On 8/1/25 5:47 PM, Keith Busch wrote:

From: Keith Busch <kbusch@kernel.org>

In furthering direct IO use from user space buffers without bouncing to
align to unnecessary kernel software constraints, this series removes
the requirement that io vector lengths align to the logical block size.
The downside (if want to call it that) is that mis-aligned io vectors
are caught further down the block stack rather than closer to the
syscall.

That's not a downside imho, it's much nicer to have the correct/expected
case be fast, and catch the unexpected error case down the line when we
have to iterate the vecs anyway.

IOW, I love this patchset. I'll spend some time going over the details.
Did you write some test cases for this?

This change also removes one walking of the io vector, so that's nice
too.

Keith Busch (7):
  block: check for valid bio while splitting
  block: align the bio after building it
  block: simplify direct io validity check
  iomap: simplify direct io validity check
  block: remove bdev_iter_is_aligned
  blk-integrity: use simpler alignment check
  iov_iter: remove iov_iter_is_aligned

 block/bio-integrity.c  |  4 +-
 block/bio.c            | 58 +++++++++++++++++---------
 block/blk-merge.c      |  5 +++
 block/fops.c           |  4 +-
 fs/iomap/direct-io.c   |  3 +-
 include/linux/blkdev.h |  7 ----
 include/linux/uio.h    |  2 -
 lib/iov_iter.c         | 95 ------------------------------------------
 8 files changed, 49 insertions(+), 129 deletions(-)

Now that's a beautiful diffstat.

-- 
Jens Axboe