[Cluster-devel] [PATCH 17/27] iomap: switch iomap_seek_hole to use iomap_iter

[Christoph Hellwig]

On Mon, Jul 19, 2021 at 10:22:47AM -0700, Darrick J. Wong wrote:
> > -static loff_t
> > -iomap_seek_hole_actor(struct inode *inode, loff_t start, loff_t length,
> > -		      void *data, struct iomap *iomap, struct iomap *srcmap)
> > +static loff_t iomap_seek_hole_iter(const struct iomap_iter *iter, loff_t *pos)
> 
> /me wonders if @pos should be named hole_pos (here and in the caller) to
> make it a little easier to read...

Sure.

> ...because what we're really saying here is that if seek_hole_iter found
> a hole (and returned zero, thereby terminating the loop before iter.len
> could reach zero), we want to return the position of the hole.

Yes.

> > +	return size;
> 
> Not sure why we return size here...?  Oh, because there's an implicit
> hole at EOF, so we return i_size.  Uh, does this do the right thing if
> ->iomap_begin returns posteof mappings?  I don't see anything in
> iomap_iter_advance that would stop iteration at EOF.

Nothing in ->iomap_begin checks that, iomap_seek_hole initializes
iter.len so that it stops at EOF.