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

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