int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
int verify)
{
u16 csum_size =
btrfs_super_csum_size(root->fs_info->super_copy);
return csum_tree_block_size(buf, csum_size, verify);
}
int main(int argc, char **argv)
{
struct btrfs_root *root;
int dev_fd;
int opt;
int ret;
while ((opt = getopt(argc, argv, "l:o:g:")) != -1) {
switch(opt) {
case 'o':
search_objectid = arg_strtou64(optarg);
break;
case 'g':
search_generation = arg_strtou64(optarg);
break;
case 'l':
search_level = arg_strtou64(optarg);
break;
default:
usage();
exit(1);
}
}
set_argv0(argv);
argc = argc - optind;
if (check_argc_min(argc, 1)) {
usage();
exit(1);
}
dev_fd = open(argv[optind], O_RDONLY);
if (dev_fd < 0) {
fprintf(stderr, "Failed to open device %s\n", argv[optind]);
exit(1);
}
root = open_ctree_broken(dev_fd, argv[optind]);
close(dev_fd);
if (!root) {
fprintf(stderr, "Open ctree failed\n");
exit(1);
}
if (search_generation == 0)
search_generation = btrfs_super_generation(root->fs_info->super_copy);
csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
ret = find_root(root);
close_ctree(root);
return ret;
}
/*
* helper function for csum removal, this expects the
* key to describe the csum pointed to by the path, and it expects
* the csum to overlap the range [bytenr, len]
*
* The csum should not be entirely contained in the range and the
* range should not be entirely contained in the csum.
*
* This calls btrfs_truncate_item with the correct args based on the
* overlap, and fixes up the key as required.
*/
static noinline int truncate_one_csum(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_key *key,
u64 bytenr, u64 len)
{
struct extent_buffer *leaf;
u16 csum_size =
btrfs_super_csum_size(&root->fs_info->super_copy);
u64 csum_end;
u64 end_byte = bytenr + len;
u32 blocksize = root->sectorsize;
int ret;
leaf = path->nodes[0];
csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
csum_end *= root->sectorsize;
csum_end += key->offset;
if (key->offset < bytenr && csum_end <= end_byte) {
/*
* [ bytenr - len ]
* [ ]
* [csum ]
* A simple truncate off the end of the item
*/
u32 new_size = (bytenr - key->offset) / blocksize;
new_size *= csum_size;
ret = btrfs_truncate_item(trans, root, path, new_size, 1);
BUG_ON(ret);
} else if (key->offset >= bytenr && csum_end > end_byte &&
end_byte > key->offset) {
/*
* [ bytenr - len ]
* [ ]
* [csum ]
* we need to truncate from the beginning of the csum
*/
u32 new_size = (csum_end - end_byte) / blocksize;
new_size *= csum_size;
ret = btrfs_truncate_item(trans, root, path, new_size, 0);
BUG_ON(ret);
key->offset = end_byte;
ret = btrfs_set_item_key_safe(trans, root, path, key);
BUG_ON(ret);
} else {
BUG();
}
return 0;
}
static struct btrfs_csum_item *
btrfs_lookup_csum(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 bytenr, int cow)
{
int ret;
struct btrfs_key file_key;
struct btrfs_key found_key;
struct btrfs_csum_item *item;
struct extent_buffer *leaf;
u64 csum_offset = 0;
u16 csum_size =
btrfs_super_csum_size(root->fs_info->super_copy);
int csums_in_item;
file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
file_key.offset = bytenr;
btrfs_set_key_type(&file_key, BTRFS_EXTENT_CSUM_KEY);
ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
if (ret < 0)
goto fail;
leaf = path->nodes[0];
if (ret > 0) {
ret = 1;
if (path->slots[0] == 0)
goto fail;
path->slots[0]--;
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
if (btrfs_key_type(&found_key) != BTRFS_EXTENT_CSUM_KEY)
goto fail;
csum_offset = (bytenr - found_key.offset) / root->sectorsize;
csums_in_item = btrfs_item_size_nr(leaf, path->slots[0]);
csums_in_item /= csum_size;
if (csum_offset >= csums_in_item) {
ret = -EFBIG;
goto fail;
}
}
item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
item = (struct btrfs_csum_item *)((unsigned char *)item +
csum_offset * csum_size);
return item;
fail:
if (ret > 0)
ret = -ENOENT;
return ERR_PTR(ret);
}
static struct btrfs_csum_item *
btrfs_lookup_csum(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 bytenr, int cow)
{
int ret;
struct btrfs_key file_key;
struct btrfs_key found_key;
struct btrfs_csum_item *item;
struct extent_buffer *leaf;
u64 csum_offset = 0;
u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
int csums_in_item;
file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
file_key.offset = bytenr;
btrfs_set_key_type(&file_key, BTRFS_EXTENT_CSUM_KEY);
ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
if (ret < 0)
goto fail;
leaf = path->nodes[0];
if (ret > 0) {
ret = 1;
if (path->slots[0] == 0)
goto fail;
path->slots[0]--;
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
if (btrfs_key_type(&found_key) != BTRFS_EXTENT_CSUM_KEY)
goto fail;
csum_offset = (bytenr - found_key.offset) >>
root->fs_info->sb->s_blocksize_bits;
csums_in_item = btrfs_item_size_nr(leaf, path->slots[0]);
csums_in_item /= csum_size;
if (csum_offset == csums_in_item) {
ret = -EFBIG;
goto fail;
} else if (csum_offset > csums_in_item) {
goto fail;
}
}
/*
* deletes the csum items from the csum tree for a given
* range of bytes.
