convert/common.c

   1 /*
   2  * This program is free software; you can redistribute it and/or
   3  * modify it under the terms of the GNU General Public
   4  * License v2 as published by the Free Software Foundation.
   5  *
   6  * This program is distributed in the hope that it will be useful,
   7  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   8  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   9  * General Public License for more details.
  10  *
  11  * You should have received a copy of the GNU General Public
  12  * License along with this program; if not, write to the
  13  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  14  * Boston, MA 021110-1307, USA.
  15  */
  16
  17 #include <unistd.h>
  18 #include <uuid/uuid.h>
  19 #include "disk-io.h"
  20 #include "volumes.h"
  21 #include "utils.h"
  22 #include "mkfs/common.h"
  23 #include "convert/common.h"
  24
  25 #define BTRFS_CONVERT_META_GROUP_SIZE SZ_32M
  26
  27 /*
  28  * Reserve space from free_tree.
  29  * The algorithm is very simple, find the first cache_extent with enough space
  30  * and allocate from its beginning.
  31  */
  32 static int reserve_free_space(struct cache_tree *free_tree, u64 len,
  33                               u64 *ret_start)
  34 {
  35         struct cache_extent *cache;
  36         int found = 0;
  37
  38         ASSERT(ret_start != NULL);
  39         cache = first_cache_extent(free_tree);
  40         while (cache) {
  41                 if (cache->size > len) {
  42                         found = 1;
  43                         *ret_start = cache->start;
  44
  45                         cache->size -= len;
  46                         if (cache->size == 0) {
  47                                 remove_cache_extent(free_tree, cache);
  48                                 free(cache);
  49                         } else {
  50                                 cache->start += len;
  51                         }
  52                         break;
  53                 }
  54                 cache = next_cache_extent(cache);
  55         }
  56         if (!found)
  57                 return -ENOSPC;
  58         return 0;
  59 }
  60
  61 static inline int write_temp_super(int fd, struct btrfs_super_block *sb,
  62                                   u64 sb_bytenr)
  63 {
  64        u32 crc = ~(u32)0;
  65        int ret;
  66
  67        crc = btrfs_csum_data((char *)sb + BTRFS_CSUM_SIZE, crc,
  68                              BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
  69        btrfs_csum_final(crc, &sb->csum[0]);
  70        ret = pwrite(fd, sb, BTRFS_SUPER_INFO_SIZE, sb_bytenr);
  71        if (ret < BTRFS_SUPER_INFO_SIZE)
  72                ret = (ret < 0 ? -errno : -EIO);
  73        else
  74                ret = 0;
  75        return ret;
  76 }
  77
  78 /*
  79  * Setup temporary superblock at cfg->super_bynter
  80  * Needed info are extracted from cfg, and root_bytenr, chunk_bytenr
  81  *
  82  * For now sys chunk array will be empty and dev_item is empty too.
  83  * They will be re-initialized at temp chunk tree setup.
  84  *
  85  * The superblock signature is not valid, denotes a partially created
  86  * filesystem, needs to be finalized.
  87  */
  88 static int setup_temp_super(int fd, struct btrfs_mkfs_config *cfg,
  89                             u64 root_bytenr, u64 chunk_bytenr)
  90 {
  91         unsigned char chunk_uuid[BTRFS_UUID_SIZE];
  92         char super_buf[BTRFS_SUPER_INFO_SIZE];
  93         struct btrfs_super_block *super = (struct btrfs_super_block *)super_buf;
  94         int ret;
  95
  96         memset(super_buf, 0, BTRFS_SUPER_INFO_SIZE);
  97         cfg->num_bytes = round_down(cfg->num_bytes, cfg->sectorsize);
  98
  99         if (*cfg->fs_uuid) {
 100                 if (uuid_parse(cfg->fs_uuid, super->fsid) != 0) {
 101                         error("cound not parse UUID: %s", cfg->fs_uuid);
 102                         ret = -EINVAL;
 103                         goto out;
 104                 }
 105                 if (!test_uuid_unique(cfg->fs_uuid)) {
 106                         error("non-unique UUID: %s", cfg->fs_uuid);
 107                         ret = -EINVAL;
 108                         goto out;
 109                 }
 110         } else {
 111                 uuid_generate(super->fsid);
 112                 uuid_unparse(super->fsid, cfg->fs_uuid);
 113         }
 114         uuid_generate(chunk_uuid);
 115         uuid_unparse(chunk_uuid, cfg->chunk_uuid);
 116
 117         btrfs_set_super_bytenr(super, cfg->super_bytenr);
 118         btrfs_set_super_num_devices(super, 1);
 119         btrfs_set_super_magic(super, BTRFS_MAGIC_TEMPORARY);
 120         btrfs_set_super_generation(super, 1);
 121         btrfs_set_super_root(super, root_bytenr);
 122         btrfs_set_super_chunk_root(super, chunk_bytenr);
 123         btrfs_set_super_total_bytes(super, cfg->num_bytes);
 124         /*
 125          * Temporary filesystem will only have 6 tree roots:
 126          * chunk tree, root tree, extent_tree, device tree, fs tree
 127          * and csum tree.
