summaryrefslogtreecommitdiff
path: root/fs/btrfs/chunk-map.c
blob: ce7330b1b77202e1c22ea95bce4938a080a69d01 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
/*
 * 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;
}