Re: [PATCH 2/4] fs: remove the never implemented aio_fsync file operation

[Dave Chinner <david@fromorbit.com>]

On Mon, Oct 31, 2016 at 02:07:54PM +0100, Christoph Hellwig wrote:
> On Mon, Oct 31, 2016 at 10:23:31AM +1100, Dave Chinner wrote:
> > This doesn't belong in this patchset.
> 
> It does.  I can't fix up the calling conventions for a methods that
> was never implemented.

That sounds like a problem with your fix - it should work
regardless of whether a valid/implemented AIO function is called
or not, right? There's no difference between an invalid command,
IOCB_CMD_FSYNC where ->aio_fsync() is null, or some supported
command that immediately returns -EIO, the end result should
be the same...

> > Regardless, can we just implement the damned thing rather than
> > removing it?  Plenty of people have asked for it and they still want
> > this functionality. I've sent a couple of different prototypes that
> > worked but got bikeshedded to death, and IIRC Ben also tried to get
> > it implemented but that went nowhere because other parts of his
> > patchset got bikeshedded to death.
> > 
> > If nothing else, just let me implement it in XFS like I did the
> > first time so when all the bikshedding stops we can convert it to
> > the One True AIO Interface that is decided on.
> 
> I'm not going to complain about a proper implementation, but right now
> we don't have any, and I'm not even sure the method signature is
> all that suitable.  E.g. for the in-kernel users we'd really want a 
> ranged fsync like the normal fsync anyway.

You mean like this version I posted a year ago:

https://lkml.org/lkml/2015/10/29/517


Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com