btrfs-image.c

   1 /*
   2  * Copyright (C) 2008 Oracle.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #define _XOPEN_SOURCE 500
  20 #define _GNU_SOURCE 1
  21 #include <pthread.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <sys/types.h>
  25 #include <sys/stat.h>
  26 #include <fcntl.h>
  27 #include <unistd.h>
  28 #include <dirent.h>
  29 #include <zlib.h>
  30 #include "kerncompat.h"
  31 #include "crc32c.h"
  32 #include "ctree.h"
  33 #include "disk-io.h"
  34 #include "transaction.h"
  35 #include "utils.h"
  36 #include "version.h"
  37
  38
  39 #define HEADER_MAGIC            0xbd5c25e27295668bULL
  40 #define MAX_PENDING_SIZE        (256 * 1024)
  41 #define BLOCK_SIZE              1024
  42 #define BLOCK_MASK              (BLOCK_SIZE - 1)
  43
  44 #define COMPRESS_NONE           0
  45 #define COMPRESS_ZLIB           1
  46
  47 struct meta_cluster_item {
  48         __le64 bytenr;
  49         __le32 size;
  50 } __attribute__ ((__packed__));
  51
  52 struct meta_cluster_header {
  53         __le64 magic;
  54         __le64 bytenr;
  55         __le32 nritems;
  56         u8 compress;
  57 } __attribute__ ((__packed__));
  58
  59 /* cluster header + index items + buffers */
  60 struct meta_cluster {
  61         struct meta_cluster_header header;
  62         struct meta_cluster_item items[];
  63 } __attribute__ ((__packed__));
  64
  65 #define ITEMS_PER_CLUSTER ((BLOCK_SIZE - sizeof(struct meta_cluster)) / \
  66                            sizeof(struct meta_cluster_item))
  67
  68 struct async_work {
  69         struct list_head list;
  70         struct list_head ordered;
  71         u64 start;
  72         u64 size;
  73         u8 *buffer;
  74         size_t bufsize;
  75 };
  76
  77 struct metadump_struct {
  78         struct btrfs_root *root;
  79         FILE *out;
  80
  81         struct meta_cluster *cluster;
  82
  83         pthread_t *threads;
  84         size_t num_threads;
  85         pthread_mutex_t mutex;
  86         pthread_cond_t cond;
  87
  88         struct list_head list;
  89         struct list_head ordered;
  90         size_t num_items;
  91         size_t num_ready;
  92
  93         u64 pending_start;
  94         u64 pending_size;
  95
  96         int compress_level;
  97         int done;
  98 };
  99
 100 struct mdrestore_struct {
 101         FILE *in;
 102         FILE *out;
 103
 104         pthread_t *threads;
 105         size_t num_threads;
 106         pthread_mutex_t mutex;
 107         pthread_cond_t cond;
 108
 109         struct list_head list;
 110         size_t num_items;
 111
 112         int compress_method;
 113         int done;
 114 };
 115
 116 static void csum_block(u8 *buf, size_t len)
 117 {
 118         char result[BTRFS_CRC32_SIZE];
 119         u32 crc = ~(u32)0;
 120         crc = crc32c(crc, buf + BTRFS_CSUM_SIZE, len - BTRFS_CSUM_SIZE);
 121         btrfs_csum_final(crc, result);
 122         memcpy(buf, result, BTRFS_CRC32_SIZE);
 123 }
 124
 125 /*
 126  * zero inline extents and csum items
 127  */
 128 static void zero_items(u8 *dst, struct extent_buffer *src)
 129 {
 130         struct btrfs_file_extent_item *fi;
 131         struct btrfs_item *item;
 132         struct btrfs_key key;
 133         u32 nritems = btrfs_header_nritems(src);
 134         size_t size;
 135         unsigned long ptr;
 136         int i, extent_type;
 137
 138         for (i = 0; i < nritems; i++) {
 139                 item = btrfs_item_nr(src, i);
 140                 btrfs_item_key_to_cpu(src, &key, i);
 141                 if (key.type == BTRFS_CSUM_ITEM_KEY) {
 142                         size = btrfs_item_size_nr(src, i);
 143                         memset(dst + btrfs_leaf_data(src) +
 144                                btrfs_item_offset_nr(src, i), 0, size);
 145                         continue;
