drivers/md/persistent-data/dm-space-map-disk.c

   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 /*----------------------------------------------------------------*/