Commit 4ef67ebe authored by Jason Wang's avatar Jason Wang Committed by Michael S. Tsirkin
Browse files

macvtap: zerocopy: fix truesize underestimation 



As the skb fragment were pinned/built from user pages, we should
account the page instead of length for truesize.

Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 3afc9621

drivers/net/macvtap.c

+4 −2
Original line number Diff line number Diff line
@@ -519,6 +519,7 @@ static int zerocopy_sg_from_iovec(struct sk_buff *skb, const struct iovec *from, 
		struct page *page[MAX_SKB_FRAGS];

		int num_pages;

		unsigned long base;

		unsigned long truesize;



		len = from->iov_len - offset;

		if (!len) {
@@ -533,10 +534,11 @@ static int zerocopy_sg_from_iovec(struct sk_buff *skb, const struct iovec *from, 
		    (num_pages > MAX_SKB_FRAGS - skb_shinfo(skb)->nr_frags))

			/* put_page is in skb free */

			return -EFAULT;

		truesize = size * PAGE_SIZE;

		skb->data_len += len;

		skb->len += len;

		skb->truesize += len;

		atomic_add(len, &skb->sk->sk_wmem_alloc);

		skb->truesize += truesize;

		atomic_add(truesize, &skb->sk->sk_wmem_alloc);

		while (len) {

			int off = base & ~PAGE_MASK;

			int size = min_t(int, len, PAGE_SIZE - off);