Re: [PATCH v7 12/12] iomap: Put struct iomap_ops into struct iomap

[Christoph Hellwig <hch@lst.de>]

On Mon, Jun 04, 2018 at 02:37:29PM +0200, Andreas Gruenbacher wrote:
> We need access to the struct iomap_ops in iomap_write_end to call the
> (optional) page_write_end hook, so instead of passing the operators to
> iomap_write_end differently depending on the code path, add an ops field
> to struct iomap.

I don't really like this.  We already pass the iomap_ops to the
function we call from iomap.c, and in fact ->iomap_begin is called
through the ops.

But what we could do is to move the page_write_end callback out of
iomap_ops and just attached it to the iomap, especially given that
it isn't really as generic as the other ops.

Can't say I like the implications of this callback in general, but
the use case is real, so..