Re: [Nbd] [PATCH v1 7/7] s390/block/dasd: remove obsolete while -EBUSY loop

[Sebastian Ott <sebott@...1294...>]

On Wed, 8 Apr 2015, Ming Lei wrote:
> From: Jarod Wilson <jarod@...696...>
> 
> With the mutex_trylock bit gone from blkdev_reread_part(), the retry logic
> in dasd_scan_partitions() shouldn't be necessary.
> 
> CC: Christoph Hellwig <hch@...1270...>
> CC: Jens Axboe <axboe@...161...>
> CC: Tejun Heo <tj@...1285...>
> CC: Alexander Viro <viro@...1300...>
> CC: Markus Pargmann <mpa@...1897...>
> CC: Stefan Weinhuber <wein@...1296...>
> CC: Stefan Haberland <stefan.haberland@...1296...>
> CC: Sebastian Ott <sebott@...1294...>
> CC: Fabian Frederick <fabf@...1980...>
> CC: Ming Lei <ming.lei@...1301...>
> CC: David Herrmann <dh.herrmann@...17...>
> CC: Andrew Morton <akpm@...133...>
> CC: Peter Zijlstra <peterz@...1270...>
> CC: nbd-general@lists.sourceforge.net
> CC: linux-s390@...25...
> Signed-off-by: Jarod Wilson <jarod@...696...>
> ---
>  drivers/s390/block/dasd_genhd.c |   13 +++----------
>  1 file changed, 3 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/s390/block/dasd_genhd.c b/drivers/s390/block/dasd_genhd.c
> index 2af4619..189ea2f 100644
> --- a/drivers/s390/block/dasd_genhd.c
> +++ b/drivers/s390/block/dasd_genhd.c
> @@ -99,9 +99,8 @@ void dasd_gendisk_free(struct dasd_block *block)
>  int dasd_scan_partitions(struct dasd_block *block)
>  {
>  	struct block_device *bdev;
> -	int retry, rc;
> +	int rc;
> 
> -	retry = 5;
>  	bdev = bdget_disk(block->gdp, 0);
>  	if (!bdev) {
>  		DBF_DEV_EVENT(DBF_ERR, block->base, "%s",
> @@ -118,14 +117,8 @@ int dasd_scan_partitions(struct dasd_block *block)
>  	}
> 
>  	rc = blkdev_reread_part(bdev);
> -	while (rc == -EBUSY && retry > 0) {
> -		schedule();
> -		rc = blkdev_reread_part(bdev);
> -		retry--;
> -		DBF_DEV_EVENT(DBF_ERR, block->base,
> -			      "scan partitions error, retry %d rc %d",
> -			      retry, rc);
> -	}
> +	DBF_DEV_EVENT(DBF_ERR, block->base,
> +		      "scan partitions error, rc %d", rc);

Could you please change that to only write the debug message in the error
case. Other than that, both dasd patches look good.

Thanks,
Sebastian

> 
>  	/*
>  	 * Since the matching blkdev_put call to the blkdev_get in
> -- 
> 1.7.9.5
> 
>