cmds-restore.c

   1 /*
   2  * Copyright (C) 2011 Red Hat.  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
  22 #include "kerncompat.h"
  23
  24 #include <ctype.h>
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27 #include <unistd.h>
  28 #include <fcntl.h>
  29 #include <sys/stat.h>
  30 #include <sys/types.h>
  31 #include <lzo/lzoconf.h>
  32 #include <lzo/lzo1x.h>
  33 #include <zlib.h>
  34 #include <regex.h>
  35 #include <getopt.h>
  36
  37 #include "ctree.h"
  38 #include "disk-io.h"
  39 #include "print-tree.h"
  40 #include "transaction.h"
  41 #include "list.h"
  42 #include "version.h"
  43 #include "volumes.h"
  44 #include "utils.h"
  45 #include "commands.h"
  46
  47 static char fs_name[4096];
  48 static char path_name[4096];
  49 static int get_snaps = 0;
  50 static int verbose = 0;
  51 static int ignore_errors = 0;
  52 static int overwrite = 0;
  53
  54 #define LZO_LEN 4
  55 #define PAGE_CACHE_SIZE 4096
  56 #define lzo1x_worst_compress(x) ((x) + ((x) / 16) + 64 + 3)
  57
  58 static int decompress_zlib(char *inbuf, char *outbuf, u64 compress_len,
  59                            u64 decompress_len)
  60 {
  61         z_stream strm;
  62         int ret;
  63
  64         memset(&strm, 0, sizeof(strm));
  65         ret = inflateInit(&strm);
  66         if (ret != Z_OK) {
  67                 fprintf(stderr, "inflate init returnd %d\n", ret);
  68                 return -1;
  69         }
  70
  71         strm.avail_in = compress_len;
  72         strm.next_in = (unsigned char *)inbuf;
  73         strm.avail_out = decompress_len;
  74         strm.next_out = (unsigned char *)outbuf;
  75         ret = inflate(&strm, Z_NO_FLUSH);
  76         if (ret != Z_STREAM_END) {
  77                 (void)inflateEnd(&strm);
  78                 fprintf(stderr, "failed to inflate: %d\n", ret);
  79                 return -1;
  80         }
  81
  82         (void)inflateEnd(&strm);
  83         return 0;
  84 }
  85 static inline size_t read_compress_length(unsigned char *buf)
  86 {
  87         __le32 dlen;
  88         memcpy(&dlen, buf, LZO_LEN);
  89         return le32_to_cpu(dlen);
  90 }
  91
  92 static int decompress_lzo(unsigned char *inbuf, char *outbuf, u64 compress_len,
  93                           u64 *decompress_len)
  94 {
  95         size_t new_len;
  96         size_t in_len;
  97         size_t out_len = 0;
  98         size_t tot_len;
  99         size_t tot_in;
 100         int ret;
 101
 102         ret = lzo_init();
 103         if (ret != LZO_E_OK) {
 104                 fprintf(stderr, "lzo init returned %d\n", ret);
 105                 return -1;
 106         }
 107
 108         tot_len = read_compress_length(inbuf);
 109         inbuf += LZO_LEN;
 110         tot_in = LZO_LEN;
 111
 112         while (tot_in < tot_len) {
 113                 in_len = read_compress_length(inbuf);
 114                 inbuf += LZO_LEN;
 115                 tot_in += LZO_LEN;
 116
 117                 new_len = lzo1x_worst_compress(PAGE_CACHE_SIZE);
 118                 ret = lzo1x_decompress_safe((const unsigned char *)inbuf, in_len,
 119                                             (unsigned char *)outbuf,
 120                                             (void *)&new_len, NULL);
 121                 if (ret != LZO_E_OK) {
 122                         fprintf(stderr, "failed to inflate: %d\n", ret);
 123                         return -1;
 124                 }
 125                 out_len += new_len;
 126                 outbuf += new_len;
 127                 inbuf += in_len;
 128                 tot_in += in_len;
 129         }
 130
 131         *decompress_len = out_len;
 132
 133         return 0;
 134 }
 135
 136 static int decompress(char *inbuf, char *outbuf, u64 compress_len,
 137                       u64 *decompress_len, int compress)
 138 {
 139         switch (compress) {
 140         case BTRFS_COMPRESS_ZLIB:
 141                 return decompress_zlib(inbuf, outbuf, compress_len,
 142                                        *decompress_len);
 143         case BTRFS_COMPRESS_LZO:
 144                 return decompress_lzo((unsigned char *)inbuf, outbuf, compress_len,
 145                                       decompress_len);
 146         default:
 147                 break;
 148         }
 149
 150         fprintf(stderr, "invalid compression type: %d\n", compress);
 151         return -1;
 152 }
 153
 154 int next_leaf(struct btrfs_root *root, struct btrfs_path *path)
 155 {
 156         int slot;
 157         int level = 1;
 158         int offset = 1;
 159         struct extent_buffer *c;
 160         struct extent_buffer *next = NULL;
 161
 162 again:
 163         for (; level < BTRFS_MAX_LEVEL; level++) {
 164                 if (path->nodes[level])
 165                         break;
 166         }
 167
 168         if (level == BTRFS_MAX_LEVEL)
 169                 return 1;
 170
 171         slot = path->slots[level] + 1;
 172
 173         while(level < BTRFS_MAX_LEVEL) {
 174                 if (!path->nodes[level])
 175                         return 1;
 176
 177                 slot = path->slots[level] + offset;
 178                 c = path->nodes[level];
 179                 if (slot >= btrfs_header_nritems(c)) {
 180                         level++;
 181                         if (level == BTRFS_MAX_LEVEL)
 182                                 return 1;
 183                         continue;
 184                 }
 185
 186                 if (path->reada)
 187                         reada_for_search(root, path, level, slot, 0);
 188
 189                 next = read_node_slot(root, c, slot);
 190                 if (next)
 191                         break;
 192                 offset++;
 193         }
 194         path->slots[level] = slot;
 195         while(1) {
 196                 level--;
 197                 c = path->nodes[level];
