Re: [patch 14/23] inodes: Support generic defragmentation

Jörn Engel
2007-11-07T18:56:17Z

On Wed, 7 November 2007 10:40:55 -0800, Christoph Lameter wrote:
> On Wed, 7 Nov 2007, Jörn Engel wrote:
> > On Tue, 6 November 2007 17:11:44 -0800, Christoph Lameter wrote:
> > >
> > > +void *get_inodes(struct kmem_cache *s, int nr, void **v)
> > > +{
> > > + int i;
> > > +
> > > + spin_lock(&inode_lock);
> > > + for (i = 0; i < nr; i++) {
> > > + struct inode *inode = v[i];
> > > +
> > > + if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE))
> > > + v[i] = NULL;
> > > + else
> > > + __iget(inode);
> > > + }
> > > + spin_unlock(&inode_lock);
> > > + return NULL;
> > > +}
> > > +EXPORT_SYMBOL(get_inodes);
> >
> > What purpose does the return type have?
>
> The pointer is for communication between the get and kick methods. get()
> can modify kick() behavior by returning a pointer to a data structure or
> using the pointer to set a flag. F.e. get() may discover that there is an
> unreclaimable object and set a flag that causes kick to simply undo the
> refcount increment. get() may build a map for the objects and indicate in
> the map special treatment.

Is there a get/kick pair that actually does this? So far I haven't
found anything like it.

Also, something vaguely matching that paragraph might make sense in a
kerneldoc header to the function. ;)

Jörn

--
There is no worse hell than that provided by the regrets
for wasted opportunities.
-- Andre-Louis Moreau in Scarabouche