On Wed, 2022-06-22 at 05:15 +0100, Al Viro wrote:
> We return length + offset in page via *size. Don't bother - the caller
> can do that arithmetics just as well; just report the length to it.
>
> Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
> ---
> lib/iov_iter.c | 22 +++++++++++-----------
> 1 file changed, 11 insertions(+), 11 deletions(-)
>
> diff --git a/lib/iov_iter.c b/lib/iov_iter.c
> index 9ef671b101dc..0bed684d91d0 100644
> --- a/lib/iov_iter.c
> +++ b/lib/iov_iter.c
> @@ -1310,7 +1310,7 @@ static unsigned long found_ubuf_segment(unsigned long addr,
> size_t len,
> size_t *size, size_t *start)
> {
> - len += (*start = addr % PAGE_SIZE);
> + *start = addr % PAGE_SIZE;
> *size = len;
> return addr & PAGE_MASK;
> }
> @@ -1354,7 +1354,7 @@ static struct page *first_bvec_segment(const struct iov_iter *i,
> len = maxsize;
> skip += i->bvec->bv_offset;
> page = i->bvec->bv_page + skip / PAGE_SIZE;
> - len += (*start = skip % PAGE_SIZE);
> + *start = skip % PAGE_SIZE;
> *size = len;
> return page;
> }
> @@ -1383,9 +1383,9 @@ static ssize_t __iov_iter_get_pages_alloc(struct iov_iter *i,
> gup_flags |= FOLL_NOFAULT;
>
> addr = first_iovec_segment(i, &len, start, maxsize);
> - if (len > maxpages * PAGE_SIZE)
> - len = maxpages * PAGE_SIZE;
> - n = DIV_ROUND_UP(len, PAGE_SIZE);
> + n = DIV_ROUND_UP(len + *start, PAGE_SIZE);
> + if (n > maxpages)
> + n = maxpages;
> if (!*pages) {
> *pages = get_pages_array(n);
> if (!*pages)
> @@ -1394,25 +1394,25 @@ static ssize_t __iov_iter_get_pages_alloc(struct iov_iter *i,
> res = get_user_pages_fast(addr, n, gup_flags, *pages);
> if (unlikely(res <= 0))
> return res;
> - return (res == n ? len : res * PAGE_SIZE) - *start;
> + return min_t(size_t, len, res * PAGE_SIZE - *start);
> }
> if (iov_iter_is_bvec(i)) {
> struct page **p;
> struct page *page;
>
> page = first_bvec_segment(i, &len, start, maxsize);
> - if (len > maxpages * PAGE_SIZE)
> - len = maxpages * PAGE_SIZE;
> - n = DIV_ROUND_UP(len, PAGE_SIZE);
> + n = DIV_ROUND_UP(len + *start, PAGE_SIZE);
> + if (n > maxpages)
> + n = maxpages;
> p = *pages;
> if (!p) {
> *pages = p = get_pages_array(n);
> if (!p)
> return -ENOMEM;
> }
> - while (n--)
> + for (int k = 0; k < n; k++)
> get_page(*p++ = page++);
> - return len - *start;
> + return min_t(size_t, len, n * PAGE_SIZE - *start);
> }
> if (iov_iter_is_pipe(i))
> return pipe_get_pages(i, pages, maxsize, maxpages, start);
Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
