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 | ||
4c7da06f | 120 | void unlock_block(struct dm_btree_info *info, struct dm_block *b) |
3241b1d3 | 121 | { |
4c7da06f | 122 | dm_tm_unlock(info->tm, b); |
3241b1d3 JT |
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++) { | |
4c7da06f | 140 | unlock_block(s->info, s->nodes[i]); |
3241b1d3 JT |
141 | } |
142 | ||
143 | return r; | |
144 | } | |
145 | ||
146 | int ro_step(struct ro_spine *s, dm_block_t new_child) | |
147 | { | |
148 | int r; | |
149 | ||
150 | if (s->count == 2) { | |
4c7da06f | 151 | unlock_block(s->info, s->nodes[0]); |
3241b1d3 JT |
152 | s->nodes[0] = s->nodes[1]; |
153 | s->count--; | |
154 | } | |
155 | ||
156 | r = bn_read_lock(s->info, new_child, s->nodes + s->count); | |
157 | if (!r) | |
158 | s->count++; | |
159 | ||
160 | return r; | |
161 | } | |
162 | ||
4e7f1f90 JT |
163 | void ro_pop(struct ro_spine *s) |
164 | { | |
165 | BUG_ON(!s->count); | |
166 | --s->count; | |
167 | unlock_block(s->info, s->nodes[s->count]); | |
168 | } | |
169 | ||
550929fa | 170 | struct btree_node *ro_node(struct ro_spine *s) |
3241b1d3 JT |
171 | { |
172 | struct dm_block *block; | |
173 | ||
174 | BUG_ON(!s->count); | |
175 | block = s->nodes[s->count - 1]; | |
176 | ||
177 | return dm_block_data(block); | |
178 | } | |
179 | ||
180 | /*----------------------------------------------------------------*/ | |
181 | ||
182 | void init_shadow_spine(struct shadow_spine *s, struct dm_btree_info *info) | |
183 | { | |
184 | s->info = info; | |
185 | s->count = 0; | |
186 | } | |
187 | ||
188 | int exit_shadow_spine(struct shadow_spine *s) | |
189 | { | |
190 | int r = 0, i; | |
191 | ||
192 | for (i = 0; i < s->count; i++) { | |
4c7da06f | 193 | unlock_block(s->info, s->nodes[i]); |
3241b1d3 JT |
194 | } |
195 | ||
196 | return r; | |
197 | } | |
198 | ||
199 | int shadow_step(struct shadow_spine *s, dm_block_t b, | |
200 | struct dm_btree_value_type *vt) | |
201 | { | |
202 | int r; | |
203 | ||
204 | if (s->count == 2) { | |
4c7da06f | 205 | unlock_block(s->info, s->nodes[0]); |
3241b1d3 JT |
206 | s->nodes[0] = s->nodes[1]; |
207 | s->count--; | |
208 | } | |
209 | ||
210 | r = bn_shadow(s->info, b, vt, s->nodes + s->count); | |
211 | if (!r) { | |
212 | if (!s->count) | |
213 | s->root = dm_block_location(s->nodes[0]); | |
214 | ||
215 | s->count++; | |
216 | } | |
217 | ||
218 | return r; | |
219 | } | |
220 | ||
221 | struct dm_block *shadow_current(struct shadow_spine *s) | |
222 | { | |
223 | BUG_ON(!s->count); | |
224 | ||
225 | return s->nodes[s->count - 1]; | |
226 | } | |
227 | ||
228 | struct dm_block *shadow_parent(struct shadow_spine *s) | |
229 | { | |
230 | BUG_ON(s->count != 2); | |
231 | ||
232 | return s->count == 2 ? s->nodes[0] : NULL; | |
233 | } | |
234 | ||
235 | int shadow_has_parent(struct shadow_spine *s) | |
236 | { | |
237 | return s->count >= 2; | |
238 | } | |
239 | ||
240 | int shadow_root(struct shadow_spine *s) | |
241 | { | |
242 | return s->root; | |
243 | } | |
b0dc3c8b JT |
244 | |
245 | static void le64_inc(void *context, const void *value_le) | |
246 | { | |
247 | struct dm_transaction_manager *tm = context; | |
248 | __le64 v_le; | |
249 | ||
250 | memcpy(&v_le, value_le, sizeof(v_le)); | |
251 | dm_tm_inc(tm, le64_to_cpu(v_le)); | |
252 | } | |
253 | ||
254 | static void le64_dec(void *context, const void *value_le) | |
255 | { | |
256 | struct dm_transaction_manager *tm = context; | |
257 | __le64 v_le; | |
258 | ||
259 | memcpy(&v_le, value_le, sizeof(v_le)); | |
260 | dm_tm_dec(tm, le64_to_cpu(v_le)); | |
261 | } | |
262 | ||
263 | static int le64_equal(void *context, const void *value1_le, const void *value2_le) | |
264 | { | |
265 | __le64 v1_le, v2_le; | |
266 | ||
267 | memcpy(&v1_le, value1_le, sizeof(v1_le)); | |
268 | memcpy(&v2_le, value2_le, sizeof(v2_le)); | |
269 | return v1_le == v2_le; | |
270 | } | |
271 | ||
272 | void init_le64_type(struct dm_transaction_manager *tm, | |
273 | struct dm_btree_value_type *vt) | |
274 | { | |
275 | vt->context = tm; | |
276 | vt->size = sizeof(__le64); | |
277 | vt->inc = le64_inc; | |
278 | vt->dec = le64_dec; | |
279 | vt->equal = le64_equal; | |
280 | } |