 146                 }
 147                 if (key.type != BTRFS_EXTENT_DATA_KEY)
 148                         continue;
 149
 150                 fi = btrfs_item_ptr(src, i, struct btrfs_file_extent_item);
 151                 extent_type = btrfs_file_extent_type(src, fi);
 152                 if (extent_type != BTRFS_FILE_EXTENT_INLINE)
 153                         continue;
 154
 155                 ptr = btrfs_file_extent_inline_start(fi);
 156                 size = btrfs_file_extent_inline_item_len(src, item);
 157                 memset(dst + ptr, 0, size);
 158         }
 159 }
 160
 161 /*
 162  * copy buffer and zero useless data in the buffer
 163  */
 164 static void copy_buffer(u8 *dst, struct extent_buffer *src)
 165 {
 166         int level;
 167         size_t size;
 168         u32 nritems;
 169
 170         memcpy(dst, src->data, src->len);
 171         if (src->start == BTRFS_SUPER_INFO_OFFSET)
 172                 return;
 173
 174         level = btrfs_header_level(src);
 175         nritems = btrfs_header_nritems(src);
 176
 177         if (nritems == 0) {
 178                 size = sizeof(struct btrfs_header);
 179                 memset(dst + size, 0, src->len - size);
 180         } else if (level == 0) {
 181                 size = btrfs_leaf_data(src) +
 182                         btrfs_item_offset_nr(src, nritems - 1) -
 183                         btrfs_item_nr_offset(nritems);
 184                 memset(dst + btrfs_item_nr_offset(nritems), 0, size);
 185                 zero_items(dst, src);
 186         } else {
 187                 size = offsetof(struct btrfs_node, ptrs) +
 188                         sizeof(struct btrfs_key_ptr) * nritems;
 189                 memset(dst + size, 0, src->len - size);
 190         }
 191         csum_block(dst, src->len);
 192 }
 193
 194 static void *dump_worker(void *data)
 195 {
 196         struct metadump_struct *md = (struct metadump_struct *)data;
 197         struct async_work *async;
 198         int ret;
 199
 200         while (1) {
 201                 pthread_mutex_lock(&md->mutex);
 202                 while (list_empty(&md->list)) {
 203                         if (md->done) {
 204                                 pthread_mutex_unlock(&md->mutex);
 205                                 goto out;
 206                         }
 207                         pthread_cond_wait(&md->cond, &md->mutex);
 208                 }
 209                 async = list_entry(md->list.next, struct async_work, list);
 210                 list_del_init(&async->list);
 211                 pthread_mutex_unlock(&md->mutex);
 212
 213                 if (md->compress_level > 0) {
 214                         u8 *orig = async->buffer;
 215
 216                         async->bufsize = compressBound(async->size);
 217                         async->buffer = malloc(async->bufsize);
 218
 219                         ret = compress2(async->buffer, &async->bufsize, orig,
 220                                         async->size, md->compress_level);
 221                         BUG_ON(ret != Z_OK);
 222
 223                         free(orig);
 224                 }
 225
 226                 pthread_mutex_lock(&md->mutex);
 227                 md->num_ready++;
 228                 pthread_mutex_unlock(&md->mutex);
 229         }
 230 out:
 231         pthread_exit(NULL);
 232 }
 233
 234 static void meta_cluster_init(struct metadump_struct *md, u64 start)
 235 {
 236         struct meta_cluster_header *header;
 237
 238         md->num_items = 0;
 239         md->num_ready = 0;
 240         header = &md->cluster->header;
 241         header->magic = cpu_to_le64(HEADER_MAGIC);
 242         header->bytenr = cpu_to_le64(start);
 243         header->nritems = cpu_to_le32(0);
 244         header->compress = md->compress_level > 0 ?