 198                 free_extent_buffer(c);
 199                 path->nodes[level] = next;
 200                 path->slots[level] = 0;
 201                 if (!level)
 202                         break;
 203                 if (path->reada)
 204                         reada_for_search(root, path, level, 0, 0);
 205                 next = read_node_slot(root, next, 0);
 206                 if (!next)
 207                         goto again;
 208         }
 209         return 0;
 210 }
 211
 212 static int copy_one_inline(int fd, struct btrfs_path *path, u64 pos)
 213 {
 214         struct extent_buffer *leaf = path->nodes[0];
 215         struct btrfs_file_extent_item *fi;
 216         char buf[4096];
 217         char *outbuf;
 218         u64 ram_size;
 219         ssize_t done;
 220         unsigned long ptr;
 221         int ret;
 222         int len;
 223         int compress;
 224
 225         fi = btrfs_item_ptr(leaf, path->slots[0],
 226                             struct btrfs_file_extent_item);
 227         ptr = btrfs_file_extent_inline_start(fi);
 228         len = btrfs_file_extent_inline_item_len(leaf,
 229                                         btrfs_item_nr(leaf, path->slots[0]));
 230         read_extent_buffer(leaf, buf, ptr, len);
 231
 232         compress = btrfs_file_extent_compression(leaf, fi);
 233         if (compress == BTRFS_COMPRESS_NONE) {
 234                 done = pwrite(fd, buf, len, pos);
 235                 if (done < len) {
 236                         fprintf(stderr, "Short inline write, wanted %d, did "
 237                                 "%zd: %d\n", len, done, errno);
 238                         return -1;
 239                 }
 240                 return 0;
 241         }
 242
 243         ram_size = btrfs_file_extent_ram_bytes(leaf, fi);
 244         outbuf = malloc(ram_size);
 245         if (!outbuf) {
 246                 fprintf(stderr, "No memory\n");
 247                 return -1;
 248         }
 249
 250         ret = decompress(buf, outbuf, len, &ram_size, compress);
 251         if (ret) {
 252                 free(outbuf);
 253                 return ret;
 254         }
 255
 256         done = pwrite(fd, outbuf, ram_size, pos);
 257         free(outbuf);
 258         if (done < ram_size) {
 259                 fprintf(stderr, "Short compressed inline write, wanted %Lu, "
 260                         "did %zd: %d\n", ram_size, done, errno);
 261                 return -1;
 262         }
 263
 264         return 0;
 265 }
 266
 267 static int copy_one_extent(struct btrfs_root *root, int fd,
 268                            struct extent_buffer *leaf,
 269                            struct btrfs_file_extent_item *fi, u64 pos)
 270 {
 271         struct btrfs_multi_bio *multi = NULL;
 272         struct btrfs_device *device;
 273         char *inbuf, *outbuf = NULL;
 274         ssize_t done, total = 0;
 275         u64 bytenr;
 276         u64 ram_size;
 277         u64 disk_size;
 278         u64 length;
 279         u64 size_left;
 280         u64 dev_bytenr;
 281         u64 offset;
 282         u64 count = 0;
 283         int compress;
 284         int ret;
 285         int dev_fd;
 286         int mirror_num = 1;
 287         int num_copies;
 288
 289         compress = btrfs_file_extent_compression(leaf, fi);
 290         bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
 291         disk_size = btrfs_file_extent_disk_num_bytes(leaf, fi);
 292         ram_size = btrfs_file_extent_ram_bytes(leaf, fi);
 293         offset = btrfs_file_extent_offset(leaf, fi);
 294         size_left = disk_size;
 295
 296         if (offset)
 297                 printf("offset is %Lu\n", offset);
 298         /* we found a hole */
 299         if (disk_size == 0)
 300                 return 0;
 301
 302         inbuf = malloc(disk_size);
 303         if (!inbuf) {
 304                 fprintf(stderr, "No memory\n");
 305                 return -1;
 306         }
 307
 308         if (compress != BTRFS_COMPRESS_NONE) {
 309                 outbuf = malloc(ram_size);
 310                 if (!outbuf) {
 311                         fprintf(stderr, "No memory\n");
 312                         free(inbuf);
 313                         return -1;
 314                 }
 315         }
 316 again:
 317         length = size_left;
 318         ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
 319                               bytenr, &length, &multi, mirror_num, NULL);
 320         if (ret) {
 321                 fprintf(stderr, "Error mapping block %d\n", ret);
 322                 goto out;
 323         }
 324         device = multi->stripes[0].dev;
 325         dev_fd = device->fd;
 326         device->total_ios++;
 327         dev_bytenr = multi->stripes[0].physical;
 328         kfree(multi);
 329
 330         if (size_left < length)
 331                 length = size_left;
 332
 333         done = pread(dev_fd, inbuf+count, length, dev_bytenr);
 334         /* Need both checks, or we miss negative values due to u64 conversion */
 335         if (done < 0 || done < length) {
 336                 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
 337                                               bytenr, length);
 338                 mirror_num++;
 339                 /* mirror_num is 1-indexed, so num_copies is a valid mirror. */
 340                 if (mirror_num > num_copies) {
 341                         ret = -1;
 342                         fprintf(stderr, "Exhausted mirrors trying to read\n");
 343                         goto out;
 344                 }
 345                 fprintf(stderr, "Trying another mirror\n");
 346                 goto again;
 347         }
 348
 349         mirror_num = 1;
 350         size_left -= length;
 351         count += length;
 352         bytenr += length;
 353         if (size_left)
