Re: [Ext2-devel] Re: [RFC] [PATCH] Generic mpage_writepage() support

[Dave Kleikamp <shaggy@austin.ibm.com>]

On Wed, 2005-02-16 at 13:38 -0800, Badari Pulavarty wrote:
> On Wed, 2005-02-16 at 11:43, Dave Kleikamp wrote:
> > The patch I am working on will call mpage_writepages() for metadata, but
> > will use my own writepage() rather than mpage_writepage(), and nothing
> > in mpage_writepages() will use page->private.
> 
> Okay, that will work. Basically, you plan to call mpage_writepages()
> with NULL as get_block(). Isn't it ?

Yes

> > > > mpage.c already assumes page->private implies bufferheads, so it's not
> > > > completely generic.  Would implementing this as nobh_write_full_page, to
> > > > complement block_write_full_page, make sense?
> > > 
> > > I guess, it can be done. So to really deal with this, we need to come
> > > up with generic writepage/writepages interfaces which doesn't deal
> > > with bufferheads.
> > 
> > I'm not sure how useful that would be.  Are there any users of a
> > non-bufferhead page->private that want to call a generic writepage(s)?
> > In other words, if a generic function is sufficient, you probably
> > wouldn't be using page->private anyway.
> 
> This goes back to original question, is there a point in creating
> new interfaces for writepage & writepages which doesn't assuming
> page->private. So far, only users are ext2+nobh and JFS. But both
> of them will not use page->private for anything else other than
> bufferheads (if at all used). For both of these, the mpage_writepage()
> I cooked up earlier would be good enough.

I agree.  I just think that nobh_write_full_page() would be a more
consistent name than mpage_writepage().

> I guess, we will do it ONLY if someone really needs it. 

Agreed ... and I don't think anyone will need it.  :^)

> Thanks,
> Badari

Thanks,
Shaggy
-- 
David Kleikamp
IBM Linux Technology Center