[dm-devel] [PATCH] dm space map: always set ev if sm_ll_mutate() succeeds

[Edward Thornber]

ack

On Sun, Dec 04, 2016 at 11:26:38PM -0600, Benjamin Marzinski wrote:
> If no block was allocated or freed, sm_ll_mutate() wasn't setting
> *ev, leaving the variable unitialized. sm_ll_insert(),
> sm_disk_inc_block(), and sm_disk_new_block() all check ev to see
> if there was an allocation event in sm_ll_mutate(), possibly
> reading unitialized data.
> 
> If no allocation event occured, sm_ll_mutate() should set *ev
> to SM_NONE.
> 
> Signed-off-by: Benjamin Marzinski <bmarzins at redhat.com>
> ---
>  drivers/md/persistent-data/dm-space-map-common.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/md/persistent-data/dm-space-map-common.c b/drivers/md/persistent-data/dm-space-map-common.c
> index 10978ba..4c28608 100644
> --- a/drivers/md/persistent-data/dm-space-map-common.c
> +++ b/drivers/md/persistent-data/dm-space-map-common.c
> @@ -464,7 +464,8 @@ static int sm_ll_mutate(struct ll_disk *ll, dm_block_t b,
>  		ll->nr_allocated--;
>  		le32_add_cpu(&ie_disk.nr_free, 1);
>  		ie_disk.none_free_before = cpu_to_le32(min(le32_to_cpu(ie_disk.none_free_before), bit));
> -	}
> +	} else
> +		*ev = SM_NONE;
>  
>  	return ll->save_ie(ll, index, &ie_disk);
>  }
> -- 
> 2.1.0
>