 354                 goto again;
 355
 356         if (compress == BTRFS_COMPRESS_NONE) {
 357                 while (total < ram_size) {
 358                         done = pwrite(fd, inbuf+total, ram_size-total,
 359                                       pos+total);
 360                         if (done < 0) {
 361                                 ret = -1;
 362                                 fprintf(stderr, "Error writing: %d %s\n", errno, strerror(errno));
 363                                 goto out;
 364                         }
 365                         total += done;
 366                 }
 367                 ret = 0;
 368                 goto out;
 369         }
 370
 371         ret = decompress(inbuf, outbuf, disk_size, &ram_size, compress);
 372         if (ret) {
 373                 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
 374                                               bytenr, length);
 375                 mirror_num++;
 376                 if (mirror_num >= num_copies) {
 377                         ret = -1;
 378                         goto out;
 379                 }
 380                 fprintf(stderr, "Trying another mirror\n");
 381                 goto again;
 382         }
 383
 384         while (total < ram_size) {
 385                 done = pwrite(fd, outbuf+total, ram_size-total, pos+total);
 386                 if (done < 0) {
 387                         ret = -1;
 388                         goto out;
 389                 }
 390                 total += done;
 391         }
 392 out:
 393         free(inbuf);
 394         free(outbuf);
 395         return ret;
 396 }
 397
 398 static int ask_to_continue(const char *file)
 399 {
 400         char buf[2];
 401         char *ret;
 402
 403         printf("We seem to be looping a lot on %s, do you want to keep going "
 404                "on ? (y/N): ", file);
 405 again:
 406         ret = fgets(buf, 2, stdin);
 407         if (*ret == '\n' || tolower(*ret) == 'n')
 408                 return 1;
 409         if (tolower(*ret) != 'y') {
 410                 printf("Please enter either 'y' or 'n': ");
 411                 goto again;
 412         }
 413
 414         return 0;
 415 }
 416
 417
 418 static int copy_file(struct btrfs_root *root, int fd, struct btrfs_key *key,
 419                      const char *file)
 420 {
 421         struct extent_buffer *leaf;
 422         struct btrfs_path *path;
 423         struct btrfs_file_extent_item *fi;
 424         struct btrfs_inode_item *inode_item;
 425         struct btrfs_key found_key;
 426         int ret;
 427         int extent_type;
 428         int compression;
 429         int loops = 0;
 430         u64 found_size = 0;
 431
 432         path = btrfs_alloc_path();
 433         if (!path) {
 434                 fprintf(stderr, "Ran out of memory\n");
 435                 return -1;
 436         }
 437         path->skip_locking = 1;
 438
 439         ret = btrfs_lookup_inode(NULL, root, path, key, 0);
 440         if (ret == 0) {
 441                 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
 442                                     struct btrfs_inode_item);
 443                 found_size = btrfs_inode_size(path->nodes[0], inode_item);
 444         }
 445         btrfs_release_path(root, path);
 446
 447         key->offset = 0;
 448         key->type = BTRFS_EXTENT_DATA_KEY;
 449
 450         ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
 451         if (ret < 0) {
 452                 fprintf(stderr, "Error searching %d\n", ret);
 453                 btrfs_free_path(path);
 454                 return ret;
 455         }
 456
 457         leaf = path->nodes[0];
 458         while (!leaf) {
 459                 ret = next_leaf(root, path);
 460                 if (ret < 0) {
 461                         fprintf(stderr, "Error getting next leaf %d\n",
 462                                 ret);
 463                         btrfs_free_path(path);
 464                         return ret;
 465                 } else if (ret > 0) {
 466                         /* No more leaves to search */
 467                         btrfs_free_path(path);
 468                         return 0;
 469                 }
 470                 leaf = path->nodes[0];
 471         }
 472
 473         while (1) {
 474                 if (loops++ >= 1024) {
 475                         ret = ask_to_continue(file);
 476                         if (ret)
 477                                 break;
 478                         loops = 0;
 479                 }
 480                 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
 481                         do {
 482                                 ret = next_leaf(root, path);
 483                                 if (ret < 0) {
 484                                         fprintf(stderr, "Error searching %d\n", ret);
 485                                         btrfs_free_path(path);
 486                                         return ret;
 487                                 } else if (ret) {
 488                                         /* No more leaves to search */
 489                                         btrfs_free_path(path);
 490                                         goto set_size;
 491                                 }
 492                                 leaf = path->nodes[0];
 493                         } while (!leaf);
 494                         continue;
 495                 }
 496                 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
 497                 if (found_key.objectid != key->objectid)
 498                         break;
 499                 if (found_key.type != key->type)
 500                         break;
 501                 fi = btrfs_item_ptr(leaf, path->slots[0],
 502                                     struct btrfs_file_extent_item);