 128          */
 129         btrfs_set_super_bytes_used(super, 6 * cfg->nodesize);
 130         btrfs_set_super_sectorsize(super, cfg->sectorsize);
 131         super->__unused_leafsize = cpu_to_le32(cfg->nodesize);
 132         btrfs_set_super_nodesize(super, cfg->nodesize);
 133         btrfs_set_super_stripesize(super, cfg->stripesize);
 134         btrfs_set_super_csum_type(super, BTRFS_CSUM_TYPE_CRC32);
 135         btrfs_set_super_chunk_root(super, chunk_bytenr);
 136         btrfs_set_super_cache_generation(super, -1);
 137         btrfs_set_super_incompat_flags(super, cfg->features);
 138         if (cfg->label)
 139                 __strncpy_null(super->label, cfg->label, BTRFS_LABEL_SIZE - 1);
 140
 141         /* Sys chunk array will be re-initialized at chunk tree init time */
 142         super->sys_chunk_array_size = 0;
 143
 144         ret = write_temp_super(fd, super, cfg->super_bytenr);
 145 out:
 146         return ret;
 147 }
 148
 149 static int setup_temp_extent_buffer(struct extent_buffer *buf,
 150                                     struct btrfs_mkfs_config *cfg,
 151                                     u64 bytenr, u64 owner)
 152 {
 153         unsigned char fsid[BTRFS_FSID_SIZE];
 154         unsigned char chunk_uuid[BTRFS_UUID_SIZE];
 155         int ret;
 156
 157         ret = uuid_parse(cfg->fs_uuid, fsid);
 158         if (ret)
 159                 return -EINVAL;
 160         ret = uuid_parse(cfg->chunk_uuid, chunk_uuid);
 161         if (ret)
 162                 return -EINVAL;
 163
 164         memset(buf->data, 0, cfg->nodesize);
 165         buf->len = cfg->nodesize;
 166         btrfs_set_header_bytenr(buf, bytenr);
 167         btrfs_set_header_generation(buf, 1);
 168         btrfs_set_header_backref_rev(buf, BTRFS_MIXED_BACKREF_REV);
 169         btrfs_set_header_owner(buf, owner);
 170         btrfs_set_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN);
 171         write_extent_buffer(buf, chunk_uuid, btrfs_header_chunk_tree_uuid(buf),
 172                             BTRFS_UUID_SIZE);
 173         write_extent_buffer(buf, fsid, btrfs_header_fsid(), BTRFS_FSID_SIZE);
 174         return 0;
 175 }
 176
 177 static void insert_temp_root_item(struct extent_buffer *buf,
 178                                   struct btrfs_mkfs_config *cfg,
 179                                   int *slot, u32 *itemoff, u64 objectid,
 180                                   u64 bytenr)
 181 {
 182         struct btrfs_root_item root_item;
 183         struct btrfs_inode_item *inode_item;
 184         struct btrfs_disk_key disk_key;
 185
 186         btrfs_set_header_nritems(buf, *slot + 1);
 187         (*itemoff) -= sizeof(root_item);
 188         memset(&root_item, 0, sizeof(root_item));
 189         inode_item = &root_item.inode;
 190         btrfs_set_stack_inode_generation(inode_item, 1);
 191         btrfs_set_stack_inode_size(inode_item, 3);
 192         btrfs_set_stack_inode_nlink(inode_item, 1);
 193         btrfs_set_stack_inode_nbytes(inode_item, cfg->nodesize);
 194         btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
 195         btrfs_set_root_refs(&root_item, 1);
 196         btrfs_set_root_used(&root_item, cfg->nodesize);
 197         btrfs_set_root_generation(&root_item, 1);
 198         btrfs_set_root_bytenr(&root_item, bytenr);
 199
 200         memset(&disk_key, 0, sizeof(disk_key));
 201         btrfs_set_disk_key_type(&disk_key, BTRFS_ROOT_ITEM_KEY);
 202         btrfs_set_disk_key_objectid(&disk_key, objectid);
 203         btrfs_set_disk_key_offset(&disk_key, 0);
 204
 205         btrfs_set_item_key(buf, &disk_key, *slot);
 206         btrfs_set_item_offset(buf, btrfs_item_nr(*slot), *itemoff);
 207         btrfs_set_item_size(buf, btrfs_item_nr(*slot), sizeof(root_item));
 208         write_extent_buffer(buf, &root_item,
 209                             btrfs_item_ptr_offset(buf, *slot),
 210                             sizeof(root_item));
 211         (*slot)++;
 212 }
 213
 214 /*
 215  * Setup an extent buffer for tree block.
 216  */
 217 static inline int write_temp_extent_buffer(int fd, struct extent_buffer *buf,
 218                                            u64 bytenr)
 219 {
 220         int ret;
 221
 222         csum_tree_block_size(buf, btrfs_csum_sizes[BTRFS_CSUM_TYPE_CRC32], 0);
 223
 224         /* Temporary extent buffer is always mapped 1:1 on disk */
 225         ret = pwrite(fd, buf->data, buf->len, bytenr);
 226         if (ret < buf->len)
 227                 ret = (ret < 0 ? ret : -EIO);
 228         else
 229                 ret = 0;
 230         return ret;
 231 }
 232
 233 static int setup_temp_root_tree(int fd, struct btrfs_mkfs_config *cfg,
 234                                 u64 root_bytenr, u64 extent_bytenr,
 235                                 u64 dev_bytenr, u64 fs_bytenr, u64 csum_bytenr)
 236 {
 237         struct extent_buffer *buf = NULL;
 238         u32 itemoff = __BTRFS_LEAF_DATA_SIZE(cfg->nodesize);
 239         int slot = 0;
 240         int ret;
 241
 242         /*
 243          * Provided bytenr must in ascending order, or tree root will have a
 244          * bad key order.
