1 // SPDX-License-Identifier: GPL-2.0+
3 * BTRFS filesystem implementation for U-Boot
5 * 2017 Marek Behun, CZ.NIC, marek.behun@nic.cz
12 int btrfs_comp_keys(struct btrfs_key *a, struct btrfs_key *b)
14 if (a->objectid > b->objectid)
16 if (a->objectid < b->objectid)
18 if (a->type > b->type)
20 if (a->type < b->type)
22 if (a->offset > b->offset)
24 if (a->offset < b->offset)
29 int btrfs_comp_keys_type(struct btrfs_key *a, struct btrfs_key *b)
31 if (a->objectid > b->objectid)
33 if (a->objectid < b->objectid)
35 if (a->type > b->type)
37 if (a->type < b->type)
42 static int generic_bin_search(void *addr, int item_size, struct btrfs_key *key,
45 int low = 0, high = max, mid, ret;
46 struct btrfs_key *tmp;
49 mid = (low + high) / 2;
51 tmp = (struct btrfs_key *) ((u8 *) addr + mid*item_size);
52 ret = btrfs_comp_keys(tmp, key);
68 int btrfs_bin_search(union btrfs_tree_node *p, struct btrfs_key *key,
74 if (p->header.level) {
76 size = sizeof(struct btrfs_key_ptr);
79 size = sizeof(struct btrfs_item);
82 return generic_bin_search(addr, size, key, p->header.nritems, slot);
85 static void clear_path(struct btrfs_path *p)
89 for (i = 0; i < BTRFS_MAX_LEVEL; ++i) {
95 void btrfs_free_path(struct btrfs_path *p)
99 for (i = 0; i < BTRFS_MAX_LEVEL; ++i) {
107 static int read_tree_node(u64 physical, union btrfs_tree_node **buf)
109 ALLOC_CACHE_ALIGN_BUFFER(struct btrfs_header, hdr,
110 sizeof(struct btrfs_header));
111 unsigned long size, offset = sizeof(*hdr);
112 union btrfs_tree_node *res;
115 if (!btrfs_devread(physical, sizeof(*hdr), hdr))
118 btrfs_header_to_cpu(hdr);
121 size = sizeof(struct btrfs_node)
122 + hdr->nritems * sizeof(struct btrfs_key_ptr);
124 size = btrfs_info.sb.nodesize;
126 res = malloc_cache_aligned(size);
128 debug("%s: malloc failed\n", __func__);
132 if (!btrfs_devread(physical + offset, size - offset,
133 ((u8 *) res) + offset)) {
138 memcpy(&res->header, hdr, sizeof(*hdr));
140 for (i = 0; i < hdr->nritems; ++i)
141 btrfs_key_ptr_to_cpu(&res->node.ptrs[i]);
143 for (i = 0; i < hdr->nritems; ++i)
144 btrfs_item_to_cpu(&res->leaf.items[i]);
151 int btrfs_search_tree(const struct btrfs_root *root, struct btrfs_key *key,
152 struct btrfs_path *p)
156 u64 logical, physical;
157 union btrfs_tree_node *buf;
161 logical = root->bytenr;
163 for (i = 0; i < BTRFS_MAX_LEVEL; ++i) {
164 physical = btrfs_map_logical_to_physical(logical);
165 if (physical == -1ULL)
168 if (read_tree_node(physical, &buf))
171 lvl = buf->header.level;
172 if (i && prev_lvl != lvl + 1) {
173 printf("%s: invalid level in header at %llu\n",
179 ret = btrfs_bin_search(buf, key, &slot);
182 if (ret && slot > 0 && lvl)
185 p->slots[lvl] = slot;
189 logical = buf->node.ptrs[slot].blockptr;
200 static int jump_leaf(struct btrfs_path *path, int dir)
204 int level = 1, from_level, i;
206 dir = dir >= 0 ? 1 : -1;
210 while (level < BTRFS_MAX_LEVEL) {
214 slot = p.slots[level];
215 if ((dir > 0 && slot + dir >= p.nodes[level]->header.nritems)
216 || (dir < 0 && !slot))
222 if (level == BTRFS_MAX_LEVEL)
225 p.slots[level] = slot + dir;
230 u64 logical, physical;
232 slot = p.slots[level + 1];
233 logical = p.nodes[level + 1]->node.ptrs[slot].blockptr;
234 physical = btrfs_map_logical_to_physical(logical);
235 if (physical == -1ULL)
238 if (read_tree_node(physical, &p.nodes[level]))
244 p.slots[level] = p.nodes[level]->header.nritems - 1;
248 /* Free rewritten nodes in path */
249 for (i = 0; i <= from_level; ++i)
250 free(path->nodes[i]);
256 /* Free rewritten nodes in p */
257 for (i = level + 1; i <= from_level; ++i)
262 int btrfs_prev_slot(struct btrfs_path *p)
265 return jump_leaf(p, -1);
271 int btrfs_next_slot(struct btrfs_path *p)
273 struct btrfs_leaf *leaf = &p->nodes[0]->leaf;
275 if (p->slots[0] + 1 >= leaf->header.nritems)
276 return jump_leaf(p, 1);