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  */
25 struct 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 
35 static 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 
42 static 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 
49 static 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 
58 static 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 
67 static 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 
75 static 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 
90 static 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 
104 static 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 
117 static 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 
130 static 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 
158 static 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 
173 static 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 
180 static 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 
200 static 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 
217 struct 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 
245 bad:
246 	kfree(smd);
247 	return ERR_PTR(r);
248 }
249 EXPORT_SYMBOL_GPL(dm_sm_disk_create);
250 
251 struct 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 
275 bad:
276 	kfree(smd);
277 	return ERR_PTR(r);
278 }
279 EXPORT_SYMBOL_GPL(dm_sm_disk_open);
280 
281 /*----------------------------------------------------------------*/
282