btrfs-corrupt-block.c

   1 /*
   2  * Copyright (C) 2009 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 <stdio.h>
  22 #include <stdlib.h>
  23 #include <fcntl.h>
  24 #include <unistd.h>
  25 #include <getopt.h>
  26 #include "kerncompat.h"
  27 #include "ctree.h"
  28 #include "volumes.h"
  29 #include "disk-io.h"
  30 #include "print-tree.h"
  31 #include "transaction.h"
  32 #include "list.h"
  33 #include "version.h"
  34
  35 struct extent_buffer *debug_corrupt_block(struct btrfs_root *root, u64 bytenr,
  36                                      u32 blocksize, int copy)
  37 {
  38         int ret;
  39         struct extent_buffer *eb;
  40         u64 length;
  41         struct btrfs_multi_bio *multi = NULL;
  42         struct btrfs_device *device;
  43         int num_copies;
  44         int mirror_num = 1;
  45
  46         eb = btrfs_find_create_tree_block(root, bytenr, blocksize);
  47         if (!eb)
  48                 return NULL;
  49
  50         length = blocksize;
  51         while (1) {
  52                 ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
  53                                       eb->start, &length, &multi, mirror_num);
  54                 BUG_ON(ret);
  55                 device = multi->stripes[0].dev;
  56                 eb->fd = device->fd;
  57                 device->total_ios++;
  58                 eb->dev_bytenr = multi->stripes[0].physical;
  59
  60                 fprintf(stdout, "mirror %d logical %Lu physical %Lu "
  61                         "device %s\n", mirror_num, (unsigned long long)bytenr,
  62                         (unsigned long long)eb->dev_bytenr, device->name);
  63                 kfree(multi);
  64
  65                 if (!copy || mirror_num == copy) {
  66                         ret = read_extent_from_disk(eb);
  67                         printf("corrupting %llu copy %d\n", eb->start,
  68                                mirror_num);
  69                         memset(eb->data, 0, eb->len);
  70                         write_extent_to_disk(eb);
  71                         fsync(eb->fd);
  72                 }
  73
  74                 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
  75                                               eb->start, eb->len);
  76                 if (num_copies == 1)
  77                         break;
  78
  79                 mirror_num++;
  80                 if (mirror_num > num_copies)
  81                         break;
  82         }
  83         return eb;
  84 }
  85
  86 static void print_usage(void)
  87 {
  88         fprintf(stderr, "usage: btrfs-corrupt-block [options] device\n");
  89         fprintf(stderr, "\t-l Logical extent to be corrupted\n");
  90         fprintf(stderr, "\t-c Copy of the extent to be corrupted"
  91                 " (usually 1 or 2, default: 0)\n");
  92         fprintf(stderr, "\t-b Number of bytes to be corrupted\n");
  93         fprintf(stderr, "\t-e Extent to be corrupted\n");
  94         fprintf(stderr, "\t-E The whole extent free to be corrupted\n");
  95         exit(1);
  96 }
  97
  98 static void corrupt_keys(struct btrfs_trans_handle *trans,
  99                          struct btrfs_root *root,
 100                          struct extent_buffer *eb)
 101 {
 102         int slot;
 103         int bad_slot;
 104         int nr;
 105         struct btrfs_disk_key bad_key;;
 106
 107         nr = btrfs_header_nritems(eb);
 108         if (nr == 0)
 109                 return;
 110
 111         slot = rand() % nr;
 112         bad_slot = rand() % nr;
 113
 114         if (bad_slot == slot)
 115                 return;
 116
 117         fprintf(stderr, "corrupting keys in block %llu slot %d swapping with %d\n",
 118                 (unsigned long long)eb->start, slot, bad_slot);
 119
 120         if (btrfs_header_level(eb) == 0) {
 121                 btrfs_item_key(eb, &bad_key, bad_slot);
 122                 btrfs_set_item_key(eb, &bad_key, slot);
 123         } else {
 124                 btrfs_node_key(eb, &bad_key, bad_slot);
 125                 btrfs_set_node_key(eb, &bad_key, slot);
 126         }
 127         btrfs_mark_buffer_dirty(eb);
 128         if (!trans) {
 129                 csum_tree_block(root, eb, 0);
 130                 write_extent_to_disk(eb);
 131         }
 132 }
 133
 134
 135 static int corrupt_keys_in_block(struct btrfs_root *root, u64 bytenr)
 136 {
 137         struct extent_buffer *eb;
 138
 139         eb = read_tree_block(root, bytenr, root->leafsize, 0);
 140         if (!eb)
 141                 return -EIO;;
 142
 143         corrupt_keys(NULL, root, eb);
 144         free_extent_buffer(eb);
 145         return 0;
 146 }
 147
 148 static int corrupt_extent(struct btrfs_trans_handle *trans,
 149                           struct btrfs_root *root, u64 bytenr, int copy)
 150 {
 151         struct btrfs_key key;