 245          */
 246         if (!(root_bytenr < extent_bytenr && extent_bytenr < dev_bytenr &&
 247               dev_bytenr < fs_bytenr && fs_bytenr < csum_bytenr)) {
 248                 error("bad tree bytenr order: "
 249                                 "root < extent %llu < %llu, "
 250                                 "extent < dev %llu < %llu, "
 251                                 "dev < fs %llu < %llu, "
 252                                 "fs < csum %llu < %llu",
 253                                 (unsigned long long)root_bytenr,
 254                                 (unsigned long long)extent_bytenr,
 255                                 (unsigned long long)extent_bytenr,
 256                                 (unsigned long long)dev_bytenr,
 257                                 (unsigned long long)dev_bytenr,
 258                                 (unsigned long long)fs_bytenr,
 259                                 (unsigned long long)fs_bytenr,
 260                                 (unsigned long long)csum_bytenr);
 261                 return -EINVAL;
 262         }
 263         buf = malloc(sizeof(*buf) + cfg->nodesize);
 264         if (!buf)
 265                 return -ENOMEM;
 266
 267         ret = setup_temp_extent_buffer(buf, cfg, root_bytenr,
 268                                        BTRFS_ROOT_TREE_OBJECTID);
 269         if (ret < 0)
 270                 goto out;
 271
 272         insert_temp_root_item(buf, cfg, &slot, &itemoff,
 273                               BTRFS_EXTENT_TREE_OBJECTID, extent_bytenr);
 274         insert_temp_root_item(buf, cfg, &slot, &itemoff,
 275                               BTRFS_DEV_TREE_OBJECTID, dev_bytenr);
 276         insert_temp_root_item(buf, cfg, &slot, &itemoff,
 277                               BTRFS_FS_TREE_OBJECTID, fs_bytenr);
 278         insert_temp_root_item(buf, cfg, &slot, &itemoff,
 279                               BTRFS_CSUM_TREE_OBJECTID, csum_bytenr);
 280
 281         ret = write_temp_extent_buffer(fd, buf, root_bytenr);
 282 out:
 283         free(buf);
 284         return ret;
 285 }
 286
 287 static int insert_temp_dev_item(int fd, struct extent_buffer *buf,
 288                                 struct btrfs_mkfs_config *cfg,
 289                                 int *slot, u32 *itemoff)
 290 {
 291         struct btrfs_disk_key disk_key;
 292         struct btrfs_dev_item *dev_item;
 293         char super_buf[BTRFS_SUPER_INFO_SIZE];
 294         unsigned char dev_uuid[BTRFS_UUID_SIZE];
 295         unsigned char fsid[BTRFS_FSID_SIZE];
 296         struct btrfs_super_block *super = (struct btrfs_super_block *)super_buf;
 297         int ret;
 298
 299         ret = pread(fd, super_buf, BTRFS_SUPER_INFO_SIZE, cfg->super_bytenr);
 300         if (ret < BTRFS_SUPER_INFO_SIZE) {
 301                 ret = (ret < 0 ? -errno : -EIO);
 302                 goto out;
 303         }
 304
 305         btrfs_set_header_nritems(buf, *slot + 1);
 306         (*itemoff) -= sizeof(*dev_item);
 307         /* setup device item 1, 0 is for replace case */
 308         btrfs_set_disk_key_type(&disk_key, BTRFS_DEV_ITEM_KEY);
 309         btrfs_set_disk_key_objectid(&disk_key, BTRFS_DEV_ITEMS_OBJECTID);
 310         btrfs_set_disk_key_offset(&disk_key, 1);
 311         btrfs_set_item_key(buf, &disk_key, *slot);
 312         btrfs_set_item_offset(buf, btrfs_item_nr(*slot), *itemoff);
 313         btrfs_set_item_size(buf, btrfs_item_nr(*slot), sizeof(*dev_item));
 314
 315         dev_item = btrfs_item_ptr(buf, *slot, struct btrfs_dev_item);
 316         /* Generate device uuid */
 317         uuid_generate(dev_uuid);
 318         write_extent_buffer(buf, dev_uuid,
 319                         (unsigned long)btrfs_device_uuid(dev_item),
 320                         BTRFS_UUID_SIZE);
 321         uuid_parse(cfg->fs_uuid, fsid);
 322         write_extent_buffer(buf, fsid,
 323                         (unsigned long)btrfs_device_fsid(dev_item),
 324                         BTRFS_FSID_SIZE);
 325         btrfs_set_device_id(buf, dev_item, 1);
 326         btrfs_set_device_generation(buf, dev_item, 0);
 327         btrfs_set_device_total_bytes(buf, dev_item, cfg->num_bytes);
 328         /*
 329          * The number must match the initial SYSTEM and META chunk size
 330          */
 331         btrfs_set_device_bytes_used(buf, dev_item,
 332                         BTRFS_MKFS_SYSTEM_GROUP_SIZE +
 333                         BTRFS_CONVERT_META_GROUP_SIZE);
 334         btrfs_set_device_io_align(buf, dev_item, cfg->sectorsize);
 335         btrfs_set_device_io_width(buf, dev_item, cfg->sectorsize);
