Re: [PATCH] rbd: report unsupported features to syslog

[Josh Durgin <jdurgin@redhat.com>]

On 04/15/2016 12:25 PM, Ilya Dryomov wrote:
> ... instead of just returning an error.
>
> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Reviewed-by: Josh Durgin <jdurgin@redhat.com>

> ---
>   drivers/block/rbd.c | 9 ++++++---
>   1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
> index 9f1eb00b5e64..78aca585e7e5 100644
> --- a/drivers/block/rbd.c
> +++ b/drivers/block/rbd.c
> @@ -4184,7 +4184,7 @@ static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
>   		__le64 features;
>   		__le64 incompat;
>   	} __attribute__ ((packed)) features_buf = { 0 };
> -	u64 incompat;
> +	u64 unsup;
>   	int ret;
>
>   	ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name,
> @@ -4197,9 +4197,12 @@ static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
>   	if (ret < sizeof (features_buf))
>   		return -ERANGE;
>
> -	incompat = le64_to_cpu(features_buf.incompat);
> -	if (incompat & ~RBD_FEATURES_SUPPORTED)
> +	unsup = le64_to_cpu(features_buf.incompat) & ~RBD_FEATURES_SUPPORTED;
> +	if (unsup) {
> +		rbd_warn(rbd_dev, "image uses unsupported features: 0x%llx",
> +			 unsup);
>   		return -ENXIO;
> +	}
>
>   	*snap_features = le64_to_cpu(features_buf.features);
>
>