*/
int btrfs_del_csums(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 bytenr, u64 len)
{
struct btrfs_path *path;
struct btrfs_key key;
u64 end_byte = bytenr + len;
u64 csum_end;
struct extent_buffer *leaf;
int ret;
u16 csum_size =
btrfs_super_csum_size(&root->fs_info->super_copy);
int blocksize = root->sectorsize;
root = root->fs_info->csum_root;
path = btrfs_alloc_path();
while (1) {
key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
key.offset = end_byte - 1;
key.type = BTRFS_EXTENT_CSUM_KEY;
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret > 0) {
if (path->slots[0] == 0)
goto out;
path->slots[0]--;
}
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
key.type != BTRFS_EXTENT_CSUM_KEY) {
break;
}
if (key.offset >= end_byte)
break;
csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
csum_end *= blocksize;
csum_end += key.offset;
/* this csum ends before we start, we're done */
if (csum_end <= bytenr)
break;
/* delete the entire item, it is inside our range */
if (key.offset >= bytenr && csum_end <= end_byte) {
ret = btrfs_del_item(trans, root, path);
BUG_ON(ret);
} else if (key.offset < bytenr && csum_end > end_byte) {
unsigned long offset;
unsigned long shift_len;
unsigned long item_offset;
/*
* [ bytenr - len ]
* [csum ]
*
* Our bytes are in the middle of the csum,
* we need to split this item and insert a new one.
*
* But we can't drop the path because the
* csum could change, get removed, extended etc.
*
* The trick here is the max size of a csum item leaves
* enough room in the tree block for a single
* item header. So, we split the item in place,
* adding a new header pointing to the existing
* bytes. Then we loop around again and we have
* a nicely formed csum item that we can neatly
* truncate.
*/
offset = (bytenr - key.offset) / blocksize;
offset *= csum_size;
shift_len = (len / blocksize) * csum_size;
item_offset = btrfs_item_ptr_offset(leaf,
path->slots[0]);
memset_extent_buffer(leaf, 0, item_offset + offset,
shift_len);
key.offset = bytenr;
/*
* btrfs_split_item returns -EAGAIN when the
* item changed size or key
*/
ret = btrfs_split_item(trans, root, path, &key, offset);
BUG_ON(ret && ret != -EAGAIN);
key.offset = end_byte - 1;
} else {
ret = truncate_one_csum(trans, root, path,
&key, bytenr, len);
BUG_ON(ret);
}
btrfs_release_path(root, path);
}
out:
btrfs_free_path(path);
return 0;
}
int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 alloc_end,
u64 bytenr, char *data, size_t len)
{
int ret;
struct btrfs_key file_key;
struct btrfs_key found_key;
u64 next_offset = (u64)-1;
int found_next = 0;
struct btrfs_path *path;
struct btrfs_csum_item *item;
struct extent_buffer *leaf = NULL;
u64 csum_offset;
u32 csum_result = ~(u32)0;
u32 nritems;
u32 ins_size;
u16 csum_size =
btrfs_super_csum_size(&root->fs_info->super_copy);
path = btrfs_alloc_path();
BUG_ON(!path);
file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
file_key.offset = bytenr;
file_key.type = BTRFS_EXTENT_CSUM_KEY;
item = btrfs_lookup_csum(trans, root, path, bytenr, 1);
if (!IS_ERR(item)) {
leaf = path->nodes[0];
goto found;
}
ret = PTR_ERR(item);
if (ret == -EFBIG) {
u32 item_size;
/* we found one, but it isn't big enough yet */
leaf = path->nodes[0];
item_size = btrfs_item_size_nr(leaf, path->slots[0]);
if ((item_size / csum_size) >= MAX_CSUM_ITEMS(root, csum_size)) {
/* already at max size, make a new one */
goto insert;
}
} else {
int slot = path->slots[0] + 1;
