[Cluster-devel] [PATCH 0/2] iomap: small block problems

[Matthew Wilcox]

On Mon, Jun 28, 2021 at 06:47:58PM +0100, Christoph Hellwig wrote:
> On Mon, Jun 28, 2021 at 06:39:09PM +0100, Matthew Wilcox wrote:
> > Not hugely happy with either of these options, tbh.  I'd rather we apply
> > a patch akin to this one (plucked from the folio tree), so won't apply:
> 
> > so permit pages without an iop to enter writeback and create an iop
> > *then*.  Would that solve your problem?
> 
> It is the right thing to do, especially when combined with a feature
> patch to not bother to create the iomap_page structure on small
> block size file systems when the extent covers the whole page.

We don't know the extent layout at the point where *this* patch creates
iomap_pages during writeback.  I imagine we can delay creating one until
we find out what our destination layout will be?