1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2011 Red Hat, Inc.
4 *
5 * This file is released under the GPL.
6 */
7
8#include "dm-space-map-common.h"
9#include "dm-space-map-disk.h"
10#include "dm-space-map.h"
11#include "dm-transaction-manager.h"
12
13#include <linux/list.h>
14#include <linux/slab.h>
15#include <linux/export.h>
16#include <linux/device-mapper.h>
17
18#define DM_MSG_PREFIX "space map disk"
19
20/*----------------------------------------------------------------*/
21
22/*
23 * Space map interface.
24 */
25struct sm_disk {
26	struct dm_space_map sm;
27
28	struct ll_disk ll;
29	struct ll_disk old_ll;
30
31	dm_block_t begin;
32	dm_block_t nr_allocated_this_transaction;
33};
34
35static void sm_disk_destroy(struct dm_space_map *sm)
36{
37	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
38
39	kfree(smd);
40}
41
42static int sm_disk_extend(struct dm_space_map *sm, dm_block_t extra_blocks)
43{
44	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
45
46	return sm_ll_extend(&smd->ll, extra_blocks);
47}
48
49static int sm_disk_get_nr_blocks(struct dm_space_map *sm, dm_block_t *count)
50{
51	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
52
53	*count = smd->old_ll.nr_blocks;
54
55	return 0;
56}
57
58static int sm_disk_get_nr_free(struct dm_space_map *sm, dm_block_t *count)
59{
60	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
61
62	*count = (smd->old_ll.nr_blocks - smd->old_ll.nr_allocated) - smd->nr_allocated_this_transaction;
63
64	return 0;
65}
66
67static int sm_disk_get_count(struct dm_space_map *sm, dm_block_t b,
68			     uint32_t *result)
69{
70	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
71
72	return sm_ll_lookup(&smd->ll, b, result);
73}
74
75static int sm_disk_count_is_more_than_one(struct dm_space_map *sm, dm_block_t b,
76					  int *result)
77{
78	int r;
79	uint32_t count;
80
81	r = sm_disk_get_count(sm, b, &count);
82	if (r)
83		return r;
84
85	*result = count > 1;
86
87	return 0;
88}
89
90static int sm_disk_set_count(struct dm_space_map *sm, dm_block_t b,
91			     uint32_t count)
92{
93	int r;
94	int32_t nr_allocations;
95	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
96
97	r = sm_ll_insert(&smd->ll, b, count, &nr_allocations);
98	if (!r)
99		smd->nr_allocated_this_transaction += nr_allocations;
100
101	return r;
102}
103
104static int sm_disk_inc_blocks(struct dm_space_map *sm, dm_block_t b, dm_block_t e)
105{
106	int r;
107	int32_t nr_allocations;
108	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
109
110	r = sm_ll_inc(&smd->ll, b, e, &nr_allocations);
111	if (!r)
112		smd->nr_allocated_this_transaction += nr_allocations;
113
114	return r;
115}
116
117static int sm_disk_dec_blocks(struct dm_space_map *sm, dm_block_t b, dm_block_t e)
118{
119	int r;
120	int32_t nr_allocations;
121	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
122
123	r = sm_ll_dec(&smd->ll, b, e, &nr_allocations);
124	if (!r)
125		smd->nr_allocated_this_transaction += nr_allocations;
126
127	return r;
128}
129
130static int sm_disk_new_block(struct dm_space_map *sm, dm_block_t *b)
131{
132	int r;
133	int32_t nr_allocations;
134	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
135
136	/*
137	 * Any block we allocate has to be free in both the old and current ll.
138	 */
139	r = sm_ll_find_common_free_block(&smd->old_ll, &smd->ll, smd->begin, smd->ll.nr_blocks, b);
140	if (r == -ENOSPC)
141		/*
142		 * There's no free block between smd->begin and the end of the metadata device.
143		 * We search before smd->begin in case something has been freed.