/* we didn't find a csum item, insert one */
nritems = btrfs_header_nritems(path->nodes[0]);
if (path->slots[0] >= nritems - 1) {
ret = btrfs_next_leaf(root, path);
if (ret == 1)
found_next = 1;
if (ret != 0)
goto insert;
slot = 0;
}
btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
found_key.type != BTRFS_EXTENT_CSUM_KEY) {
found_next = 1;
goto insert;
}
next_offset = found_key.offset;
found_next = 1;
goto insert;
}
/*
* at this point, we know the tree has an item, but it isn't big
* enough yet to put our csum in. Grow it
*/
btrfs_release_path(root, path);
ret = btrfs_search_slot(trans, root, &file_key, path,
csum_size, 1);
if (ret < 0)
goto fail;
if (ret == 0) {
BUG();
}
if (path->slots[0] == 0) {
goto insert;
}
path->slots[0]--;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
csum_offset = (file_key.offset - found_key.offset) / root->sectorsize;
if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
found_key.type != BTRFS_EXTENT_CSUM_KEY ||
csum_offset >= MAX_CSUM_ITEMS(root, csum_size)) {
goto insert;
}
if (csum_offset >= btrfs_item_size_nr(leaf, path->slots[0]) /
csum_size) {
u32 diff = (csum_offset + 1) * csum_size;
diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
if (diff != csum_size)
goto insert;
ret = btrfs_extend_item(trans, root, path, diff);
BUG_ON(ret);
goto csum;
}
insert:
btrfs_release_path(root, path);
csum_offset = 0;
if (found_next) {
u64 tmp = min(alloc_end, next_offset);
tmp -= file_key.offset;
tmp /= root->sectorsize;
tmp = max((u64)1, tmp);
tmp = min(tmp, (u64)MAX_CSUM_ITEMS(root, csum_size));
ins_size = csum_size * tmp;
} else {
ins_size = csum_size;
}
ret = btrfs_insert_empty_item(trans, root, path, &file_key,
ins_size);
if (ret < 0)
goto fail;
if (ret != 0) {
WARN_ON(1);
goto fail;
}
csum:
leaf = path->nodes[0];
item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
ret = 0;
item = (struct btrfs_csum_item *)((unsigned char *)item +
csum_offset * csum_size);
found:
csum_result = btrfs_csum_data(root, data, csum_result, len);
btrfs_csum_final(csum_result, (char *)&csum_result);
if (csum_result == 0) {
printk("csum result is 0 for block %llu\n",
(unsigned long long)bytenr);
}
write_extent_buffer(leaf, &csum_result, (unsigned long)item,
csum_size);
btrfs_mark_buffer_dirty(path->nodes[0]);
fail:
btrfs_release_path(root, path);
btrfs_free_path(path);
return ret;
}
static void dump_superblock(struct btrfs_super_block *sb, int full)
{
int i;
char *s, buf[BTRFS_UUID_UNPARSED_SIZE];
u8 *p;
printf("csum\t\t\t0x");
for (i = 0, p = sb->csum; i < btrfs_super_csum_size(sb); i++)
printf("%02x", p[i]);
if (check_csum_sblock(sb, btrfs_super_csum_size(sb)))
printf(" [match]");
else
printf(" [DON'T MATCH]");
putchar('\n');
printf("bytenr\t\t\t%llu\n",
(unsigned long long)btrfs_super_bytenr(sb));
printf("flags\t\t\t0x%llx\n",
(unsigned long long)btrfs_super_flags(sb));
print_readable_super_flag(btrfs_super_flags(sb));
printf("magic\t\t\t");
s = (char *) &sb->magic;
for (i = 0; i < 8; i++)
putchar(isprint(s[i]) ? s[i] : '.');
if (btrfs_super_magic(sb) == BTRFS_MAGIC)
printf(" [match]\n");
else
printf(" [DON'T MATCH]\n");
uuid_unparse(sb->fsid, buf);
printf("fsid\t\t\t%s\n", buf);
printf("label\t\t\t");
s = sb->label;
for (i = 0; i < BTRFS_LABEL_SIZE && s[i]; i++)
putchar(isprint(s[i]) ? s[i] : '.');
putchar('\n');
printf("generation\t\t%llu\n",
(unsigned long long)btrfs_super_generation(sb));
printf("root\t\t\t%llu\n", (unsigned long long)btrfs_super_root(sb));
printf("sys_array_size\t\t%llu\n",
