Re: [PATCH 4/6] USB-BKL: Remove BKL use in uhci-debug

From: Greg KH
Date: Thu Jun 17 2010 - 13:53:14 EST


On Wed, Jun 02, 2010 at 09:47:46AM -0400, Alan Stern wrote:
> On Tue, 1 Jun 2010, Arnd Bergmann wrote:
>
> > From: Andi Kleen <ak@xxxxxxxxxxxxxxx>
> >
> > BKL was not really needed, just came from earlier push downs.
>
> Yes.
>
> > The only part that's a bit dodgy is the lseek function. Would
> > need another lock or atomic access to fpos on 32bit?
> > Better to have a libfs lseek
>
> It doesn't matter. Anyone who tries to do lseeks on this file
> from two different threads, simultaneously, deserves what they get.
>
> > @@ -539,11 +534,11 @@ static loff_t uhci_debug_lseek(struct file *file, loff_t off, int whence)
> > new = file->f_pos + off;
> > break;
> > }
> > +
> > + /* XXX: Can size shrink? */
> > if (new < 0 || new > up->size) {
> > - unlock_kernel();
> > return -EINVAL;
> > }
> > - unlock_kernel();
> > return (file->f_pos = new);
> > }
>
> This comment isn't needed; the size cannot change after the file has
> been opened.

I've removed the comment in the version I just committed.

thanks,

greg k-h
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/