144		 */
145		r = sm_ll_find_common_free_block(&smd->old_ll, &smd->ll, 0, smd->begin, b);
146
147	if (r)
148		return r;
149
150	smd->begin = *b + 1;
151	r = sm_ll_inc(&smd->ll, *b, *b + 1, &nr_allocations);
152	if (!r)
153		smd->nr_allocated_this_transaction += nr_allocations;
154
155	return r;
156}
157
158static int sm_disk_commit(struct dm_space_map *sm)
159{
160	int r;
161	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
162
163	r = sm_ll_commit(&smd->ll);
164	if (r)
165		return r;
166
167	memcpy(&smd->old_ll, &smd->ll, sizeof(smd->old_ll));
168	smd->nr_allocated_this_transaction = 0;
169
170	return 0;
171}
172
173static int sm_disk_root_size(struct dm_space_map *sm, size_t *result)
174{
175	*result = sizeof(struct disk_sm_root);
176
177	return 0;
178}
179
180static int sm_disk_copy_root(struct dm_space_map *sm, void *where_le, size_t max)
181{
182	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
183	struct disk_sm_root root_le;
184
185	root_le.nr_blocks = cpu_to_le64(smd->ll.nr_blocks);
186	root_le.nr_allocated = cpu_to_le64(smd->ll.nr_allocated);
187	root_le.bitmap_root = cpu_to_le64(smd->ll.bitmap_root);
188	root_le.ref_count_root = cpu_to_le64(smd->ll.ref_count_root);
189
190	if (max < sizeof(root_le))
191		return -ENOSPC;
192
193	memcpy(where_le, &root_le, sizeof(root_le));
194
195	return 0;
196}
197
198/*----------------------------------------------------------------*/
199
200static struct dm_space_map ops = {
201	.destroy = sm_disk_destroy,
202	.extend = sm_disk_extend,
203	.get_nr_blocks = sm_disk_get_nr_blocks,
204	.get_nr_free = sm_disk_get_nr_free,
205	.get_count = sm_disk_get_count,
206	.count_is_more_than_one = sm_disk_count_is_more_than_one,
207	.set_count = sm_disk_set_count,
208	.inc_blocks = sm_disk_inc_blocks,
209	.dec_blocks = sm_disk_dec_blocks,
210	.new_block = sm_disk_new_block,
211	.commit = sm_disk_commit,
212	.root_size = sm_disk_root_size,
213	.copy_root = sm_disk_copy_root,
214	.register_threshold_callback = NULL
215};
216
217struct dm_space_map *dm_sm_disk_create(struct dm_transaction_manager *tm,
218				       dm_block_t nr_blocks)
219{
220	int r;
221	struct sm_disk *smd;
222
223	smd = kmalloc(sizeof(*smd), GFP_KERNEL);
224	if (!smd)
225		return ERR_PTR(-ENOMEM);
226
227	smd->begin = 0;
228	smd->nr_allocated_this_transaction = 0;
229	memcpy(&smd->sm, &ops, sizeof(smd->sm));
230
231	r = sm_ll_new_disk(&smd->ll, tm);
232	if (r)
233		goto bad;
234
235	r = sm_ll_extend(&smd->ll, nr_blocks);
236	if (r)
237		goto bad;
238
239	r = sm_disk_commit(&smd->sm);
240	if (r)
241		goto bad;
242
243	return &smd->sm;
244
245bad:
246	kfree(smd);
247	return ERR_PTR(r);
248}
249EXPORT_SYMBOL_GPL(dm_sm_disk_create);
250
251struct dm_space_map *dm_sm_disk_open(struct dm_transaction_manager *tm,
252				     void *root_le, size_t len)
253{
254	int r;
255	struct sm_disk *smd;
256
257	smd = kmalloc(sizeof(*smd), GFP_KERNEL);
258	if (!smd)
259		return ERR_PTR(-ENOMEM);
260
261	smd->begin = 0;
262	smd->nr_allocated_this_transaction = 0;
263	memcpy(&smd->sm, &ops, sizeof(smd->sm));
264
265	r = sm_ll_open_disk(&smd->ll, tm, root_le, len);
266	if (r)
267		goto bad;
268
269	r = sm_disk_commit(&smd->sm);
270	if (r)
271		goto bad;
272
273	return &smd->sm;
274
275bad:
276	kfree(smd);
277	return ERR_PTR(r);
278}
279EXPORT_SYMBOL_GPL(dm_sm_disk_open);
280
281/*----------------------------------------------------------------*/
282