Re: [RESEND][PATCH 4/6] Add page becoming writable notification

[Christoph Hellwig <hch@infradead.org>]

On Fri, Oct 15, 2004 at 04:05:03PM +0100, David Howells wrote:
> 
> > > +	/* notification that a page is about to become writable */
> > > +	int (*page_mkwrite)(struct page *page);
> > 
> > This doesn't fit into address_space operations at all.  The vm_operation
> > below is enough.
> 
> Filesystems shouldn't be overloading vm_operations on ordinary files, or so
> I've been instructed.

huh?  that doesn't make any sense.  if a filesystem needs to do something
special win regards to the VM it should overload vm_operations.  Currently
that's only ncpfs and xfs.

> > This prototype shows pretty much that splitting it out doesn't make much
> > sense.  Why not add a goto reuse_page; where you call it currently and
> > append it at the end of do_wp_page?
> 
> Judging by the CodingStyle doc - which you like throwing at me - it should be
> split into a separate inline function. I could come up with a better name, I
> suppose to keep Willy happy too - perhaps make_pte_writable(); it's just that
> I wanted to name it to show its derivation.

Splitting in helpers makes sense if there's a sane interface.  The number of
arguments doesn't exactly imply that it's the case here.