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#include <linux/module.h>
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
int btrfs_alloc_file_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 objectid, u64 offset,
u64 num_blocks, u64 hint_block,
u64 *result)
{
struct btrfs_key ins;
int ret = 0;
struct btrfs_file_extent_item *item;
struct btrfs_key file_key;
struct btrfs_path path;
btrfs_init_path(&path);
ret = btrfs_alloc_extent(trans, root, num_blocks, hint_block,
(u64)-1, objectid, &ins);
BUG_ON(ret);
file_key.objectid = objectid;
file_key.offset = offset;
file_key.flags = 0;
btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
ret = btrfs_insert_empty_item(trans, root, &path, &file_key,
sizeof(*item));
BUG_ON(ret);
item = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]), path.slots[0],
struct btrfs_file_extent_item);
btrfs_set_file_extent_disk_blocknr(item, ins.objectid);
btrfs_set_file_extent_disk_num_blocks(item, ins.offset);
btrfs_set_file_extent_offset(item, 0);
btrfs_set_file_extent_num_blocks(item, ins.offset);
btrfs_set_file_extent_generation(item, trans->transid);
btrfs_mark_buffer_dirty(path.nodes[0]);
*result = ins.objectid;
btrfs_release_path(root, &path);
return 0;
}
int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path, u64 objectid,
u64 offset, int mod)
{
int ret;
struct btrfs_key file_key;
int ins_len = mod < 0 ? -1 : 0;
int cow = mod != 0;
file_key.objectid = objectid;
file_key.offset = offset;
file_key.flags = 0;
btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
return ret;
}
int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 objectid, u64 offset,
char *data, size_t len)
{
int ret;
struct btrfs_key file_key;
struct btrfs_path path;
struct btrfs_csum_item *item;
btrfs_init_path(&path);
file_key.objectid = objectid;
file_key.offset = offset;
file_key.flags = 0;
btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
ret = btrfs_insert_empty_item(trans, root, &path, &file_key,
BTRFS_CSUM_SIZE);
if (ret != 0 && ret != -EEXIST)
goto fail;
item = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]), path.slots[0],
struct btrfs_csum_item);
ret = 0;
ret = btrfs_csum_data(root, data, len, item->csum);
btrfs_mark_buffer_dirty(path.nodes[0]);
fail:
btrfs_release_path(root, &path);
return ret;
}
int btrfs_csum_verify_file_block(struct btrfs_root *root,
u64 objectid, u64 offset,
char *data, size_t len)
{
int ret;
struct btrfs_key file_key;
struct btrfs_path path;
struct btrfs_csum_item *item;
char result[BTRFS_CSUM_SIZE];
btrfs_init_path(&path);
file_key.objectid = objectid;
file_key.offset = offset;
file_key.flags = 0;
btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
ret = btrfs_search_slot(NULL, root, &file_key, &path, 0, 0);
if (ret)
goto fail;
item = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]), path.slots[0],
struct btrfs_csum_item);
ret = 0;
ret = btrfs_csum_data(root, data, len, result);
WARN_ON(ret);
if (memcmp(result, item->csum, BTRFS_CSUM_SIZE))
ret = 1;
fail:
btrfs_release_path(root, &path);
return ret;
}
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