1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 2011 Red Hat, Inc.
5 * This file is released under the GPL.
8 #include "dm-btree-internal.h"
9 #include "dm-transaction-manager.h"
11 #include <linux/device-mapper.h>
13 #define DM_MSG_PREFIX "btree spine"
15 /*----------------------------------------------------------------*/
17 #define BTREE_CSUM_XOR 121107
19 static void node_prepare_for_write(struct dm_block_validator *v,
23 struct btree_node *n = dm_block_data(b);
24 struct node_header *h = &n->header;
26 h->blocknr = cpu_to_le64(dm_block_location(b));
27 h->csum = cpu_to_le32(dm_bm_checksum(&h->flags,
28 block_size - sizeof(__le32),
32 static int node_check(struct dm_block_validator *v,
36 struct btree_node *n = dm_block_data(b);
37 struct node_header *h = &n->header;
40 uint32_t flags, nr_entries, max_entries;
42 if (dm_block_location(b) != le64_to_cpu(h->blocknr)) {
43 DMERR_LIMIT("%s failed: blocknr %llu != wanted %llu", __func__,
44 le64_to_cpu(h->blocknr), dm_block_location(b));
48 csum_disk = cpu_to_le32(dm_bm_checksum(&h->flags,
49 block_size - sizeof(__le32),
51 if (csum_disk != h->csum) {
52 DMERR_LIMIT("%s failed: csum %u != wanted %u", __func__,
53 le32_to_cpu(csum_disk), le32_to_cpu(h->csum));
57 nr_entries = le32_to_cpu(h->nr_entries);
58 max_entries = le32_to_cpu(h->max_entries);
59 value_size = le32_to_cpu(h->value_size);
61 if (sizeof(struct node_header) +
62 (sizeof(__le64) + value_size) * max_entries > block_size) {
63 DMERR_LIMIT("%s failed: max_entries too large", __func__);
67 if (nr_entries > max_entries) {
68 DMERR_LIMIT("%s failed: too many entries", __func__);
73 * The node must be either INTERNAL or LEAF.
75 flags = le32_to_cpu(h->flags);
76 if (!(flags & INTERNAL_NODE) && !(flags & LEAF_NODE)) {
77 DMERR_LIMIT("%s failed: node is neither INTERNAL or LEAF", __func__);
84 struct dm_block_validator btree_node_validator = {
86 .prepare_for_write = node_prepare_for_write,
90 /*----------------------------------------------------------------*/
92 int bn_read_lock(struct dm_btree_info *info, dm_block_t b,
93 struct dm_block **result)
95 return dm_tm_read_lock(info->tm, b, &btree_node_validator, result);
98 static int bn_shadow(struct dm_btree_info *info, dm_block_t orig,
99 struct dm_btree_value_type *vt,
100 struct dm_block **result)
104 r = dm_tm_shadow_block(info->tm, orig, &btree_node_validator,
107 inc_children(info->tm, dm_block_data(*result), vt);
112 int new_block(struct dm_btree_info *info, struct dm_block **result)
114 return dm_tm_new_block(info->tm, &btree_node_validator, result);
117 void unlock_block(struct dm_btree_info *info, struct dm_block *b)
119 dm_tm_unlock(info->tm, b);
122 /*----------------------------------------------------------------*/
124 void init_ro_spine(struct ro_spine *s, struct dm_btree_info *info)
132 void exit_ro_spine(struct ro_spine *s)
136 for (i = 0; i < s->count; i++)
137 unlock_block(s->info, s->nodes[i]);
140 int ro_step(struct ro_spine *s, dm_block_t new_child)
145 unlock_block(s->info, s->nodes[0]);
146 s->nodes[0] = s->nodes[1];
150 r = bn_read_lock(s->info, new_child, s->nodes + s->count);
157 void ro_pop(struct ro_spine *s)
161 unlock_block(s->info, s->nodes[s->count]);
164 struct btree_node *ro_node(struct ro_spine *s)
166 struct dm_block *block;
169 block = s->nodes[s->count - 1];
171 return dm_block_data(block);
174 /*----------------------------------------------------------------*/
176 void init_shadow_spine(struct shadow_spine *s, struct dm_btree_info *info)
182 void exit_shadow_spine(struct shadow_spine *s)
186 for (i = 0; i < s->count; i++)
187 unlock_block(s->info, s->nodes[i]);
190 int shadow_step(struct shadow_spine *s, dm_block_t b,
191 struct dm_btree_value_type *vt)
196 unlock_block(s->info, s->nodes[0]);
197 s->nodes[0] = s->nodes[1];
201 r = bn_shadow(s->info, b, vt, s->nodes + s->count);
204 s->root = dm_block_location(s->nodes[0]);
212 struct dm_block *shadow_current(struct shadow_spine *s)
216 return s->nodes[s->count - 1];
219 struct dm_block *shadow_parent(struct shadow_spine *s)
221 BUG_ON(s->count != 2);
223 return s->count == 2 ? s->nodes[0] : NULL;
226 int shadow_has_parent(struct shadow_spine *s)
228 return s->count >= 2;
231 dm_block_t shadow_root(struct shadow_spine *s)
236 static void le64_inc(void *context, const void *value_le, unsigned int count)
238 dm_tm_with_runs(context, value_le, count, dm_tm_inc_range);
241 static void le64_dec(void *context, const void *value_le, unsigned int count)
243 dm_tm_with_runs(context, value_le, count, dm_tm_dec_range);
246 static int le64_equal(void *context, const void *value1_le, const void *value2_le)
250 memcpy(&v1_le, value1_le, sizeof(v1_le));
251 memcpy(&v2_le, value2_le, sizeof(v2_le));
252 return v1_le == v2_le;
255 void init_le64_type(struct dm_transaction_manager *tm,
256 struct dm_btree_value_type *vt)
259 vt->size = sizeof(__le64);
262 vt->equal = le64_equal;