 152         struct extent_buffer *leaf;
 153         u32 item_size;
 154         unsigned long ptr;
 155         struct btrfs_path *path;
 156         int ret;
 157         int slot;
 158         int should_del = rand() % 3;
 159
 160         path = btrfs_alloc_path();
 161
 162         key.objectid = bytenr;
 163         key.type = (u8)-1;
 164         key.offset = (u64)-1;
 165
 166         while(1) {
 167                 ret = btrfs_search_slot(trans, root->fs_info->extent_root,
 168                                         &key, path, -1, 1);
 169                 if (ret < 0)
 170                         break;
 171
 172                 if (ret > 0) {
 173                         if (path->slots[0] == 0)
 174                                 break;
 175                         path->slots[0]--;
 176                         ret = 0;
 177                 }
 178                 leaf = path->nodes[0];
 179                 slot = path->slots[0];
 180                 btrfs_item_key_to_cpu(leaf, &key, slot);
 181                 if (key.objectid != bytenr)
 182                         break;
 183
 184                 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
 185                     key.type != BTRFS_TREE_BLOCK_REF_KEY &&
 186                     key.type != BTRFS_EXTENT_DATA_REF_KEY &&
 187                     key.type != BTRFS_EXTENT_REF_V0_KEY &&
 188                     key.type != BTRFS_SHARED_BLOCK_REF_KEY &&
 189                     key.type != BTRFS_SHARED_DATA_REF_KEY)
 190                         goto next;
 191
 192                 if (should_del) {
 193                         fprintf(stderr, "deleting extent record: key %Lu %u %Lu\n",
 194                                 key.objectid, key.type, key.offset);
 195
 196                         if (key.type == BTRFS_EXTENT_ITEM_KEY) {
 197                                 /* make sure this extent doesn't get
 198                                  * reused for other purposes */
 199                                 btrfs_pin_extent(root->fs_info,
 200                                                  key.objectid, key.offset);
 201                         }
 202
 203                         btrfs_del_item(trans, root, path);
 204                 } else {
 205                         fprintf(stderr, "corrupting extent record: key %Lu %u %Lu\n",
 206                                 key.objectid, key.type, key.offset);
 207                         ptr = btrfs_item_ptr_offset(leaf, slot);
 208                         item_size = btrfs_item_size_nr(leaf, slot);
 209                         memset_extent_buffer(leaf, 0, ptr, item_size);
 210                         btrfs_mark_buffer_dirty(leaf);
 211                 }
 212 next:
 213                 btrfs_release_path(NULL, path);
 214
 215                 if (key.offset > 0)
 216                         key.offset--;
 217                 if (key.offset == 0)
 218                         break;
 219         }
 220
 221         btrfs_free_path(path);
 222         return 0;
 223 }
 224
 225 static void btrfs_corrupt_extent_leaf(struct btrfs_trans_handle *trans,
 226                                       struct btrfs_root *root, struct extent_buffer *eb)
 227 {
 228         u32 nr = btrfs_header_nritems(eb);
 229         u32 victim = rand() % nr;
 230         u64 objectid;
 231         struct btrfs_key key;
 232
 233         btrfs_item_key_to_cpu(eb, &key, victim);
 234         objectid = key.objectid;
 235         corrupt_extent(trans, root, objectid, 1);
 236 }
 237
 238 static void btrfs_corrupt_extent_tree(struct btrfs_trans_handle *trans,
 239                                       struct btrfs_root *root, struct extent_buffer *eb)
 240 {
 241         int i;
 242         u32 nr;
 243
 244         if (!eb)
 245                 return;
 246
 247         nr = btrfs_header_nritems(eb);
 248         if (btrfs_is_leaf(eb)) {
 249                 btrfs_corrupt_extent_leaf(trans, root, eb);
 250                 return;
 251         }
 252
 253         if (btrfs_header_level(eb) == 1 && eb != root->node) {
 254                 if (rand() % 5)
 255                         return;
 256         }
 257
 258         for (i = 0; i < nr; i++) {
 259                 struct extent_buffer *next;
 260
 261                 next = read_tree_block(root, btrfs_node_blockptr(eb, i),
 262                                        root->leafsize, btrfs_node_ptr_generation(eb, i));
 263                 if (!next)
 264                         continue;
 265                 btrfs_corrupt_extent_tree(trans, root, next);
 266                 free_extent_buffer(next);
 267         }
 268 }
 269
 270 static struct option long_options[] = {
 271         /* { "byte-count", 1, NULL, 'b' }, */
 272         { "logical", 1, NULL, 'l' },
 273         { "copy", 1, NULL, 'c' },
 274         { "bytes", 1, NULL, 'b' },