 336         btrfs_set_device_sector_size(buf, dev_item, cfg->sectorsize);
 337         btrfs_set_device_type(buf, dev_item, 0);
 338
 339         /* Super dev_item is not complete, copy the complete one to sb */
 340         read_extent_buffer(buf, &super->dev_item, (unsigned long)dev_item,
 341                            sizeof(*dev_item));
 342         ret = write_temp_super(fd, super, cfg->super_bytenr);
 343         (*slot)++;
 344 out:
 345         return ret;
 346 }
 347
 348 static int insert_temp_chunk_item(int fd, struct extent_buffer *buf,
 349                                   struct btrfs_mkfs_config *cfg,
 350                                   int *slot, u32 *itemoff, u64 start, u64 len,
 351                                   u64 type)
 352 {
 353         struct btrfs_chunk *chunk;
 354         struct btrfs_disk_key disk_key;
 355         char super_buf[BTRFS_SUPER_INFO_SIZE];
 356         struct btrfs_super_block *sb = (struct btrfs_super_block *)super_buf;
 357         int ret = 0;
 358
 359         ret = pread(fd, super_buf, BTRFS_SUPER_INFO_SIZE,
 360                     cfg->super_bytenr);
 361         if (ret < BTRFS_SUPER_INFO_SIZE) {
 362                 ret = (ret < 0 ? ret : -EIO);
 363                 return ret;
 364         }
 365
 366         btrfs_set_header_nritems(buf, *slot + 1);
 367         (*itemoff) -= btrfs_chunk_item_size(1);
 368         btrfs_set_disk_key_type(&disk_key, BTRFS_CHUNK_ITEM_KEY);
 369         btrfs_set_disk_key_objectid(&disk_key, BTRFS_FIRST_CHUNK_TREE_OBJECTID);
 370         btrfs_set_disk_key_offset(&disk_key, start);
 371         btrfs_set_item_key(buf, &disk_key, *slot);
 372         btrfs_set_item_offset(buf, btrfs_item_nr(*slot), *itemoff);
 373         btrfs_set_item_size(buf, btrfs_item_nr(*slot),
 374                             btrfs_chunk_item_size(1));
 375
 376         chunk = btrfs_item_ptr(buf, *slot, struct btrfs_chunk);
 377         btrfs_set_chunk_length(buf, chunk, len);
 378         btrfs_set_chunk_owner(buf, chunk, BTRFS_EXTENT_TREE_OBJECTID);
 379         btrfs_set_chunk_stripe_len(buf, chunk, BTRFS_STRIPE_LEN);
 380         btrfs_set_chunk_type(buf, chunk, type);
 381         btrfs_set_chunk_io_align(buf, chunk, cfg->sectorsize);
 382         btrfs_set_chunk_io_width(buf, chunk, cfg->sectorsize);
 383         btrfs_set_chunk_sector_size(buf, chunk, cfg->sectorsize);
 384         btrfs_set_chunk_num_stripes(buf, chunk, 1);
 385         /* TODO: Support DUP profile for system chunk */
 386         btrfs_set_stripe_devid_nr(buf, chunk, 0, 1);
 387         /* We are doing 1:1 mapping, so start is its dev offset */
 388         btrfs_set_stripe_offset_nr(buf, chunk, 0, start);
 389         write_extent_buffer(buf, &sb->dev_item.uuid,
 390                             (unsigned long)btrfs_stripe_dev_uuid_nr(chunk, 0),
 391                             BTRFS_UUID_SIZE);
 392         (*slot)++;
 393
 394         /*
 395          * If it's system chunk, also copy it to super block.
 396          */
 397         if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
 398                 char *cur;
 399                 u32 array_size;
 400
 401                 cur = (char *)sb->sys_chunk_array
 402                         + btrfs_super_sys_array_size(sb);
 403                 memcpy(cur, &disk_key, sizeof(disk_key));
 404                 cur += sizeof(disk_key);
 405                 read_extent_buffer(buf, cur, (unsigned long int)chunk,
 406                                    btrfs_chunk_item_size(1));
 407                 array_size = btrfs_super_sys_array_size(sb);
 408                 array_size += btrfs_chunk_item_size(1) +
 409                                             sizeof(disk_key);
 410                 btrfs_set_super_sys_array_size(sb, array_size);
 411
 412                 ret = write_temp_super(fd, sb, cfg->super_bytenr);
 413         }
 414         return ret;
 415 }
 416
 417 static int setup_temp_chunk_tree(int fd, struct btrfs_mkfs_config *cfg,
 418                                  u64 sys_chunk_start, u64 meta_chunk_start,
 419                                  u64 chunk_bytenr)
 420 {
 421         struct extent_buffer *buf = NULL;
 422         u32 itemoff = __BTRFS_LEAF_DATA_SIZE(cfg->nodesize);
 423         int slot = 0;
 424         int ret;
 425
 426         /* Must ensure SYS chunk starts before META chunk */
 427         if (meta_chunk_start < sys_chunk_start) {
 428                 error("wrong chunk order: meta < system %llu < %llu",
 429                                 (unsigned long long)meta_chunk_start,
 430                                 (unsigned long long)sys_chunk_start);
 431                 return -EINVAL;
