Commit | Line | Data |
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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 | */ | |
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 | ||
145b9006 MS |
81 | *result = count > 1; |
82 | ||
83 | return 0; | |
3241b1d3 JT |
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 | uint32_t old_count; | |
91 | enum allocation_event ev; | |
92 | struct sm_disk *smd = container_of(sm, struct sm_disk, sm); | |
93 | ||
94 | r = sm_ll_insert(&smd->ll, b, count, &ev); | |
95 | if (!r) { | |
96 | switch (ev) { | |
97 | case SM_NONE: | |
98 | break; | |
99 | ||
100 | case SM_ALLOC: | |
101 | /* | |
102 | * This _must_ be free in the prior transaction | |
103 | * otherwise we've lost atomicity. | |
104 | */ | |
105 | smd->nr_allocated_this_transaction++; | |
106 | break; | |
107 | ||
108 | case SM_FREE: | |
109 | /* | |
110 | * It's only free if it's also free in the last | |
111 | * transaction. | |
112 | */ | |
113 | r = sm_ll_lookup(&smd->old_ll, b, &old_count); | |
114 | if (r) | |
115 | return r; | |
116 | ||
117 | if (!old_count) | |
118 | smd->nr_allocated_this_transaction--; | |
119 | break; | |
120 | } | |
121 | } | |
122 | ||
123 | return r; | |
124 | } | |
125 | ||
126 | static int sm_disk_inc_block(struct dm_space_map *sm, dm_block_t b) | |
127 | { | |
128 | int r; | |
129 | enum allocation_event ev; | |
130 | struct sm_disk *smd = container_of(sm, struct sm_disk, sm); | |
131 | ||
132 | r = sm_ll_inc(&smd->ll, b, &ev); | |
133 | if (!r && (ev == SM_ALLOC)) | |
134 | /* | |
135 | * This _must_ be free in the prior transaction | |
136 | * otherwise we've lost atomicity. | |
137 | */ | |
138 | smd->nr_allocated_this_transaction++; | |
139 | ||
140 | return r; | |
141 | } | |
142 | ||
143 | static int sm_disk_dec_block(struct dm_space_map *sm, dm_block_t b) | |
144 | { | |
3241b1d3 JT |
145 | enum allocation_event ev; |
146 | struct sm_disk *smd = container_of(sm, struct sm_disk, sm); | |
147 | ||
40c57f47 | 148 | return sm_ll_dec(&smd->ll, b, &ev); |
3241b1d3 JT |
149 | } |
150 | ||
151 | static int sm_disk_new_block(struct dm_space_map *sm, dm_block_t *b) | |
152 | { | |
153 | int r; | |
154 | enum allocation_event ev; | |
155 | struct sm_disk *smd = container_of(sm, struct sm_disk, sm); | |
156 | ||
157 | /* FIXME: we should loop round a couple of times */ | |
158 | r = sm_ll_find_free_block(&smd->old_ll, smd->begin, smd->old_ll.nr_blocks, b); | |
159 | if (r) | |
160 | return r; | |
161 | ||
162 | smd->begin = *b + 1; | |
163 | r = sm_ll_inc(&smd->ll, *b, &ev); | |
164 | if (!r) { | |
165 | BUG_ON(ev != SM_ALLOC); | |
166 | smd->nr_allocated_this_transaction++; | |
167 | } | |
168 | ||
169 | return r; | |
170 | } | |
171 | ||
172 | static int sm_disk_commit(struct dm_space_map *sm) | |
173 | { | |
174 | int r; | |
175 | dm_block_t nr_free; | |
176 | struct sm_disk *smd = container_of(sm, struct sm_disk, sm); | |
177 | ||
178 | r = sm_disk_get_nr_free(sm, &nr_free); | |
179 | if (r) | |
180 | return r; | |
181 | ||
182 | r = sm_ll_commit(&smd->ll); | |
183 | if (r) | |
184 | return r; | |
185 | ||
186 | memcpy(&smd->old_ll, &smd->ll, sizeof(smd->old_ll)); | |
187 | smd->begin = 0; | |
188 | smd->nr_allocated_this_transaction = 0; | |
189 | ||
190 | r = sm_disk_get_nr_free(sm, &nr_free); | |
191 | if (r) | |
192 | return r; | |
193 | ||
194 | return 0; | |
195 | } | |
196 | ||
197 | static int sm_disk_root_size(struct dm_space_map *sm, size_t *result) | |
