384 lines
7.9 KiB
C
384 lines
7.9 KiB
C
// SPDX-License-Identifier: GPL-2.0+
|
|
/*
|
|
* BTRFS filesystem implementation for U-Boot
|
|
*
|
|
* 2017 Marek Behun, CZ.NIC, marek.behun@nic.cz
|
|
*/
|
|
|
|
#include "btrfs.h"
|
|
#include <malloc.h>
|
|
|
|
u64 btrfs_lookup_inode_ref(struct btrfs_root *root, u64 inr,
|
|
struct btrfs_inode_ref *refp, char *name)
|
|
{
|
|
struct btrfs_path path;
|
|
struct btrfs_key *key;
|
|
struct btrfs_inode_ref *ref;
|
|
u64 res = -1ULL;
|
|
|
|
key = btrfs_search_tree_key_type(root, inr, BTRFS_INODE_REF_KEY,
|
|
&path);
|
|
|
|
if (!key)
|
|
return -1ULL;
|
|
|
|
ref = btrfs_path_item_ptr(&path, struct btrfs_inode_ref);
|
|
btrfs_inode_ref_to_cpu(ref);
|
|
|
|
if (refp)
|
|
*refp = *ref;
|
|
|
|
if (name) {
|
|
if (ref->name_len > BTRFS_NAME_MAX) {
|
|
printf("%s: inode name too long: %u\n", __func__,
|
|
ref->name_len);
|
|
goto out;
|
|
}
|
|
|
|
memcpy(name, ref + 1, ref->name_len);
|
|
}
|
|
|
|
res = key->offset;
|
|
out:
|
|
btrfs_free_path(&path);
|
|
return res;
|
|
}
|
|
|
|
int btrfs_lookup_inode(const struct btrfs_root *root,
|
|
struct btrfs_key *location,
|
|
struct btrfs_inode_item *item,
|
|
struct btrfs_root *new_root)
|
|
{
|
|
struct btrfs_root tmp_root = *root;
|
|
struct btrfs_path path;
|
|
int res = -1;
|
|
|
|
if (location->type == BTRFS_ROOT_ITEM_KEY) {
|
|
if (btrfs_find_root(location->objectid, &tmp_root, NULL))
|
|
return -1;
|
|
|
|
location->objectid = tmp_root.root_dirid;
|
|
location->type = BTRFS_INODE_ITEM_KEY;
|
|
location->offset = 0;
|
|
}
|
|
|
|
if (btrfs_search_tree(&tmp_root, location, &path))
|
|
return res;
|
|
|
|
if (btrfs_comp_keys(location, btrfs_path_leaf_key(&path)))
|
|
goto out;
|
|
|
|
if (item) {
|
|
*item = *btrfs_path_item_ptr(&path, struct btrfs_inode_item);
|
|
btrfs_inode_item_to_cpu(item);
|
|
}
|
|
|
|
if (new_root)
|
|
*new_root = tmp_root;
|
|
|
|
res = 0;
|
|
|
|
out:
|
|
btrfs_free_path(&path);
|
|
return res;
|
|
}
|
|
|
|
int btrfs_readlink(const struct btrfs_root *root, u64 inr, char *target)
|
|
{
|
|
struct btrfs_path path;
|
|
struct btrfs_key key;
|
|
struct btrfs_file_extent_item *extent;
|
|
const char *data_ptr;
|
|
int res = -1;
|
|
|
|
key.objectid = inr;
|
|
key.type = BTRFS_EXTENT_DATA_KEY;
|
|
key.offset = 0;
|
|
|
|
if (btrfs_search_tree(root, &key, &path))
|
|
return -1;
|
|
|
|
if (btrfs_comp_keys(&key, btrfs_path_leaf_key(&path)))
|
|
goto out;
|
|
|
|
extent = btrfs_path_item_ptr(&path, struct btrfs_file_extent_item);
|
|
if (extent->type != BTRFS_FILE_EXTENT_INLINE) {
|
|
printf("%s: Extent for symlink %llu not of INLINE type\n",
|
|
__func__, inr);
|
|
goto out;
|
|
}
|
|
|
|
btrfs_file_extent_item_to_cpu_inl(extent);
|
|
|
|
if (extent->compression != BTRFS_COMPRESS_NONE) {
|
|
printf("%s: Symlink %llu extent data compressed!\n", __func__,
|
|
inr);
|
|
goto out;
|
|