 503                 extent_type = btrfs_file_extent_type(leaf, fi);
 504                 compression = btrfs_file_extent_compression(leaf, fi);
 505                 if (compression >= BTRFS_COMPRESS_LAST) {
 506                         fprintf(stderr, "Don't support compression yet %d\n",
 507                                 compression);
 508                         btrfs_free_path(path);
 509                         return -1;
 510                 }
 511
 512                 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC)
 513                         goto next;
 514                 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
 515                         ret = copy_one_inline(fd, path, found_key.offset);
 516                         if (ret) {
 517                                 btrfs_free_path(path);
 518                                 return -1;
 519                         }
 520                 } else if (extent_type == BTRFS_FILE_EXTENT_REG) {
 521                         ret = copy_one_extent(root, fd, leaf, fi,
 522                                               found_key.offset);
 523                         if (ret) {
 524                                 btrfs_free_path(path);
 525                                 return ret;
 526                         }
 527                 } else {
 528                         printf("Weird extent type %d\n", extent_type);
 529                 }
 530 next:
 531                 path->slots[0]++;
 532         }
 533
 534         btrfs_free_path(path);
 535 set_size:
 536         if (found_size) {
 537                 ret = ftruncate(fd, (loff_t)found_size);
 538                 if (ret)
 539                         return ret;
 540         }
 541         return 0;
 542 }
 543
 544 static int search_dir(struct btrfs_root *root, struct btrfs_key *key,
 545                       const char *output_rootdir, const char *dir,
 546                       const regex_t *mreg)
 547 {
 548         struct btrfs_path *path;
 549         struct extent_buffer *leaf;
 550         struct btrfs_dir_item *dir_item;
 551         struct btrfs_key found_key, location;
 552         char filename[BTRFS_NAME_LEN + 1];
 553         unsigned long name_ptr;
 554         int name_len;
 555         int ret;
 556         int fd;
 557         int loops = 0;
 558         u8 type;
 559
 560         path = btrfs_alloc_path();
 561         if (!path) {
 562                 fprintf(stderr, "Ran out of memory\n");
 563                 return -1;
 564         }
 565         path->skip_locking = 1;
 566
 567         key->offset = 0;
 568         key->type = BTRFS_DIR_INDEX_KEY;
 569
 570         ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
 571         if (ret < 0) {
 572                 fprintf(stderr, "Error searching %d\n", ret);
 573                 btrfs_free_path(path);
 574                 return ret;
 575         }
 576
 577         leaf = path->nodes[0];
 578         while (!leaf) {
 579                 if (verbose > 1)
 580                         printf("No leaf after search, looking for the next "
 581                                "leaf\n");
 582                 ret = next_leaf(root, path);
 583                 if (ret < 0) {
 584                         fprintf(stderr, "Error getting next leaf %d\n",
 585                                 ret);
 586                         btrfs_free_path(path);
 587                         return ret;
 588                 } else if (ret > 0) {
 589                         /* No more leaves to search */
 590                         if (verbose)
 591                                 printf("Reached the end of the tree looking "
 592                                        "for the directory\n");
 593                         btrfs_free_path(path);
 594                         return 0;
 595                 }
 596                 leaf = path->nodes[0];
 597         }
 598
 599         while (leaf) {
 600                 if (loops++ >= 1024) {
 601                         printf("We have looped trying to restore files in %s "
 602                                "too many times to be making progress, "
 603                                "stopping\n", dir);
 604                         break;
 605                 }
 606
 607                 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
 608                         do {
 609                                 ret = next_leaf(root, path);
 610                                 if (ret < 0) {
 611                                         fprintf(stderr, "Error searching %d\n",
 612                                                 ret);
 613                                         btrfs_free_path(path);
 614                                         return ret;
 615                                 } else if (ret > 0) {
 616                                         /* No more leaves to search */
 617                                         if (verbose)
 618                                                 printf("Reached the end of "
 619                                                        "the tree searching the"
 620                                                        " directory\n");
 621                                         btrfs_free_path(path);
 622                                         return 0;
 623                                 }
 624                                 leaf = path->nodes[0];
 625                         } while (!leaf);
 626                         continue;
 627                 }
 628                 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
 629                 if (found_key.objectid != key->objectid) {
 630                         if (verbose > 1)
 631                                 printf("Found objectid=%Lu, key=%Lu\n",
 632                                        found_key.objectid, key->objectid);
 633                         break;
