Re: [PATCH 02/15] btrfs-progs: Remove root argument from btrfs_del_csums

[Qu Wenruo <quwenruo.btrfs@gmx.com>]

On 2018年06月08日 20:47, Nikolay Borisov wrote:
> It's not needed, since we can obtain a reference to fs_info from the
> passed transaction handle. This is needed by delayed refs code.

This looks a little too aggressive to me.

Normally we would expect parameters like @trans then @fs_info.
Although @trans only let us get @fs_info, under certain case @trans
could be NULL (like btrfs_search_slot).

Although for btrfs_del_csums() @tran can be NULL, I still prefer the
@trans, @fs_info parameters.

Thanks,
Qu


> 
> Signed-off-by: Nikolay Borisov <nborisov@suse.com>
> ---
>  btrfs-corrupt-block.c |  2 +-
>  ctree.h               |  3 +--
>  extent-tree.c         |  2 +-
>  file-item.c           | 20 ++++++++++----------
>  4 files changed, 13 insertions(+), 14 deletions(-)
> 
> diff --git a/btrfs-corrupt-block.c b/btrfs-corrupt-block.c
> index 4fbea26cda20..3add8e63b7bb 100644
> --- a/btrfs-corrupt-block.c
> +++ b/btrfs-corrupt-block.c
> @@ -926,7 +926,7 @@ static int delete_csum(struct btrfs_root *root, u64 bytenr, u64 bytes)
>  		return PTR_ERR(trans);
>  	}
>  
> -	ret = btrfs_del_csums(trans, root, bytenr, bytes);
> +	ret = btrfs_del_csums(trans, bytenr, bytes);
>  	if (ret)
>  		fprintf(stderr, "Error deleting csums %d\n", ret);
>  	btrfs_commit_transaction(trans, root);
> diff --git a/ctree.h b/ctree.h
> index de4b1b7e6416..082726238b91 100644
> --- a/ctree.h
> +++ b/ctree.h
> @@ -2752,8 +2752,7 @@ int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
>  			u64 ino, u64 parent_ino, u64 *index);
>  
>  /* file-item.c */
> -int btrfs_del_csums(struct btrfs_trans_handle *trans,
> -		    struct btrfs_root *root, u64 bytenr, u64 len);
> +int btrfs_del_csums(struct btrfs_trans_handle *trans, u64 bytenr, u64 len);
>  int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
>  			     struct btrfs_root *root,
>  			     u64 objectid, u64 pos, u64 offset,
> diff --git a/extent-tree.c b/extent-tree.c
> index cbc022f6cef6..c6f09b52800f 100644
> --- a/extent-tree.c
> +++ b/extent-tree.c
> @@ -2372,7 +2372,7 @@ static int __free_extent(struct btrfs_trans_handle *trans,
>  		btrfs_release_path(path);
>  
>  		if (is_data) {
> -			ret = btrfs_del_csums(trans, root, bytenr, num_bytes);
> +			ret = btrfs_del_csums(trans, bytenr, num_bytes);
>  			BUG_ON(ret);
>  		}
>  
> diff --git a/file-item.c b/file-item.c
> index 7b0ff3585509..71d4e89f78d1 100644
> --- a/file-item.c
> +++ b/file-item.c
> @@ -394,8 +394,7 @@ static noinline int truncate_one_csum(struct btrfs_root *root,
>   * 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)
> +int btrfs_del_csums(struct btrfs_trans_handle *trans, u64 bytenr, u64 len)
>  {
>  	struct btrfs_path *path;
>  	struct btrfs_key key;
> @@ -403,11 +402,10 @@ int btrfs_del_csums(struct btrfs_trans_handle *trans,
>  	u64 csum_end;
>  	struct extent_buffer *leaf;
>  	int ret;
> -	u16 csum_size =
> -		btrfs_super_csum_size(root->fs_info->super_copy);
> -	int blocksize = root->fs_info->sectorsize;
> +	u16 csum_size = btrfs_super_csum_size(trans->fs_info->super_copy);
> +	int blocksize = trans->fs_info->sectorsize;
> +	struct btrfs_root *csum_root = trans->fs_info->csum_root;
>  
> -	root = root->fs_info->csum_root;
>  
>  	path = btrfs_alloc_path();
>  	if (!path)
> @@ -418,7 +416,7 @@ int btrfs_del_csums(struct btrfs_trans_handle *trans,
>  		key.offset = end_byte - 1;
>  		key.type = BTRFS_EXTENT_CSUM_KEY;
>  
> -		ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
> +		ret = btrfs_search_slot(trans, csum_root, &key, path, -1, 1);
>  		if (ret > 0) {
>  			if (path->slots[0] == 0)
>  				goto out;
> @@ -445,7 +443,7 @@ int btrfs_del_csums(struct btrfs_trans_handle *trans,
>  
>  		/* delete the entire item, it is inside our range */
>  		if (key.offset >= bytenr && csum_end <= end_byte) {
> -			ret = btrfs_del_item(trans, root, path);
> +			ret = btrfs_del_item(trans, csum_root, path);
>  			BUG_ON(ret);
>  		} else if (key.offset < bytenr && csum_end > end_byte) {
>  			unsigned long offset;
> @@ -485,12 +483,14 @@ int btrfs_del_csums(struct btrfs_trans_handle *trans,
>  			 * btrfs_split_item returns -EAGAIN when the
>  			 * item changed size or key
>  			 */
> -			ret = btrfs_split_item(trans, root, path, &key, offset);
> +			ret = btrfs_split_item(trans, csum_root, path, &key,
> +					       offset);
>  			BUG_ON(ret && ret != -EAGAIN);
>  
>  			key.offset = end_byte - 1;
>  		} else {
> -			ret = truncate_one_csum(root, path, &key, bytenr, len);
> +			ret = truncate_one_csum(csum_root, path, &key, bytenr,
> +						len);
>  			BUG_ON(ret);
>  		}
>  		btrfs_release_path(path);
>