Re: [PATCH 2/5] btrfs: Use common error handling code in __btrfs_free_extent()

[Jeff Mahoney <jeffm@suse.com>]

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On 8/21/17 8:38 AM, SF Markus Elfring wrote:
> From: Markus Elfring <elfring@users.sourceforge.net>
> Date: Mon, 21 Aug 2017 10:03:00 +0200
> 
> Add a jump target so that a bit of exception handling can be better reused
> at the end of this function.
> 
> This issue was detected by using the Coccinelle software.

btrfs_abort_transaction dumps __FILE__:__LINE__ in the log so this patch
makes the code more difficult to debug.

-Jeff


> Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
> ---
>  fs/btrfs/extent-tree.c | 69 ++++++++++++++++++++------------------------------
>  1 file changed, 27 insertions(+), 42 deletions(-)
> 
> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
> index 116c5615d6c2..c6b7aca88491 100644
> --- a/fs/btrfs/extent-tree.c
> +++ b/fs/btrfs/extent-tree.c
> @@ -6913,10 +6913,9 @@ static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
>  			ret = remove_extent_backref(trans, info, path, NULL,
>  						    refs_to_drop,
>  						    is_data, &last_ref);
> -			if (ret) {
> -				btrfs_abort_transaction(trans, ret);
> -				goto out;
> -			}
> +			if (ret)
> +				goto abort_transaction;
> +
>  			btrfs_release_path(path);
>  			path->leave_spinning = 1;
>  
> @@ -6962,10 +6961,9 @@ static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
>  				if (ret > 0)
>  					btrfs_print_leaf(path->nodes[0]);
>  			}
> -			if (ret < 0) {
> -				btrfs_abort_transaction(trans, ret);
> -				goto out;
> -			}
> +			if (ret < 0)
> +				goto abort_transaction;
> +
>  			extent_slot = path->slots[0];
>  		}
>  	} else if (WARN_ON(ret == -ENOENT)) {
> @@ -6974,11 +6972,9 @@ static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
>  			"unable to find ref byte nr %llu parent %llu root %llu  owner %llu offset %llu",
>  			bytenr, parent, root_objectid, owner_objectid,
>  			owner_offset);
> -		btrfs_abort_transaction(trans, ret);
> -		goto out;
> +		goto abort_transaction;
>  	} else {
> -		btrfs_abort_transaction(trans, ret);
> -		goto out;
> +		goto abort_transaction;
>  	}
>  
>  	leaf = path->nodes[0];
> @@ -6988,10 +6984,8 @@ static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
>  		BUG_ON(found_extent || extent_slot != path->slots[0]);
>  		ret = convert_extent_item_v0(trans, info, path, owner_objectid,
>  					     0);
> -		if (ret < 0) {
> -			btrfs_abort_transaction(trans, ret);
> -			goto out;
> -		}
> +		if (ret < 0)
> +			goto abort_transaction;
>  
>  		btrfs_release_path(path);
>  		path->leave_spinning = 1;
> @@ -7008,10 +7002,8 @@ static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
>  				ret, bytenr);
>  			btrfs_print_leaf(path->nodes[0]);
>  		}
> -		if (ret < 0) {
> -			btrfs_abort_transaction(trans, ret);
> -			goto out;
> -		}
> +		if (ret < 0)
> +			goto abort_transaction;
>  
>  		extent_slot = path->slots[0];
>  		leaf = path->nodes[0];
> @@ -7035,8 +7027,7 @@ static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
>  			  "trying to drop %d refs but we only have %Lu for bytenr %Lu",
>  			  refs_to_drop, refs, bytenr);
>  		ret = -EINVAL;
> -		btrfs_abort_transaction(trans, ret);
> -		goto out;
> +		goto abort_transaction;
>  	}
>  	refs -= refs_to_drop;
>  
> @@ -7057,10 +7048,8 @@ static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
>  			ret = remove_extent_backref(trans, info, path,
>  						    iref, refs_to_drop,
>  						    is_data, &last_ref);
> -			if (ret) {
> -				btrfs_abort_transaction(trans, ret);
> -				goto out;
> -			}
> +			if (ret)
> +				goto abort_transaction;
>  		}
>  	} else {
>  		if (found_extent) {
> @@ -7078,37 +7067,33 @@ static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
>  		last_ref = 1;
>  		ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
>  				      num_to_del);
> -		if (ret) {
> -			btrfs_abort_transaction(trans, ret);
> -			goto out;
> -		}
> +		if (ret)
> +			goto abort_transaction;
> +
>  		btrfs_release_path(path);
>  
>  		if (is_data) {
>  			ret = btrfs_del_csums(trans, info, bytenr, num_bytes);
> -			if (ret) {
> -				btrfs_abort_transaction(trans, ret);
> -				goto out;
> -			}
> +			if (ret)
> +				goto abort_transaction;
>  		}
>  
>  		ret = add_to_free_space_tree(trans, info, bytenr, num_bytes);
> -		if (ret) {
> -			btrfs_abort_transaction(trans, ret);
> -			goto out;
> -		}
> +		if (ret)
> +			goto abort_transaction;
>  
>  		ret = update_block_group(trans, info, bytenr, num_bytes, 0);
> -		if (ret) {
> -			btrfs_abort_transaction(trans, ret);
> -			goto out;
> -		}
> +		if (ret)
> +			goto abort_transaction;
>  	}
>  	btrfs_release_path(path);
>  
>  out:
>  	btrfs_free_path(path);
>  	return ret;
> +abort_transaction:
> +	btrfs_abort_transaction(trans, ret);
> +	goto out;
>  }
>  
>  /*
> 


-- 
Jeff Mahoney
SUSE Labs


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