 634                 }
 635                 if (found_key.type != key->type) {
 636                         if (verbose > 1)
 637                                 printf("Found type=%u, want=%u\n",
 638                                        found_key.type, key->type);
 639                         break;
 640                 }
 641                 dir_item = btrfs_item_ptr(leaf, path->slots[0],
 642                                           struct btrfs_dir_item);
 643                 name_ptr = (unsigned long)(dir_item + 1);
 644                 name_len = btrfs_dir_name_len(leaf, dir_item);
 645                 read_extent_buffer(leaf, filename, name_ptr, name_len);
 646                 filename[name_len] = '\0';
 647                 type = btrfs_dir_type(leaf, dir_item);
 648                 btrfs_dir_item_key_to_cpu(leaf, dir_item, &location);
 649
 650                 /* full path from root of btrfs being restored */
 651                 snprintf(fs_name, 4096, "%s/%s", dir, filename);
 652
 653                 if (mreg && REG_NOMATCH == regexec(mreg, fs_name, 0, NULL, 0))
 654                         goto next;
 655
 656                 /* full path from system root */
 657                 snprintf(path_name, 4096, "%s%s", output_rootdir, fs_name);
 658
 659                 /*
 660                  * At this point we're only going to restore directories and
 661                  * files, no symlinks or anything else.
 662                  */
 663                 if (type == BTRFS_FT_REG_FILE) {
 664                         if (!overwrite) {
 665                                 static int warn = 0;
 666                                 struct stat st;
 667
 668                                 ret = stat(path_name, &st);
 669                                 if (!ret) {
 670                                         loops = 0;
 671                                         if (verbose || !warn)
 672                                                 printf("Skipping existing file"
 673                                                        " %s\n", path_name);
 674                                         if (warn)
 675                                                 goto next;
 676                                         printf("If you wish to overwrite use "
 677                                                "the -o option to overwrite\n");
 678                                         warn = 1;
 679                                         goto next;
 680                                 }
 681                                 ret = 0;
 682                         }
 683                         if (verbose)
 684                                 printf("Restoring %s\n", path_name);
 685                         fd = open(path_name, O_CREAT|O_WRONLY, 0644);
 686                         if (fd < 0) {
 687                                 fprintf(stderr, "Error creating %s: %d\n",
 688                                         path_name, errno);
 689                                 if (ignore_errors)
 690                                         goto next;
 691                                 btrfs_free_path(path);
 692                                 return -1;
 693                         }
 694                         loops = 0;
 695                         ret = copy_file(root, fd, &location, path_name);
 696                         close(fd);
 697                         if (ret) {
 698                                 if (ignore_errors)
 699                                         goto next;
 700                                 btrfs_free_path(path);
 701                                 return ret;
 702                         }
 703                 } else if (type == BTRFS_FT_DIR) {
 704                         struct btrfs_root *search_root = root;
 705                         char *dir = strdup(fs_name);
 706
 707                         if (!dir) {
 708                                 fprintf(stderr, "Ran out of memory\n");
 709                                 btrfs_free_path(path);
 710                                 return -1;
 711                         }
 712
 713                         if (location.type == BTRFS_ROOT_ITEM_KEY) {
 714                                 /*
 715                                  * If we are a snapshot and this is the index
 716                                  * object to ourselves just skip it.
 717                                  */
 718                                 if (location.objectid ==
 719                                     root->root_key.objectid) {
 720                                         free(dir);
 721                                         goto next;
 722                                 }
 723
 724                                 location.offset = (u64)-1;
 725                                 search_root = btrfs_read_fs_root(root->fs_info,
 726                                                                  &location);
 727                                 if (IS_ERR(search_root)) {
 728                                         free(dir);
 729                                         fprintf(stderr, "Error reading "
 730                                                 "subvolume %s: %lu\n",
 731                                                 path_name,
 732                                                 PTR_ERR(search_root));
 733                                         if (ignore_errors)
 734                                                 goto next;
 735                                         btrfs_free_path(path);
 736                                         return PTR_ERR(search_root);
 737                                 }
 738
 739                                 /*
 740                                  * A subvolume will have a key.offset of 0, a
 741                                  * snapshot will have key.offset of a transid.
