1/*
  2 * Copyright (C) 2011 Red Hat, Inc.
  3 *
  4 * This file is released under the GPL.
  5 */
  6
  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>
 14#include <linux/export.h>
 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	*result = count > 1;
 82
 83	return 0;
 84}
 85
 86static int sm_disk_set_count(struct dm_space_map *sm, dm_block_t b,
 87			     uint32_t count)
 88{
 89	int r;
 90	int32_t nr_allocations;
 91	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
 92
 93	r = sm_ll_insert(&smd->ll, b, count, &nr_allocations);
 94	if (!r) {
 95		smd->nr_allocated_this_transaction += nr_allocations;
 96	}
 97
 98	return r;
 99}
100
101static int sm_disk_inc_blocks(struct dm_space_map *sm, dm_block_t b, dm_block_t e)
102{
103	int r;
104	int32_t nr_allocations;
105	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
106
107	r = sm_ll_inc(&smd->ll, b, e, &nr_allocations);
108	if (!r)
109		smd->nr_allocated_this_transaction += nr_allocations;
110
111	return r;
112}
113
114static int sm_disk_dec_blocks(struct dm_space_map *sm, dm_block_t b, dm_block_t e)
115{
116	int r;
117	int32_t nr_allocations;
118	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
119
120	r = sm_ll_dec(&smd->ll, b, e, &nr_allocations);
121	if (!r)
122		smd->nr_allocated_this_transaction += nr_allocations;
123
124	return r;
125}
126
127static int sm_disk_new_block(struct dm_space_map *sm, dm_block_t *b)
128{
129	int r;
130	int32_t nr_allocations;
131	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
132
133	/*
134	 * Any block we allocate has to be free in both the old and current ll.
135	 */
136	r = sm_ll_find_common_free_block(&smd->old_ll, &smd->ll, smd->begin, smd->ll.nr_blocks, b);
137	if (r == -ENOSPC) {
138		/*
139		 * There's no free block between smd->begin and the end of the metadata device.
140		 * We search before smd->begin in case something has been freed.
141		 */
142		r = sm_ll_find_common_free_block(&smd->old_ll, &smd->ll, 0, smd->begin, b);
143	}
144
145	if (r)
146		return r;
147
148	smd->begin = *b + 1;
149	r = sm_ll_inc(&smd->ll, *b, *b + 1, &nr_allocations);
150	if (!r) {
151		smd->nr_allocated_this_transaction += nr_allocations;
152	}
153
154	return r;
155}
156
157static int sm_disk_commit(struct dm_space_map *sm)
158{
159	int r;
160	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
161
162	r = sm_ll_commit(&smd->ll);
163	if (r)
164		return r;
165
166	memcpy(&smd->old_ll, &smd->ll, sizeof(smd->old_ll));
167	smd->nr_allocated_this_transaction = 0;
168
169	return 0;
170}
171
172static int sm_disk_root_size(struct dm_space_map *sm, size_t *result)
173{
174	*result = sizeof(struct disk_sm_root);
175
176	return 0;
177}
178
179static int sm_disk_copy_root(struct dm_space_map *sm, void *where_le, size_t max)
180{
181	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
182	struct disk_sm_root root_le;
183
184	root_le.nr_blocks = cpu_to_le64(smd->ll.nr_blocks);
185	root_le.nr_allocated = cpu_to_le64(smd->ll.nr_allocated);
186	root_le.bitmap_root = cpu_to_le64(smd->ll.bitmap_root);
187	root_le.ref_count_root = cpu_to_le64(smd->ll.ref_count_root);
188
189	if (max < sizeof(root_le))
190		return -ENOSPC;
191
192	memcpy(where_le, &root_le, sizeof(root_le));
193
194	return 0;
195}
196
197/*----------------------------------------------------------------*/
198
199static struct dm_space_map ops = {
200	.destroy = sm_disk_destroy,
201	.extend = sm_disk_extend,
202	.get_nr_blocks = sm_disk_get_nr_blocks,
203	.get_nr_free = sm_disk_get_nr_free,
204	.get_count = sm_disk_get_count,
205	.count_is_more_than_one = sm_disk_count_is_more_than_one,
206	.set_count = sm_disk_set_count,
207	.inc_blocks = sm_disk_inc_blocks,
208	.dec_blocks = sm_disk_dec_blocks,
209	.new_block = sm_disk_new_block,
210	.commit = sm_disk_commit,
211	.root_size = sm_disk_root_size,
212	.copy_root = sm_disk_copy_root,
213	.register_threshold_callback = NULL
214};
215
216struct dm_space_map *dm_sm_disk_create(struct dm_transaction_manager *tm,
217				       dm_block_t nr_blocks)
218{
219	int r;
220	struct sm_disk *smd;
221
222	smd = kmalloc(sizeof(*smd), GFP_KERNEL);
223	if (!smd)
224		return ERR_PTR(-ENOMEM);
225
226	smd->begin = 0;
227	smd->nr_allocated_this_transaction = 0;
228	memcpy(&smd->sm, &ops, sizeof(smd->sm));
229
230	r = sm_ll_new_disk(&smd->ll, tm);
231	if (r)
232		goto bad;
233
234	r = sm_ll_extend(&smd->ll, nr_blocks);
235	if (r)
236		goto bad;
237
238	r = sm_disk_commit(&smd->sm);
239	if (r)
240		goto bad;
241
242	return &smd->sm;
243
244bad:
245	kfree(smd);
246	return ERR_PTR(r);
247}
248EXPORT_SYMBOL_GPL(dm_sm_disk_create);
249
250struct dm_space_map *dm_sm_disk_open(struct dm_transaction_manager *tm,
251				     void *root_le, size_t len)
252{
253	int r;
254	struct sm_disk *smd;
255
256	smd = kmalloc(sizeof(*smd), GFP_KERNEL);
257	if (!smd)
258		return ERR_PTR(-ENOMEM);
259
260	smd->begin = 0;
261	smd->nr_allocated_this_transaction = 0;
262	memcpy(&smd->sm, &ops, sizeof(smd->sm));
263
264	r = sm_ll_open_disk(&smd->ll, tm, root_le, len);
265	if (r)
266		goto bad;
267
268	r = sm_disk_commit(&smd->sm);
269	if (r)
270		goto bad;
271
272	return &smd->sm;
273
274bad:
275	kfree(smd);
276	return ERR_PTR(r);
277}
278EXPORT_SYMBOL_GPL(dm_sm_disk_open);
279
280/*----------------------------------------------------------------*/