(unsigned long long)btrfs_super_sys_array_size(sb));
printf("chunk_root_generation\t%llu\n",
(unsigned long long)btrfs_super_chunk_root_generation(sb));
printf("root_level\t\t%llu\n",
(unsigned long long)btrfs_super_root_level(sb));
printf("chunk_root\t\t%llu\n",
(unsigned long long)btrfs_super_chunk_root(sb));
printf("chunk_root_level\t%llu\n",
(unsigned long long)btrfs_super_chunk_root_level(sb));
printf("log_root\t\t%llu\n",
(unsigned long long)btrfs_super_log_root(sb));
printf("log_root_transid\t%llu\n",
(unsigned long long)btrfs_super_log_root_transid(sb));
printf("log_root_level\t\t%llu\n",
(unsigned long long)btrfs_super_log_root_level(sb));
printf("total_bytes\t\t%llu\n",
(unsigned long long)btrfs_super_total_bytes(sb));
printf("bytes_used\t\t%llu\n",
(unsigned long long)btrfs_super_bytes_used(sb));
printf("sectorsize\t\t%llu\n",
(unsigned long long)btrfs_super_sectorsize(sb));
printf("nodesize\t\t%llu\n",
(unsigned long long)btrfs_super_nodesize(sb));
printf("leafsize\t\t%llu\n",
(unsigned long long)btrfs_super_leafsize(sb));
printf("stripesize\t\t%llu\n",
(unsigned long long)btrfs_super_stripesize(sb));
printf("root_dir\t\t%llu\n",
(unsigned long long)btrfs_super_root_dir(sb));
printf("num_devices\t\t%llu\n",
(unsigned long long)btrfs_super_num_devices(sb));
printf("compat_flags\t\t0x%llx\n",
(unsigned long long)btrfs_super_compat_flags(sb));
printf("compat_ro_flags\t\t0x%llx\n",
(unsigned long long)btrfs_super_compat_ro_flags(sb));
printf("incompat_flags\t\t0x%llx\n",
(unsigned long long)btrfs_super_incompat_flags(sb));
print_readable_incompat_flag(btrfs_super_incompat_flags(sb));
printf("csum_type\t\t%llu\n",
(unsigned long long)btrfs_super_csum_type(sb));
printf("csum_size\t\t%llu\n",
(unsigned long long)btrfs_super_csum_size(sb));
printf("cache_generation\t%llu\n",
(unsigned long long)btrfs_super_cache_generation(sb));
printf("uuid_tree_generation\t%llu\n",
(unsigned long long)btrfs_super_uuid_tree_generation(sb));
uuid_unparse(sb->dev_item.uuid, buf);
printf("dev_item.uuid\t\t%s\n", buf);
uuid_unparse(sb->dev_item.fsid, buf);
printf("dev_item.fsid\t\t%s %s\n", buf,
!memcmp(sb->dev_item.fsid, sb->fsid, BTRFS_FSID_SIZE) ?
"[match]" : "[DON'T MATCH]");
printf("dev_item.type\t\t%llu\n", (unsigned long long)
btrfs_stack_device_type(&sb->dev_item));
printf("dev_item.total_bytes\t%llu\n", (unsigned long long)
btrfs_stack_device_total_bytes(&sb->dev_item));
printf("dev_item.bytes_used\t%llu\n", (unsigned long long)
btrfs_stack_device_bytes_used(&sb->dev_item));
printf("dev_item.io_align\t%u\n", (unsigned int)
btrfs_stack_device_io_align(&sb->dev_item));
printf("dev_item.io_width\t%u\n", (unsigned int)
btrfs_stack_device_io_width(&sb->dev_item));
printf("dev_item.sector_size\t%u\n", (unsigned int)
btrfs_stack_device_sector_size(&sb->dev_item));
printf("dev_item.devid\t\t%llu\n",
btrfs_stack_device_id(&sb->dev_item));
printf("dev_item.dev_group\t%u\n", (unsigned int)
btrfs_stack_device_group(&sb->dev_item));
printf("dev_item.seek_speed\t%u\n", (unsigned int)
btrfs_stack_device_seek_speed(&sb->dev_item));
printf("dev_item.bandwidth\t%u\n", (unsigned int)
btrfs_stack_device_bandwidth(&sb->dev_item));
printf("dev_item.generation\t%llu\n", (unsigned long long)
btrfs_stack_device_generation(&sb->dev_item));
if (full) {
printf("sys_chunk_array[%d]:\n", BTRFS_SYSTEM_CHUNK_ARRAY_SIZE);
print_sys_chunk_array(sb);
printf("backup_roots[%d]:\n", BTRFS_NUM_BACKUP_ROOTS);
print_backup_roots(sb);
}
}
