[v2,0/6] btrfs: remove buffer heads form superblock handling

Message

Johannes Thumshirn Jan. 23, 2020, 8:18 a.m. UTC

This patch series removes the use of buffer_heads from btrfs' super block read
and write paths. It also converts the integrity-checking code to only work
with pages and BIOs.

Compared to buffer heads, this gives us a leaner call path, as the
buffer_head code wraps around getting pages from the page-cache and adding
them to BIOs to submit.

The first patch is from Nikolay and exports btrfs_release_disk_super(), so it
can be used in the patchews follwing in this series.
The second patch removes buffer_heads from superblock reading.
The third from super_block writing and the subsequent patches remove the
buffer_heads from the integrity check code.

It's based on misc-next from Wednesday January 22, and doesn't show any
regressions in xfstests to the baseline.

Cahnges to v1:
- Added patch #1
- Converted sb reading and integrity checking to use the page cache
- Added rationale behind the conversion to the commit messages.
- For more details see the idividual patches.

Johannes Thumshirn (5):
  btrfs: remove buffer heads from super block reading
  btrfs: remove use of buffer_heads from superblock writeout
  btrfs: remove btrfsic_submit_bh()
  btrfs: remove buffer_heads from btrfsic_process_written_block()
  btrfs: remove buffer_heads form superblock mirror integrity checking

Nikolay Borisov (1):
  btrfs: export btrfs_release_disk_super

 fs/btrfs/check-integrity.c | 204 ++++++++++---------------------------
 fs/btrfs/check-integrity.h |   2 -
 fs/btrfs/disk-io.c         | 194 +++++++++++++++++++++--------------
 fs/btrfs/disk-io.h         |   4 +-
 fs/btrfs/volumes.c         |  64 +++++++-----
 fs/btrfs/volumes.h         |   3 +-
 6 files changed, 216 insertions(+), 255 deletions(-)