Re: [PATCH 5/8] btrfs: run clean_dirty_subvols if we fail to start a trans

[David Sterba <dsterba@suse.cz>]

On Wed, Mar 04, 2020 at 11:18:27AM -0500, Josef Bacik wrote:
> If we do merge_reloc_roots() we could insert a few roots onto the dirty
> subvol roots list, where we hold a ref on them.  If we fail to start the
> transaction we need to run clean_dirty_subvols() in order to cleanup the
> refs.
> 
> Signed-off-by: Josef Bacik <josef@toxicpanda.com>
> ---
>  fs/btrfs/relocation.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
> index f6237d885fe0..53509c367eff 100644
> --- a/fs/btrfs/relocation.c
> +++ b/fs/btrfs/relocation.c
> @@ -4279,10 +4279,10 @@ static noinline_for_stack int relocate_block_group(struct reloc_control *rc)
>  		goto out_free;
>  	}
>  	btrfs_commit_transaction(trans);
> +out_free:
>  	ret = clean_dirty_subvols(rc);
>  	if (ret < 0 && !err)
>  		err = ret;
> -out_free:
>  	btrfs_free_block_rsv(fs_info, rc->block_rsv);
>  	btrfs_free_path(path);
>  	return err;
> @@ -4711,6 +4711,7 @@ int btrfs_recover_relocation(struct btrfs_root *root)
>  
>  	trans = btrfs_join_transaction(rc->extent_root);
>  	if (IS_ERR(trans)) {
> +		clean_dirty_subvols(rc);
>  		err = PTR_ERR(trans);
>  		goto out_free;
>  	}

The update to btrfs_recover_relocation should follow the same pattern,
like

@@ -4682,12 +4682,12 @@ int btrfs_recover_relocation(struct btrfs_root *root)
 
        trans = btrfs_join_transaction(rc->extent_root);
        if (IS_ERR(trans)) {
-               clean_dirty_subvols(rc);
                err = PTR_ERR(trans);
-               goto out_free;
+               goto out_clean;
        }
        err = btrfs_commit_transaction(trans);
 
+out_clean:
        ret = clean_dirty_subvols(rc);
        if (ret < 0 && !err)
                err = ret;