Re: [PATCH v6 06/22] Replace XIP read and write with DAX I/O

From: Matthew Wilcox
Date: Tue Mar 11 2014 - 08:54:09 EST


On Mon, Mar 10, 2014 at 06:32:38PM -0600, Toshi Kani wrote:
> On Tue, 2014-02-25 at 09:18 -0500, Matthew Wilcox wrote:
> > Use the generic AIO infrastructure instead of custom read and write
> > methods. In addition to giving us support for AIO, this adds the missing
> > locking between read() and truncate().
> >
> :
> > +static void dax_new_buf(void *addr, unsigned size, unsigned first,
> > + loff_t offset, loff_t end, int rw)
> > +{
> > + loff_t final = end - offset; /* The final byte in this buffer */
>
> I may be missing something, but shouldn't it take first into account?
>
> loff_t final = end - offset + first;

Yes it should. Thanks! (Fortunately, this is only a performance problem
as we'll end up zeroing more than we ought to, which is fine as it will
be overwritten by the copy_from_user later)

--
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/