[PATCH 00/15] btrfs: read repair/direct I/O improvements

[Omar Sandoval <osandov@osandov.com>]

From: Omar Sandoval <osandov@fb.com>

Hi,

This series includes several fixes, cleanups, and improvements to direct
I/O and read repair. It's preparation for adding read repair to my
RWF_ENCODED series [1], but it can go in independently.

Patches 1 and 2 are direct I/O error handling fixes. Patch 3 is a
buffered read repair fix. Patch 4 is a buffered read repair improvement.
Patches 5-9 are trivial cleanups. Patch 10 converts direct I/O to use
refcount_t, which would've helped catch the bug fixed by patch 1.
Patches 11-14 drastically simplify the direct I/O code. Patch 15 gets
unifies buffered and direct I/O read repair, which also makes direct I/O
repair actually do validation for large failed reads instead of
rewriting the whole thing.

Overall, this is net about -400 lines of code and actually makes direct
I/O more functional.

Note that this series causes btrfs/142 to fail. This is a bug in the
test, as it assumes that direct I/O doesn't do read validation. I'm
working on a fix for the test.

Christoph is cc'd for patch 3. The fix looks at the bio internals in a
way that I wasn't sure was recommended, although there is precedent in
the bcache code. I'd appreciate if Christoph acked that patch or
suggested a better approach.

This series is based on misc-next.

Thanks!

1: https://lore.kernel.org/linux-fsdevel/cover.1582930832.git.osandov@fb.com/

Omar Sandoval (15):
  btrfs: fix error handling when submitting direct I/O bio
  btrfs: fix double __endio_write_update_ordered in direct I/O
  btrfs: look at full bi_io_vec for repair decision
  btrfs: don't do repair validation for checksum errors
  btrfs: clarify btrfs_lookup_bio_sums documentation
  btrfs: rename __readpage_endio_check to check_data_csum
  btrfs: make btrfs_check_repairable() static
  btrfs: move btrfs_dio_private to inode.c
  btrfs: kill btrfs_dio_private->private
  btrfs: convert btrfs_dio_private->pending_bios to refcount_t
  btrfs: put direct I/O checksums in btrfs_dio_private instead of bio
  btrfs: get rid of one layer of bios in direct I/O
  btrfs: simplify direct I/O read repair
  btrfs: get rid of endio_repair_workers
  btrfs: unify buffered and direct I/O read repair

 fs/btrfs/btrfs_inode.h |  30 --
 fs/btrfs/ctree.h       |   1 -
 fs/btrfs/disk-io.c     |   8 +-
 fs/btrfs/disk-io.h     |   1 -
 fs/btrfs/extent_io.c   | 141 +++++----
 fs/btrfs/extent_io.h   |  19 +-
 fs/btrfs/file-item.c   |  11 +-
 fs/btrfs/inode.c       | 694 ++++++++++-------------------------------
 8 files changed, 260 insertions(+), 645 deletions(-)

-- 
2.25.1