 245                            COMPRESS_ZLIB : COMPRESS_NONE;
 246 }
 247
 248 static int metadump_init(struct metadump_struct *md, struct btrfs_root *root,
 249                          FILE *out, int num_threads, int compress_level)
 250 {
 251         int i, ret;
 252
 253         memset(md, 0, sizeof(*md));
 254         pthread_cond_init(&md->cond, NULL);
 255         pthread_mutex_init(&md->mutex, NULL);
 256         INIT_LIST_HEAD(&md->list);
 257         INIT_LIST_HEAD(&md->ordered);
 258         md->root = root;
 259         md->out = out;
 260         md->pending_start = (u64)-1;
 261         md->compress_level = compress_level;
 262         md->cluster = calloc(1, BLOCK_SIZE);
 263         if (!md->cluster)
 264                 return -ENOMEM;
 265
 266         meta_cluster_init(md, 0);
 267         if (!num_threads)
 268                 return 0;
 269
 270         md->num_threads = num_threads;
 271         md->threads = calloc(num_threads, sizeof(pthread_t));
 272         if (!md->threads)
 273                 return -ENOMEM;
 274         for (i = 0; i < num_threads; i++) {
 275                 ret = pthread_create(md->threads + i, NULL, dump_worker, md);
 276                 if (ret)
 277                         break;
 278         }
 279         return ret;
 280 }
 281
 282 static void metadump_destroy(struct metadump_struct *md)
 283 {
 284         int i;
 285         pthread_mutex_lock(&md->mutex);
 286         md->done = 1;
 287         pthread_cond_broadcast(&md->cond);
 288         pthread_mutex_unlock(&md->mutex);
 289
 290         for (i = 0; i < md->num_threads; i++)
 291                 pthread_join(md->threads[i], NULL);
 292
 293         pthread_cond_destroy(&md->cond);
 294         pthread_mutex_destroy(&md->mutex);
 295         free(md->threads);
 296         free(md->cluster);
 297 }
 298
 299 static int write_zero(FILE *out, size_t size)
 300 {
 301         static char zero[BLOCK_SIZE];
 302         return fwrite(zero, size, 1, out);
 303 }
 304
 305 static int write_buffers(struct metadump_struct *md, u64 *next)
 306 {
 307         struct meta_cluster_header *header = &md->cluster->header;
 308         struct meta_cluster_item *item;
 309         struct async_work *async;
 310         u64 bytenr = 0;
 311         u32 nritems = 0;
 312         int ret;
 313
 314         if (list_empty(&md->ordered))
 315                 goto out;
 316
 317         /* wait until all buffers are compressed */
 318         while (md->num_items > md->num_ready) {
 319                 struct timespec ts = {
 320                         .tv_sec = 0,
 321                         .tv_nsec = 10000000,
 322                 };
 323                 pthread_mutex_unlock(&md->mutex);
 324                 nanosleep(&ts, NULL);
 325                 pthread_mutex_lock(&md->mutex);
 326         }
 327
 328         /* setup and write index block */
 329         list_for_each_entry(async, &md->ordered, ordered) {
 330                 item = md->cluster->items + nritems;
 331                 item->bytenr = cpu_to_le64(async->start);
 332                 item->size = cpu_to_le32(async->bufsize);
 333                 nritems++;
 334         }
 335         header->nritems = cpu_to_le32(nritems);
 336
 337         ret = fwrite(md->cluster, BLOCK_SIZE, 1, md->out);
 338         BUG_ON(ret != 1);
 339
 340         /* write buffers */
 341         bytenr += le64_to_cpu(header->bytenr) + BLOCK_SIZE;
 342         while (!list_empty(&md->ordered)) {
 343                 async = list_entry(md->ordered.next, struct async_work,
 344                                    ordered);
 345                 list_del_init(&async->ordered);
 346
 347                 bytenr += async->bufsize;
 348                 ret = fwrite(async->buffer, async->bufsize, 1, md->out);
 349                 BUG_ON(ret != 1);
 350
 351                 free(async->buffer);
 352                 free(async);
 353         }
 354
 355         /* zero unused space in the last block */
 356         if (bytenr & BLOCK_MASK) {
 357                 size_t size = BLOCK_SIZE - (bytenr & BLOCK_MASK);
 358
 359                 bytenr += size;
 360                 ret = write_zero(md->out, size);
 361                 BUG_ON(ret != 1);
 362         }
 363 out:
 364         *next = bytenr;
 365         return 0;
 366 }
 367
 368 static int flush_pending(struct metadump_struct *md, int done)
 369 {
 370         struct async_work *async = NULL;
 371         struct extent_buffer *eb;
 372         u64 blocksize = md->root->nodesize;
 373         u64 start;
 374         u64 size;
 375         size_t offset;
 376         int ret;
 377
 378         if (md->pending_size) {
 379                 async = calloc(1, sizeof(*async));
 380                 if (!async)
 381                         return -ENOMEM;
 382
 383                 async->start = md->pending_start;
 384                 async->size = md->pending_size;
 385                 async->bufsize = async->size;
 386                 async->buffer = malloc(async->bufsize);
 387
 388                 offset = 0;
 389                 start = async->start;
 390                 size = async->size;
 391                 while (size > 0) {
 392                         eb = read_tree_block(md->root, start, blocksize, 0);
 393                         BUG_ON(!eb);
 394                         copy_buffer(async->buffer + offset, eb);
 395                         free_extent_buffer(eb);
 396                         start += blocksize;
 397                         offset += blocksize;
 398                         size -= blocksize;
 399                 }
 400
 401                 md->pending_start = (u64)-1;
 402                 md->pending_size = 0;
 403         } else if (!done) {
 404                 return 0;
 405         }
 406
 407         pthread_mutex_lock(&md->mutex);
 408         if (async) {
 409                 list_add_tail(&async->ordered, &md->ordered);
 410                 md->num_items++;
 411                 if (md->compress_level > 0) {
 412                         list_add_tail(&async->list, &md->list);
 413                         pthread_cond_signal(&md->cond);
 414                 } else {
 415                         md->num_ready++;
 416                 }
 417         }
 418         if (md->num_items >= ITEMS_PER_CLUSTER || done) {
 419                 ret = write_buffers(md, &start);
 420                 BUG_ON(ret);
 421                 meta_cluster_init(md, start);
 422         }
 423         pthread_mutex_unlock(&md->mutex);
 424         return 0;
 425 }
 426
 427 static int add_metadata(u64 start, u64 size, struct metadump_struct *md)
 428 {
 429         int ret;
 430         if (md->pending_size + size > MAX_PENDING_SIZE ||
 431             md->pending_start + md->pending_size != start) {
 432                 ret = flush_pending(md, 0);
 433                 if (ret)
 434                         return ret;
 435                 md->pending_start = start;
 436         }
 437         readahead_tree_block(md->root, start, size, 0);
 438         md->pending_size += size;
 439         return 0;
 440 }
 441
 442 static int create_metadump(const char *input, FILE *out, int num_threads,
 443                            int compress_level)
 444 {
 445         struct btrfs_root *root;
 446         struct btrfs_root *extent_root;
 447         struct btrfs_path *path;
 448         struct extent_buffer *leaf;
 449         struct btrfs_extent_ref *ref_item;
 450         struct btrfs_key key;
 451         struct metadump_struct metadump;
 452         u64 bytenr;
 453         u64 num_bytes;
 454         u64 ref_objectid;
 455         int ret;
 456
 457         root = open_ctree(input, 0, 0);
 458         BUG_ON(root->nodesize != root->leafsize);
 459
 460         ret = metadump_init(&metadump, root, out, num_threads,
 461                             compress_level);
 462         BUG_ON(ret);
 463
 464         ret = add_metadata(BTRFS_SUPER_INFO_OFFSET, 4096, &metadump);
 465         BUG_ON(ret);
 466
 467         extent_root = root->fs_info->extent_root;
 468         path = btrfs_alloc_path();
 469
 470         bytenr = BTRFS_SUPER_INFO_OFFSET + 4096;
 471         key.objectid = bytenr;
 472         key.type = BTRFS_EXTENT_ITEM_KEY;
 473         key.offset = 0;
 474
 475         ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
 476         BUG_ON(ret < 0);
 477
 478         while (1) {
 479                 leaf = path->nodes[0];
 480                 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
 481                         ret = btrfs_next_leaf(extent_root, path);
 482                         BUG_ON(ret < 0);
 483                         if (ret > 0)
 484                                 break;
 485                         leaf = path->nodes[0];
 486                 }
 487
 488                 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
 489                 if (key.objectid < bytenr ||
 490                     key.type != BTRFS_EXTENT_ITEM_KEY) {
 491                         path->slots[0]++;
 492                         continue;
 493                 }
 494
 495                 bytenr = key.objectid;
 496                 num_bytes = key.offset;
 497                 while (1) {
 498                         path->slots[0]++;
 499                         if (path->slots[0] >= btrfs_header_nritems(leaf)) {
 500                                 ret = btrfs_next_leaf(extent_root, path);
 501                                 BUG_ON(ret < 0);
 502                                 if (ret > 0)
 503                                         break;
 504                                 leaf = path->nodes[0];
 505                         }
 506                         btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
 507                         if (key.objectid != bytenr)
 508                                 break;
 509                         if (key.type != BTRFS_EXTENT_REF_KEY)
 510                                 continue;
 511                         ref_item = btrfs_item_ptr(leaf, path->slots[0],
 512                                                   struct btrfs_extent_ref);
 513                         ref_objectid = btrfs_ref_objectid(leaf, ref_item);
 514                         if (ref_objectid < BTRFS_FIRST_FREE_OBJECTID) {
 515                                 ret = add_metadata(bytenr, num_bytes,
 516                                                    &metadump);
 517                                 BUG_ON(ret);
 518                                 break;
 519                         }
 520                 }
 521                 bytenr += num_bytes;
 522         }
 523
 524         ret = flush_pending(&metadump, 1);
 525         BUG_ON(ret);
 526
 527         metadump_destroy(&metadump);
 528
 529         btrfs_free_path(path);
 530         ret = close_ctree(root);
 531         return 0;
 532 }
 533
 534 static void update_super(u8 *buffer)
 535 {
 536         struct btrfs_super_block *super = (struct btrfs_super_block *)buffer;
 537         struct btrfs_chunk *chunk;
 538         struct btrfs_disk_key *key;
 539         u32 sectorsize = btrfs_super_sectorsize(super);
 540         u64 flags = btrfs_super_flags(super);
 541
 542         flags |= BTRFS_SUPER_FLAG_METADUMP;
 543         btrfs_set_super_flags(super, flags);
 544
 545         key = (struct btrfs_disk_key *)(super->sys_chunk_array);
 546         chunk = (struct btrfs_chunk *)(super->sys_chunk_array +
 547                                        sizeof(struct btrfs_disk_key));
 548
 549         btrfs_set_disk_key_objectid(key, BTRFS_FIRST_CHUNK_TREE_OBJECTID);
 550         btrfs_set_disk_key_type(key, BTRFS_CHUNK_ITEM_KEY);
 551         btrfs_set_disk_key_offset(key, 0);
 552
 553         btrfs_set_stack_chunk_length(chunk, (u64)-1);
 554         btrfs_set_stack_chunk_owner(chunk, BTRFS_EXTENT_TREE_OBJECTID);
 555         btrfs_set_stack_chunk_stripe_len(chunk, 64 * 1024);
 556         btrfs_set_stack_chunk_type(chunk, BTRFS_BLOCK_GROUP_SYSTEM);
 557         btrfs_set_stack_chunk_io_align(chunk, sectorsize);
 558         btrfs_set_stack_chunk_io_width(chunk, sectorsize);
 559         btrfs_set_stack_chunk_sector_size(chunk, sectorsize);
 560         btrfs_set_stack_chunk_num_stripes(chunk, 1);
 561         btrfs_set_stack_chunk_sub_stripes(chunk, 0);
 562         chunk->stripe.devid = super->dev_item.devid;
 563         chunk->stripe.offset = cpu_to_le64(0);
 564         memcpy(chunk->stripe.dev_uuid, super->dev_item.uuid, BTRFS_UUID_SIZE);
 565         btrfs_set_super_sys_array_size(super, sizeof(*key) + sizeof(*chunk));
 566         csum_block(buffer, 4096);
 567 }
 568
 569 static void *restore_worker(void *data)
 570 {
 571         struct mdrestore_struct *mdres = (struct mdrestore_struct *)data;
 572         struct async_work *async;
 573         size_t size;
 574         u8 *buffer;
 575         u8 *outbuf;
 576         int outfd;
 577         int ret;
 578
 579         outfd = fileno(mdres->out);
 580         buffer = malloc(MAX_PENDING_SIZE * 2);
 581         BUG_ON(!buffer);
 582
 583         while (1) {
 584                 pthread_mutex_lock(&mdres->mutex);
 585                 while (list_empty(&mdres->list)) {
 586                         if (mdres->done) {
 587                                 pthread_mutex_unlock(&mdres->mutex);
 588                                 goto out;
 589                         }
 590                         pthread_cond_wait(&mdres->cond, &mdres->mutex);
 591                 }
 592                 async = list_entry(mdres->list.next, struct async_work, list);
 593                 list_del_init(&async->list);
 594                 pthread_mutex_unlock(&mdres->mutex);
 595
 596                 if (mdres->compress_method == COMPRESS_ZLIB) {
