Commit dda8e5d1 authored by Al Viro's avatar Al Viro
Browse files

iov_iter: first_{iovec,bvec}_segment() - simplify a bit 



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: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 599a0bdd

lib/iov_iter.c

+16 −16
Original line number Diff line number Diff line
@@ -1308,7 +1308,7 @@ static unsigned long first_iovec_segment(const struct iov_iter *i, 
			continue;

		if (len > maxsize)

			len = maxsize;

		len += (*start = addr % PAGE_SIZE);

		*start = addr % PAGE_SIZE;

		*size = len;

		return addr & PAGE_MASK;

	}
@@ -1328,7 +1328,7 @@ 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;

}
@@ -1357,24 +1357,24 @@ ssize_t iov_iter_get_pages(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;

		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 *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);

		while (n--)

		n = DIV_ROUND_UP(len + *start, PAGE_SIZE);

		if (n > maxpages)

			n = maxpages;

		for (int k = 0; k < n; k++)

			get_page(*pages++ = 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);
@@ -1489,7 +1489,7 @@ ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, 
			gup_flags |= FOLL_NOFAULT;



		addr = first_iovec_segment(i, &len, start, maxsize);

		n = DIV_ROUND_UP(len, PAGE_SIZE);

		n = DIV_ROUND_UP(len + *start, PAGE_SIZE);

		p = get_pages_array(n);

		if (!p)

			return -ENOMEM;
@@ -1500,19 +1500,19 @@ ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, 
			return res;

		}

		*pages = p;

		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 *page;



		page = first_bvec_segment(i, &len, start, maxsize);

		n = DIV_ROUND_UP(len, PAGE_SIZE);

		n = DIV_ROUND_UP(len + *start, PAGE_SIZE);

		*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_alloc(i, pages, maxsize, start);