gro: Allow tunnel stacking in the case of FOU/GUE
[linux/fpc-iii.git] / drivers / md / persistent-data / dm-btree-spine.c
blob0dee514ba4c5f9e8d34d16e9d239ef333395c7d4
1 /*
2 * Copyright (C) 2011 Red Hat, Inc.
4 * This file is released under the GPL.
5 */
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,
19 struct dm_block *b,
20 size_t block_size);
22 static void node_prepare_for_write(struct dm_block_validator *v,
23 struct dm_block *b,
24 size_t block_size)
26 struct btree_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),
32 BTREE_CSUM_XOR));
34 BUG_ON(node_check(v, b, 4096));
37 static int node_check(struct dm_block_validator *v,
38 struct dm_block *b,
39 size_t block_size)
41 struct btree_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;
47 if (dm_block_location(b) != le64_to_cpu(h->blocknr)) {
48 DMERR_LIMIT("node_check failed: blocknr %llu != wanted %llu",
49 le64_to_cpu(h->blocknr), dm_block_location(b));
50 return -ENOTBLK;
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_LIMIT("node_check failed: csum %u != wanted %u",
58 le32_to_cpu(csum_disk), le32_to_cpu(h->csum));
59 return -EILSEQ;
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_LIMIT("node_check failed: max_entries too large");
67 return -EILSEQ;
70 if (le32_to_cpu(h->nr_entries) > le32_to_cpu(h->max_entries)) {
71 DMERR_LIMIT("node_check failed: too many entries");
72 return -EILSEQ;
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_LIMIT("node_check failed: node is neither INTERNAL or LEAF");
81 return -EILSEQ;
84 return 0;
87 struct dm_block_validator btree_node_validator = {
88 .name = "btree_node",
89 .prepare_for_write = node_prepare_for_write,
90 .check = node_check
93 /*----------------------------------------------------------------*/
95 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)
105 int r, inc;
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);
112 return r;
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)
129 s->info = info;
130 s->count = 0;
131 s->nodes[0] = NULL;
132 s->nodes[1] = NULL;
135 int exit_ro_spine(struct ro_spine *s)
137 int r = 0, i;
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;
145 return r;
148 int ro_step(struct ro_spine *s, dm_block_t new_child)
150 int r;
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--;
160 r = bn_read_lock(s->info, new_child, s->nodes + s->count);
161 if (!r)
162 s->count++;
164 return r;
167 void ro_pop(struct ro_spine *s)
169 BUG_ON(!s->count);
170 --s->count;
171 unlock_block(s->info, s->nodes[s->count]);
174 struct btree_node *ro_node(struct ro_spine *s)
176 struct dm_block *block;
178 BUG_ON(!s->count);
179 block = s->nodes[s->count - 1];
181 return dm_block_data(block);
184 /*----------------------------------------------------------------*/
186 void init_shadow_spine(struct shadow_spine *s, struct dm_btree_info *info)
188 s->info = info;
189 s->count = 0;
192 int exit_shadow_spine(struct shadow_spine *s)
194 int r = 0, i;
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;
202 return r;
205 int shadow_step(struct shadow_spine *s, dm_block_t b,
206 struct dm_btree_value_type *vt)
208 int r;
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--;
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]);
223 s->count++;
226 return r;
229 struct dm_block *shadow_current(struct shadow_spine *s)
231 BUG_ON(!s->count);
233 return s->nodes[s->count - 1];
236 struct dm_block *shadow_parent(struct shadow_spine *s)
238 BUG_ON(s->count != 2);
240 return s->count == 2 ? s->nodes[0] : NULL;
243 int shadow_has_parent(struct shadow_spine *s)
245 return s->count >= 2;
248 int shadow_root(struct shadow_spine *s)
250 return s->root;
253 static void le64_inc(void *context, const void *value_le)
255 struct dm_transaction_manager *tm = context;
256 __le64 v_le;
258 memcpy(&v_le, value_le, sizeof(v_le));
259 dm_tm_inc(tm, le64_to_cpu(v_le));
262 static void le64_dec(void *context, const void *value_le)
264 struct dm_transaction_manager *tm = context;
265 __le64 v_le;
267 memcpy(&v_le, value_le, sizeof(v_le));
268 dm_tm_dec(tm, le64_to_cpu(v_le));
271 static int le64_equal(void *context, const void *value1_le, const void *value2_le)
273 __le64 v1_le, v2_le;
275 memcpy(&v1_le, value1_le, sizeof(v1_le));
276 memcpy(&v2_le, value2_le, sizeof(v2_le));
277 return v1_le == v2_le;
280 void init_le64_type(struct dm_transaction_manager *tm,
281 struct dm_btree_value_type *vt)
283 vt->context = tm;
284 vt->size = sizeof(__le64);
285 vt->inc = le64_inc;
286 vt->dec = le64_dec;
287 vt->equal = le64_equal;