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dm thin: detect metadata device resizing
[linux-2.6-block.git] / drivers / md / persistent-data / dm-space-map-disk.c
CommitLineData
3241b1d3
JT		 1/*
2 * Copyright (C) 2011 Red Hat, Inc.
3 *
4 * This file is released under the GPL.
5 */
6
3241b1d3
JT		 7#include "dm-space-map-common.h"
8#include "dm-space-map-disk.h"
9#include "dm-space-map.h"
10#include "dm-transaction-manager.h"
11
12#include <linux/list.h>
13#include <linux/slab.h>
1944ce60 14#include <linux/export.h>
3241b1d3
JT		 15#include <linux/device-mapper.h>
16
17#define DM_MSG_PREFIX "space map disk"
18
19/*----------------------------------------------------------------*/
20
21/*
22 * Space map interface.
23 */
24struct sm_disk {
25 struct dm_space_map sm;
26
27 struct ll_disk ll;
28 struct ll_disk old_ll;
29
30 dm_block_t begin;
31 dm_block_t nr_allocated_this_transaction;
32};
33
34static void sm_disk_destroy(struct dm_space_map *sm)
35{
36 struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
37
38 kfree(smd);
39}
40
41static int sm_disk_extend(struct dm_space_map *sm, dm_block_t extra_blocks)
42{
43 struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
44
45 return sm_ll_extend(&smd->ll, extra_blocks);
46}
47
48static int sm_disk_get_nr_blocks(struct dm_space_map *sm, dm_block_t *count)
49{
50 struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
51 *count = smd->old_ll.nr_blocks;
52
53 return 0;
54}
55
56static int sm_disk_get_nr_free(struct dm_space_map *sm, dm_block_t *count)
57{
58 struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
59 *count = (smd->old_ll.nr_blocks - smd->old_ll.nr_allocated) - smd->nr_allocated_this_transaction;
60
61 return 0;
62}
63
64static int sm_disk_get_count(struct dm_space_map *sm, dm_block_t b,
65 uint32_t *result)
66{
67 struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
68 return sm_ll_lookup(&smd->ll, b, result);
69}
70
71static int sm_disk_count_is_more_than_one(struct dm_space_map *sm, dm_block_t b,
72 int *result)
73{
74 int r;
75 uint32_t count;
76
77 r = sm_disk_get_count(sm, b, &count);
78 if (r)
79 return r;
80
81 return count > 1;
82}
83
84static int sm_disk_set_count(struct dm_space_map *sm, dm_block_t b,
85 uint32_t count)
86{
87 int r;
88 uint32_t old_count;
89 enum allocation_event ev;
90 struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
91
92 r = sm_ll_insert(&smd->ll, b, count, &ev);
93 if (!r) {
94 switch (ev) {
95 case SM_NONE:
96 break;
97
98 case SM_ALLOC:
99 /*
100 * This _must_ be free in the prior transaction
101 * otherwise we've lost atomicity.
102 */
103 smd->nr_allocated_this_transaction++;
104 break;
105
106 case SM_FREE:
107 /*
108 * It's only free if it's also free in the last
109 * transaction.
110 */
111 r = sm_ll_lookup(&smd->old_ll, b, &old_count);
112 if (r)
113 return r;
114
115 if (!old_count)
116 smd->nr_allocated_this_transaction--;
117 break;
118 }
119 }
120
121 return r;
122}
123
124static int sm_disk_inc_block(struct dm_space_map *sm, dm_block_t b)
125{
126 int r;
127 enum allocation_event ev;
128 struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
129
130 r = sm_ll_inc(&smd->ll, b, &ev);
131 if (!r && (ev == SM_ALLOC))
132 /*
133 * This _must_ be free in the prior transaction
134 * otherwise we've lost atomicity.
135 */
136 smd->nr_allocated_this_transaction++;
137
138 return r;
139}
140
141static int sm_disk_dec_block(struct dm_space_map *sm, dm_block_t b)
142{
143 int r;
144 uint32_t old_count;
145 enum allocation_event ev;
146 struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
147
148 r = sm_ll_dec(&smd->ll, b, &ev);
149 if (!r && (ev == SM_FREE)) {
150 /*
151 * It's only free if it's also free in the last
152 * transaction.