 432         }
 433         buf = malloc(sizeof(*buf) + cfg->nodesize);
 434         if (!buf)
 435                 return -ENOMEM;
 436         ret = setup_temp_extent_buffer(buf, cfg, chunk_bytenr,
 437                                        BTRFS_CHUNK_TREE_OBJECTID);
 438         if (ret < 0)
 439                 goto out;
 440
 441         ret = insert_temp_dev_item(fd, buf, cfg, &slot, &itemoff);
 442         if (ret < 0)
 443                 goto out;
 444         ret = insert_temp_chunk_item(fd, buf, cfg, &slot, &itemoff,
 445                                      sys_chunk_start,
 446                                      BTRFS_MKFS_SYSTEM_GROUP_SIZE,
 447                                      BTRFS_BLOCK_GROUP_SYSTEM);
 448         if (ret < 0)
 449                 goto out;
 450         ret = insert_temp_chunk_item(fd, buf, cfg, &slot, &itemoff,
 451                                      meta_chunk_start,
 452                                      BTRFS_CONVERT_META_GROUP_SIZE,
 453                                      BTRFS_BLOCK_GROUP_METADATA);
 454         if (ret < 0)
 455                 goto out;
 456         ret = write_temp_extent_buffer(fd, buf, chunk_bytenr);
 457
 458 out:
 459         free(buf);
 460         return ret;
 461 }
 462
 463 static void insert_temp_dev_extent(struct extent_buffer *buf,
 464                                    int *slot, u32 *itemoff, u64 start, u64 len)
 465 {
 466         struct btrfs_dev_extent *dev_extent;
 467         struct btrfs_disk_key disk_key;
 468
 469         btrfs_set_header_nritems(buf, *slot + 1);
 470         (*itemoff) -= sizeof(*dev_extent);
 471         btrfs_set_disk_key_type(&disk_key, BTRFS_DEV_EXTENT_KEY);
 472         btrfs_set_disk_key_objectid(&disk_key, 1);
 473         btrfs_set_disk_key_offset(&disk_key, start);
 474         btrfs_set_item_key(buf, &disk_key, *slot);
 475         btrfs_set_item_offset(buf, btrfs_item_nr(*slot), *itemoff);
 476         btrfs_set_item_size(buf, btrfs_item_nr(*slot), sizeof(*dev_extent));
 477
 478         dev_extent = btrfs_item_ptr(buf, *slot, struct btrfs_dev_extent);
 479         btrfs_set_dev_extent_chunk_objectid(buf, dev_extent,
 480                                             BTRFS_FIRST_CHUNK_TREE_OBJECTID);
 481         btrfs_set_dev_extent_length(buf, dev_extent, len);
 482         btrfs_set_dev_extent_chunk_offset(buf, dev_extent, start);
 483         btrfs_set_dev_extent_chunk_tree(buf, dev_extent,
 484                                         BTRFS_CHUNK_TREE_OBJECTID);
 485         (*slot)++;
 486 }
 487
 488 static int setup_temp_dev_tree(int fd, struct btrfs_mkfs_config *cfg,
 489                                u64 sys_chunk_start, u64 meta_chunk_start,
 490                                u64 dev_bytenr)
 491 {
 492         struct extent_buffer *buf = NULL;
 493         u32 itemoff = __BTRFS_LEAF_DATA_SIZE(cfg->nodesize);
 494         int slot = 0;
 495         int ret;
 496
 497         /* Must ensure SYS chunk starts before META chunk */
 498         if (meta_chunk_start < sys_chunk_start) {
 499                 error("wrong chunk order: meta < system %llu < %llu",
 500                                 (unsigned long long)meta_chunk_start,
 501                                 (unsigned long long)sys_chunk_start);
 502                 return -EINVAL;
 503         }
 504         buf = malloc(sizeof(*buf) + cfg->nodesize);
 505         if (!buf)
 506                 return -ENOMEM;
 507         ret = setup_temp_extent_buffer(buf, cfg, dev_bytenr,
 508                                        BTRFS_DEV_TREE_OBJECTID);
 509         if (ret < 0)
 510                 goto out;
 511         insert_temp_dev_extent(buf, &slot, &itemoff, sys_chunk_start,
 512                                BTRFS_MKFS_SYSTEM_GROUP_SIZE);
 513         insert_temp_dev_extent(buf, &slot, &itemoff, meta_chunk_start,
 514                                BTRFS_CONVERT_META_GROUP_SIZE);
 515         ret = write_temp_extent_buffer(fd, buf, dev_bytenr);
 516 out:
 517         free(buf);
 518         return ret;
 519 }
 520
 521 static int setup_temp_fs_tree(int fd, struct btrfs_mkfs_config *cfg,
 522                               u64 fs_bytenr)
 523 {
 524         struct extent_buffer *buf = NULL;
 525         int ret;
 526
 527         buf = malloc(sizeof(*buf) + cfg->nodesize);
 528         if (!buf)
 529                 return -ENOMEM;
 530         ret = setup_temp_extent_buffer(buf, cfg, fs_bytenr,
 531                                        BTRFS_FS_TREE_OBJECTID);
 532         if (ret < 0)
 533                 goto out;
 534         /*
 535          * Temporary fs tree is completely empty.
