Re: [PATCH v6 10/11] blksnap: Kconfig and Makefile

[Christoph Hellwig]

> +config BLKSNAP_DIFF_BLKDEV
> +	bool "Use an optimized algorithm to store difference on a block device"
> +	depends on BLKSNAP
> +	default y
> +	help
> +	  The difference storage for a snapshot can be a regular file or a
> +	  block device. We can work with a block device through the interface
> +	  of a regular file. However, direct management of I/O units should
> +	  allow for higher performance.

Is there much of a point in making this option?

Btw, Linus hates defaul y, so we should not have one in there.

> +config BLKSNAP_CHUNK_DIFF_BIO_SYNC
> +	bool "Use a synchronous I/O unit processing algorithm for the snapshot image"
> +	depends on BLKSNAP
> +	default n

n the default default, so no need to add it.  But unless there is a
really good reason to have two different bio submission mechanisms
upstream I'd strongly suggest dropping one of them and this option.