 742                                  */
 743                                 if (search_root->root_key.offset != 0 &&
 744                                     get_snaps == 0) {
 745                                         free(dir);
 746                                         printf("Skipping snapshot %s\n",
 747                                                filename);
 748                                         goto next;
 749                                 }
 750                                 location.objectid = BTRFS_FIRST_FREE_OBJECTID;
 751                         }
 752
 753                         if (verbose)
 754                                 printf("Restoring %s\n", path_name);
 755
 756                         errno = 0;
 757                         ret = mkdir(path_name, 0755);
 758                         if (ret && errno != EEXIST) {
 759                                 free(dir);
 760                                 fprintf(stderr, "Error mkdiring %s: %d\n",
 761                                         path_name, errno);
 762                                 if (ignore_errors)
 763                                         goto next;
 764                                 btrfs_free_path(path);
 765                                 return -1;
 766                         }
 767                         loops = 0;
 768                         ret = search_dir(search_root, &location,
 769                                          output_rootdir, dir, mreg);
 770                         free(dir);
 771                         if (ret) {
 772                                 if (ignore_errors)
 773                                         goto next;
 774                                 btrfs_free_path(path);
 775                                 return ret;
 776                         }
 777                 }
 778 next:
 779                 path->slots[0]++;
 780         }
 781
 782         if (verbose)
 783                 printf("Done searching %s\n", dir);
 784         btrfs_free_path(path);
 785         return 0;
 786 }
 787
 788 static int do_list_roots(struct btrfs_root *root)
 789 {
 790         struct btrfs_key key;
 791         struct btrfs_key found_key;
 792         struct btrfs_disk_key disk_key;
 793         struct btrfs_path *path;
 794         struct extent_buffer *leaf;
 795         struct btrfs_root_item ri;
 796         unsigned long offset;
 797         int slot;
 798         int ret;
 799
 800         root = root->fs_info->tree_root;
 801         path = btrfs_alloc_path();
 802         if (!path) {
 803                 fprintf(stderr, "Failed to alloc path\n");
 804                 return -1;
 805         }
 806
 807         key.offset = 0;
 808         key.objectid = 0;
 809         key.type = BTRFS_ROOT_ITEM_KEY;
 810
 811         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
 812         if (ret < 0) {
 813                 fprintf(stderr, "Failed to do search %d\n", ret);
 814                 btrfs_free_path(path);
 815                 return -1;
 816         }
 817
 818         while (1) {
 819                 leaf = path->nodes[0];
 820                 slot = path->slots[0];
 821                 if (slot >= btrfs_header_nritems(leaf)) {
 822                         ret = btrfs_next_leaf(root, path);
 823                         if (ret)
 824                                 break;
 825                         leaf = path->nodes[0];
 826                         slot = path->slots[0];
 827                 }
 828                 btrfs_item_key(leaf, &disk_key, slot);
 829                 btrfs_disk_key_to_cpu(&found_key, &disk_key);
 830                 if (btrfs_key_type(&found_key) != BTRFS_ROOT_ITEM_KEY) {
 831                         path->slots[0]++;
 832                         continue;
 833                 }
 834
 835                 offset = btrfs_item_ptr_offset(leaf, slot);
 836                 read_extent_buffer(leaf, &ri, offset, sizeof(ri));
 837                 printf(" tree ");
 838                 btrfs_print_key(&disk_key);
 839                 printf(" %Lu level %d\n", btrfs_root_bytenr(&ri),
 840                        btrfs_root_level(&ri));
 841                 path->slots[0]++;
 842         }
 843         btrfs_free_path(path);
 844
 845         return 0;
 846 }
 847
 848 static struct btrfs_root *open_fs(const char *dev, u64 root_location,
 849                                   int super_mirror, int list_roots)
 850 {
 851         struct btrfs_fs_info *fs_info = NULL;
 852         struct btrfs_root *root = NULL;
 853         u64 bytenr;
 854         int i;
 855
 856         for (i = super_mirror; i < BTRFS_SUPER_MIRROR_MAX; i++) {
 857                 bytenr = btrfs_sb_offset(i);
 858                 fs_info = open_ctree_fs_info(dev, bytenr, root_location, 0, 1);
 859                 if (fs_info)
 860                         break;
 861                 fprintf(stderr, "Could not open root, trying backup super\n");
 862         }
 863
 864         if (!fs_info)
 865                 return NULL;
 866
 867         /*
 868          * All we really need to succeed is reading the chunk tree, everything
 869          * else we can do by hand, since we only need to read the tree root and
 870          * the fs_root.
