chunk-map.c
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/*
* BTRFS filesystem implementation for U-Boot
*
* 2017 Marek Behun, CZ.NIC, marek.behun@nic.cz
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include "btrfs.h"
#include <malloc.h>
struct chunk_map_item {
struct rb_node node;
u64 logical;
u64 length;
u64 physical;
};
static int add_chunk_mapping(struct btrfs_key *key, struct btrfs_chunk *chunk)
{
struct btrfs_stripe *stripe;
u64 block_profile = chunk->type & BTRFS_BLOCK_GROUP_PROFILE_MASK;
struct rb_node **new = &(btrfs_info.chunks_root.rb_node), *prnt = NULL;
struct chunk_map_item *map_item;
if (block_profile && block_profile != BTRFS_BLOCK_GROUP_DUP) {
printf("%s: unsupported chunk profile %llu\n", __func__,
block_profile);
return -1;
} else if (!chunk->length) {
printf("%s: zero length chunk\n", __func__);
return -1;
}
stripe = &chunk->stripe;
btrfs_stripe_to_cpu(stripe);
while (*new) {
struct chunk_map_item *this;
this = rb_entry(*new, struct chunk_map_item, node);
prnt = *new;
if (key->offset < this->logical) {
new = &((*new)->rb_left);
} else if (key->offset > this->logical) {
new = &((*new)->rb_right);
} else {
debug("%s: Logical address %llu already in map!\n",
__func__, key->offset);
return 0;
}
}
map_item = malloc(sizeof(struct chunk_map_item));
if (!map_item)
return -1;
map_item->logical = key->offset;
map_item->length = chunk->length;
map_item->physical = le64_to_cpu(chunk->stripe.offset);
rb_link_node(&map_item->node, prnt, new);
rb_insert_color(&map_item->node, &btrfs_info.chunks_root);
debug("%s: Mapping %llu to %llu\n", __func__, map_item->logical,
map_item->physical);
return 0;
}
u64 btrfs_map_logical_to_physical(u64 logical)
{
struct rb_node *node = btrfs_info.chunks_root.rb_node;
while (node) {
struct chunk_map_item *item;
item = rb_entry(node, struct chunk_map_item, node);
if (item->logical > logical)
node = node->rb_left;
else if (logical > item->logical + item->length)
node = node->rb_right;
else
return item->physical + logical - item->logical;
}
printf("%s: Cannot map logical address %llu to physical\n", __func__,
logical);
return -1ULL;
}
void btrfs_chunk_map_exit(void)
{
struct rb_node *now, *next;
struct chunk_map_item *item;
for (now = rb_first_postorder(&btrfs_info.chunks_root); now; now = next)
{
item = rb_entry(now, struct chunk_map_item, node);
next = rb_next_postorder(now);
free(item);
}
}
int btrfs_chunk_map_init(void)
{
u8 sys_chunk_array_copy[sizeof(btrfs_info.sb.sys_chunk_array)];
u8 * const start = sys_chunk_array_copy;
u8 * const end = start + btrfs_info.sb.sys_chunk_array_size;
u8 *cur;
struct btrfs_key *key;
struct btrfs_chunk *chunk;
btrfs_info.chunks_root = RB_ROOT;
memcpy(sys_chunk_array_copy, btrfs_info.sb.sys_chunk_array,
sizeof(sys_chunk_array_copy));
for (cur = start; cur < end;) {
key = (struct btrfs_key *) cur;
cur += sizeof(struct btrfs_key);
chunk = (struct btrfs_chunk *) cur;
btrfs_key_to_cpu(key);
btrfs_chunk_to_cpu(chunk);
if (key->type != BTRFS_CHUNK_ITEM_KEY) {
printf("%s: invalid key type %u\n", __func__,
key->type);
return -1;
}
if (add_chunk_mapping(key, chunk))
return -1;
cur += sizeof(struct btrfs_chunk);
cur += sizeof(struct btrfs_stripe) * (chunk->num_stripes - 1);
}
return 0;
}
int btrfs_read_chunk_tree(void)
{
struct btrfs_path path;
struct btrfs_key key, *found_key;
struct btrfs_chunk *chunk;
int res = 0;
key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
key.type = BTRFS_CHUNK_ITEM_KEY;
key.offset = 0;
if (btrfs_search_tree(&btrfs_info.chunk_root, &key, &path))
return -1;
do {
found_key = btrfs_path_leaf_key(&path);
if (btrfs_comp_keys_type(&key, found_key))
break;
chunk = btrfs_path_item_ptr(&path, struct btrfs_chunk);
btrfs_chunk_to_cpu(chunk);
if (add_chunk_mapping(found_key, chunk)) {
res = -1;
break;
}
} while (!(res = btrfs_next_slot(&path)));
btrfs_free_path(&path);
if (res < 0)
return -1;
return 0;
}