[PATCHSET v2 0/12] Move io_buffer_list out of struct io_kiocb

[Jens Axboe <axboe@kernel.dk>]

Hi,

One thing that has annoyed me is that struct io_buffer_list is inside
struct io_kiocb, as they have potentially drastically different
lifetimes. This makes it easy to screw up, even if you think you know
what you are doing, as you need to understand the intricacies of
provided buffer ring lifetimes.

This patchset adds a struct io_br_sel, which is used for buffer
selection, and which also then stores the io_buffer_list whenever it
is safe to do so. io_br_sel resides on the stack of the user, and
hence cannot leak outside of that scope.

With this, we can also cleanup some of the random recycle points we
have in the code base in general.

Should not have any functional changes, unless I screwed up of course.
Passes full liburing tests as well.

Can also be found here:

https://git.kernel.dk/cgit/linux/log/?h=io_uring-buf-list

 include/linux/io_uring_types.h |   6 --
 io_uring/io_uring.c            |   4 +-
 io_uring/kbuf.c                |  67 ++++++++-------
 io_uring/kbuf.h                |  57 +++++++-----
 io_uring/net.c                 | 153 ++++++++++++++++-----------------
 io_uring/poll.c                |   4 -
 io_uring/rw.c                  |  56 ++++++------
 7 files changed, 177 insertions(+), 170 deletions(-)

Since v1:
- Drop 'issue_flags' from both io_put_kbuf() and io_put_kbufs(),
  unused in both.
- Add patch folding 'ret' in io_send_finish() with io_br_sel, just
  like was previously done on the receive side.
- Add patch checking for REQ_F_BUFFER_RING first in recycling.
- Rebase on current for-6.18/io_uring branch.

-- 
Jens Axboe