iov_iter.c: convert copy_to_iter() to iterate_and_advance

	i->iov_offset = skip;					\

}

static size_t copy_to_iter_iovec(void *from, size_t bytes, struct iov_iter *i)

{

	size_t skip, copy, left, wanted;

	const struct iovec *iov;

	char __user *buf;

	if (unlikely(bytes > i->count))

		bytes = i->count;

	if (unlikely(!bytes))

		return 0;

	wanted = bytes;

	iov = i->iov;

	skip = i->iov_offset;

	buf = iov->iov_base + skip;

	copy = min(bytes, iov->iov_len - skip);

	left = __copy_to_user(buf, from, copy);

	copy -= left;

	skip += copy;

	from += copy;

	bytes -= copy;

	while (unlikely(!left && bytes)) {

		iov++;

		buf = iov->iov_base;

		copy = min(bytes, iov->iov_len);

		left = __copy_to_user(buf, from, copy);

		copy -= left;

		skip = copy;

		from += copy;

		bytes -= copy;

	}

	if (skip == iov->iov_len) {

		iov++;

		skip = 0;

	}

	i->count -= wanted - bytes;

	i->nr_segs -= iov - i->iov;

	i->iov = iov;

	i->iov_offset = skip;

	return wanted - bytes;

}

static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes,

			 struct iov_iter *i)

{

	kunmap_atomic(addr);

}

static size_t copy_to_iter_bvec(void *from, size_t bytes, struct iov_iter *i)

size_t copy_to_iter(void *addr, size_t bytes, struct iov_iter *i)

{

	size_t skip, copy, wanted;

	const struct bio_vec *bvec;

	char *from = addr;

	if (unlikely(bytes > i->count))

		bytes = i->count;

	if (unlikely(!bytes))

		return 0;

	wanted = bytes;

	bvec = i->bvec;

	skip = i->iov_offset;

	copy = min_t(size_t, bytes, bvec->bv_len - skip);

	memcpy_to_page(bvec->bv_page, skip + bvec->bv_offset, from, copy);

	skip += copy;

	from += copy;

	bytes -= copy;

	while (bytes) {

		bvec++;

		copy = min(bytes, (size_t)bvec->bv_len);

		memcpy_to_page(bvec->bv_page, bvec->bv_offset, from, copy);

		skip = copy;

		from += copy;

		bytes -= copy;

	}

	if (skip == bvec->bv_len) {

		bvec++;

		skip = 0;

	}

	i->count -= wanted - bytes;

	i->nr_segs -= bvec - i->bvec;

	i->bvec = bvec;

	i->iov_offset = skip;

	return wanted - bytes;

}

	iterate_and_advance(i, bytes, v,

		__copy_to_user(v.iov_base, (from += v.iov_len) - v.iov_len,

			       v.iov_len),

		memcpy_to_page(v.bv_page, v.bv_offset,

			       (from += v.bv_len) - v.bv_len, v.bv_len)

	)

size_t copy_to_iter(void *addr, size_t bytes, struct iov_iter *i)

{

	if (i->type & ITER_BVEC)

		return copy_to_iter_bvec(addr, bytes, i);

	else

		return copy_to_iter_iovec(addr, bytes, i);

	return bytes;

}

EXPORT_SYMBOL(copy_to_iter);