Re: [PATCH 08/20] drbd: add DAX/PMEM support for metadata access

Christoph Hellwig <[email protected]> Tue, 7 Apr 2026 22:46:26 -0700

Newsgroups	dev.linux.lists.drbd-dev,dev.linux.lists.nvdimm,org.kernel.vger.linux-block,org.kernel.vger.linux-kernel
Message-ID	<[email protected]>

Adding the dax maintainers and they really need to review this.

> +	long want = (drbd_md_last_sector(bdev) + 1 - first_sector) >> (PAGE_SHIFT - SECTOR_SHIFT);
> +	pgoff_t pgoff = first_sector >> (PAGE_SHIFT - SECTOR_SHIFT);
> +	long md_offset_byte = (bdev->md.md_offset - first_sector) << SECTOR_SHIFT;
> +	long al_offset_byte = (al_sector - first_sector) << SECTOR_SHIFT;

You really want helpers to make all these unit conversions maintainable.