 597                         size = MAX_PENDING_SIZE * 2;
 598                         ret = uncompress(buffer, &size, async->buffer,
 599                                          async->bufsize);
 600                         BUG_ON(ret != Z_OK);
 601                         outbuf = buffer;
 602                 } else {
 603                         outbuf = async->buffer;
 604                         size = async->bufsize;
 605                 }
 606
 607                 if (async->start == BTRFS_SUPER_INFO_OFFSET)
 608                         update_super(outbuf);
 609
 610                 ret = pwrite64(outfd, outbuf, size, async->start);
 611                 BUG_ON(ret != size);
 612
 613                 pthread_mutex_lock(&mdres->mutex);
 614                 mdres->num_items--;
 615                 pthread_mutex_unlock(&mdres->mutex);
 616
 617                 free(async->buffer);
 618                 free(async);
 619         }
 620 out:
 621         free(buffer);
 622         pthread_exit(NULL);
 623 }
 624
 625 static int mdresotre_init(struct mdrestore_struct *mdres,
 626                           FILE *in, FILE *out, int num_threads)
 627 {
 628         int i, ret = 0;
 629
 630         memset(mdres, 0, sizeof(*mdres));
 631         pthread_cond_init(&mdres->cond, NULL);
 632         pthread_mutex_init(&mdres->mutex, NULL);
 633         INIT_LIST_HEAD(&mdres->list);
 634         mdres->in = in;
 635         mdres->out = out;
 636
 637         if (!num_threads)
 638                 return 0;
 639
 640         mdres->num_threads = num_threads;
 641         mdres->threads = calloc(num_threads, sizeof(pthread_t));
 642         if (!mdres->threads)
 643                 return -ENOMEM;
 644         for (i = 0; i < num_threads; i++) {
 645                 ret = pthread_create(mdres->threads + i, NULL, restore_worker,
 646                                      mdres);
 647                 if (ret)
 648                         break;
 649         }
 650         return ret;
 651 }
 652
 653 static void mdresotre_destroy(struct mdrestore_struct *mdres)
 654 {
 655         int i;
 656         pthread_mutex_lock(&mdres->mutex);
 657         mdres->done = 1;
 658         pthread_cond_broadcast(&mdres->cond);
 659         pthread_mutex_unlock(&mdres->mutex);
 660
 661         for (i = 0; i < mdres->num_threads; i++)
 662                 pthread_join(mdres->threads[i], NULL);
 663
 664         pthread_cond_destroy(&mdres->cond);
 665         pthread_mutex_destroy(&mdres->mutex);
 666         free(mdres->threads);
 667 }
 668
 669 static int add_cluster(struct meta_cluster *cluster,
 670                        struct mdrestore_struct *mdres, u64 *next)
 671 {
 672         struct meta_cluster_item *item;
 673         struct meta_cluster_header *header = &cluster->header;
 674         struct async_work *async;
 675         u64 bytenr;
 676         u32 i, nritems;
 677         int ret;
 678
 679         BUG_ON(mdres->num_items);
 680         mdres->compress_method = header->compress;
 681
 682         bytenr = le64_to_cpu(header->bytenr) + BLOCK_SIZE;
 683         nritems = le32_to_cpu(header->nritems);
 684         for (i = 0; i < nritems; i++) {
 685                 item = &cluster->items[i];
 686                 async = calloc(1, sizeof(*async));
 687                 async->start = le64_to_cpu(item->bytenr);
 688                 async->bufsize = le32_to_cpu(item->size);
 689                 async->buffer = malloc(async->bufsize);
 690                 ret = fread(async->buffer, async->bufsize, 1, mdres->in);
 691                 BUG_ON(ret != 1);
 692                 bytenr += async->bufsize;
 693
 694                 pthread_mutex_lock(&mdres->mutex);
 695                 list_add_tail(&async->list, &mdres->list);
 696                 mdres->num_items++;
 697                 pthread_cond_signal(&mdres->cond);
 698                 pthread_mutex_unlock(&mdres->mutex);
 699         }
 700         if (bytenr & BLOCK_MASK) {
 701                 char buffer[BLOCK_MASK];
 702                 size_t size = BLOCK_SIZE - (bytenr & BLOCK_MASK);
 703
 704                 bytenr += size;
 705                 ret = fread(buffer, size, 1, mdres->in);
 706                 BUG_ON(ret != 1);
 707         }
 708         *next = bytenr;
 709         return 0;
 710 }
 711
 712 static int wait_for_worker(struct mdrestore_struct *mdres)
 713 {
 714         pthread_mutex_lock(&mdres->mutex);
 715         while (mdres->num_items > 0) {
 716                 struct timespec ts = {
 717                         .tv_sec = 0,
 718                         .tv_nsec = 10000000,
 719                 };
 720                 pthread_mutex_unlock(&mdres->mutex);
 721                 nanosleep(&ts, NULL);
 722                 pthread_mutex_lock(&mdres->mutex);
 723         }
 724         pthread_mutex_unlock(&mdres->mutex);
 725         return 0;
 726 }
 727
 728 static int restore_metadump(const char *input, FILE *out, int num_threads)
 729 {
 730         struct meta_cluster *cluster;
 731         struct meta_cluster_header *header;
 732         struct mdrestore_struct mdrestore;
 733         u64 bytenr = 0;
 734         FILE *in;
 735         int ret;
 736
 737         if (!strcmp(input, "-")) {
 738                 in = stdin;
 739         } else {
 740                 in = fopen(input, "r");
 741                 if (!in) {
 742                         perror("unable to open metadump image");
 743                         exit(1);
 744                 }
 745         }
 746
 747         cluster = malloc(BLOCK_SIZE);
 748         BUG_ON(!cluster);
 749
 750         ret = mdresotre_init(&mdrestore, in, out, num_threads);
 751         BUG_ON(ret);
 752
 753         while (1) {
 754                 ret = fread(cluster, BLOCK_SIZE, 1, in);
 755                 if (!ret)
 756                         break;
 757
 758                 header = &cluster->header;
 759                 if (le64_to_cpu(header->magic) != HEADER_MAGIC ||
 760                     le64_to_cpu(header->bytenr) != bytenr) {
 761                         fprintf(stderr, "bad header in metadump image\n");
 762                         exit(1);
 763                 }
 764                 ret = add_cluster(cluster, &mdrestore, &bytenr);
 765                 BUG_ON(ret);
 766
 767                 wait_for_worker(&mdrestore);
 768         }
 769
 770         mdresotre_destroy(&mdrestore);
 771         free(cluster);
 772         if (in != stdin)
 773                 fclose(in);
 774         return ret;
 775 }
 776
 777 static void print_usage(void)
 778 {
 779         fprintf(stderr, "usage: btrfs-image [options] source target\n");
 780         fprintf(stderr, "\t-r      \trestore metadump image\n");
 781         fprintf(stderr, "\t-c value\tcompression level (0 ~ 9)\n");
 782         fprintf(stderr, "\t-t value\tnumber of threads (1 ~ 32)\n");
 783         exit(1);
 784 }
 785
 786 int main(int argc, char *argv[])
 787 {
 788         char *source;
 789         char *target;
 790         int num_threads = 0;
 791         int compress_level = 0;
 792         int create = 1;
 793         int ret;
 794         FILE *out;
 795
 796         while (1) {
 797                 int c = getopt(argc, argv, "rc:t:");
 798                 if (c < 0)
 799                         break;
 800                 switch (c) {
 801                 case 'r':
 802                         create = 0;
 803                         break;
 804                 case 't':
 805                         num_threads = atoi(optarg);
 806                         if (num_threads <= 0 || num_threads > 32)
 807                                 print_usage();
 808                         break;
 809                 case 'c':
 810                         compress_level = atoi(optarg);
 811                         if (compress_level < 0 || compress_level > 9)
 812                                 print_usage();
 813                         break;
 814                 default:
 815                         print_usage();
 816                 }
 817         }
 818
 819         argc = argc - optind;
 820         if (argc != 2)
 821                 print_usage();
 822         source = argv[optind];
 823         target = argv[optind + 1];
 824
 825         if (create && !strcmp(target, "-")) {
 826                 out = stdout;
 827         } else {
 828                 out = fopen(target, "w+");
 829                 if (!out) {
 830                         perror("unable to create target file");
 831                         exit(1);
 832                 }
 833         }
 834
 835         if (num_threads == 0 && compress_level > 0) {
 836                 num_threads = sysconf(_SC_NPROCESSORS_ONLN);
 837                 if (num_threads <= 0)
 838                         num_threads = 1;
 839         }
 840
 841         if (create)
 842                 ret = create_metadump(source, out, num_threads,
 843                                       compress_level);
 844         else
 845                 ret = restore_metadump(source, out, 1);
 846
 847         if (out == stdout)
 848                 fflush(out);
 849         else
 850                 fclose(out);
 851
 852         exit(0);
 853 }