On Fri, 2011-03-04 at 14:17 -0500, Neil Horman wrote:
> On Fri, Mar 04, 2011 at 02:01:55PM -0500, Trond Myklebust wrote:
> > On Fri, 2011-03-04 at 11:44 -0500, Neil Horman wrote:
> > >
> > > +static int buf_to_pages_noslab(const void *buf, size_t buflen,
> > > + struct page **pages, unsigned int *pgbase)
> > > +{
> > > + const void *p = buf;
> > > + struct page *page, *newpage, **spages;
> > > + int rc = -ENOMEM;
> > > +
> > > + spages = pages;
> > > + *pgbase = offset_in_page(buf);
> > > + p -= *pgbase;
> > > + while (p < buf + buflen) {
> > > + page = virt_to_page(p);
> > > + newpage = alloc_page(GFP_KERNEL);
> > > + if (!newpage)
> > > + goto unwind;
> > > + memcpy(page_address(newpage), page_address(page),
> > > + PAGE_CACHE_SIZE);
> >
> > Why do we need to keep this byzantian offset_in_page() and
> > virt_to_page() logic in order to copying data from a linear buffer into
> > a set of pages?
> >
> We don't I suppose, but I thought it best to follow the byzantine style of the
> function immediately above it. :) If you have a better suggestion, I'm
> listening.
Why isn't something like the following good enough?
do {
size_t len = min(PAGE_CACHE_SIZE, buflen);
struct page *newpage = alloc_page(GFP_KERNEL);
if (newpage == NULL)
goto unwind;
memcpy(page_address(newpage), buf, len);
copied += len;
buf += len;
buflen -= len;
} while (buflen != 0);
--
Trond Myklebust
Linux NFS client maintainer
NetApp
Trond.Myklebust@xxxxxxxxxx
www.netapp.com
--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
