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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2011 Red Hat, Inc.
4 *
5 * This file is released under the GPL.
6 */
7
8#include "dm-btree-internal.h"
9#include "dm-transaction-manager.h"
10
11#include <linux/device-mapper.h>
12
13#define DM_MSG_PREFIX "btree spine"
14
15/*----------------------------------------------------------------*/
16
17#define BTREE_CSUM_XOR 121107
18
19static void node_prepare_for_write(struct dm_block_validator *v,
20 struct dm_block *b,
21 size_t block_size)
22{
23 struct btree_node *n = dm_block_data(b);
24 struct node_header *h = &n->header;
25
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),
29 BTREE_CSUM_XOR));
30}
31
32static int node_check(struct dm_block_validator *v,
33 struct dm_block *b,
34 size_t block_size)
35{
36 struct btree_node *n = dm_block_data(b);
37 struct node_header *h = &n->header;
38 size_t value_size;
39 __le32 csum_disk;
40 uint32_t flags, nr_entries, max_entries;
41
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));
45 return -ENOTBLK;
46 }
47
48 csum_disk = cpu_to_le32(dm_bm_checksum(&h->flags,
49 block_size - sizeof(__le32),
50 BTREE_CSUM_XOR));
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));
54 return -EILSEQ;
55 }
56
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);
60
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__);
64 return -EILSEQ;
65 }
66
67 if (nr_entries > max_entries) {
68 DMERR_LIMIT("%s failed: too many entries", __func__);
69 return -EILSEQ;
70 }
71
72 /*
73 * The node must be either INTERNAL or LEAF.
74 */
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__);
78 return -EILSEQ;
79 }
80
81 return 0;
82}
83
84struct dm_block_validator btree_node_validator = {
85 .name = "btree_node",
86 .prepare_for_write = node_prepare_for_write,
87 .check = node_check
88};
89
90/*----------------------------------------------------------------*/
91
92int bn_read_lock(struct dm_btree_info *info, dm_block_t b,
93 struct dm_block **result)
94{
95 return dm_tm_read_lock(info->tm, b, &btree_node_validator, result);
96}
97
98static int bn_shadow(struct dm_btree_info *info, dm_block_t orig,
99 struct dm_btree_value_type *vt,
100 struct dm_block **result)
101{
102 int r, inc;
103
104 r = dm_tm_shadow_block(info->tm, orig, &btree_node_validator,
105 result, &inc);
106 if (!r && inc)
107 inc_children(info->tm, dm_block_data(*result), vt);
108
109 return r;
110}
111
112int new_block(struct dm_btree_info *info, struct dm_block **result)
113{
114 return dm_tm_new_block(info->tm, &btree_node_validator, result);
115}
116
117void unlock_block(struct dm_btree_info *info, struct dm_block *b)
118{
119 dm_tm_unlock(info->tm, b);
120}
121
122/*----------------------------------------------------------------*/
123
124void init_ro_spine(struct ro_spine *s, struct dm_btree_info *info)
125{
126 s->info = info;
127 s->count = 0;
128 s->nodes[0] = NULL;
129 s->nodes[1] = NULL;
130}
131
132void exit_ro_spine(struct ro_spine *s)
133{
134 int i;
135
136 for (i = 0; i < s->count; i++)
137 unlock_block(s->info, s->nodes[i]);
138}
139
140int ro_step(struct ro_spine *s, dm_block_t new_child)
141{
142 int r;
143
144 if (s->count == 2) {
145 unlock_block(s->info, s->nodes[0]);
146 s->nodes[0] = s->nodes[1];
147 s->count--;
148 }
149
150 r = bn_read_lock(s->info, new_child, s->nodes + s->count);
151 if (!r)
152 s->count++;
153
154 return r;
155}
156
157void ro_pop(struct ro_spine *s)
158{
159 BUG_ON(!s->count);
160 --s->count;
161 unlock_block(s->info, s->nodes[s->count]);
162}
163
164struct btree_node *ro_node(struct ro_spine *s)
165{
166 struct dm_block *block;
167
168 BUG_ON(!s->count);
169 block = s->nodes[s->count - 1];
170
171 return dm_block_data(block);
172}
173
174/*----------------------------------------------------------------*/
175
176void init_shadow_spine(struct shadow_spine *s, struct dm_btree_info *info)
