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Btrfs: verify csums on read

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Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Chris Mason
2007-03-29 15:15:27 -04:00
committed by David Woodhouse
parent 75dfe3960e
commit f254e52c1c
6 changed files with 279 additions and 60 deletions
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60
fs/btrfs/file-item.c
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@ -57,3 +57,63 @@ int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
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);
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;
}