 275         { "extent-record", 0, NULL, 'e' },
 276         { "extent-tree", 0, NULL, 'E' },
 277         { "keys", 0, NULL, 'k' },
 278         { 0, 0, 0, 0}
 279 };
 280
 281
 282 int main(int ac, char **av)
 283 {
 284         struct cache_tree root_cache;
 285         struct btrfs_root *root;
 286         struct extent_buffer *eb;
 287         char *dev;
 288         u64 logical = 0;
 289         int ret = 0;
 290         int option_index = 0;
 291         int copy = 0;
 292         u64 bytes = 4096;
 293         int extent_rec = 0;
 294         int extent_tree = 0;
 295         int corrupt_block_keys = 0;
 296
 297         srand(128);
 298
 299         while(1) {
 300                 int c;
 301                 c = getopt_long(ac, av, "l:c:b:eEk", long_options,
 302                                 &option_index);
 303                 if (c < 0)
 304                         break;
 305                 switch(c) {
 306                         case 'l':
 307                                 logical = atoll(optarg);
 308                                 if (logical == 0) {
 309                                         fprintf(stderr,
 310                                                 "invalid extent number\n");
 311                                         print_usage();
 312                                 }
 313                                 break;
 314                         case 'c':
 315                                 copy = atoi(optarg);
 316                                 if (copy == 0) {
 317                                         fprintf(stderr,
 318                                                 "invalid copy number\n");
 319                                         print_usage();
 320                                 }
 321                                 break;
 322                         case 'b':
 323                                 bytes = atoll(optarg);
 324                                 if (bytes == 0) {
 325                                         fprintf(stderr,
 326                                                 "invalid byte count\n");
 327                                         print_usage();
 328                                 }
 329                                 break;
 330                         case 'e':
 331                                 extent_rec = 1;
 332                                 break;
 333                         case 'E':
 334                                 extent_tree = 1;
 335                                 break;
 336                         case 'k':
 337                                 corrupt_block_keys = 1;
 338                                 break;
 339                         default:
 340                                 print_usage();
 341                 }
 342         }
 343         ac = ac - optind;
 344         if (ac == 0)
 345                 print_usage();
 346         if (logical == 0 && !extent_tree)
 347                 print_usage();
 348         if (copy < 0)
 349                 print_usage();
 350
 351         dev = av[optind];
 352
 353         radix_tree_init();
 354         cache_tree_init(&root_cache);
 355
 356         root = open_ctree(dev, 0, 1);
 357         if (!root) {
 358                 fprintf(stderr, "Open ctree failed\n");
 359                 exit(1);
 360         }
 361         if (extent_rec) {
 362                 struct btrfs_trans_handle *trans;
 363                 trans = btrfs_start_transaction(root, 1);
 364                 ret = corrupt_extent (trans, root, logical, 0);
 365                 btrfs_commit_transaction(trans, root);
 366                 goto out_close;
 367         }
 368         if (extent_tree) {
 369                 struct btrfs_trans_handle *trans;
 370                 trans = btrfs_start_transaction(root, 1);
 371                 btrfs_corrupt_extent_tree(trans, root->fs_info->extent_root,
 372                                           root->fs_info->extent_root->node);
 373                 btrfs_commit_transaction(trans, root);
 374                 goto out_close;
 375         }
 376
 377         if (bytes == 0)
 378                 bytes = root->sectorsize;
 379
 380         bytes = (bytes + root->sectorsize - 1) / root->sectorsize;
 381         bytes *= root->sectorsize;
 382
 383         while (bytes > 0) {
 384                 if (corrupt_block_keys) {
 385                         corrupt_keys_in_block(root, logical);
 386                 } else {
 387                         eb = debug_corrupt_block(root, logical,
 388                                                  root->sectorsize, copy);
 389                         free_extent_buffer(eb);
 390                 }
 391                 logical += root->sectorsize;
 392                 bytes -= root->sectorsize;
 393         }
 394         return ret;
 395 out_close:
 396         close_ctree(root);
 397         return ret;
 398 }