177{
178 s->info = info;
179 s->count = 0;
180}
181
182void exit_shadow_spine(struct shadow_spine *s)
183{
184 int i;
185
186 for (i = 0; i < s->count; i++)
187 unlock_block(s->info, s->nodes[i]);
188}
189
190int shadow_step(struct shadow_spine *s, dm_block_t b,
191 struct dm_btree_value_type *vt)
192{
193 int r;
194
195 if (s->count == 2) {
196 unlock_block(s->info, s->nodes[0]);
197 s->nodes[0] = s->nodes[1];
198 s->count--;
199 }
200
201 r = bn_shadow(s->info, b, vt, s->nodes + s->count);
202 if (!r) {
203 if (!s->count)
204 s->root = dm_block_location(s->nodes[0]);
205
206 s->count++;
207 }
208
209 return r;
210}
211
212struct dm_block *shadow_current(struct shadow_spine *s)
213{
214 BUG_ON(!s->count);
215
216 return s->nodes[s->count - 1];
217}
218
219struct dm_block *shadow_parent(struct shadow_spine *s)
220{
221 BUG_ON(s->count != 2);
222
223 return s->count == 2 ? s->nodes[0] : NULL;
224}
225
226int shadow_has_parent(struct shadow_spine *s)
227{
228 return s->count >= 2;
229}
230
231dm_block_t shadow_root(struct shadow_spine *s)
232{
233 return s->root;
234}
235
236static void le64_inc(void *context, const void *value_le, unsigned int count)
237{
238 dm_tm_with_runs(context, value_le, count, dm_tm_inc_range);
239}
240
241static void le64_dec(void *context, const void *value_le, unsigned int count)
242{
243 dm_tm_with_runs(context, value_le, count, dm_tm_dec_range);
244}
245
246static int le64_equal(void *context, const void *value1_le, const void *value2_le)
247{
248 __le64 v1_le, v2_le;
249
250 memcpy(&v1_le, value1_le, sizeof(v1_le));
251 memcpy(&v2_le, value2_le, sizeof(v2_le));
252 return v1_le == v2_le;
253}
254
255void init_le64_type(struct dm_transaction_manager *tm,
256 struct dm_btree_value_type *vt)
257{
258 vt->context = tm;
259 vt->size = sizeof(__le64);
260 vt->inc = le64_inc;
261 vt->dec = le64_dec;
262 vt->equal = le64_equal;
263}
1/*
2 * Copyright (C) 2011 Red Hat, Inc.
3 *
4 * This file is released under the GPL.
5 */
6
7#include "dm-btree-internal.h"
8#include "dm-transaction-manager.h"
9
10#include <linux/device-mapper.h>
11
12#define DM_MSG_PREFIX "btree spine"
13
14/*----------------------------------------------------------------*/
15
16#define BTREE_CSUM_XOR 121107
17
18static int node_check(struct dm_block_validator *v,
19 struct dm_block *b,
20 size_t block_size);
21
22static void node_prepare_for_write(struct dm_block_validator *v,
23 struct dm_block *b,
24 size_t block_size)
25{
26 struct node *n = dm_block_data(b);
27 struct node_header *h = &n->header;
28
29 h->blocknr = cpu_to_le64(dm_block_location(b));
30 h->csum = cpu_to_le32(dm_bm_checksum(&h->flags,
31 block_size - sizeof(__le32),
32 BTREE_CSUM_XOR));
33
34 BUG_ON(node_check(v, b, 4096));
35}
36
37static int node_check(struct dm_block_validator *v,
38 struct dm_block *b,
39 size_t block_size)
40{
41 struct node *n = dm_block_data(b);
42 struct node_header *h = &n->header;
43 size_t value_size;
44 __le32 csum_disk;
45 uint32_t flags;
46
47 if (dm_block_location(b) != le64_to_cpu(h->blocknr)) {
48 DMERR("node_check failed blocknr %llu wanted %llu",
49 le64_to_cpu(h->blocknr), dm_block_location(b));
50 return -ENOTBLK;
51 }
52
53 csum_disk = cpu_to_le32(dm_bm_checksum(&h->flags,
54 block_size - sizeof(__le32),
55 BTREE_CSUM_XOR));
56 if (csum_disk != h->csum) {
57 DMERR("node_check failed csum %u wanted %u",
58 le32_to_cpu(csum_disk), le32_to_cpu(h->csum));
59 return -EILSEQ;
60 }
61
62 value_size = le32_to_cpu(h->value_size);
63
64 if (sizeof(struct node_header) +
65 (sizeof(__le64) + value_size) * le32_to_cpu(h->max_entries) > block_size) {
66 DMERR("node_check failed: max_entries too large");
67 return -EILSEQ;
68 }
69
70 if (le32_to_cpu(h->nr_entries) > le32_to_cpu(h->max_entries)) {
71 DMERR("node_check failed, too many entries");
72 return -EILSEQ;
73 }
74
75 /*
76 * The node must be either INTERNAL or LEAF.
