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Btrfs-progs: add ability to corrupt metadata block fields 

This patch allows us to garble the generation field of a metadata block.  We
will search down to the block, set the bogus generation and write the block back
out.  I used this for verifying a transid fix patch for btrfsck.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
master
Josef Bacik 2013-10-01 08:54:58 -04:00 committed by Chris Mason
parent 0d342f8fcb
commit fd815de859
1 changed files with 117 additions and 3 deletions
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120
btrfs-corrupt-block.c
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@ -103,6 +103,8 @@ static void print_usage(void)
"the field to corrupt)\n");
fprintf(stderr, "\t-x The file extent item to corrupt (must also "
"specify -i for the inode and -f for the field to corrupt)\n");
fprintf(stderr, "\t-m The metadata block to corrupt (must also "
"specify -f for the field to corrupt)\n");
fprintf(stderr, "\t-f The field in the item to corrupt\n");
exit(1);
}
@ -139,7 +141,9 @@ static void corrupt_keys(struct btrfs_trans_handle *trans,
}
btrfs_mark_buffer_dirty(eb);
if (!trans) {
csum_tree_block(root, eb, 0);
u16 csum_size =
btrfs_super_csum_size(root->fs_info->super_copy);
csum_tree_block_size(eb, csum_size, 0);
write_extent_to_disk(eb);
}
}
@ -297,6 +301,11 @@ enum btrfs_file_extent_field {
BTRFS_FILE_EXTENT_BAD,
};
enum btrfs_metadata_block_field {
BTRFS_METADATA_BLOCK_GENERATION,
BTRFS_METADATA_BLOCK_BAD,
};
static enum btrfs_inode_field convert_inode_field(char *field)
{
if (!strncmp(field, "isize", FIELD_BUF_LEN))
@ -311,6 +320,14 @@ static enum btrfs_file_extent_field convert_file_extent_field(char *field)
return BTRFS_FILE_EXTENT_BAD;
}
static enum btrfs_metadata_block_field
convert_metadata_block_field(char *field)
{
if (!strncmp(field, "generation", FIELD_BUF_LEN))
return BTRFS_METADATA_BLOCK_GENERATION;
return BTRFS_METADATA_BLOCK_BAD;
}
static u64 generate_u64(u64 orig)
{
u64 ret;
@ -436,6 +453,87 @@ out:
return ret;
}
static int corrupt_metadata_block(struct btrfs_root *root, u64 block,
char *field)
{
struct btrfs_trans_handle *trans;
struct btrfs_path *path;
struct extent_buffer *eb;
struct btrfs_key key, root_key;
enum btrfs_metadata_block_field corrupt_field;
u64 root_objectid;
u64 orig, bogus;
u8 level;
int ret;
corrupt_field = convert_metadata_block_field(field);
if (corrupt_field == BTRFS_METADATA_BLOCK_BAD) {
fprintf(stderr, "Invalid field %s\n", field);
return -EINVAL;
}
eb = read_tree_block(root, block, root->leafsize, 0);
if (!eb) {
fprintf(stderr, "Couldn't read in tree block %s\n", field);
return -EINVAL;
}
root_objectid = btrfs_header_owner(eb);
level = btrfs_header_level(eb);
if (level)
btrfs_node_key_to_cpu(eb, &key, 0);
else
btrfs_item_key_to_cpu(eb, &key, 0);
free_extent_buffer(eb);
root_key.objectid = root_objectid;
root_key.type = BTRFS_ROOT_ITEM_KEY;
root_key.offset = (u64)-1;
root = btrfs_read_fs_root(root->fs_info, &root_key);
if (IS_ERR(root)) {
fprintf(stderr, "Couldn't finde owner root %llu\n",
key.objectid);
return PTR_ERR(root);
}
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans)) {
btrfs_free_path(path);
fprintf(stderr, "Couldn't start transaction %ld\n",
PTR_ERR(trans));
return PTR_ERR(trans);
}
path->lowest_level = level;
ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
if (ret < 0) {
fprintf(stderr, "Error searching to node %d\n", ret);
goto out;
}
eb = path->nodes[level];
ret = 0;
switch (corrupt_field) {
case BTRFS_METADATA_BLOCK_GENERATION:
orig = btrfs_header_generation(eb);
bogus = generate_u64(orig);
btrfs_set_header_generation(eb, bogus);
break;
default:
ret = -EINVAL;
break;
}
btrfs_mark_buffer_dirty(path->nodes[level]);
out:
btrfs_commit_transaction(trans, root);
btrfs_free_path(path);
return ret;
}
static struct option long_options[] = {
/* { "byte-count", 1, NULL, 'b' }, */
{ "logical", 1, NULL, 'l' },
@ -448,6 +546,7 @@ static struct option long_options[] = {
{ "chunk-tree", 0, NULL, 'U' },
{ "inode", 1, NULL, 'i'},
{ "file-extent", 1, NULL, 'x'},
{ "metadata-block", 1, NULL, 'm'},
{ "field", 1, NULL, 'f'},
{ 0, 0, 0, 0}
};
@ -609,6 +708,7 @@ int main(int ac, char **av)
int corrupt_block_keys = 0;
int chunk_rec = 0;
int chunk_tree = 0;
u64 metadata_block = 0;
u64 inode = 0;
u64 file_extent = (u64)-1;
char field[FIELD_BUF_LEN];
@ -618,7 +718,7 @@ int main(int ac, char **av)
while(1) {
int c;
c = getopt_long(ac, av, "l:c:b:eEkuUi:f:x:", long_options,
c = getopt_long(ac, av, "l:c:b:eEkuUi:f:x:m:", long_options,
&option_index);
if (c < 0)
break;
@ -676,6 +776,15 @@ int main(int ac, char **av)
print_usage();
}
break;
case 'm':
errno = 0;
metadata_block = atoll(optarg);
if (errno) {
fprintf(stderr, "error converting "
"%d\n", errno);
print_usage();
}
break;
default:
print_usage();
}
@ -761,7 +870,12 @@ int main(int ac, char **av)
btrfs_commit_transaction(trans, root);
goto out_close;
}
if (metadata_block) {
if (!strlen(field))
print_usage();
ret = corrupt_metadata_block(root, metadata_block, field);
goto out_close;
}
/*
* If we made it here and we have extent set then we didn't specify
* inode and we're screwed.