From fd815de85937c8ef64adcee6596c0b7f6655c461 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Tue, 1 Oct 2013 08:54:58 -0400 Subject: 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 Signed-off-by: David Sterba Signed-off-by: Chris Mason --- btrfs-corrupt-block.c | 120 ++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 117 insertions(+), 3 deletions(-) (limited to 'btrfs-corrupt-block.c') diff --git a/btrfs-corrupt-block.c b/btrfs-corrupt-block.c index 9e72ca8..c4f80fc 100644 --- a/btrfs-corrupt-block.c +++ b/btrfs-corrupt-block.c @@ -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. -- cgit v1.2.1