 536          */
 537         ret = write_temp_extent_buffer(fd, buf, fs_bytenr);
 538 out:
 539         free(buf);
 540         return ret;
 541 }
 542
 543 static int setup_temp_csum_tree(int fd, struct btrfs_mkfs_config *cfg,
 544                                 u64 csum_bytenr)
 545 {
 546         struct extent_buffer *buf = NULL;
 547         int ret;
 548
 549         buf = malloc(sizeof(*buf) + cfg->nodesize);
 550         if (!buf)
 551                 return -ENOMEM;
 552         ret = setup_temp_extent_buffer(buf, cfg, csum_bytenr,
 553                                        BTRFS_CSUM_TREE_OBJECTID);
 554         if (ret < 0)
 555                 goto out;
 556         /*
 557          * Temporary csum tree is completely empty.
 558          */
 559         ret = write_temp_extent_buffer(fd, buf, csum_bytenr);
 560 out:
 561         free(buf);
 562         return ret;
 563 }
 564
 565 /*
 566  * Insert one temporary extent item.
 567  *
 568  * NOTE: if skinny_metadata is not enabled, this function must be called
 569  * after all other trees are initialized.
 570  * Or fs without skinny-metadata will be screwed up.
 571  */
 572 static int insert_temp_extent_item(int fd, struct extent_buffer *buf,
 573                                    struct btrfs_mkfs_config *cfg,
 574                                    int *slot, u32 *itemoff, u64 bytenr,
 575                                    u64 ref_root)
 576 {
 577         struct extent_buffer *tmp;
 578         struct btrfs_extent_item *ei;
 579         struct btrfs_extent_inline_ref *iref;
 580         struct btrfs_disk_key disk_key;
 581         struct btrfs_disk_key tree_info_key;
 582         struct btrfs_tree_block_info *info;
 583         int itemsize;
 584         int skinny_metadata = cfg->features &
 585                               BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA;
 586         int ret;
 587
 588         if (skinny_metadata)
 589                 itemsize = sizeof(*ei) + sizeof(*iref);
 590         else
 591                 itemsize = sizeof(*ei) + sizeof(*iref) +
 592                            sizeof(struct btrfs_tree_block_info);
 593
 594         btrfs_set_header_nritems(buf, *slot + 1);
 595         *(itemoff) -= itemsize;
 596
 597         if (skinny_metadata) {
 598                 btrfs_set_disk_key_type(&disk_key, BTRFS_METADATA_ITEM_KEY);
 599                 btrfs_set_disk_key_offset(&disk_key, 0);
 600         } else {
 601                 btrfs_set_disk_key_type(&disk_key, BTRFS_EXTENT_ITEM_KEY);
 602                 btrfs_set_disk_key_offset(&disk_key, cfg->nodesize);
 603         }
 604         btrfs_set_disk_key_objectid(&disk_key, bytenr);
 605
 606         btrfs_set_item_key(buf, &disk_key, *slot);
 607         btrfs_set_item_offset(buf, btrfs_item_nr(*slot), *itemoff);
 608         btrfs_set_item_size(buf, btrfs_item_nr(*slot), itemsize);
 609
 610         ei = btrfs_item_ptr(buf, *slot, struct btrfs_extent_item);
 611         btrfs_set_extent_refs(buf, ei, 1);
 612         btrfs_set_extent_generation(buf, ei, 1);
 613         btrfs_set_extent_flags(buf, ei, BTRFS_EXTENT_FLAG_TREE_BLOCK);
 614
 615         if (skinny_metadata) {
 616                 iref = (struct btrfs_extent_inline_ref *)(ei + 1);
 617         } else {
 618                 info = (struct btrfs_tree_block_info *)(ei + 1);
 619                 iref = (struct btrfs_extent_inline_ref *)(info + 1);
 620         }
 621         btrfs_set_extent_inline_ref_type(buf, iref,
 622                                          BTRFS_TREE_BLOCK_REF_KEY);
 623         btrfs_set_extent_inline_ref_offset(buf, iref, ref_root);
 624
 625         (*slot)++;
 626         if (skinny_metadata)
 627                 return 0;
 628
 629         /*
 630          * Lastly, check the tree block key by read the tree block
 631          * Since we do 1:1 mapping for convert case, we can directly
 632          * read the bytenr from disk
 633          */
 634         tmp = malloc(sizeof(*tmp) + cfg->nodesize);
 635         if (!tmp)
 636                 return -ENOMEM;
 637         ret = setup_temp_extent_buffer(tmp, cfg, bytenr, ref_root);
 638         if (ret < 0)
 639                 goto out;
 640         ret = pread(fd, tmp->data, cfg->nodesize, bytenr);
 641         if (ret < cfg->nodesize) {
 642                 ret = (ret < 0 ? -errno : -EIO);
 643                 goto out;
 644         }
 645         if (btrfs_header_nritems(tmp) == 0) {
 646                 btrfs_set_disk_key_type(&tree_info_key, 0);
 647                 btrfs_set_disk_key_objectid(&tree_info_key, 0);
 648                 btrfs_set_disk_key_offset(&tree_info_key, 0);
 649         } else {
 650                 btrfs_item_key(tmp, &tree_info_key, 0);
 651         }
 652         btrfs_set_tree_block_key(buf, info, &tree_info_key);
 653
 654 out:
 655         free(tmp);
 656         return ret;
 657 }
 658
 659 static void insert_temp_block_group(struct extent_buffer *buf,
 660                                    struct btrfs_mkfs_config *cfg,
 661                                    int *slot, u32 *itemoff,
 662                                    u64 bytenr, u64 len, u64 used, u64 flag)