 871          */
 872         if (!extent_buffer_uptodate(fs_info->tree_root->node)) {
 873                 u64 generation;
 874
 875                 root = fs_info->tree_root;
 876                 if (!root_location)
 877                         root_location = btrfs_super_root(fs_info->super_copy);
 878                 generation = btrfs_super_generation(fs_info->super_copy);
 879                 root->node = read_tree_block(root, root_location,
 880                                              root->leafsize, generation);
 881                 if (!extent_buffer_uptodate(root->node)) {
 882                         fprintf(stderr, "Error opening tree root\n");
 883                         close_ctree(root);
 884                         return NULL;
 885                 }
 886         }
 887
 888         if (!list_roots && !fs_info->fs_root) {
 889                 struct btrfs_key key;
 890
 891                 key.objectid = BTRFS_FS_TREE_OBJECTID;
 892                 key.type = BTRFS_ROOT_ITEM_KEY;
 893                 key.offset = (u64)-1;
 894                 fs_info->fs_root = btrfs_read_fs_root_no_cache(fs_info, &key);
 895                 if (IS_ERR(fs_info->fs_root)) {
 896                         fprintf(stderr, "Couldn't read fs root: %ld\n",
 897                                 PTR_ERR(fs_info->fs_root));
 898                         close_ctree(fs_info->tree_root);
 899                         return NULL;
 900                 }
 901         }
 902
 903         if (list_roots && do_list_roots(fs_info->tree_root)) {
 904                 close_ctree(fs_info->tree_root);
 905                 return NULL;
 906         }
 907
 908         return fs_info->fs_root;
 909 }
 910
 911 static int find_first_dir(struct btrfs_root *root, u64 *objectid)
 912 {
 913         struct btrfs_path *path;
 914         struct btrfs_key found_key;
 915         struct btrfs_key key;
 916         int ret = -1;
 917         int i;
 918
 919         key.objectid = 0;
 920         key.type = BTRFS_DIR_INDEX_KEY;
 921         key.offset = 0;
 922
 923         path = btrfs_alloc_path();
 924         if (!path) {
 925                 fprintf(stderr, "Ran out of memory\n");
 926                 return ret;
 927         }
 928
 929         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
 930         if (ret < 0) {
 931                 fprintf(stderr, "Error searching %d\n", ret);
 932                 goto out;
 933         }
 934
 935         if (!path->nodes[0]) {
 936                 fprintf(stderr, "No leaf!\n");
 937                 goto out;
 938         }
 939 again:
 940         for (i = path->slots[0];
 941              i < btrfs_header_nritems(path->nodes[0]); i++) {
 942                 btrfs_item_key_to_cpu(path->nodes[0], &found_key, i);
 943                 if (found_key.type != key.type)
 944                         continue;
 945
 946                 printf("Using objectid %Lu for first dir\n",
 947                        found_key.objectid);
 948                 *objectid = found_key.objectid;
 949                 ret = 0;
 950                 goto out;
 951         }
 952         do {
 953                 ret = next_leaf(root, path);
 954                 if (ret < 0) {
 955                         fprintf(stderr, "Error getting next leaf %d\n",
 956                                 ret);
 957                         goto out;
 958                 } else if (ret > 0) {
 959                         fprintf(stderr, "No more leaves\n");
 960                         goto out;
 961                 }
 962         } while (!path->nodes[0]);
 963         if (path->nodes[0])
 964                 goto again;
 965         printf("Couldn't find a dir index item\n");
 966 out:
 967         btrfs_free_path(path);
 968         return ret;
 969 }
 970
 971 static struct option long_options[] = {
 972         { "path-regex", 1, NULL, 256},
 973         { 0, 0, 0, 0}
 974 };
 975
 976 const char * const cmd_restore_usage[] = {
 977         "btrfs restore [options] <device>",
 978         "Try to restore files from a damaged filesystem (unmounted)",
 979         "",
 980         "-s              get snapshots",
 981         "-v              verbose",
 982         "-i              ignore errors",
 983         "-o              overwrite",
 984         "-t              tree location",
 985         "-f <offset>     filesystem location",
 986         "-u <block>      super mirror",
 987         "-d              find dir",
 988         "--path-regex <regex>",
 989         "                restore only filenames matching regex,",
 990         "                you have to use following syntax (possibly quoted):",
 991         "                ^/(|home(|/username(|/Desktop(|/.*))))$",
 992         NULL
 993 };
 994
 995 int cmd_restore(int argc, char **argv)
 996 {
 997         struct btrfs_root *root;
 998         struct btrfs_key key;
 999         char dir_name[128];
1000         u64 tree_location = 0;
1001         u64 fs_location = 0;
1002         u64 root_objectid = 0;
1003         int len;
1004         int ret;
1005         int opt;
1006         int option_index = 0;
1007         int super_mirror = 0;
1008         int find_dir = 0;
1009         int list_roots = 0;
1010         const char *match_regstr = NULL;
1011         int match_cflags = REG_EXTENDED | REG_NOSUB | REG_NEWLINE;
1012         regex_t match_reg, *mreg = NULL;
1013         char reg_err[256];
1014
1015         while ((opt = getopt_long(argc, argv, "sviot:u:df:r:lc", long_options,
1016                                         &option_index)) != -1) {
1017
1018                 switch (opt) {
1019                         case 's':
1020                                 get_snaps = 1;
1021                                 break;
1022                         case 'v':
1023                                 verbose++;
1024                                 break;
1025                         case 'i':
1026                                 ignore_errors = 1;
1027                                 break;
