Re: [PATCH 5/8] dio: refactor __blockdev_direct_IO()

[Jeff Moyer <jmoyer@redhat.com>]

Zach Brown <zach.brown@oracle.com> writes:

> This patch moves code around so that __blockdev_direct_IO() becomes a function
> which only iterates over its iovec argument while calling helper functions.
> This wil let us add functions in the future which call the same helper
> functions while iterating over other ways of specifying memory for the IO.
>
> direct_io_worker() was only called once from __blockdev_direct_IO() but took
> the iovec argument.  Instead of trying to pass down other ways of specifying
> memory, we move its body up into __blockdev_direct_IO() before pulling the
> initilization and teardown steps of this resulting huge function off into
> helpers.  What's left is a small function that mostly concerns itself with
> calling helpers on the iovec.
>
> The dio_unaligned() helper is a little strange, but it reflects the flow of the
> original code.  If we were to clean it up we'd run the risk of introducing
> bugs.
>
> Comments have not been updated to reflect the code change yet.

Wow, that's a dense patch.  It looks right to me, and I like the
cleanup.

Cheers,
Jeff