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ext4_fs_set_xattr, ext4_fs_get_xattr and ext4_fs_remove_xattr introduced.(EXPERIMENTAL, POTENTIAL DEADLOCKgit add .

pull/8/head
ngkaho1234 9 years ago
parent
18bebd19be
commit
15ace36d9b
4 changed files with 173 additions and 12 deletions
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  1. 10
      lwext4/ext4.c
  2. 2
      lwext4/ext4_errno.h
  3. 152
      lwext4/ext4_xattr.c
  4. 21
      lwext4/ext4_xattr.h

10
lwext4/ext4.c
View File

@ -739,7 +739,17 @@ static int ext4_generic_open2(ext4_file *f, const char *path, int flags,
private_ret = ext4_fs_get_xattr_ref(&f->mp->fs, &ref,
&xattr_ref);
if (private_ret == EOK) {
#define EXT4_XATTR_TEST_DATA_SIZE 1024
#define EXT4_XATTR_TEST_NAME "bad_boy"
static char test_data[EXT4_XATTR_TEST_DATA_SIZE] = {'a'};
ext4_dmask_set(EXT4_DEBUG_ALL);
/*ext4_fs_set_xattr(&xattr_ref,*/
/*EXT4_XATTR_INDEX_USER,*/
/*EXT4_XATTR_TEST_NAME,*/
/*strlen(EXT4_XATTR_TEST_NAME),*/
/*test_data,*/
/*EXT4_XATTR_TEST_DATA_SIZE,*/
/*0);*/
ext4_fs_put_xattr_ref(&xattr_ref);
}
}

2
lwext4/ext4_errno.h
View File

@ -76,6 +76,8 @@
#define EDOM 33 /* Math argument out of domain of func */
#define ERANGE 34 /* Math result not representable */
#define ENOTEMPTY 39 /* Directory not empty */
#define ENODATA 61 /* No data available */
#define ENOATTR ENODATA /* No attribute available */
#define ENOTSUP 95 /* Not supported */
#endif

