2 * Copyright (C) 2011 Red Hat, Inc.
4 * This file is released under the GPL.
7 #include "dm-btree-internal.h"
8 #include "dm-transaction-manager.h"
10 #include <linux/device-mapper.h>
12 #define DM_MSG_PREFIX "btree spine"
14 /*----------------------------------------------------------------*/
16 #define BTREE_CSUM_XOR 121107
18 static int node_check(struct dm_block_validator *v,
22 static void node_prepare_for_write(struct dm_block_validator *v,
26 struct node *n = dm_block_data(b);
27 struct node_header *h = &n->header;
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),
34 BUG_ON(node_check(v, b, 4096));
37 static int node_check(struct dm_block_validator *v,
41 struct node *n = dm_block_data(b);
42 struct node_header *h = &n->header;
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));
53 csum_disk = cpu_to_le32(dm_bm_checksum(&h->flags,
54 block_size - sizeof(__le32),
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));
62 value_size = le32_to_cpu(h->value_size);
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");
70 if (le32_to_cpu(h->nr_entries) > le32_to_cpu(h->max_entries)) {
71 DMERR("node_check failed, too many entries");
76 * The node must be either INTERNAL or LEAF.
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");
87 struct dm_block_validator btree_node_validator = {
89 .prepare_for_write = node_prepare_for_write,
93 /*----------------------------------------------------------------*/
95 static int bn_read_lock(struct dm_btree_info *info, dm_block_t b,
96 struct dm_block **result)
98 return dm_tm_read_lock(info->tm, b, &btree_node_validator, result);
101 static int bn_shadow(struct dm_btree_info *info, dm_block_t orig,
102 struct dm_btree_value_type *vt,
103 struct dm_block **result)
107 r = dm_tm_shadow_block(info->tm, orig, &btree_node_validator,
110 inc_children(info->tm, dm_block_data(*result), vt);
115 int new_block(struct dm_btree_info *info, struct dm_block **result)
117 return dm_tm_new_block(info->tm, &btree_node_validator, result);
120 int unlock_block(struct dm_btree_info *info, struct dm_block *b)
122 return dm_tm_unlock(info->tm, b);
125 /*----------------------------------------------------------------*/
127 void init_ro_spine(struct ro_spine *s, struct dm_btree_info *info)
135 int exit_ro_spine(struct ro_spine *s)
139 for (i = 0; i < s->count; i++) {
140 int r2 = unlock_block(s->info, s->nodes[i]);
148 int ro_step(struct ro_spine *s, dm_block_t new_child)
153 r = unlock_block(s->info, s->nodes[0]);
156 s->nodes[0] = s->nodes[1];
160 r = bn_read_lock(s->info, new_child, s->nodes + s->count);
167 struct node *ro_node(struct ro_spine *s)
169 struct dm_block *block;
172 block = s->nodes[s->count - 1];
174 return dm_block_data(block);
177 /*----------------------------------------------------------------*/
179 void init_shadow_spine(struct shadow_spine *s, struct dm_btree_info *info)
185 int exit_shadow_spine(struct shadow_spine *s)
189 for (i = 0; i < s->count; i++) {
190 int r2 = unlock_block(s->info, s->nodes[i]);
198 int shadow_step(struct shadow_spine *s, dm_block_t b,
199 struct dm_btree_value_type *vt)
204 r = unlock_block(s->info, s->nodes[0]);
207 s->nodes[0] = s->nodes[1];
211 r = bn_shadow(s->info, b, vt, s->nodes + s->count);
214 s->root = dm_block_location(s->nodes[0]);
222 struct dm_block *shadow_current(struct shadow_spine *s)
226 return s->nodes[s->count - 1];
229 struct dm_block *shadow_parent(struct shadow_spine *s)
231 BUG_ON(s->count != 2);
233 return s->count == 2 ? s->nodes[0] : NULL;
236 int shadow_has_parent(struct shadow_spine *s)
238 return s->count >= 2;
241 int shadow_root(struct shadow_spine *s)