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: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index bd4a70d8605f251eab702fed43cc8f1a6da5f246..7cb2684a8792f28b734cf0ef56e5b9719383b3f1 100644 (file)
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -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);