[RFC PATCH 1/2] block: add simple copy support

[Aleksei Marov]

On Tue, 2020-12-01 at 11:09 +0530, SelvaKumar S wrote:
> +	ret = __blkdev_issue_copy(bdev, dest, nr_srcs, rlist, gfp_mask, flags,
> +			&bio);
> +	if (!ret && bio) {
> +		ret = submit_bio_wait(bio);
> +		if (ret == -EOPNOTSUPP)
> +			ret = 0;
> +
> +		kfree(page_address(bio_first_bvec_all(bio)->bv_page) +
> +				bio_first_bvec_all(bio)->bv_offset);
> +		bio_put(bio);
> +	}
> +
> +	return ret;
> +}
I think  there is an issue here that if bio_add_page  returns error in
__blkdev_issue_copy then ret is -ENOMEM and we never do bio_put for bio
allocated in  __blkdev_issue_copy so it is small memory leak.