drivers/block/loop.c |   55 ++++++++++++++++++-
  fs/ext3/file.c       |    2 +
  fs/ext3/inode.c      |  149 ++++++++++++++++++++++++++++++++++----------------
  include/linux/loop.h |    1 +
  4 files changed, 160 insertions(+), 47 deletions(-)

It looks like the patch that teaches loop to use the kernel aio
interface got combined with the patch that adds the _bvec entry points
to ext3.

+	if (file->f_op->write_iter&&  file->f_op->read_iter) {
+		file->f_flags |= O_DIRECT;
+		lo_flags |= LO_FLAGS_USE_AIO;
+	}

This manual setting of f_flags still looks very fishy to me.  I remember
finding that pattern somewhere else but that's not very comforting :).

- z