_size, bool replace)
{
int ret = EOK;
struct ext4_xattr_item *item =
ext4_xattr_lookup_item(ref, name_index, name, name_len);
if (replace) {
if (!item) {
ret = ENODATA;
goto Finish;
}
if (item->data_size != data_size)
ret = ext4_xattr_resize_item(ref, item, data_size);
if (ret != EOK) {
goto Finish;
}
memcpy(item->data, data, data_size);
} else {
if (item) {
ret = EEXIST;
goto Finish;
}
item = ext4_xattr_insert_item(ref, name_index, name, name_len,
data, data_size);
if (!item)
ret = ENOMEM;
}
Finish:
return ret;
}
int ext4_fs_remove_xattr(struct ext4_xattr_ref *ref, uint8_t name_index,
const char *name, size_t name_len)
{
return ext4_xattr_remove_item(ref, name_index, name, name_len);
}
int ext4_fs_get_xattr(struct ext4_xattr_ref *ref, uint8_t name_index,
const char *name, size_t name_len, void *buf,
size_t buf_size, size_t *data_size)
{
int ret = EOK;
size_t item_size = 0;
struct ext4_xattr_item *item =
ext4_xattr_lookup_item(ref, name_index, name, name_len);
if (!item) {
ret = ENODATA;
goto Finish;
}
item_size = item->data_size;
if (buf_size > item_size)
buf_size = item_size;
if (buf)
memcpy(buf, item->data, buf_size);
Finish:
if (data_size)
*data_size = item_size;
return ret;
}
int ext4_fs_get_xattr_ref(struct ext4_fs *fs, struct ext4_inode_ref *inode_ref,
struct ext4_xattr_ref *ref)
{
int rc;
ext4_fsblk_t xattr_block;
xattr_block = ext4_inode_get_file_acl(inode_ref->inode, &fs->sb);
RB_INIT(&ref->root);
ref->ea_size = 0;
ref->iter_from = NULL;
if (xattr_block) {
rc = ext4_trans_block_get(fs->bdev, &ref->block, xattr_block);
if (rc != EOK)
return EIO;
ref->block_loaded = true;
} else
ref->block_loaded = false;
ref->inode_ref = inode_ref;
ref->fs = fs;
ref->inode_size_rem = ext4_xattr_inode_space(ref) -
sizeof(struct ext4_xattr_ibody_header);
if (ref->inode_size_rem < 0)
ref->inode_size_rem = 0;
ref->block_size_rem = ext4_xattr_block_space(ref) -
sizeof(struct ext4_xattr_header);
rc = ext4_xattr_fetch(ref);
if (rc != EOK) {
ext4_xattr_purge_items(ref);
if (xattr_block)
ext4_block_set(fs->bdev, &ref->block);
ref->block_loaded = false;
return rc;
}
return EOK;
}
void ext4_fs_put_xattr_ref(struct ext4_xattr_ref *ref)
{
ext4_xattr_write_to_disk(ref);
if (ref->block_loaded) {
ext4_block_set(ref->fs->bdev, &ref->block);
ref->block_loaded = false;
}
ext4_xattr_purge_items(ref);
ref->inode_ref = NULL;
ref->fs = NULL;
}
struct xattr_prefix {
const char *prefix;
uint8_t name_index;
};
static const struct xattr_prefix prefix_tbl[] = {
{"user.", EXT4_XATTR_INDEX_USER},
{"system.posix_acl_access", EXT4_XATTR_INDEX_POSIX_ACL_ACCESS},
{"system.posix_acl_default", EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT},
{"trusted.", EXT4_XATTR_INDEX_TRUSTED},
{"security.", EXT4_XATTR_INDEX_SECURITY},
{"system.", EXT4_XATTR_INDEX_SYSTEM},
{"system.richacl", EXT4_XATTR_INDEX_RICHACL},
{NULL, 0},
};
const char *ext4_extract_xattr_name(const char *full_name, size_t full_name_len,
uint8_t *name_index, size_t *name_len,
bool *found)
{
int i;
ext4_assert(name_index);
ext4_assert(found);
*found = false;
if (!full_name_len) {
if (name_len)
*name_len = 0;
return NULL;
}
for (i = 0; prefix_tbl[i].prefix; i++) {
size_t prefix_len = strlen(prefix_tbl[i].prefix);
if (full_name_len >= prefix_len &&
!memcmp(full_name, prefix_tbl[i].prefix, prefix_len)) {
bool require_name =
prefix_tbl[i].prefix[prefix_len - 1] == '.';
*name_index = prefix_tbl[i].name_index;
if (name_len)
*name_len = full_name_len - prefix_len;
if (!(full_name_len - prefix_len) && require_name)
return NULL;
*found = true;
if (require_name)
return full_name + prefix_len;
return NULL;
}
}
if (name_len)
*name_len = 0;
return NULL;
}
const char *ext4_get_xattr_name_prefix(uint8_t name_index,
size_t *ret_prefix_len)
{
int i;
for (i = 0; prefix_tbl[i].prefix; i++) {
size_t prefix_len = strlen(prefix_tbl[i].prefix);
if (prefix_tbl[i].name_index == name_index) {
if (ret_prefix_len)
*ret_prefix_len = prefix_len;
return prefix_tbl[i].prefix;
}
}
if (ret_prefix_len)
*ret_prefix_len = 0;
return NULL;
}
/**
* @}
*/