skbuff: clear tx zero-copy flag

This patch clears tx zero-copy flag as needed.
Signed-off-by: Shirley Ma <xma@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core/skbuff.c

@@ -677,6 +677,7 @@ struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t gfp_mask)
 	if (skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY) {
 		if (skb_copy_ubufs(skb, gfp_mask))
 			return NULL;
+		skb_shinfo(skb)->tx_flags &= ~SKBTX_DEV_ZEROCOPY;
 	}
 
 	n = skb + 1;
@@ -801,6 +802,7 @@ struct sk_buff *pskb_copy(struct sk_buff *skb, gfp_t gfp_mask)
 				kfree(n);
 				goto out;
 			}
+			skb_shinfo(skb)->tx_flags &= ~SKBTX_DEV_ZEROCOPY;
 		}
 		for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
 			skb_shinfo(n)->frags[i] = skb_shinfo(skb)->frags[i];
@@ -893,6 +895,7 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail,
 		if (skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY) {
 			if (skb_copy_ubufs(skb, gfp_mask))
 				goto nofrags;
+			skb_shinfo(skb)->tx_flags &= ~SKBTX_DEV_ZEROCOPY;
 		}
 		for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
 			get_page(skb_shinfo(skb)->frags[i].page);