blob: 007cf32c1603beadf6af05fe581d9185edf8faf9 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0+
/*
* BTRFS filesystem implementation for U-Boot
*
* 2017 Marek Behun, CZ.NIC, marek.behun@nic.cz
*/
#include <malloc.h>
#include "btrfs.h"
#include "disk-io.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_LEN) {
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;
}
/*
* Read the content of symlink inode @ino of @root, into @target.
* NOTE: @target will not be \0 termiated, caller should handle it properly.
*
* Return the number of read data.
* Return <0 for error.
*/
int btrfs_readlink(struct btrfs_root *root, u64 ino, char *target)
{
struct btrfs_path path;
struct btrfs_key key;
struct btrfs_file_extent_item *fi;
int ret;
key.objectid = ino;
key.type = BTRFS_EXTENT_DATA_KEY;
key.offset = 0;
btrfs_init_path(&path);
ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
if (ret < 0)
return ret;
if (ret > 0) {
ret = -ENOENT;
goto out;
}
fi = btrfs_item_ptr(path.nodes[0], path.slots[0],
struct btrfs_file_extent_item);
if (btrfs_file_extent_type(path.nodes[0], fi) !=
BTRFS_FILE_EXTENT_INLINE) {
ret = -EUCLEAN;
error("Extent for symlink %llu must be INLINE type!", ino);
goto out;
}
if (btrfs_file_extent_compression(path.nodes[0], fi) !=
BTRFS_COMPRESS_NONE) {
ret = -EUCLEAN;
error("Extent for symlink %llu must not be compressed!", ino);
goto out;
}
if (btrfs_file_extent_ram_bytes(path.nodes[0], fi) >=
root->fs_info->sectorsize) {
ret = -EUCLEAN;
error("Symlink %llu extent data too large (%llu)!\n",
ino, btrfs_file_extent_ram_bytes(path.nodes[0], fi));
goto out;
}
read_extent_buffer(path.nodes[0], target,
btrfs_file_extent_inline_start(fi),
btrfs_file_extent_ram_bytes(path.nodes[0], fi));
ret = btrfs_file_extent_ram_bytes(path.nodes[0], fi);
out:
btrfs_release_path(&path);
return ret;
}
int __btrfs_readlink(const struct __btrfs_root *root, u64 inr, char *target)
{
struct btrfs_root *subvolume;
struct btrfs_fs_info *fs_info = current_fs_info;
struct btrfs_key key;
int ret;
ASSERT(fs_info);
key.objectid = root->objectid;
key.type = BTRFS_ROOT_ITEM_KEY;
key.offset = (u64)-1;
subvolume = btrfs_read_fs_root(fs_info, &key);
if (IS_ERR(subvolume))
return -1;
ret = btrfs_readlink(subvolume, inr, target);
if (ret < 0)
return -1;
target[ret] = '\0';
return 0;
}
/* 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, (struct btrfs_key *)&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;
}