153 */
154 r = sm_ll_lookup(&smd->old_ll, b, &old_count);
155 if (r)
156 return r;
157
158 if (!old_count)
159 smd->nr_allocated_this_transaction--;
160 }
161
162 return r;
163}
164
165static int sm_disk_new_block(struct dm_space_map *sm, dm_block_t *b)
166{
167 int r;
168 enum allocation_event ev;
169 struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
170
171 /* FIXME: we should loop round a couple of times */
172 r = sm_ll_find_free_block(&smd->old_ll, smd->begin, smd->old_ll.nr_blocks, b);
173 if (r)
174 return r;
175
176 smd->begin = *b + 1;
177 r = sm_ll_inc(&smd->ll, *b, &ev);
178 if (!r) {
179 BUG_ON(ev != SM_ALLOC);
180 smd->nr_allocated_this_transaction++;
181 }
182
183 return r;
184}
185
186static int sm_disk_commit(struct dm_space_map *sm)
187{
188 int r;
189 dm_block_t nr_free;
190 struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
191
192 r = sm_disk_get_nr_free(sm, &nr_free);
193 if (r)
194 return r;
195
196 r = sm_ll_commit(&smd->ll);
197 if (r)
198 return r;
199
200 memcpy(&smd->old_ll, &smd->ll, sizeof(smd->old_ll));
201 smd->begin = 0;
202 smd->nr_allocated_this_transaction = 0;
203
204 r = sm_disk_get_nr_free(sm, &nr_free);
205 if (r)
206 return r;
207
208 return 0;
209}
210
211static int sm_disk_root_size(struct dm_space_map *sm, size_t *result)
212{
213 *result = sizeof(struct disk_sm_root);
214
215 return 0;
216}
217
218static int sm_disk_copy_root(struct dm_space_map *sm, void *where_le, size_t max)
219{
220 struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
221 struct disk_sm_root root_le;
222
223 root_le.nr_blocks = cpu_to_le64(smd->ll.nr_blocks);
224 root_le.nr_allocated = cpu_to_le64(smd->ll.nr_allocated);
225 root_le.bitmap_root = cpu_to_le64(smd->ll.bitmap_root);
226 root_le.ref_count_root = cpu_to_le64(smd->ll.ref_count_root);
227
228 if (max < sizeof(root_le))
229 return -ENOSPC;
230
231 memcpy(where_le, &root_le, sizeof(root_le));
232
233 return 0;
234}
235
236/*----------------------------------------------------------------*/
237
238static struct dm_space_map ops = {
239 .destroy = sm_disk_destroy,
240 .extend = sm_disk_extend,
241 .get_nr_blocks = sm_disk_get_nr_blocks,
242 .get_nr_free = sm_disk_get_nr_free,
243 .get_count = sm_disk_get_count,
244 .count_is_more_than_one = sm_disk_count_is_more_than_one,
245 .set_count = sm_disk_set_count,
246 .inc_block = sm_disk_inc_block,
247 .dec_block = sm_disk_dec_block,
248 .new_block = sm_disk_new_block,
249 .commit = sm_disk_commit,
250 .root_size = sm_disk_root_size,
251 .copy_root = sm_disk_copy_root
252};
253
3caf6d73
JT		 254struct dm_space_map *dm_sm_disk_create(struct dm_transaction_manager *tm,
255 dm_block_t nr_blocks)
3241b1d3
JT		 256{
257 int r;
258 struct sm_disk *smd;
259
260 smd = kmalloc(sizeof(*smd), GFP_KERNEL);
261 if (!smd)
262 return ERR_PTR(-ENOMEM);
263
264 smd->begin = 0;
265 smd->nr_allocated_this_transaction = 0;
266 memcpy(&smd->sm, &ops, sizeof(smd->sm));
267
268 r = sm_ll_new_disk(&smd->ll, tm);
269 if (r)
270 goto bad;
271
272 r = sm_ll_extend(&smd->ll, nr_blocks);
273 if (r)
274 goto bad;
275
276 r = sm_disk_commit(&smd->sm);
277 if (r)
278 goto bad;
279
280 return &smd->sm;
281
282bad:
283 kfree(smd);
284 return ERR_PTR(r);
285}
3241b1d3
JT		 286EXPORT_SYMBOL_GPL(dm_sm_disk_create);
287
3caf6d73
JT		 288struct dm_space_map *dm_sm_disk_open(struct dm_transaction_manager *tm,
289 void *root_le, size_t len)
3241b1d3
JT		 290{
291 int r;
292 struct sm_disk *smd;
293
294 smd = kmalloc(sizeof(*smd), GFP_KERNEL);
295 if (!smd)
296 return ERR_PTR(-ENOMEM);
297
298 smd->begin = 0;
299 smd->nr_allocated_this_transaction = 0;
300 memcpy(&smd->sm, &ops, sizeof(smd->sm));
301
302 r = sm_ll_open_disk(&smd->ll, tm, root_le, len);
303 if (r)
304 goto bad;
305
306 r = sm_disk_commit(&smd->sm);
307 if (r)
308 goto bad;
309
310 return &smd->sm;
311
312bad:
313 kfree(smd);
314 return ERR_PTR(r);
315}
3241b1d3
JT		 316EXPORT_SYMBOL_GPL(dm_sm_disk_open);
317
318/*----------------------------------------------------------------*/
Linux 6.x block layer and io_uring tree(s)