1028                         case 'o':
1029                                 overwrite = 1;
1030                                 break;
1031                         case 't':
1032                                 errno = 0;
1033                                 tree_location = (u64)strtoll(optarg, NULL, 10);
1034                                 if (errno != 0) {
1035                                         fprintf(stderr, "Tree location not valid\n");
1036                                         exit(1);
1037                                 }
1038                                 break;
1039                         case 'f':
1040                                 errno = 0;
1041                                 fs_location = (u64)strtoll(optarg, NULL, 10);
1042                                 if (errno != 0) {
1043                                         fprintf(stderr, "Fs location not valid\n");
1044                                         exit(1);
1045                                 }
1046                                 break;
1047                         case 'u':
1048                                 errno = 0;
1049                                 super_mirror = (int)strtol(optarg, NULL, 10);
1050                                 if (errno != 0 ||
1051                                     super_mirror >= BTRFS_SUPER_MIRROR_MAX) {
1052                                         fprintf(stderr, "Super mirror not "
1053                                                 "valid\n");
1054                                         exit(1);
1055                                 }
1056                                 break;
1057                         case 'd':
1058                                 find_dir = 1;
1059                                 break;
1060                         case 'r':
1061                                 errno = 0;
1062                                 root_objectid = (u64)strtoll(optarg, NULL, 10);
1063                                 if (errno != 0) {
1064                                         fprintf(stderr, "Root objectid not valid\n");
1065                                         exit(1);
1066                                 }
1067                                 break;
1068                         case 'l':
1069                                 list_roots = 1;
1070                                 break;
1071                         case 'c':
1072                                 match_cflags |= REG_ICASE;
1073                                 break;
1074                         /* long option without single letter alternative */
1075                         case 256:
1076                                 match_regstr = optarg;
1077                                 break;
1078                         default:
1079                                 usage(cmd_restore_usage);
1080                 }
1081         }
1082
1083         if (!list_roots && optind + 1 >= argc)
1084                 usage(cmd_restore_usage);
1085         else if (list_roots && optind >= argc)
1086                 usage(cmd_restore_usage);
1087
1088         if ((ret = check_mounted(argv[optind])) < 0) {
1089                 fprintf(stderr, "Could not check mount status: %s\n",
1090                         strerror(-ret));
1091                 return ret;
1092         } else if (ret) {
1093                 fprintf(stderr, "%s is currently mounted.  Aborting.\n", argv[optind]);
1094                 return 1;
1095         }
1096
1097         root = open_fs(argv[optind], tree_location, super_mirror, list_roots);
1098         if (root == NULL)
1099                 return 1;
1100
1101         if (list_roots)
1102                 goto out;
1103
1104         if (fs_location != 0) {
1105                 free_extent_buffer(root->node);
1106                 root->node = read_tree_block(root, fs_location, root->leafsize, 0);
1107                 if (!root->node) {
1108                         fprintf(stderr, "Failed to read fs location\n");
1109                         goto out;
1110                 }
1111         }
1112
1113         memset(path_name, 0, 4096);
1114
1115         strncpy(dir_name, argv[optind + 1], sizeof dir_name);
1116         dir_name[sizeof dir_name - 1] = 0;
1117
1118         /* Strip the trailing / on the dir name */
1119         len = strlen(dir_name);
1120         while (len && dir_name[--len] == '/') {
1121                 dir_name[len] = '\0';
1122         }
1123
1124         if (root_objectid != 0) {
1125                 struct btrfs_root *orig_root = root;
1126
1127                 key.objectid = root_objectid;
1128                 key.type = BTRFS_ROOT_ITEM_KEY;
1129                 key.offset = (u64)-1;
1130                 root = btrfs_read_fs_root(orig_root->fs_info, &key);
1131                 if (IS_ERR(root)) {
1132                         fprintf(stderr, "Error reading root\n");
1133                         root = orig_root;
1134                         ret = 1;
1135                         goto out;
1136                 }
1137                 key.type = 0;
1138                 key.offset = 0;
1139         }
1140
1141         if (find_dir) {
1142                 ret = find_first_dir(root, &key.objectid);
1143                 if (ret)
1144                         goto out;
1145         } else {
1146                 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
1147         }
1148
1149         if (match_regstr) {
1150                 ret = regcomp(&match_reg, match_regstr, match_cflags);
1151                 if (ret) {
1152                         regerror(ret, &match_reg, reg_err, sizeof(reg_err));
1153                         fprintf(stderr, "Regex compile failed: %s\n", reg_err);
1154                         goto out;
1155                 }
1156                 mreg = &match_reg;
1157         }
1158
1159         ret = search_dir(root, &key, dir_name, "", mreg);
1160
1161 out:
1162         if (mreg)
1163                 regfree(mreg);
1164         close_ctree(root);
1165         return ret;
1166 }