Re: [PATCH 1/7] Prepare for adding a new readv/writev with user flags.

From: Christoph Hellwig
Date: Mon Sep 15 2014 - 17:18:11 EST


On Mon, Sep 15, 2014 at 09:28:28PM +0100, Al Viro wrote:
> On Mon, Sep 15, 2014 at 04:20:17PM -0400, Milosz Tanski wrote:
> > Plumbing the flags argument through the vfs code so they can be passed down to
> > __generic_file_(read/write)_iter function that do the acctual work.
>
> NAK. Put these flags into iocb, it'll be less noisy that way.

Fine with me. My initial prototype had it in the iov_iter type field
which is another possibility.

But if we get rid of the explicit flags field and make it more invisible
I'd really like to add a features field struct file_operations where
instances can advertize that they support it (and other things like
actual AIO support in the future) so that we won't have a situation
like with AIO where we can submit I/O but it might actually still block
anyway because lots of operations don't support it.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/