btrfs-progs/btrfs-corrupt-block.c
Chris Mason e22827e9bb btrfsck: add early code to handle corrupted block groups
This is mostly disabled, but it is step one in handling
corrupted block groups in the extent allocation tree.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-02-22 10:59:55 -05:00

397 lines
8.9 KiB
C

/*
* Copyright (C) 2009 Oracle. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#define _XOPEN_SOURCE 500
#define _GNU_SOURCE 1
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <getopt.h>
#include "kerncompat.h"
#include "ctree.h"
#include "volumes.h"
#include "disk-io.h"
#include "print-tree.h"
#include "transaction.h"
#include "list.h"
#include "version.h"
struct extent_buffer *debug_corrupt_block(struct btrfs_root *root, u64 bytenr,
u32 blocksize, int copy)
{
int ret;
struct extent_buffer *eb;
u64 length;
struct btrfs_multi_bio *multi = NULL;
struct btrfs_device *device;
int num_copies;
int mirror_num = 1;
eb = btrfs_find_create_tree_block(root, bytenr, blocksize);
if (!eb)
return NULL;
length = blocksize;
while (1) {
ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
eb->start, &length, &multi, mirror_num);
BUG_ON(ret);
device = multi->stripes[0].dev;
eb->fd = device->fd;
device->total_ios++;
eb->dev_bytenr = multi->stripes[0].physical;
fprintf(stdout, "mirror %d logical %Lu physical %Lu "
"device %s\n", mirror_num, (unsigned long long)bytenr,
(unsigned long long)eb->dev_bytenr, device->name);
kfree(multi);
if (!copy || mirror_num == copy) {
ret = read_extent_from_disk(eb);
printf("corrupting %llu copy %d\n", eb->start,
mirror_num);
memset(eb->data, 0, eb->len);
write_extent_to_disk(eb);
fsync(eb->fd);
}
num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
eb->start, eb->len);
if (num_copies == 1)
break;
mirror_num++;
if (mirror_num > num_copies)
break;
}
return eb;
}
static void print_usage(void)
{
fprintf(stderr, "usage: btrfs-map-logical [options] mount_point\n");
fprintf(stderr, "\t-l Logical extent to map\n");
fprintf(stderr, "\t-c Copy of the extent to read (usually 1 or 2)\n");
fprintf(stderr, "\t-o Output file to hold the extent\n");
fprintf(stderr, "\t-b Number of bytes to read\n");
exit(1);
}
static void corrupt_keys(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *eb)
{
int slot;
int bad_slot;
int nr;
struct btrfs_disk_key bad_key;;
nr = btrfs_header_nritems(eb);
if (nr == 0)
return;
slot = rand() % nr;
bad_slot = rand() % nr;
if (bad_slot == slot)
return;
fprintf(stderr, "corrupting keys in block %llu slot %d swapping with %d\n",
(unsigned long long)eb->start, slot, bad_slot);
if (btrfs_header_level(eb) == 0) {
btrfs_item_key(eb, &bad_key, bad_slot);
btrfs_set_item_key(eb, &bad_key, slot);
} else {
btrfs_node_key(eb, &bad_key, bad_slot);
btrfs_set_node_key(eb, &bad_key, slot);
}
btrfs_mark_buffer_dirty(eb);
if (!trans) {
csum_tree_block(root, eb, 0);
write_extent_to_disk(eb);
}
}
static int corrupt_keys_in_block(struct btrfs_root *root, u64 bytenr)
{
struct extent_buffer *eb;
eb = read_tree_block(root, bytenr, root->leafsize, 0);
if (!eb)
return -EIO;;
corrupt_keys(NULL, root, eb);
free_extent_buffer(eb);
return 0;
}
static int corrupt_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 bytenr, int copy)
{
struct btrfs_key key;
struct extent_buffer *leaf;
u32 item_size;
unsigned long ptr;
struct btrfs_path *path;
int ret;
int slot;
int should_del = rand() % 3;
path = btrfs_alloc_path();
key.objectid = bytenr;
key.type = (u8)-1;
key.offset = (u64)-1;
while(1) {
ret = btrfs_search_slot(trans, root->fs_info->extent_root,
&key, path, -1, 1);
if (ret < 0)
break;
if (ret > 0) {
if (path->slots[0] == 0)
break;
path->slots[0]--;
ret = 0;
}
leaf = path->nodes[0];
slot = path->slots[0];
btrfs_item_key_to_cpu(leaf, &key, slot);
if (key.objectid != bytenr)
break;
if (key.type != BTRFS_EXTENT_ITEM_KEY &&
key.type != BTRFS_TREE_BLOCK_REF_KEY &&
key.type != BTRFS_EXTENT_DATA_REF_KEY &&
key.type != BTRFS_EXTENT_REF_V0_KEY &&
key.type != BTRFS_SHARED_BLOCK_REF_KEY &&
