[PATCH 4/6] nvme-discover: Retry discovery log if the generation counter changes

[hch@lst.de (Christoph Hellwig)]

On Fri, Aug 17, 2018@09:29:06AM +0200, Hannes Reinecke wrote:
> If the generation counter changes we need to validate if the number
> of records has changed, too.
> If so we need to retry retrieving the discovery log to the most recent
> values. The retry will be terminated after MAX_DISC_RETRIES (currently
> set to 30) to avoid infinite recursion.

30 retries seems pretty crazy.

> @@ -311,6 +312,7 @@ static int nvmf_get_log_page_discovery(const char *dev_path,
>  		goto out_free_log;
>  	}
>  
> +retry_log:
>  	/* check numrec limits */
>  	*numrec = le64_to_cpu(log->numrec);
>  	genctr = le64_to_cpu(log->genctr);
> @@ -346,7 +348,12 @@ static int nvmf_get_log_page_discovery(const char *dev_path,
>  		goto out_free_log;
>  	}
>  
> -	if (*numrec != le32_to_cpu(log->numrec) || genctr != le64_to_cpu(log->genctr)) {
> +	if (genctr != le64_to_cpu(log->genctr) &&
> +	    *numrec != le32_to_cpu(log->numrec) &&
> +	    ++retries < max_retries)
> +		goto retry_log;

Any way we could factor this into a do { } while loop?