Re: [PATCH 4/7] btrfs: run clean_dirty_subvols if we fail to start a trans

[David Sterba <dsterba@suse.cz>]

On Mon, Mar 02, 2020 at 01:47:54PM -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 | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
> index f42589cb351c..e60450c44406 100644
> --- a/fs/btrfs/relocation.c
> +++ b/fs/btrfs/relocation.c
> @@ -4275,6 +4275,7 @@ static noinline_for_stack int relocate_block_group(struct reloc_control *rc)
>  	/* get rid of pinned extents */
>  	trans = btrfs_join_transaction(rc->extent_root);
>  	if (IS_ERR(trans)) {
> +		clean_dirty_subvols(rc);
>  		err = PTR_ERR(trans);
>  		goto out_free;
>  	}
> @@ -4701,6 +4702,7 @@ 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;
>  	}

Call to clean_dirty subvolumes is just before the out_free label and
also handles errors so the cleanup should be done there and not before
the gotos.