Sometimes we need to coalesce the rx frags to avoid frag list. One example is
virtio-net driver which tries to use small frags for both MTU sized packet and
GSO packet. So this patch introduce skb_coalesce_rx_frag() to do this.
Cc: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
Cc: Michael S. Tsirkin <mst@xxxxxxxxxx>
Cc: Michael Dalton <mwdalton@xxxxxxxxxx>
Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
---
Changes from V2:
- remove the skb_frag_unref() and let the called to put the page reference
Changes from V1:
- remove the useless off parameter.
---
include/linux/skbuff.h | 3 +++
net/core/skbuff.c | 12 ++++++++++++
2 files changed, 15 insertions(+)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 2c15497..fffaeaf 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -1372,6 +1372,9 @@ static inline void skb_fill_page_desc(struct sk_buff *skb, int i,
void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, int off,
int size, unsigned int truesize);
+void skb_coalesce_rx_frag(struct sk_buff *skb, int i, int size,
+ unsigned int truesize);
+
#define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
#define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frag_list(skb))
#define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 0ab32fa..a729b97 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -476,6 +476,18 @@ void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, int off,
}
EXPORT_SYMBOL(skb_add_rx_frag);
+void skb_coalesce_rx_frag(struct sk_buff *skb, int i, int size,
+ unsigned int truesize)
+{
+ skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
+
+ skb_frag_size_add(frag, size);
+ skb->len += size;
+ skb->data_len += size;
+ skb->truesize += truesize;
+}
+EXPORT_SYMBOL(skb_coalesce_rx_frag);
+
static void skb_drop_list(struct sk_buff **listp)
{
kfree_skb_list(*listp);
--
1.8.1.2
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