Re: [PATCH 02/13] block: refactor bd_may_claim

[Jan Kara <jack@suse.cz>]

On Thu 18-05-23 06:23:11, Christoph Hellwig wrote:
> The long if/else chain obsfucates the actual logic.  Tidy it up to be
> more structured.  Also drop the whole argument, as it can be trivially
> derived from bdev using bdev_whole, and having the bdev_whole in the
> function makes it easier to follow.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Looks good to me. Just one nit below but regardless of how you decided feel
free to add:

Reviewed-by: Jan Kara <jack@suse.cz>

> +static bool bd_may_claim(struct block_device *bdev, void *holder)
>  {
> -	if (bdev->bd_holder == holder)
> -		return true;	 /* already a holder */
> -	else if (bdev->bd_holder != NULL)
> -		return false; 	 /* held by someone else */
> -	else if (whole == bdev)
> -		return true;  	 /* is a whole device which isn't held */
> -
> -	else if (whole->bd_holder == bd_may_claim)
> -		return true; 	 /* is a partition of a device that is being partitioned */
> -	else if (whole->bd_holder != NULL)
> -		return false;	 /* is a partition of a held device */
> -	else
> -		return true;	 /* is a partition of an un-held device */
> +	struct block_device *whole = bdev_whole(bdev);
> +
> +	if (bdev->bd_holder) {
> +		/*
> +		 * The same holder can always re-claim.
> +		 */
> +		if (bdev->bd_holder == holder)
> +			return true;
> +		return false;

With this simple condition I'd just do:
		/* The same holder can always re-claim. */
		return bdev->bd_holder == holder;

								Honza
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR