[dm-devel] [PATCH] dm-persistent-data: free sm_metadata on failed create

[Edward Thornber]

ack

On Wed, Nov 30, 2016 at 05:56:14PM -0600, Benjamin Marzinski wrote:
> In dm_sm_metadata_create we temporarily change the dm_space_map
> operations from ops, whose destroy function deallocates the
> sm_metadata, to bootstrap_ops, whose destroy function doesn't. If we
> fail in dm_ll_new_metadata or sm_ll_extend, we exit back to
> dm_tm_create_internal, which calls dm_sm_destroy with the intention
> of freeing the sm_metadata, but it doesn't.
> 
> This patch sets the dm_space_map operations back to ops if
> dm_sm_metadata_create fails when it is set to bootstrap_ops.
> 
> Signed-off-by: Benjamin Marzinski <bmarzins at redhat.com>
> ---
>  drivers/md/persistent-data/dm-space-map-metadata.c | 14 ++++++--------
>  1 file changed, 6 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/md/persistent-data/dm-space-map-metadata.c b/drivers/md/persistent-data/dm-space-map-metadata.c
> index 7e44005..20557e2 100644
> --- a/drivers/md/persistent-data/dm-space-map-metadata.c
> +++ b/drivers/md/persistent-data/dm-space-map-metadata.c
> @@ -775,17 +775,15 @@ int dm_sm_metadata_create(struct dm_space_map *sm,
>  	memcpy(&smm->sm, &bootstrap_ops, sizeof(smm->sm));
>  
>  	r = sm_ll_new_metadata(&smm->ll, tm);
> +	if (!r) {
> +		if (nr_blocks > DM_SM_METADATA_MAX_BLOCKS)
> +			nr_blocks = DM_SM_METADATA_MAX_BLOCKS;
> +		r = sm_ll_extend(&smm->ll, nr_blocks);
> +	}
> +	memcpy(&smm->sm, &ops, sizeof(smm->sm));
>  	if (r)
>  		return r;
>  
> -	if (nr_blocks > DM_SM_METADATA_MAX_BLOCKS)
> -		nr_blocks = DM_SM_METADATA_MAX_BLOCKS;
> -	r = sm_ll_extend(&smm->ll, nr_blocks);
> -	if (r)
> -		return r;
> -
> -	memcpy(&smm->sm, &ops, sizeof(smm->sm));
> -
>  	/*
>  	 * Now we need to update the newly created data structures with the
>  	 * allocated blocks that they were built from.
> -- 
> 2.1.0
>