1 // SPDX-License-Identifier: GPL-2.0+
3 * BTRFS filesystem implementation for U-Boot
5 * 2017 Marek Behun, CZ.NIC, marek.behun@nic.cz
11 u64 btrfs_lookup_inode_ref(struct btrfs_root *root, u64 inr,
12 struct btrfs_inode_ref *refp, char *name)
14 struct btrfs_path path;
15 struct btrfs_key *key;
16 struct btrfs_inode_ref *ref;
19 key = btrfs_search_tree_key_type(root, inr, BTRFS_INODE_REF_KEY,
25 ref = btrfs_path_item_ptr(&path, struct btrfs_inode_ref);
26 btrfs_inode_ref_to_cpu(ref);
32 if (ref->name_len > BTRFS_NAME_MAX) {
33 printf("%s: inode name too long: %u\n", __func__,
38 memcpy(name, ref + 1, ref->name_len);
43 btrfs_free_path(&path);
47 int btrfs_lookup_inode(const struct btrfs_root *root,
48 struct btrfs_key *location,
49 struct btrfs_inode_item *item,
50 struct btrfs_root *new_root)
52 struct btrfs_root tmp_root = *root;
53 struct btrfs_path path;
56 if (location->type == BTRFS_ROOT_ITEM_KEY) {
57 if (btrfs_find_root(location->objectid, &tmp_root, NULL))
60 location->objectid = tmp_root.root_dirid;
61 location->type = BTRFS_INODE_ITEM_KEY;
65 if (btrfs_search_tree(&tmp_root, location, &path))
68 if (btrfs_comp_keys(location, btrfs_path_leaf_key(&path)))
72 *item = *btrfs_path_item_ptr(&path, struct btrfs_inode_item);
73 btrfs_inode_item_to_cpu(item);
82 btrfs_free_path(&path);
86 int btrfs_readlink(const struct btrfs_root *root, u64 inr, char *target)
88 struct btrfs_path path;
90 struct btrfs_file_extent_item *extent;
95 key.type = BTRFS_EXTENT_DATA_KEY;
98 if (btrfs_search_tree(root, &key, &path))
101 if (btrfs_comp_keys(&key, btrfs_path_leaf_key(&path)))
104 extent = btrfs_path_item_ptr(&path, struct btrfs_file_extent_item);
105 if (extent->type != BTRFS_FILE_EXTENT_INLINE) {
106 printf("%s: Extent for symlink %llu not of INLINE type\n",
111 btrfs_file_extent_item_to_cpu_inl(extent);
113 if (extent->compression != BTRFS_COMPRESS_NONE) {
114 printf("%s: Symlink %llu extent data compressed!\n", __func__,
117 } else if (extent->encryption != 0) {
118 printf("%s: Symlink %llu extent data encrypted!\n", __func__,
121 } else if (extent->ram_bytes >= btrfs_info.sb.sectorsize) {
122 printf("%s: Symlink %llu extent data too long (%llu)!\n",
123 __func__, inr, extent->ram_bytes);
127 data_ptr = (const char *) extent
128 + offsetof(struct btrfs_file_extent_item, disk_bytenr);
130 memcpy(target, data_ptr, extent->ram_bytes);
131 target[extent->ram_bytes] = '\0';
134 btrfs_free_path(&path);
138 /* inr must be a directory (for regular files with multiple hard links this
139 function returns only one of the parents of the file) */
140 static u64 get_parent_inode(struct btrfs_root *root, u64 inr,
141 struct btrfs_inode_item *inode_item)
143 struct btrfs_key key;
146 if (inr == BTRFS_FIRST_FREE_OBJECTID) {
147 if (root->objectid != btrfs_info.fs_root.objectid) {
149 struct btrfs_root_ref ref;
151 parent = btrfs_lookup_root_ref(root->objectid, &ref,
156 if (btrfs_find_root(parent, root, NULL))
