Re: [PATCH] dm thin: return ENOSPC instead of EIO when error_if_no_space enabled

[Joe Thornber <thornber@redhat.com>]

ack

On Thu, May 22, 2014 at 02:12:44PM -0400, Mike Snitzer wrote:
> Update the DM thin provisioning target's allocation failure error to be
> consistent with commit a9d6ceb8 ("[SCSI] return ENOSPC on thin
> provisioning failure").
> 
> The DM thin target now returns -ENOSPC rather than -EIO when
> block allocation fails due to the pool being out of data space (and
> the 'error_if_no_space' thin-pool feature is enabled).
> 
> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
> ---
>  drivers/md/dm-thin.c |   16 +++++++++-------
>  1 files changed, 9 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
> index c31f5f1..b77e919 100644
> --- a/drivers/md/dm-thin.c
> +++ b/drivers/md/dm-thin.c
> @@ -1021,7 +1021,7 @@ static void retry_on_resume(struct bio *bio)
>  	spin_unlock_irqrestore(&tc->lock, flags);
>  }
>  
> -static bool should_error_unserviceable_bio(struct pool *pool)
> +static int should_error_unserviceable_bio(struct pool *pool)
>  {
>  	enum pool_mode m = get_pool_mode(pool);
>  
> @@ -1029,25 +1029,27 @@ static bool should_error_unserviceable_bio(struct pool *pool)
>  	case PM_WRITE:
>  		/* Shouldn't get here */
>  		DMERR_LIMIT("bio unserviceable, yet pool is in PM_WRITE mode");
> -		return true;
> +		return -EIO;
>  
>  	case PM_OUT_OF_DATA_SPACE:
> -		return pool->pf.error_if_no_space;
> +		return pool->pf.error_if_no_space ? -ENOSPC : 0;
>  
>  	case PM_READ_ONLY:
>  	case PM_FAIL:
> -		return true;
> +		return -EIO;
>  	default:
>  		/* Shouldn't get here */
>  		DMERR_LIMIT("bio unserviceable, yet pool has an unknown mode");
> -		return true;
> +		return -EIO;
>  	}
>  }
>  
>  static void handle_unserviceable_bio(struct pool *pool, struct bio *bio)
>  {
> -	if (should_error_unserviceable_bio(pool))
> -		bio_io_error(bio);
> +	int error = should_error_unserviceable_bio(pool);
> +
> +	if (error)
> +		bio_endio(bio, error);
>  	else
>  		retry_on_resume(bio);
>  }
> -- 
> 1.7.4.4
>