On Tue, 12 Aug 2008, Al Viro wrote:
>
> Doesn't work well for readdir(2)...
Sure it does.
> > error = vfs_readdir(file, filldir, &buf);
> > lastdirent = buf.previous;
> > if (lastdirent) {
> > error = count - buf.count;
> > if (put_user(file->f_pos, &lastdirent->d_off))
> > error = -EFAULT;
> > }
> > fput(file);
> > return error;
> >
> > and we wouldn't need any other logic at all.
>
> you've just lost e.g. -EIO for getdents().
No I've not.
If we returned a partial result, we _should_ return a partial result.
And if we got EIO on the first entry, we should return EIO.
The _current_ code is crap. It sometimes returns the error (if the
->readdir() function returned error), and sometimes returns the partial
result (if the "buf.error" was set).
> Frankly, I'd rather keep ->readdir() instances simpler. There are far
> more of those, for one thing. As it is, we only have "stop"/"continue"
> ->readdir() has to care about...
Keeping them simple (and not changing them - always returning zero is what
the _original_ readdir() thing did!) is why the current situation exists.
So if we keep it that way, then we really *KEEP* it that way. Don't go
around changing any of the existing rules. Just make sure that the
callbacks keep on always returning negative or zero (and never positive).
Linus
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