Re: [PATCH v8 8/8] btrfs: remove buffer_heads form superblock mirror integrity checking

[David Sterba <dsterba@suse.cz>]

On Fri, Feb 14, 2020 at 12:24:36AM +0900, Johannes Thumshirn wrote:
> The integrity checking code for the superblock mirrors is the last remaining
> user of buffer_heads in BTRFS, change it to using plain BIOs as well.
> 
> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
> Reviewed-by: Josef Bacik <josef@toxicpanda.com>
> Reviewed-by: Nikolay Borisov <nborisov@suse.com>
> 
> ---
> Changes to v7:
> - Use read_Cache_page_gfp()
> - Don't kmap() block device mappings (David)
> 
> Changes to v4:
> - Remove mapping_gfp_constraint()
> 
> Changes to v2:
> - Open-code kunmap() + put_page() (David)
> - Remove __GFP_NOFAIL from allocation (Josef)
> - Merge error paths (David)

The per-patch changes are a nice bonus, let me use it to point out a
thing that the reviews from previous iterations should be kept only if
there are cosmetic changes (like renaming identifiers, formatting or
comments) and not functional changes like the kmap/kunmap or
read_cache_gfp.

If the rev-by lines are there I would expect that the respective
reviewers will skip reading the patch. Good if not, but without an
explicit reply 'still ok' we're losing some information.