btrfs: introduce subpage metadata validation check

For subpage metadata validation check, there are some differences:

- Read must finish in one bvec
  Since we're just reading one subpage range in one page, it should
  never be split into two bios nor two bvecs.

- How to grab the existing eb
  Instead of grabbing eb using page->private, we have to go search radix
  tree as we don't have any direct pointer at hand.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Qu Wenruo 2021-01-26 16:33:59 +08:00 • committed by David Sterba
commit 371cdc0700