} else if (extent->encryption != 0) {
|
|
printf("%s: Symlink %llu extent data encrypted!\n", __func__,
|
|
inr);
|
|
goto out;
|
|
} else if (extent->ram_bytes >= btrfs_info.sb.sectorsize) {
|
|
printf("%s: Symlink %llu extent data too long (%llu)!\n",
|
|
__func__, inr, extent->ram_bytes);
|
|
goto out;
|
|
}
|
|
|
|
data_ptr = (const char *) extent
|
|
+ offsetof(struct btrfs_file_extent_item, disk_bytenr);
|
|
|
|
memcpy(target, data_ptr, extent->ram_bytes);
|
|
target[extent->ram_bytes] = '\0';
|
|
res = 0;
|
|
out:
|
|
btrfs_free_path(&path);
|
|
return res;
|
|
}
|
|
|
|
/* inr must be a directory (for regular files with multiple hard links this
|
|
function returns only one of the parents of the file) */
|
|
static u64 get_parent_inode(struct btrfs_root *root, u64 inr,
|
|
struct btrfs_inode_item *inode_item)
|
|
{
|
|
struct btrfs_key key;
|
|
u64 res;
|
|
|
|
if (inr == BTRFS_FIRST_FREE_OBJECTID) {
|
|
if (root->objectid != btrfs_info.fs_root.objectid) {
|
|
u64 parent;
|
|
struct btrfs_root_ref ref;
|
|
|
|
parent = btrfs_lookup_root_ref(root->objectid, &ref,
|
|
NULL);
|
|
if (parent == -1ULL)
|
|
return -1ULL;
|
|
|
|
if (btrfs_find_root(parent, root, NULL))
|
|
return -1ULL;
|
|
|
|
inr = ref.dirid;
|
|
}
|
|
|
|
if (inode_item) {
|
|
key.objectid = inr;
|
|
key.type = BTRFS_INODE_ITEM_KEY;
|
|
key.offset = 0;
|
|
|
|
if (btrfs_lookup_inode(root, &key, inode_item, NULL))
|
|
return -1ULL;
|
|
}
|
|
|
|
return inr;
|
|
}
|
|
|
|
res = btrfs_lookup_inode_ref(root, inr, NULL, NULL);
|
|
if (res == -1ULL)
|
|
return -1ULL;
|
|
|
|
if (inode_item) {
|
|
key.objectid = res;
|
|
key.type = BTRFS_INODE_ITEM_KEY;
|
|
key.offset = 0;
|
|
|
|
if (btrfs_lookup_inode(root, &key, inode_item, NULL))
|
|
return -1ULL;
|
|
}
|
|
|
|
return res;
|
|
}
|
|
|
|
static inline int next_length(const char *path)
|
|
{
|
|
int res = 0;
|
|
while (*path != '\0' && *path != '/' && res <= BTRFS_NAME_LEN)
|
|
++res, ++path;
|
|
return res;
|
|
}
|
|
|
|
static inline const char *skip_current_directories(const char *cur)
|
|
{
|
|
while (1) {
|
|
if (cur[0] == '/')
|
|
++cur;
|
|
else if (cur[0] == '.' && cur[1] == '/')
|
|
cur += 2;
|
|
else
|
|
break;
|
|
}
|
|
|
|
return cur;
|
|
}
|
|
|
|
u64 btrfs_lookup_path(struct btrfs_root *root, u64 inr, const char *path,
|
|
u8 *type_p, struct btrfs_inode_item *inode_item_p,
|
|
int symlink_limit)
|
|
{
|
|
struct btrfs_dir_item item;
|
|
struct btrfs_inode_item inode_item;
|
|
u8 type = BTRFS_FT_DIR;
|
|
int len, have_inode = 0;
|
|
const char *cur = path;
|
|
|
|
if (*cur == '/') {
|
|
++cur;
|
|
inr = root->root_dirid;
|
|
}
|
|
|
|
do {
|
|
cur = skip_current_directories(cur);
|
|
|
|
len = next_length(cur);
|
|
if (len > BTRFS_NAME_LEN) {
|
|
printf("%s: Name too long at \"%.*s\"\n", __func__,
|
|
BTRFS_NAME_LEN, cur);
|
|
return -1ULL;
|
|
}
|
|
|
|
if (len == 1 && cur[0] == '.')