164 key.type = BTRFS_INODE_ITEM_KEY;
167 if (btrfs_lookup_inode(root, &key, inode_item, NULL))
174 res = btrfs_lookup_inode_ref(root, inr, NULL, NULL);
180 key.type = BTRFS_INODE_ITEM_KEY;
183 if (btrfs_lookup_inode(root, &key, inode_item, NULL))
190 static inline int next_length(const char *path)
193 while (*path != '\0' && *path != '/' && res <= BTRFS_NAME_LEN)
198 static inline const char *skip_current_directories(const char *cur)
203 else if (cur[0] == '.' && cur[1] == '/')
212 u64 btrfs_lookup_path(struct btrfs_root *root, u64 inr, const char *path,
213 u8 *type_p, struct btrfs_inode_item *inode_item_p,
216 struct btrfs_dir_item item;
217 struct btrfs_inode_item inode_item;
218 u8 type = BTRFS_FT_DIR;
219 int len, have_inode = 0;
220 const char *cur = path;
224 inr = root->root_dirid;
228 cur = skip_current_directories(cur);
230 len = next_length(cur);
231 if (len > BTRFS_NAME_LEN) {
232 printf("%s: Name too long at \"%.*s\"\n", __func__,
233 BTRFS_NAME_LEN, cur);
237 if (len == 1 && cur[0] == '.')
240 if (len == 2 && cur[0] == '.' && cur[1] == '.') {
242 inr = get_parent_inode(root, inr, &inode_item);
253 if (btrfs_lookup_dir_item(root, inr, cur, len, &item))
258 if (btrfs_lookup_inode(root, &item.location, &inode_item, root))
261 if (item.type == BTRFS_FT_SYMLINK && symlink_limit >= 0) {
264 if (!symlink_limit) {
265 printf("%s: Too much symlinks!\n", __func__);
269 target = malloc(min(inode_item.size + 1,
270 (u64) btrfs_info.sb.sectorsize));
274 if (btrfs_readlink(root, item.location.objectid,
280 inr = btrfs_lookup_path(root, inr, target, &type,
281 &inode_item, symlink_limit - 1);
287 } else if (item.type != BTRFS_FT_DIR && cur[len]) {
288 printf("%s: \"%.*s\" not a directory\n", __func__,
289 (int) (cur - path + len), path);
292 inr = item.location.objectid;
303 struct btrfs_key key;
306 key.type = BTRFS_INODE_ITEM_KEY;
309 if (btrfs_lookup_inode(root, &key, &inode_item, NULL))
313 *inode_item_p = inode_item;
319 u64 btrfs_file_read(const struct btrfs_root *root, u64 inr, u64 offset,
322 struct btrfs_path path;
323 struct btrfs_key key;
324 struct btrfs_file_extent_item *extent;
326 u64 rd, rd_all = -1ULL;
329 key.type = BTRFS_EXTENT_DATA_KEY;
332 if (btrfs_search_tree(root, &key, &path))
335 if (btrfs_comp_keys(&key, btrfs_path_leaf_key(&path)) < 0) {
336 if (btrfs_prev_slot(&path))
339 if (btrfs_comp_keys_type(&key, btrfs_path_leaf_key(&path)))
346 if (btrfs_comp_keys_type(&key, btrfs_path_leaf_key(&path)))
349 extent = btrfs_path_item_ptr(&path,
350 struct btrfs_file_extent_item);
352 if (extent->type == BTRFS_FILE_EXTENT_INLINE) {
353 btrfs_file_extent_item_to_cpu_inl(extent);
354 rd = btrfs_read_extent_inline(&path, extent, offset,
357 btrfs_file_extent_item_to_cpu(extent);
358 rd = btrfs_read_extent_reg(&path, extent, offset, size,
363 printf("%s: Error reading extent\n", __func__);
375 } while (!(res = btrfs_next_slot(&path)));
381 btrfs_free_path(&path);