btrfs-progs: mkfs: Move the tree root creation to own function

make_btrfs is too long to understand, make creatation of root tree
in a function.

Some of the tree roots are now created in a loop, where the code is just
copypasted. We now make use of the reference_root_table to translate
block index to root objectid.

Signed-off-by: Gu Jinxiang <gujx@cn.fujitsu.com>
[ updated changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Gu Jinxiang 2017-08-25 15:23:36 +08:00 committed by David Sterba
parent df4a04484a
commit 944e14da14

View File

@ -34,6 +34,67 @@ static u64 reference_root_table[] = {
[6] = BTRFS_CSUM_TREE_OBJECTID,
};
static int btrfs_create_tree_root(int fd, struct btrfs_mkfs_config *cfg,
struct extent_buffer *buf)
{
struct btrfs_root_item root_item;
struct btrfs_inode_item *inode_item;
struct btrfs_disk_key disk_key;
u32 nritems = 0;
u32 itemoff;
int ret = 0;
int blk;
memset(buf->data + sizeof(struct btrfs_header), 0,
cfg->nodesize - sizeof(struct btrfs_header));
memset(&root_item, 0, sizeof(root_item));
memset(&disk_key, 0, sizeof(disk_key));
/* create the items for the root tree */
inode_item = &root_item.inode;
btrfs_set_stack_inode_generation(inode_item, 1);
btrfs_set_stack_inode_size(inode_item, 3);
btrfs_set_stack_inode_nlink(inode_item, 1);
btrfs_set_stack_inode_nbytes(inode_item, cfg->nodesize);
btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
btrfs_set_root_refs(&root_item, 1);
btrfs_set_root_used(&root_item, cfg->nodesize);
btrfs_set_root_generation(&root_item, 1);
btrfs_set_disk_key_type(&disk_key, BTRFS_ROOT_ITEM_KEY);
btrfs_set_disk_key_offset(&disk_key, 0);
itemoff = __BTRFS_LEAF_DATA_SIZE(cfg->nodesize) - sizeof(root_item);
for (blk = 0; blk < MKFS_BLOCK_COUNT; blk++) {
if (blk == MKFS_SUPER_BLOCK || blk == MKFS_ROOT_TREE
|| blk == MKFS_CHUNK_TREE)
continue;
btrfs_set_root_bytenr(&root_item, cfg->blocks[blk]);
btrfs_set_disk_key_objectid(&disk_key,
reference_root_table[blk]);
btrfs_set_item_key(buf, &disk_key, nritems);
btrfs_set_item_offset(buf, btrfs_item_nr(nritems), itemoff);
btrfs_set_item_size(buf, btrfs_item_nr(nritems),
sizeof(root_item));
write_extent_buffer(buf, &root_item,
btrfs_item_ptr_offset(buf, nritems),
sizeof(root_item));
nritems++;
itemoff -= sizeof(root_item);
}
/* generate checksum */
csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);
/* write back root tree */
ret = pwrite(fd, buf->data, cfg->nodesize, cfg->blocks[MKFS_ROOT_TREE]);
if (ret != cfg->nodesize)
return (ret < 0 ? -errno : -EIO);
return ret;
}
/*
* @fs_uuid - if NULL, generates a UUID, returns back the new filesystem UUID
*
@ -44,10 +105,8 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
{
struct btrfs_super_block super;
struct extent_buffer *buf;
struct btrfs_root_item root_item;
struct btrfs_disk_key disk_key;
struct btrfs_extent_item *extent_item;
struct btrfs_inode_item *inode_item;
struct btrfs_chunk *chunk;
struct btrfs_dev_item *dev_item;
struct btrfs_dev_extent *dev_extent;
