Re: [PATCH 33/35] btrfs: fix insert_reserved error handling

[Nikolay Borisov <nborisov@suse.com>]

On 30.08.2018 20:42, Josef Bacik wrote:
> We were not handling the reserved byte accounting properly for data
> references.  Metadata was fine, if it errored out the error paths would
> free the bytes_reserved count and pin the extent, but it even missed one
> of the error cases.  So instead move this handling up into
> run_one_delayed_ref so we are sure that both cases are properly cleaned
> up in case of a transaction abort.
> 
> Signed-off-by: Josef Bacik <josef@toxicpanda.com>

Reviewed-by: Nikolay Borisov <nborisov@suse.com>

> ---
>  fs/btrfs/extent-tree.c | 12 ++++--------
>  1 file changed, 4 insertions(+), 8 deletions(-)
> 
> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
> index 132a1157982c..fd9169f80de0 100644
> --- a/fs/btrfs/extent-tree.c
> +++ b/fs/btrfs/extent-tree.c
> @@ -2405,6 +2405,9 @@ static int run_one_delayed_ref(struct btrfs_trans_handle *trans,
>  					   insert_reserved);
>  	else
>  		BUG();
> +	if (ret && insert_reserved)> +		btrfs_pin_extent(trans->fs_info, node->bytenr,
> +				 node->num_bytes, 1);
>  	return ret;
>  }
>  
> @@ -8227,21 +8230,14 @@ static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
>  	}
>  
>  	path = btrfs_alloc_path();
> -	if (!path) {
> -		btrfs_free_and_pin_reserved_extent(fs_info,
> -						   extent_key.objectid,
> -						   fs_info->nodesize);
> +	if (!path)
>  		return -ENOMEM;
> -	}
>  
>  	path->leave_spinning = 1;
>  	ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
>  				      &extent_key, size);
>  	if (ret) {
>  		btrfs_free_path(path);
> -		btrfs_free_and_pin_reserved_extent(fs_info,
> -						   extent_key.objectid,
> -						   fs_info->nodesize);
>  		return ret;
>  	}
>  
>