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  */
24 struct 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 
34 static 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 
41 static 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 
48 static 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 
56 static 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 
64 static 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 
71 static 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 
86 static 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 
101 static 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 
114 static 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 
127 static 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 
157 static 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 
172 static 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 
179 static 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 
199 static 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 
216 struct 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 
244 bad:
245 	kfree(smd);
246 	return ERR_PTR(r);
247 }
248 EXPORT_SYMBOL_GPL(dm_sm_disk_create);
249 
250 struct 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 
274 bad:
275 	kfree(smd);
276 	return ERR_PTR(r);
277 }
278 EXPORT_SYMBOL_GPL(dm_sm_disk_open);
279 
280 /*----------------------------------------------------------------*/
281