[PATCH v4 0/2] Fix libaio cancellation support

[Bart Van Assche <bvanassche@acm.org>]

Hi Christian,

This patch series fixes cancellation support in libaio as follows:
 - Restore the code for completing cancelled I/O.
 - Ignore requests to support cancellation for I/O not submitted by libaio.

Please consider this patch series for the next merge window.

Thanks,

Bart.

Changes between v3 and v4:
 - Restored libaio cancellation support.
 - Changed the approach to marking libaio requests with a flag in struct kiocb
   instead of adding a new operation in struct file_operations.
 
Changes between v2 and v3:
 - Removed libaio cancellation support instead of trying to fix it.

Changes between v1 and v2:
 - Fixed a race between request completion and addition to the list of
   active requests.
 - Changed the return type of .cancel_kiocb() from int into void.
 - Simplified the .cancel_kiocb() implementations.
 - Introduced the ki_opcode member in struct aio_kiocb.
 - aio_cancel_and_del() now checks .ki_opcode before accessing union members.
 - Left out the include/include/mm changes.

Bart Van Assche (2):
  fs/aio: Restrict kiocb_set_cancel_fn() to I/O submitted via libaio
  fs/aio: Make io_cancel() generate completions again

 fs/aio.c           | 36 +++++++++++++++++++-----------------
 include/linux/fs.h |  2 ++
 2 files changed, 21 insertions(+), 17 deletions(-)