Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2011 Red Hat, Inc. |
| 3 | * |
| 4 | * This file is released under the GPL. |
| 5 | */ |
| 6 | |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 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> |
Paul Gortmaker | 1944ce6 | 2011-09-28 18:29:32 -0400 | [diff] [blame] | 14 | #include <linux/export.h> |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 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 | |
Mike Snitzer | 145b900 | 2015-02-12 16:25:05 -0500 | [diff] [blame] | 81 | *result = count > 1; |
| 82 | |
| 83 | return 0; |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 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 | { |
Joe Thornber | 0377a07 | 2017-05-15 09:45:40 -0400 | [diff] [blame] | 145 | int r; |
| 146 | uint32_t old_count; |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 147 | enum allocation_event ev; |
| 148 | struct sm_disk *smd = container_of(sm, struct sm_disk, sm); |
| 149 | |
Joe Thornber | 0377a07 | 2017-05-15 09:45:40 -0400 | [diff] [blame] | 150 | r = sm_ll_dec(&smd->ll, b, &ev); |
| 151 | if (!r && (ev == SM_FREE)) { |
| 152 | /* |
| 153 | * It's only free if it's also free in the last |
| 154 | * transaction. |
| 155 | */ |
| 156 | r = sm_ll_lookup(&smd->old_ll, b, &old_count); |
| 157 | if (!r && !old_count) |
| 158 | smd->nr_allocated_this_transaction--; |
| 159 | } |
| 160 | |
| 161 | return r; |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 162 | } |
| 163 | |
| 164 | static int sm_disk_new_block(struct dm_space_map *sm, dm_block_t *b) |
| 165 | { |
| 166 | int r; |
| 167 | enum allocation_event ev; |
| 168 | struct sm_disk *smd = container_of(sm, struct sm_disk, sm); |
| 169 | |
| 170 | /* FIXME: we should loop round a couple of times */ |
| 171 | r = sm_ll_find_free_block(&smd->old_ll, smd->begin, smd->old_ll.nr_blocks, b); |
| 172 | if (r) |
| 173 | return r; |
| 174 | |
| 175 | smd->begin = *b + 1; |
| 176 | r = sm_ll_inc(&smd->ll, *b, &ev); |
| 177 | if (!r) { |
| 178 | BUG_ON(ev != SM_ALLOC); |
| 179 | smd->nr_allocated_this_transaction++; |
| 180 | } |
| 181 | |
| 182 | return r; |
| 183 | } |
| 184 | |
| 185 | static int sm_disk_commit(struct dm_space_map *sm) |
| 186 | { |
| 187 | int r; |
| 188 | dm_block_t nr_free; |
| 189 | struct sm_disk *smd = container_of(sm, struct sm_disk, sm); |
| 190 | |
| 191 | r = sm_disk_get_nr_free(sm, &nr_free); |
| 192 | if (r) |
| 193 | return r; |
| 194 | |
| 195 | r = sm_ll_commit(&smd->ll); |
| 196 | if (r) |
| 197 | return r; |
| 198 | |
| 199 | memcpy(&smd->old_ll, &smd->ll, sizeof(smd->old_ll)); |
| 200 | smd->begin = 0; |
| 201 | smd->nr_allocated_this_transaction = 0; |
| 202 | |
| 203 | r = sm_disk_get_nr_free(sm, &nr_free); |
| 204 | if (r) |
| 205 | return r; |
| 206 | |
| 207 | return 0; |
| 208 | } |
| 209 | |
| 210 | static int sm_disk_root_size(struct dm_space_map *sm, size_t *result) |
| 211 | { |
| 212 | *result = sizeof(struct disk_sm_root); |
| 213 | |
| 214 | return 0; |
| 215 | } |
| 216 | |
| 217 | static int sm_disk_copy_root(struct dm_space_map *sm, void *where_le, size_t max) |
| 218 | { |
| 219 | struct sm_disk *smd = container_of(sm, struct sm_disk, sm); |
| 220 | struct disk_sm_root root_le; |
| 221 | |
| 222 | root_le.nr_blocks = cpu_to_le64(smd->ll.nr_blocks); |
| 223 | root_le.nr_allocated = cpu_to_le64(smd->ll.nr_allocated); |
