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Date: Mon, 26 Jan 2015 09:00:48 -0800
From: Christoph Hellwig <hch@infradead.org>
To: Ming Lei <ming.lei@canonical.com>
Cc: Christoph Hellwig <hch@infradead.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
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Subject: Re: [PATCH v2 1/4] aio: add aio_kernel_() interface
Message-ID: <20150126170048.GA2080@infradead.org>
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On Tue, Jan 27, 2015 at 12:18:23AM +0800, Ming Lei wrote:
> > Also it might make sense to just offer aio_kernel_read/write intefaces
> > instead of the common submit wrapper, as that's much closer to other
> > kernel APIs, e.g.
> >
> > int aio_kernel_read(struct kiocb *iocb, struct file *file,
> >                 struct iov_iter *iter, loff_t off,
> >                 void (*complete)(struct kiocb *iocb, long res));
> > int aio_kernel_write(struct kiocb *iocb, struct file *file,
> >                 struct iov_iter *iter, loff_t off,
> >                 void (*complete)(struct kiocb *iocb, long res));
> 
> It is like style of sync APIs, looks submit/complete is common
> for async APIs, like io_submit().

io_submit is a fairly horrible API.  While Posix AIO isn't too much
better it does have separate APIs for read/write.  Given that there
isn't much code shared I'd keep an API that feels familar.