@ -133,77 +192,9 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
btrfs_header_chunk_tree_uuid(buf),
BTRFS_UUID_SIZE);
/* create the items for the root tree */
memset(&root_item, 0, sizeof(root_item));
inode_item = &root_item.inode;
btrfs_set_stack_inode_generation(inode_item, 1);
btrfs_set_stack_inode_size(inode_item, 3);
btrfs_set_stack_inode_nlink(inode_item, 1);
btrfs_set_stack_inode_nbytes(inode_item, cfg->nodesize);
btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
btrfs_set_root_refs(&root_item, 1);
btrfs_set_root_used(&root_item, cfg->nodesize);
btrfs_set_root_generation(&root_item, 1);
memset(&disk_key, 0, sizeof(disk_key));
btrfs_set_disk_key_type(&disk_key, BTRFS_ROOT_ITEM_KEY);
btrfs_set_disk_key_offset(&disk_key, 0);
nritems = 0;
itemoff = __BTRFS_LEAF_DATA_SIZE(cfg->nodesize) - sizeof(root_item);
btrfs_set_root_bytenr(&root_item, cfg->blocks[MKFS_EXTENT_TREE]);
btrfs_set_disk_key_objectid(&disk_key, BTRFS_EXTENT_TREE_OBJECTID);
btrfs_set_item_key(buf, &disk_key, nritems);
btrfs_set_item_offset(buf, btrfs_item_nr(nritems), itemoff);
btrfs_set_item_size(buf, btrfs_item_nr(nritems),
sizeof(root_item));
write_extent_buffer(buf, &root_item, btrfs_item_ptr_offset(buf,
nritems), sizeof(root_item));
nritems++;
itemoff = itemoff - sizeof(root_item);
btrfs_set_root_bytenr(&root_item, cfg->blocks[MKFS_DEV_TREE]);
btrfs_set_disk_key_objectid(&disk_key, BTRFS_DEV_TREE_OBJECTID);
btrfs_set_item_key(buf, &disk_key, nritems);
btrfs_set_item_offset(buf, btrfs_item_nr(nritems), itemoff);
btrfs_set_item_size(buf, btrfs_item_nr(nritems),
sizeof(root_item));
write_extent_buffer(buf, &root_item,
btrfs_item_ptr_offset(buf, nritems),
sizeof(root_item));
nritems++;
itemoff = itemoff - sizeof(root_item);
btrfs_set_root_bytenr(&root_item, cfg->blocks[MKFS_FS_TREE]);
btrfs_set_disk_key_objectid(&disk_key, BTRFS_FS_TREE_OBJECTID);
btrfs_set_item_key(buf, &disk_key, nritems);
btrfs_set_item_offset(buf, btrfs_item_nr(nritems), itemoff);
btrfs_set_item_size(buf, btrfs_item_nr(nritems),
sizeof(root_item));
write_extent_buffer(buf, &root_item,
btrfs_item_ptr_offset(buf, nritems),
sizeof(root_item));
nritems++;
itemoff = itemoff - sizeof(root_item);
btrfs_set_root_bytenr(&root_item, cfg->blocks[MKFS_CSUM_TREE]);
btrfs_set_disk_key_objectid(&disk_key, BTRFS_CSUM_TREE_OBJECTID);
btrfs_set_item_key(buf, &disk_key, nritems);
btrfs_set_item_offset(buf, btrfs_item_nr(nritems), itemoff);
btrfs_set_item_size(buf, btrfs_item_nr(nritems),
sizeof(root_item));
write_extent_buffer(buf, &root_item,
btrfs_item_ptr_offset(buf, nritems),
sizeof(root_item));
nritems++;
csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);
ret = pwrite(fd, buf->data, cfg->nodesize, cfg->blocks[MKFS_ROOT_TREE]);
if (ret != cfg->nodesize) {
ret = (ret < 0 ? -errno : -EIO);
ret = btrfs_create_tree_root(fd, cfg, buf);
if (ret < 0)
goto out;
}
/* create the items for the extent tree */
memset(buf->data + sizeof(struct btrfs_header), 0,