Re: [PATCH 1/2] direct-io: move aio_complete into ->end_io

Jan Kara
2010-06-25T10:33:35Z

On Fri 25-06-10 02:36:10, Christoph Hellwig wrote:
> On Thu, Jun 24, 2010 at 11:59:22PM +0200, Jan Kara wrote:
> > Moreover the async testing you do does not seem to be completely right.
> > dio->is_async is a flag that controls whether dio code waits for IO to be
> > completed or not. In particular it is not set for AIO that spans beyond
> > current i_size so it does not seem to be exactly what you need (at least
> > for ext4 it isn't). I think that is_sync_kiocb() is a test that should be
> > used to recognize AIO - and that has an advantage that you don't have to
> > pass the is_async flag around.
>
> No. is_sync_kiocb() means the ioctb was not intended as sync I/O from
> the start. But we can only call aio_complete when we returned
> -EIOCBQUEUED from ->aio_read/write. Take a look at the comment near the
> end of direct_io_worker().
Ah, I see. Thanks for explanation. It's ugly but I also don't see a
nicer way how to handle this.

Honza
--
Jan Kara <jack@suse.cz>
SUSE Labs, CR