Commit | Line | Data |
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3241b1d3 JT |
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 | ||
18 | static int node_check(struct dm_block_validator *v, | |
19 | struct dm_block *b, | |
20 | size_t block_size); | |
21 | ||
22 | static void node_prepare_for_write(struct dm_block_validator *v, | |
23 | struct dm_block *b, | |
24 | size_t block_size) | |
25 | { | |
550929fa | 26 | struct btree_node *n = dm_block_data(b); |
3241b1d3 JT |
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 | ||
37 | static int node_check(struct dm_block_validator *v, | |
38 | struct dm_block *b, | |
39 | size_t block_size) | |
40 | { | |
550929fa | 41 | struct btree_node *n = dm_block_data(b); |
3241b1d3 JT |
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)) { | |
89ddeb8c MS |
48 | DMERR_LIMIT("node_check failed: blocknr %llu != wanted %llu", |
49 | le64_to_cpu(h->blocknr), dm_block_location(b)); | |
3241b1d3 JT |
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) { | |
89ddeb8c MS |
57 | DMERR_LIMIT("node_check failed: csum %u != wanted %u", |
58 | le32_to_cpu(csum_disk), le32_to_cpu(h->csum)); | |
3241b1d3 JT |
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) { | |
89ddeb8c | 66 | DMERR_LIMIT("node_check failed: max_entries too large"); |
3241b1d3 JT |
67 | return -EILSEQ; |
68 | } | |
69 | ||
70 | if (le32_to_cpu(h->nr_entries) > le32_to_cpu(h->max_entries)) { | |
89ddeb8c | 71 | DMERR_LIMIT("node_check failed: too many entries"); |
3241b1d3 JT |
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)) { | |
89ddeb8c | 80 | DMERR_LIMIT("node_check failed: node is neither INTERNAL or LEAF"); |
3241b1d3 JT |
81 | return -EILSEQ; |
82 | } | |
83 | ||
84 | return 0; | |
85 | } | |
86 | ||
87 | struct 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 | ||
9b460d36 | 95 | int bn_read_lock(struct dm_btree_info *info, dm_block_t b, |
3241b1d3 JT |
96 | struct dm_block **result) |
97 | { | |
98 | return dm_tm_read_lock(info->tm, b, &btree_node_validator, result); | |
99 | } | |
100 | ||
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) | |
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 | ||
115 | int 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 | ||
120 | int unlock_block(struct dm_btree_info *info, struct dm_block *b) | |
121 | { | |
122 | return dm_tm_unlock(info->tm, b); | |
123 | } | |
124 | ||
125 | /*----------------------------------------------------------------*/ | |
126 | ||
127 | void 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 | ||
135 | int 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 | ||
148 | int 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 | ||
4e7f1f90 JT |
167 | void ro_pop(struct ro_spine *s) |
168 | { | |
169 | BUG_ON(!s->count); | |
170 | --s->count; | |
171 | unlock_block(s->info, s->nodes[s->count]); | |
172 | } | |
173 | ||
550929fa | 174 | struct btree_node *ro_node(struct ro_spine *s) |
3241b1d3 JT |
175 | { |
176 | struct dm_block *block; | |
177 | ||
178 | BUG_ON(!s->count); | |
179 | block = s->nodes[s->count - 1]; | |
180 | ||
181 | return dm_block_data(block); | |
182 | } | |
183 | ||
184 | /*----------------------------------------------------------------*/ | |
185 | ||
186 | void init_shadow_spine(struct shadow_spine *s, struct dm_btree_info *info) | |
187 | { | |
188 | s->info = info; | |
189 | s->count = 0; | |
190 | } | |
191 | ||
192 | int exit_shadow_spine(struct shadow_spine *s) | |
193 | { | |
194 | int r = 0, i; | |
195 | ||
196 | for (i = 0; i < s->count; i++) { | |
197 | int r2 = unlock_block(s->info, s->nodes[i]); | |
198 | if (r2 < 0) | |
199 | r = r2; | |
200 | } | |
201 | ||
202 | return r; | |
203 | } | |
204 | ||
205 | int shadow_step(struct shadow_spine *s, dm_block_t b, | |
206 | struct dm_btree_value_type *vt) | |
207 | { | |
208 | int r; | |
209 | ||
210 | if (s->count == 2) { | |
211 | r = unlock_block(s->info, s->nodes[0]); | |
212 | if (r < 0) | |
213 | return r; | |
214 | s->nodes[0] = s->nodes[1]; | |
215 | s->count--; | |
216 | } | |
217 | ||
218 | r = bn_shadow(s->info, b, vt, s->nodes + s->count); | |
219 | if (!r) { | |
220 | if (!s->count) | |
221 | s->root = dm_block_location(s->nodes[0]); | |
222 | ||
223 | s->count++; | |
224 | } | |
225 | ||
226 | return r; | |
227 | } | |
228 | ||
229 | struct dm_block *shadow_current(struct shadow_spine *s) | |
230 | { | |
231 | BUG_ON(!s->count); | |
232 | ||
233 | return s->nodes[s->count - 1]; | |
234 | } | |
235 | ||
236 | struct dm_block *shadow_parent(struct shadow_spine *s) | |
237 | { | |
238 | BUG_ON(s->count != 2); | |
239 | ||
240 | return s->count == 2 ? s->nodes[0] : NULL; | |
241 | } | |
242 | ||
243 | int shadow_has_parent(struct shadow_spine *s) | |
244 | { | |
245 | return s->count >= 2; | |
246 | } | |
247 | ||
248 | int shadow_root(struct shadow_spine *s) | |
249 | { | |
250 | return s->root; | |
251 | } |