On Mon, Oct 28, 2024 at 12:51:32PM +0100, Christoph Hellwig wrote:

As pointed out by Bart last time, you can't simply give the write hints
to all block device.  Assume we'd want to wire up the write stream based
separate to f2fs (which btw would be a good demonstration), and you'd
have two different f2fs file systems on separate partitions that'd
now start sharing the write streams if they simply started from stream
1.  Same for our pending XFS data placement work.

And I'm an idiot and should have looked at the next patch patch first.
Sorry for that.