On Wed, 2022-06-22 at 05:15 +0100, Al Viro wrote:
> Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
> ---
> lib/iov_iter.c | 23 +++++++++++------------
> 1 file changed, 11 insertions(+), 12 deletions(-)
>
> diff --git a/lib/iov_iter.c b/lib/iov_iter.c
> index 92a566f839f9..9ef671b101dc 100644
> --- a/lib/iov_iter.c
> +++ b/lib/iov_iter.c
> @@ -1308,12 +1308,9 @@ static ssize_t iter_xarray_get_pages(struct iov_iter *i,
>
> static unsigned long found_ubuf_segment(unsigned long addr,
> size_t len,
> - size_t *size, size_t *start,
> - unsigned maxpages)
> + size_t *size, size_t *start)
> {
> len += (*start = addr % PAGE_SIZE);
> - if (len > maxpages * PAGE_SIZE)
> - len = maxpages * PAGE_SIZE;
> *size = len;
> return addr & PAGE_MASK;
> }
> @@ -1321,14 +1318,14 @@ static unsigned long found_ubuf_segment(unsigned long addr,
> /* must be done on non-empty ITER_UBUF or ITER_IOVEC one */
> static unsigned long first_iovec_segment(const struct iov_iter *i,
> size_t *size, size_t *start,
> - size_t maxsize, unsigned maxpages)
> + size_t maxsize)
> {
> size_t skip;
> long k;
>
> if (iter_is_ubuf(i)) {
> unsigned long addr = (unsigned long)i->ubuf + i->iov_offset;
> - return found_ubuf_segment(addr, maxsize, size, start, maxpages);
> + return found_ubuf_segment(addr, maxsize, size, start);
> }
>
> for (k = 0, skip = i->iov_offset; k < i->nr_segs; k++, skip = 0) {
> @@ -1339,7 +1336,7 @@ static unsigned long first_iovec_segment(const struct iov_iter *i,
> continue;
> if (len > maxsize)
> len = maxsize;
> - return found_ubuf_segment(addr, len, size, start, maxpages);
> + return found_ubuf_segment(addr, len, size, start);
> }
> BUG(); // if it had been empty, we wouldn't get called
> }
> @@ -1347,7 +1344,7 @@ static unsigned long first_iovec_segment(const struct iov_iter *i,
> /* must be done on non-empty ITER_BVEC one */
> static struct page *first_bvec_segment(const struct iov_iter *i,
> size_t *size, size_t *start,
> - size_t maxsize, unsigned maxpages)
> + size_t maxsize)
> {
> struct page *page;
> size_t skip = i->iov_offset, len;
> @@ -1358,8 +1355,6 @@ static struct page *first_bvec_segment(const struct iov_iter *i,
> skip += i->bvec->bv_offset;
> page = i->bvec->bv_page + skip / PAGE_SIZE;
> len += (*start = skip % PAGE_SIZE);
> - if (len > maxpages * PAGE_SIZE)
> - len = maxpages * PAGE_SIZE;
> *size = len;
> return page;
> }
> @@ -1387,7 +1382,9 @@ static ssize_t __iov_iter_get_pages_alloc(struct iov_iter *i,
> if (i->nofault)
> gup_flags |= FOLL_NOFAULT;
>
> - addr = first_iovec_segment(i, &len, start, maxsize, maxpages);
> + addr = first_iovec_segment(i, &len, start, maxsize);
> + if (len > maxpages * PAGE_SIZE)
> + len = maxpages * PAGE_SIZE;
> n = DIV_ROUND_UP(len, PAGE_SIZE);
> if (!*pages) {
> *pages = get_pages_array(n);
> @@ -1403,7 +1400,9 @@ static ssize_t __iov_iter_get_pages_alloc(struct iov_iter *i,
> struct page **p;
> struct page *page;
>
> - page = first_bvec_segment(i, &len, start, maxsize, maxpages);
> + page = first_bvec_segment(i, &len, start, maxsize);
> + if (len > maxpages * PAGE_SIZE)
> + len = maxpages * PAGE_SIZE;
> n = DIV_ROUND_UP(len, PAGE_SIZE);
> p = *pages;
> if (!p) {
Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