key.type != BTRFS_SHARED_DATA_REF_KEY)
goto next;
if (should_del) {
fprintf(stderr, "deleting extent record: key %Lu %u %Lu\n",
key.objectid, key.type, key.offset);
if (key.type == BTRFS_EXTENT_ITEM_KEY) {
/* make sure this extent doesn't get
* reused for other purposes */
btrfs_pin_extent(root->fs_info,
key.objectid, key.offset);
}
btrfs_del_item(trans, root, path);
} else {
fprintf(stderr, "corrupting extent record: key %Lu %u %Lu\n",
key.objectid, key.type, key.offset);
ptr = btrfs_item_ptr_offset(leaf, slot);
item_size = btrfs_item_size_nr(leaf, slot);
memset_extent_buffer(leaf, 0, ptr, item_size);
btrfs_mark_buffer_dirty(leaf);
}
next:
btrfs_release_path(NULL, path);
if (key.offset > 0)
key.offset--;
if (key.offset == 0)
break;
}
btrfs_free_path(path);
return 0;
}
static void btrfs_corrupt_extent_leaf(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct extent_buffer *eb)
{
u32 nr = btrfs_header_nritems(eb);
u32 victim = rand() % nr;
u64 objectid;
struct btrfs_key key;
btrfs_item_key_to_cpu(eb, &key, victim);
objectid = key.objectid;
corrupt_extent(trans, root, objectid, 1);
}
static void btrfs_corrupt_extent_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct extent_buffer *eb)
{
int i;
u32 nr;
if (!eb)
return;
nr = btrfs_header_nritems(eb);
if (btrfs_is_leaf(eb)) {
btrfs_corrupt_extent_leaf(trans, root, eb);
return;
}
if (btrfs_header_level(eb) == 1 && eb != root->node) {
if (rand() % 5)
return;
}
for (i = 0; i < nr; i++) {
struct extent_buffer *next;
next = read_tree_block(root, btrfs_node_blockptr(eb, i),
root->leafsize, btrfs_node_ptr_generation(eb, i));
if (!next)
continue;
btrfs_corrupt_extent_tree(trans, root, next);
free_extent_buffer(next);
}
}
static struct option long_options[] = {
/* { "byte-count", 1, NULL, 'b' }, */
{ "logical", 1, NULL, 'l' },
{ "copy", 1, NULL, 'c' },
{ "bytes", 1, NULL, 'b' },
{ "extent-record", 0, NULL, 'e' },
{ "extent-tree", 0, NULL, 'E' },
{ "keys", 0, NULL, 'k' },
{ 0, 0, 0, 0}
};
int main(int ac, char **av)
{
struct cache_tree root_cache;
struct btrfs_root *root;
struct extent_buffer *eb;
char *dev;
u64 logical = 0;
int ret = 0;
int option_index = 0;
int copy = 0;
u64 bytes = 4096;
int extent_rec = 0;
int extent_tree = 0;
int corrupt_block_keys = 0;
srand(128);
while(1) {
int c;
c = getopt_long(ac, av, "l:c:eEk", long_options,
&option_index);
if (c < 0)
break;
switch(c) {
case 'l':
logical = atoll(optarg);
if (logical == 0) {
fprintf(stderr,
"invalid extent number\n");
print_usage();
}
break;
case 'c':
copy = atoi(optarg);
if (copy == 0) {
fprintf(stderr,
"invalid copy number\n");
print_usage();
}
break;
case 'b':
bytes = atoll(optarg);
if (bytes == 0) {
fprintf(stderr,
"invalid byte count\n");
print_usage();
}
break;
case 'e':
extent_rec = 1;
break;
case 'E':
extent_tree = 1;
break;
case 'k':
corrupt_block_keys = 1;
break;
default:
print_usage();
}
}
ac = ac - optind;
if (ac == 0)
print_usage();
if (logical == 0 && !extent_tree)
print_usage();
if (copy < 0)
print_usage();
dev = av[optind];
radix_tree_init();
cache_tree_init(&root_cache);
root = open_ctree(dev, 0, 1);
if (!root) {
fprintf(stderr, "Open ctree failed\n");
exit(1);
}
if (extent_rec) {
struct btrfs_trans_handle *trans;
trans = btrfs_start_transaction(root, 1);
ret = corrupt_extent (trans, root, logical, 0);
btrfs_commit_transaction(trans, root);
goto out_close;
}
if (extent_tree) {
struct btrfs_trans_handle *trans;
trans = btrfs_start_transaction(root, 1);
btrfs_corrupt_extent_tree(trans, root->fs_info->extent_root,
root->fs_info->extent_root->node);
btrfs_commit_transaction(trans, root);
goto out_close;
}
if (bytes == 0)
bytes = root->sectorsize;
bytes = (bytes + root->sectorsize - 1) / root->sectorsize;
bytes *= root->sectorsize;
while (bytes > 0) {
if (corrupt_block_keys) {
corrupt_keys_in_block(root, logical);
} else {
eb = debug_corrupt_block(root, logical,
root->sectorsize, copy);
free_extent_buffer(eb);
}
logical += root->sectorsize;
bytes -= root->sectorsize;
}
return ret;
out_close:
close_ctree(root);
return ret;
}