 663 {
 664         struct btrfs_block_group_item bgi;
 665         struct btrfs_disk_key disk_key;
 666
 667         btrfs_set_header_nritems(buf, *slot + 1);
 668         (*itemoff) -= sizeof(bgi);
 669         btrfs_set_disk_key_type(&disk_key, BTRFS_BLOCK_GROUP_ITEM_KEY);
 670         btrfs_set_disk_key_objectid(&disk_key, bytenr);
 671         btrfs_set_disk_key_offset(&disk_key, len);
 672         btrfs_set_item_key(buf, &disk_key, *slot);
 673         btrfs_set_item_offset(buf, btrfs_item_nr(*slot), *itemoff);
 674         btrfs_set_item_size(buf, btrfs_item_nr(*slot), sizeof(bgi));
 675
 676         btrfs_set_block_group_flags(&bgi, flag);
 677         btrfs_set_block_group_used(&bgi, used);
 678         btrfs_set_block_group_chunk_objectid(&bgi,
 679                         BTRFS_FIRST_CHUNK_TREE_OBJECTID);
 680         write_extent_buffer(buf, &bgi, btrfs_item_ptr_offset(buf, *slot),
 681                             sizeof(bgi));
 682         (*slot)++;
 683 }
 684
 685 static int setup_temp_extent_tree(int fd, struct btrfs_mkfs_config *cfg,
 686                                   u64 chunk_bytenr, u64 root_bytenr,
 687                                   u64 extent_bytenr, u64 dev_bytenr,
 688                                   u64 fs_bytenr, u64 csum_bytenr)
 689 {
 690         struct extent_buffer *buf = NULL;
 691         u32 itemoff = __BTRFS_LEAF_DATA_SIZE(cfg->nodesize);
 692         int slot = 0;
 693         int ret;
 694
 695         /*
 696          * We must ensure provided bytenr are in ascending order,
 697          * or extent tree key order will be broken.
 698          */
 699         if (!(chunk_bytenr < root_bytenr && root_bytenr < extent_bytenr &&
 700               extent_bytenr < dev_bytenr && dev_bytenr < fs_bytenr &&
 701               fs_bytenr < csum_bytenr)) {
 702                 error("bad tree bytenr order: "
 703                                 "chunk < root %llu < %llu, "
 704                                 "root < extent %llu < %llu, "
 705                                 "extent < dev %llu < %llu, "
 706                                 "dev < fs %llu < %llu, "
 707                                 "fs < csum %llu < %llu",
 708                                 (unsigned long long)chunk_bytenr,
 709                                 (unsigned long long)root_bytenr,
 710                                 (unsigned long long)root_bytenr,
 711                                 (unsigned long long)extent_bytenr,
 712                                 (unsigned long long)extent_bytenr,
 713                                 (unsigned long long)dev_bytenr,
 714                                 (unsigned long long)dev_bytenr,
 715                                 (unsigned long long)fs_bytenr,
 716                                 (unsigned long long)fs_bytenr,
 717                                 (unsigned long long)csum_bytenr);
 718                 return -EINVAL;
 719         }
 720         buf = malloc(sizeof(*buf) + cfg->nodesize);
 721         if (!buf)
 722                 return -ENOMEM;
 723
 724         ret = setup_temp_extent_buffer(buf, cfg, extent_bytenr,
 725                                        BTRFS_EXTENT_TREE_OBJECTID);
 726         if (ret < 0)
 727                 goto out;
 728
 729         ret = insert_temp_extent_item(fd, buf, cfg, &slot, &itemoff,
 730                         chunk_bytenr, BTRFS_CHUNK_TREE_OBJECTID);
 731         if (ret < 0)
 732                 goto out;
 733
 734         insert_temp_block_group(buf, cfg, &slot, &itemoff, chunk_bytenr,
 735                         BTRFS_MKFS_SYSTEM_GROUP_SIZE, cfg->nodesize,
 736                         BTRFS_BLOCK_GROUP_SYSTEM);
 737
 738         ret = insert_temp_extent_item(fd, buf, cfg, &slot, &itemoff,
 739                         root_bytenr, BTRFS_ROOT_TREE_OBJECTID);
 740         if (ret < 0)
 741                 goto out;
 742
 743         /* 5 tree block used, root, extent, dev, fs and csum*/
 744         insert_temp_block_group(buf, cfg, &slot, &itemoff, root_bytenr,
 745                         BTRFS_CONVERT_META_GROUP_SIZE, cfg->nodesize * 5,
 746                         BTRFS_BLOCK_GROUP_METADATA);
 747
 748         ret = insert_temp_extent_item(fd, buf, cfg, &slot, &itemoff,
 749                         extent_bytenr, BTRFS_EXTENT_TREE_OBJECTID);
 750         if (ret < 0)
 751                 goto out;
 752         ret = insert_temp_extent_item(fd, buf, cfg, &slot, &itemoff,
 753                         dev_bytenr, BTRFS_DEV_TREE_OBJECTID);
 754         if (ret < 0)
 755                 goto out;
 756         ret = insert_temp_extent_item(fd, buf, cfg, &slot, &itemoff,
 757                         fs_bytenr, BTRFS_FS_TREE_OBJECTID);
 758         if (ret < 0)
 759                 goto out;
 760         ret = insert_temp_extent_item(fd, buf, cfg, &slot, &itemoff,
 761                         csum_bytenr, BTRFS_CSUM_TREE_OBJECTID);
 762         if (ret < 0)
 763                 goto out;
 764
 765         ret = write_temp_extent_buffer(fd, buf, extent_bytenr);
 766 out:
 767         free(buf);
 768         return ret;
 769 }
 770
 771 /*
 772  * Improved version of make_btrfs().