|
|
break;
|
|
|
|
if (len == 2 && cur[0] == '.' && cur[1] == '.') {
|
|
cur += 2;
|
|
inr = get_parent_inode(root, inr, &inode_item);
|
|
if (inr == -1ULL)
|
|
return -1ULL;
|
|
|
|
type = BTRFS_FT_DIR;
|
|
continue;
|
|
}
|
|
|
|
if (!*cur)
|
|
break;
|
|
|
|
if (btrfs_lookup_dir_item(root, inr, cur, len, &item))
|
|
return -1ULL;
|
|
|
|
type = item.type;
|
|
have_inode = 1;
|
|
if (btrfs_lookup_inode(root, &item.location, &inode_item, root))
|
|
return -1ULL;
|
|
|
|
if (item.type == BTRFS_FT_SYMLINK && symlink_limit >= 0) {
|
|
char *target;
|
|
|
|
if (!symlink_limit) {
|
|
printf("%s: Too much symlinks!\n", __func__);
|
|
return -1ULL;
|
|
}
|
|
|
|
target = malloc(min(inode_item.size + 1,
|
|
(u64) btrfs_info.sb.sectorsize));
|
|
if (!target)
|
|
return -1ULL;
|
|
|
|
if (btrfs_readlink(root, item.location.objectid,
|
|
target)) {
|
|
free(target);
|
|
return -1ULL;
|
|
}
|
|
|
|
inr = btrfs_lookup_path(root, inr, target, &type,
|
|
&inode_item, symlink_limit - 1);
|
|
|
|
free(target);
|
|
|
|
if (inr == -1ULL)
|
|
return -1ULL;
|
|
} else if (item.type != BTRFS_FT_DIR && cur[len]) {
|
|
printf("%s: \"%.*s\" not a directory\n", __func__,
|
|
(int) (cur - path + len), path);
|
|
return -1ULL;
|
|
} else {
|
|
inr = item.location.objectid;
|
|
}
|
|
|
|
cur += len;
|
|
} while (*cur);
|
|
|
|
if (type_p)
|
|
*type_p = type;
|
|
|
|
if (inode_item_p) {
|
|
if (!have_inode) {
|
|
struct btrfs_key key;
|
|
|
|
key.objectid = inr;
|
|
key.type = BTRFS_INODE_ITEM_KEY;
|
|
key.offset = 0;
|
|
|
|
if (btrfs_lookup_inode(root, &key, &inode_item, NULL))
|
|
return -1ULL;
|
|
}
|
|
|
|
*inode_item_p = inode_item;
|
|
}
|
|
|
|
return inr;
|
|
}
|
|
|
|
u64 btrfs_file_read(const struct btrfs_root *root, u64 inr, u64 offset,
|
|
u64 size, char *buf)
|
|
{
|
|
struct btrfs_path path;
|
|
struct btrfs_key key;
|
|
struct btrfs_file_extent_item *extent;
|
|
int res = 0;
|
|
u64 rd, rd_all = -1ULL;
|
|
|
|
key.objectid = inr;
|
|
key.type = BTRFS_EXTENT_DATA_KEY;
|
|
key.offset = offset;
|
|
|
|
if (btrfs_search_tree(root, &key, &path))
|
|
return -1ULL;
|
|
|
|
if (btrfs_comp_keys(&key, btrfs_path_leaf_key(&path)) < 0) {
|
|
if (btrfs_prev_slot(&path))
|
|
goto out;
|
|
|
|
if (btrfs_comp_keys_type(&key, btrfs_path_leaf_key(&path)))
|
|
goto out;
|
|
}
|
|
|
|
rd_all = 0;
|
|
|
|
do {
|
|
if (btrfs_comp_keys_type(&key, btrfs_path_leaf_key(&path)))
|
|
break;
|
|
|
|
extent = btrfs_path_item_ptr(&path,
|
|
struct btrfs_file_extent_item);
|
|
|
|
if (extent->type == BTRFS_FILE_EXTENT_INLINE) {
|
|
btrfs_file_extent_item_to_cpu_inl(extent);
|
|
rd = btrfs_read_extent_inline(&path, extent, offset,
|
|
size, buf);
|
|
} else {
|
|
btrfs_file_extent_item_to_cpu(extent);
|
|
rd = btrfs_read_extent_reg(&path, extent, offset, size,
|
|
buf);
|
|
}
|
|
|
|
if (rd == -1ULL) {
|
|
printf("%s: Error reading extent\n", __func__);
|
|
rd_all = -1;
|
|
goto out;
|
|
}
|
|
|
|
offset = 0;
|
|
buf += rd;
|
|
rd_all += rd;
|
|
size -= rd;
|
|
|
|
if (!size)
|
|
break;
|
|
} while (!(res = btrfs_next_slot(&path)));
|
|
|
|
if (res)
|
|
return -1ULL;
|
|
|
|
out:
|
|
btrfs_free_path(&path);
|
|
return rd_all;
|
|
}
|