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 */ 24struct 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 34static 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 41static 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 48static 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 56static 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 64static 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 71static 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 86static 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 126static 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 143static int sm_disk_dec_block(struct dm_space_map *sm, dm_block_t b) 144{ 145 enum allocation_event ev; 146 struct sm_disk *smd = container_of(sm, struct sm_disk, sm); 147 148 return sm_ll_dec(&smd->ll, b, &ev); 149} 150 151static 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 172static 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 197static 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 204static 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 224static 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, 237 .copy_root = sm_disk_copy_root, 238 .register_threshold_callback = NULL 239}; 240 241struct dm_space_map *dm_sm_disk_create(struct dm_transaction_manager *tm, 242 dm_block_t nr_blocks) 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 269bad: 270 kfree(smd); 271 return ERR_PTR(r); 272} 273EXPORT_SYMBOL_GPL(dm_sm_disk_create); 274 275struct dm_space_map *dm_sm_disk_open(struct dm_transaction_manager *tm, 276 void *root_le, size_t len) 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 299bad: 300 kfree(smd); 301 return ERR_PTR(r); 302} 303EXPORT_SYMBOL_GPL(dm_sm_disk_open); 304 305/*----------------------------------------------------------------*/ 306