Re: [RFC] readdir mess

[Al Viro <viro@ZenIV.linux.org.uk>]

On Tue, Aug 12, 2008 at 07:10:57PM +0100, Al Viro wrote:
> There's one more thing in that mess: a bunch of vfs_readdir() callers
> end up playing very sick games to make sure they get the entire
> directory.  The trick is to find whether the damn thing has reached
> the end; as it is, there are instances of ->readdir() that do _not_
> (e.g. call filldir only once and let the caller repeat).
> 
> I'm certainly not too fond of buf->error.  If you see a better interface
> I'd love to hear about it, but I don't think that "just return anything
> non-zero we'd got from callback" is going to be good.  And if we go for
> flagday changes in ->readdir(), we'd better get it right...

PS: we might get away with both, if we used _positive_ values as well.
E.g. have getdents() filldir return 1 if we are out of buffer *and*
have ->previous != NULL (and -EINVAL if we are out of buffer on the
first call)...  And have some other positive constant for "->readdir()
didn't feel like going all the way to the end of directory".