| 224 | root_le.bitmap_root = cpu_to_le64(smd->ll.bitmap_root); |
| 225 | root_le.ref_count_root = cpu_to_le64(smd->ll.ref_count_root); |
| 226 | |
| 227 | if (max < sizeof(root_le)) |
| 228 | return -ENOSPC; |
| 229 | |
| 230 | memcpy(where_le, &root_le, sizeof(root_le)); |
| 231 | |
| 232 | return 0; |
| 233 | } |
| 234 | |
| 235 | /*----------------------------------------------------------------*/ |
| 236 | |
| 237 | static struct dm_space_map ops = { |
| 238 | .destroy = sm_disk_destroy, |
| 239 | .extend = sm_disk_extend, |
| 240 | .get_nr_blocks = sm_disk_get_nr_blocks, |
| 241 | .get_nr_free = sm_disk_get_nr_free, |
| 242 | .get_count = sm_disk_get_count, |
| 243 | .count_is_more_than_one = sm_disk_count_is_more_than_one, |
| 244 | .set_count = sm_disk_set_count, |
| 245 | .inc_block = sm_disk_inc_block, |
| 246 | .dec_block = sm_disk_dec_block, |
| 247 | .new_block = sm_disk_new_block, |
| 248 | .commit = sm_disk_commit, |
| 249 | .root_size = sm_disk_root_size, |
Joe Thornber | 7c3d3f2 | 2013-05-10 14:37:20 +0100 | [diff] [blame] | 250 | .copy_root = sm_disk_copy_root, |
| 251 | .register_threshold_callback = NULL |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 252 | }; |
| 253 | |
Joe Thornber | 3caf6d7 | 2012-07-27 15:07:58 +0100 | [diff] [blame] | 254 | struct dm_space_map *dm_sm_disk_create(struct dm_transaction_manager *tm, |
| 255 | dm_block_t nr_blocks) |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 256 | { |
| 257 | int r; |
| 258 | struct sm_disk *smd; |
| 259 | |
| 260 | smd = kmalloc(sizeof(*smd), GFP_KERNEL); |
| 261 | if (!smd) |
| 262 | return ERR_PTR(-ENOMEM); |
| 263 | |
| 264 | smd->begin = 0; |
| 265 | smd->nr_allocated_this_transaction = 0; |
| 266 | memcpy(&smd->sm, &ops, sizeof(smd->sm)); |
| 267 | |
| 268 | r = sm_ll_new_disk(&smd->ll, tm); |
| 269 | if (r) |
| 270 | goto bad; |
| 271 | |
| 272 | r = sm_ll_extend(&smd->ll, nr_blocks); |
| 273 | if (r) |
| 274 | goto bad; |
| 275 | |
| 276 | r = sm_disk_commit(&smd->sm); |
| 277 | if (r) |
| 278 | goto bad; |
| 279 | |
| 280 | return &smd->sm; |
| 281 | |
| 282 | bad: |
| 283 | kfree(smd); |
| 284 | return ERR_PTR(r); |
| 285 | } |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 286 | EXPORT_SYMBOL_GPL(dm_sm_disk_create); |
| 287 | |
Joe Thornber | 3caf6d7 | 2012-07-27 15:07:58 +0100 | [diff] [blame] | 288 | struct dm_space_map *dm_sm_disk_open(struct dm_transaction_manager *tm, |
| 289 | void *root_le, size_t len) |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 290 | { |
| 291 | int r; |
| 292 | struct sm_disk *smd; |
| 293 | |
| 294 | smd = kmalloc(sizeof(*smd), GFP_KERNEL); |
| 295 | if (!smd) |
| 296 | return ERR_PTR(-ENOMEM); |
| 297 | |
| 298 | smd->begin = 0; |
| 299 | smd->nr_allocated_this_transaction = 0; |
| 300 | memcpy(&smd->sm, &ops, sizeof(smd->sm)); |
| 301 | |
| 302 | r = sm_ll_open_disk(&smd->ll, tm, root_le, len); |
| 303 | if (r) |
| 304 | goto bad; |
| 305 | |
| 306 | r = sm_disk_commit(&smd->sm); |
| 307 | if (r) |
| 308 | goto bad; |
| 309 | |
| 310 | return &smd->sm; |
| 311 | |
| 312 | bad: |
| 313 | kfree(smd); |
| 314 | return ERR_PTR(r); |
| 315 | } |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 316 | EXPORT_SYMBOL_GPL(dm_sm_disk_open); |
| 317 | |
| 318 | /*----------------------------------------------------------------*/ |