[PATCH 0/2] btrfs: paramater refactors for data and metadata endio call backs

[Qu Wenruo <wqu@suse.com>]

This is another cleanup exposed when I'm fixing my subpage patchset.

Dating back to the old time where we still have hooks for data/metadata
endio, we have a parameter called @phy_offset for both hooks.

That @phy_offset is the number of sectors compared to the bio on-disk
bytenr, and is used to grab the csum from btrfs_io_bio.

This is far from straightforward, and costs reader tons of time to grasp
the basic.

This patchset will change it by:
- Remove phy_offset completely for metadata
  Since metadata doesn't use btrfs_io_bio::csums[] at all, there is no
  need for it.

- Use @disk_bytenr to replace @phy_offset/@icsum
  Let the callee, check_data_csum() to calculate the offset from
  @disk_bytenr and bio to get the csum offset.

Also, since we know the @disk_bytenr should alwasy be inside the bio
range, add ASSERT() to check such assumption.

Qu Wenruo (2):
  btrfs: remove the phy_offset parameter for
    btrfs_validate_metadata_buffer()
  btrfs: use more straightforward disk_bytenr to replace icsum for
    check_data_csum()

 fs/btrfs/disk-io.c   |  2 +-
 fs/btrfs/disk-io.h   |  2 +-
 fs/btrfs/extent_io.c | 16 +++++++++-------
 fs/btrfs/inode.c     | 35 ++++++++++++++++++++++++++---------
 4 files changed, 37 insertions(+), 18 deletions(-)

-- 
2.29.2