152
lwext4/ext4_xattr.c
View File

@ -90,6 +90,35 @@ ext4_xattr_compute_hash(struct ext4_xattr_header *header,
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);
}
static int ext4_xattr_item_cmp(struct ext4_xattr_item *a,
struct ext4_xattr_item *b)
{
@ -260,7 +289,8 @@ static int ext4_xattr_block_fetch(struct ext4_xattr_ref *xattr_ref)
goto Finish;
}
RB_INSERT(ext4_xattr_tree, &xattr_ref->root, item);
xattr_ref->ea_size += item->data_size;
xattr_ref->ea_size += EXT4_XATTR_SIZE(item->data_size) +
EXT4_XATTR_LEN(item->name_len);
}
Finish:
@ -312,7 +342,8 @@ static int ext4_xattr_inode_fetch(struct ext4_xattr_ref *xattr_ref)
goto Finish;
}
RB_INSERT(ext4_xattr_tree, &xattr_ref->root, item);
xattr_ref->ea_size += item->data_size;
xattr_ref->ea_size += EXT4_XATTR_SIZE(item->data_size) +
EXT4_XATTR_LEN(item->name_len);
}
Finish:
@ -379,14 +410,7 @@ ext4_xattr_insert_item(struct ext4_xattr_ref *xattr_ref,
void *data,
size_t data_size)
{
struct ext4_xattr_item *item =
ext4_xattr_lookup_item(xattr_ref,
name_index,
name,
name_len);
if (item)
return item;
struct ext4_xattr_item *item;
item = ext4_xattr_item_alloc(name_index,
name,
name_len);
@ -535,6 +559,7 @@ static int
ext4_xattr_write_to_disk(struct ext4_xattr_ref *xattr_ref)
{
int ret = EOK;
bool block_modified = false;
void *ibody_data, *block_data;
struct ext4_xattr_item *item, *save_item;
size_t inode_size_rem, block_size_rem;
@ -545,7 +570,7 @@ ext4_xattr_write_to_disk(struct ext4_xattr_ref *xattr_ref)
inode_size_rem = ext4_xattr_inode_space(xattr_ref);
block_size_rem = ext4_xattr_block_space(xattr_ref);
if (inode_size_rem) {
if (inode_size_rem > sizeof(struct ext4_xattr_ibody_header)) {
ibody_header = EXT4_XATTR_IHDR(xattr_ref->inode_ref->inode);
entry = EXT4_XATTR_IFIRST(ibody_header);
}
@ -557,6 +582,7 @@ ext4_xattr_write_to_disk(struct ext4_xattr_ref *xattr_ref)
ibody_header->h_magic = EXT4_XATTR_MAGIC;
xattr_ref->inode_ref->dirty = true;
ibody_data = (char *)ibody_header + inode_size_rem;
inode_size_rem -= sizeof(struct ext4_xattr_ibody_header);
}
/* If we need an extra block to hold the EA entries*/
if (xattr_ref->ea_size > inode_size_rem) {
@ -573,6 +599,7 @@ ext4_xattr_write_to_disk(struct ext4_xattr_ref *xattr_ref)
header->h_refcount = to_le32(1);
header->h_blocks = to_le32(1);
block_data = (char *)header + block_size_rem;
block_size_rem -= sizeof(struct ext4_xattr_header);
xattr_ref->block.dirty = true;
} else {
/* We don't need an extra block.*/
@ -587,6 +614,7 @@ ext4_xattr_write_to_disk(struct ext4_xattr_ref *xattr_ref)
xattr_ref->block.dirty = true;
block_entry = EXT4_XATTR_BFIRST(&xattr_ref->block);
block_data = (char *)header + block_size_rem;
block_size_rem -= sizeof(struct ext4_xattr_header);
}
}
}
@ -630,11 +658,109 @@ ext4_xattr_write_to_disk(struct ext4_xattr_ref *xattr_ref)
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(header,
EXT4_XATTR_BFIRST(&xattr_ref->block));
}
}
Finish:
return ret;
}
int ext4_fs_set_xattr(struct ext4_xattr_ref *ref,
uint8_t name_index,
char *name,
size_t name_len,
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 = ENOATTR;
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,
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,
char *name,
size_t name_len,
void *buf,
size_t buf_size,
size_t *size_got)
{
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 = ENOATTR;
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 (size_got)
*size_got = buf_size;
return ret;
}
@ -662,7 +788,8 @@ int ext4_fs_get_xattr_ref(struct ext4_fs *fs,
ref->inode_ref = inode_ref;
ref->fs = fs;
if (ext4_xattr_inode_space(ref))
if (ext4_xattr_inode_space(ref) >
sizeof(struct ext4_xattr_ibody_header))
ref->ea_size += sizeof(struct ext4_xattr_ibody_header);
rc = ext4_xattr_fetch(ref);
@ -683,6 +810,7 @@ void ext4_fs_put_xattr_ref(struct ext4_xattr_ref *ref)
ext4_block_set(ref->fs->bdev, &ref->block);
ref->block_loaded = false;
}
ext4_xattr_write_to_disk(ref);
ext4_xattr_purge_items(ref);
ref->inode_ref = NULL;
ref->fs = NULL;

21
lwext4/ext4_xattr.h
View File

@ -10,4 +10,25 @@ int ext4_fs_get_xattr_ref(struct ext4_fs *fs,
void ext4_fs_put_xattr_ref(struct ext4_xattr_ref *ref);
int ext4_fs_set_xattr(struct ext4_xattr_ref *ref,
uint8_t name_index,
char *name,
size_t name_len,
void *data,
size_t data_size,
bool replace);
int ext4_fs_remove_xattr(struct ext4_xattr_ref *ref,
uint8_t name_index,
char *name,
size_t name_len);
int ext4_fs_get_xattr(struct ext4_xattr_ref *ref,
uint8_t name_index,
char *name,
size_t name_len,
void *buf,
size_t buf_size,
size_t *size_got);
#endif

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