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Date:   Tue, 22 Mar 2022 02:45:00 +0000
From:   Matthew Wilcox <willy@infradead.org>
To:     Jens Axboe <axboe@kernel.dk>
Cc:     Christoph Hellwig <hch@lst.de>, linux-block@vger.kernel.org,
        linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH 1/2] fs: remove kiocb.ki_hint
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On Mon, Mar 21, 2022 at 08:13:10PM -0600, Jens Axboe wrote:
> On 3/8/22 5:55 PM, Jens Axboe wrote:
> > On Tue, 8 Mar 2022 07:05:28 +0100, Christoph Hellwig wrote:
> >> This field is entirely unused now except for a tracepoint in f2fs, so
> >> remove it.
> >>
> >>
> > 
> > Applied, thanks!
> > 
> > [1/2] fs: remove kiocb.ki_hint
> >       commit: 41d36a9f3e5336f5b48c3adba0777b8e217020d7
> > [2/2] fs: remove fs.f_write_hint
> >       commit: 7b12e49669c99f63bc12351c57e581f1f14d4adf
> 
> Upon thinking about the EINVAL solution a bit more, I do have a one
> worry - if you're currently using write_hints in your application,
> nobody should expect upgrading the kernel to break it. It's a fine
> solution for anything else, but that particular point does annoy me.

But if your application is run on an earlier kernel, it'll get -EINVAL.
So it must already be prepared to deal with that?