198 | { | |
199 | *result = sizeof(struct disk_sm_root); | |
200 | ||
201 | return 0; | |
202 | } | |
203 | ||
204 | static int sm_disk_copy_root(struct dm_space_map *sm, void *where_le, size_t max) | |
205 | { | |
206 | struct sm_disk *smd = container_of(sm, struct sm_disk, sm); | |
207 | struct disk_sm_root root_le; | |
208 | ||
209 | root_le.nr_blocks = cpu_to_le64(smd->ll.nr_blocks); | |
210 | root_le.nr_allocated = cpu_to_le64(smd->ll.nr_allocated); | |
211 | root_le.bitmap_root = cpu_to_le64(smd->ll.bitmap_root); | |
212 | root_le.ref_count_root = cpu_to_le64(smd->ll.ref_count_root); | |
213 | ||
214 | if (max < sizeof(root_le)) | |
215 | return -ENOSPC; | |
216 | ||
217 | memcpy(where_le, &root_le, sizeof(root_le)); | |
218 | ||
219 | return 0; | |
220 | } | |
221 | ||
222 | /*----------------------------------------------------------------*/ | |
223 | ||
224 | static struct dm_space_map ops = { | |
225 | .destroy = sm_disk_destroy, | |
226 | .extend = sm_disk_extend, | |
227 | .get_nr_blocks = sm_disk_get_nr_blocks, | |
228 | .get_nr_free = sm_disk_get_nr_free, | |
229 | .get_count = sm_disk_get_count, | |
230 | .count_is_more_than_one = sm_disk_count_is_more_than_one, | |
231 | .set_count = sm_disk_set_count, | |
232 | .inc_block = sm_disk_inc_block, | |
233 | .dec_block = sm_disk_dec_block, | |
234 | .new_block = sm_disk_new_block, | |
235 | .commit = sm_disk_commit, | |
236 | .root_size = sm_disk_root_size, | |
7c3d3f2a JT |
237 | .copy_root = sm_disk_copy_root, |
238 | .register_threshold_callback = NULL | |
3241b1d3 JT |
239 | }; |
240 | ||
3caf6d73 JT |
241 | struct dm_space_map *dm_sm_disk_create(struct dm_transaction_manager *tm, |
242 | dm_block_t nr_blocks) | |
3241b1d3 JT |
243 | { |
244 | int r; | |
245 | struct sm_disk *smd; | |
246 | ||
247 | smd = kmalloc(sizeof(*smd), GFP_KERNEL); | |
248 | if (!smd) | |
249 | return ERR_PTR(-ENOMEM); | |
250 | ||
251 | smd->begin = 0; | |
252 | smd->nr_allocated_this_transaction = 0; | |
253 | memcpy(&smd->sm, &ops, sizeof(smd->sm)); | |
254 | ||
255 | r = sm_ll_new_disk(&smd->ll, tm); | |
256 | if (r) | |
257 | goto bad; | |
258 | ||
259 | r = sm_ll_extend(&smd->ll, nr_blocks); | |
260 | if (r) | |
261 | goto bad; | |
262 | ||
263 | r = sm_disk_commit(&smd->sm); | |
264 | if (r) | |
265 | goto bad; | |
266 | ||
267 | return &smd->sm; | |
268 | ||
269 | bad: | |
270 | kfree(smd); | |
271 | return ERR_PTR(r); | |
272 | } | |
3241b1d3 JT |
273 | EXPORT_SYMBOL_GPL(dm_sm_disk_create); |
274 | ||
3caf6d73 JT |
275 | struct dm_space_map *dm_sm_disk_open(struct dm_transaction_manager *tm, |
276 | void *root_le, size_t len) | |
3241b1d3 JT |
277 | { |
278 | int r; | |
279 | struct sm_disk *smd; | |
280 | ||
281 | smd = kmalloc(sizeof(*smd), GFP_KERNEL); | |
282 | if (!smd) | |
283 | return ERR_PTR(-ENOMEM); | |
284 | ||
285 | smd->begin = 0; | |
286 | smd->nr_allocated_this_transaction = 0; | |
287 | memcpy(&smd->sm, &ops, sizeof(smd->sm)); | |
288 | ||
289 | r = sm_ll_open_disk(&smd->ll, tm, root_le, len); | |
290 | if (r) | |
291 | goto bad; | |
292 | ||
293 | r = sm_disk_commit(&smd->sm); | |
294 | if (r) | |
295 | goto bad; | |
296 | ||
297 | return &smd->sm; | |
298 | ||
299 | bad: | |
300 | kfree(smd); | |
301 | return ERR_PTR(r); | |
302 | } | |
3241b1d3 JT |
303 | EXPORT_SYMBOL_GPL(dm_sm_disk_open); |
304 | ||
305 | /*----------------------------------------------------------------*/ |