1 files changed, 18 insertions, 6 deletions

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 2342a7250391..effa75d0e318 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -245,6 +245,7 @@ EXPORT_SYMBOL(__alloc_skb);
 /**
  * build_skb - build a network buffer
  * @data: data buffer provided by caller
+ * @frag_size: size of fragment, or 0 if head was kmalloced
  *
  * Allocate a new &sk_buff. Caller provides space holding head and
  * skb_shared_info. @data must have been allocated by kmalloc()
@@ -258,20 +259,21 @@ EXPORT_SYMBOL(__alloc_skb);
  *  before giving packet to stack.
  *  RX rings only contains data buffers, not full skbs.
  */
-struct sk_buff *build_skb(void *data)
+struct sk_buff *build_skb(void *data, unsigned int frag_size)
 {
 	struct skb_shared_info *shinfo;
 	struct sk_buff *skb;
-	unsigned int size;
+	unsigned int size = frag_size ? : ksize(data);
 
 	skb = kmem_cache_alloc(skbuff_head_cache, GFP_ATOMIC);
 	if (!skb)
 		return NULL;
 
-	size = ksize(data) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+	size -= SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 
 	memset(skb, 0, offsetof(struct sk_buff, tail));
 	skb->truesize = SKB_TRUESIZE(size);
+	skb->head_frag = frag_size != 0;
 	atomic_set(&skb->users, 1);
 	skb->head = data;
 	skb->data = data;
@@ -376,6 +378,14 @@ static void skb_clone_fraglist(struct sk_buff *skb)
 		skb_get(list);
 }
 
+static void skb_free_head(struct sk_buff *skb)
+{
+	if (skb->head_frag)
+		put_page(virt_to_head_page(skb->head));
+	else
+		kfree(skb->head);
+}
+
 static void skb_release_data(struct sk_buff *skb)
 {
 	if (!skb->cloned ||
@@ -402,7 +412,7 @@ static void skb_release_data(struct sk_buff *skb)
 		if (skb_has_frag_list(skb))
 			skb_drop_fraglist(skb);
 
-		kfree(skb->head);
+		skb_free_head(skb);
 	}
 }
 
@@ -644,6 +654,7 @@ static struct sk_buff *__skb_clone(struct sk_buff *n, struct sk_buff *skb)
 	C(tail);
 	C(end);
 	C(head);
+	C(head_frag);
 	C(data);
 	C(truesize);
 	atomic_set(&n->users, 1);
@@ -940,7 +951,7 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail,
 		fastpath = atomic_read(&skb_shinfo(skb)->dataref) == delta;
 	}
 
-	if (fastpath &&
+	if (fastpath && !skb->head_frag &&
 	    size + sizeof(struct skb_shared_info) <= ksize(skb->head)) {
 		memmove(skb->head + size, skb_shinfo(skb),
 			offsetof(struct skb_shared_info,
@@ -967,7 +978,7 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail,
 	       offsetof(struct skb_shared_info, frags[skb_shinfo(skb)->nr_frags]));
 
 	if (fastpath) {
-		kfree(skb->head);
+		skb_free_head(skb);
 	} else {
 		/* copy this zero copy skb frags */
 		if (skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY) {
@@ -985,6 +996,7 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail,
 	off = (data + nhead) - skb->head;
 
 	skb->head     = data;
+	skb->head_frag = 0;
 adjust_others:
 	skb->data    += off;
 #ifdef NET_SKBUFF_DATA_USES_OFFSET