 773  *
 774  * This one will
 775  * 1) Do chunk allocation to avoid used data
 776  *    And after this function, extent type matches chunk type
 777  * 2) Better structured code
 778  *    No super long hand written codes to initialized all tree blocks
 779  *    Split into small blocks and reuse codes.
 780  *    TODO: Reuse tree operation facilities by introducing new flags
 781  */
 782 int make_convert_btrfs(int fd, struct btrfs_mkfs_config *cfg,
 783                               struct btrfs_convert_context *cctx)
 784 {
 785         struct cache_tree *free_space = &cctx->free_space;
 786         struct cache_tree *used_space = &cctx->used_space;
 787         u64 sys_chunk_start;
 788         u64 meta_chunk_start;
 789         /* chunk tree bytenr, in system chunk */
 790         u64 chunk_bytenr;
 791         /* metadata trees bytenr, in metadata chunk */
 792         u64 root_bytenr;
 793         u64 extent_bytenr;
 794         u64 dev_bytenr;
 795         u64 fs_bytenr;
 796         u64 csum_bytenr;
 797         int ret;
 798
 799         /* Source filesystem must be opened, checked and analyzed in advance */
 800         ASSERT(!cache_tree_empty(used_space));
 801
 802         /*
 803          * reserve space for temporary superblock first
 804          * Here we allocate a little larger space, to keep later
 805          * free space will be STRIPE_LEN aligned
 806          */
 807         ret = reserve_free_space(free_space, BTRFS_STRIPE_LEN,
 808                                  &cfg->super_bytenr);
 809         if (ret < 0)
 810                 goto out;
 811
 812         /*
 813          * Then reserve system chunk space
 814          * TODO: Change system group size depending on cctx->total_bytes.
 815          * If using current 4M, it can only handle less than one TB for
 816          * worst case and then run out of sys space.
 817          */
 818         ret = reserve_free_space(free_space, BTRFS_MKFS_SYSTEM_GROUP_SIZE,
 819                                  &sys_chunk_start);
 820         if (ret < 0)
 821                 goto out;
 822         ret = reserve_free_space(free_space, BTRFS_CONVERT_META_GROUP_SIZE,
 823                                  &meta_chunk_start);
 824         if (ret < 0)
 825                 goto out;
 826
 827         /*
 828          * Allocated meta/sys chunks will be mapped 1:1 with device offset.
 829          *
 830          * Inside the allocated metadata chunk, the layout will be:
 831          *  | offset            | contents      |
 832          *  -------------------------------------
 833          *  | +0                | tree root     |
 834          *  | +nodesize         | extent root   |
 835          *  | +nodesize * 2     | device root   |
 836          *  | +nodesize * 3     | fs tree       |
 837          *  | +nodesize * 4     | csum tree     |
 838          *  -------------------------------------
 839          * Inside the allocated system chunk, the layout will be:
 840          *  | offset            | contents      |
 841          *  -------------------------------------
 842          *  | +0                | chunk root    |
 843          *  -------------------------------------
 844          */
 845         chunk_bytenr = sys_chunk_start;
 846         root_bytenr = meta_chunk_start;
 847         extent_bytenr = meta_chunk_start + cfg->nodesize;
 848         dev_bytenr = meta_chunk_start + cfg->nodesize * 2;
 849         fs_bytenr = meta_chunk_start + cfg->nodesize * 3;
 850         csum_bytenr = meta_chunk_start + cfg->nodesize * 4;
 851
 852         ret = setup_temp_super(fd, cfg, root_bytenr, chunk_bytenr);
 853         if (ret < 0)
 854                 goto out;
 855
 856         ret = setup_temp_root_tree(fd, cfg, root_bytenr, extent_bytenr,
 857                                    dev_bytenr, fs_bytenr, csum_bytenr);
 858         if (ret < 0)
 859                 goto out;
 860         ret = setup_temp_chunk_tree(fd, cfg, sys_chunk_start, meta_chunk_start,
 861                                     chunk_bytenr);
 862         if (ret < 0)
 863                 goto out;
 864         ret = setup_temp_dev_tree(fd, cfg, sys_chunk_start, meta_chunk_start,
 865                                   dev_bytenr);
 866         if (ret < 0)
 867                 goto out;
 868         ret = setup_temp_fs_tree(fd, cfg, fs_bytenr);
 869         if (ret < 0)
 870                 goto out;
 871         ret = setup_temp_csum_tree(fd, cfg, csum_bytenr);
 872         if (ret < 0)
 873                 goto out;
 874         /*
 875          * Setup extent tree last, since it may need to read tree block key
 876          * for non-skinny metadata case.
 877          */
 878         ret = setup_temp_extent_tree(fd, cfg, chunk_bytenr, root_bytenr,
 879                                      extent_bytenr, dev_bytenr, fs_bytenr,
 880                                      csum_bytenr);
 881 out:
 882         return ret;
 883 }
 884