77 */
78 flags = le32_to_cpu(h->flags);
79 if (!(flags & INTERNAL_NODE) && !(flags & LEAF_NODE)) {
80 DMERR("node_check failed, node is neither INTERNAL or LEAF");
81 return -EILSEQ;
82 }
83
84 return 0;
85}
86
87struct dm_block_validator btree_node_validator = {
88 .name = "btree_node",
89 .prepare_for_write = node_prepare_for_write,
90 .check = node_check
91};
92
93/*----------------------------------------------------------------*/
94
95static int bn_read_lock(struct dm_btree_info *info, dm_block_t b,
96 struct dm_block **result)
97{
98 return dm_tm_read_lock(info->tm, b, &btree_node_validator, result);
99}
100
101static int bn_shadow(struct dm_btree_info *info, dm_block_t orig,
102 struct dm_btree_value_type *vt,
103 struct dm_block **result)
104{
105 int r, inc;
106
107 r = dm_tm_shadow_block(info->tm, orig, &btree_node_validator,
108 result, &inc);
109 if (!r && inc)
110 inc_children(info->tm, dm_block_data(*result), vt);
111
112 return r;
113}
114
115int new_block(struct dm_btree_info *info, struct dm_block **result)
116{
117 return dm_tm_new_block(info->tm, &btree_node_validator, result);
118}
119
120int unlock_block(struct dm_btree_info *info, struct dm_block *b)
121{
122 return dm_tm_unlock(info->tm, b);
123}
124
125/*----------------------------------------------------------------*/
126
127void init_ro_spine(struct ro_spine *s, struct dm_btree_info *info)
128{
129 s->info = info;
130 s->count = 0;
131 s->nodes[0] = NULL;
132 s->nodes[1] = NULL;
133}
134
135int exit_ro_spine(struct ro_spine *s)
136{
137 int r = 0, i;
138
139 for (i = 0; i < s->count; i++) {
140 int r2 = unlock_block(s->info, s->nodes[i]);
141 if (r2 < 0)
142 r = r2;
143 }
144
145 return r;
146}
147
148int ro_step(struct ro_spine *s, dm_block_t new_child)
149{
150 int r;
151
152 if (s->count == 2) {
153 r = unlock_block(s->info, s->nodes[0]);
154 if (r < 0)
155 return r;
156 s->nodes[0] = s->nodes[1];
157 s->count--;
158 }
159
160 r = bn_read_lock(s->info, new_child, s->nodes + s->count);
161 if (!r)
162 s->count++;
163
164 return r;
165}
166
167struct node *ro_node(struct ro_spine *s)
168{
169 struct dm_block *block;
170
171 BUG_ON(!s->count);
172 block = s->nodes[s->count - 1];
173
174 return dm_block_data(block);
175}
176
177/*----------------------------------------------------------------*/
178
179void init_shadow_spine(struct shadow_spine *s, struct dm_btree_info *info)
180{
181 s->info = info;
182 s->count = 0;
183}
184
185int exit_shadow_spine(struct shadow_spine *s)
186{
187 int r = 0, i;
188
189 for (i = 0; i < s->count; i++) {
190 int r2 = unlock_block(s->info, s->nodes[i]);
191 if (r2 < 0)
192 r = r2;
193 }
194
195 return r;
196}
197
198int shadow_step(struct shadow_spine *s, dm_block_t b,
199 struct dm_btree_value_type *vt)
200{
201 int r;
202
203 if (s->count == 2) {
204 r = unlock_block(s->info, s->nodes[0]);
205 if (r < 0)
206 return r;
207 s->nodes[0] = s->nodes[1];
208 s->count--;
209 }
210
211 r = bn_shadow(s->info, b, vt, s->nodes + s->count);
212 if (!r) {
213 if (!s->count)
214 s->root = dm_block_location(s->nodes[0]);
215
216 s->count++;
217 }
218
219 return r;
220}
221
222struct dm_block *shadow_current(struct shadow_spine *s)
223{
224 BUG_ON(!s->count);
225
226 return s->nodes[s->count - 1];
227}
228
229struct dm_block *shadow_parent(struct shadow_spine *s)
230{
231 BUG_ON(s->count != 2);
232
233 return s->count == 2 ? s->nodes[0] : NULL;
234}
235
236int shadow_has_parent(struct shadow_spine *s)
237{
238 return s->count >= 2;
239}
240
241int shadow_root(struct shadow_spine *s)
242{
243 return s->root;
244}