From: Ilias Apalodimas <ilias.apalodi...@linaro.org>
This patch is changing struct sk_buff, and is thus per-definition
controversial.
Place a new member 'mem_info' of type struct xdp_mem_info, just after
members (flags) head_frag and pfmemalloc, And not in between
headers_start/end to ensure skb_copy() and pskb_copy() work as-is.
Copying mem_info during skb_clone() is required. This makes sure that
pages are correctly freed or recycled during the altered
skb_free_head() invocation.
The 'mem_info' name is chosen as this is not strictly tied to XDP,
although the XDP return infrastructure is used. As a future plan, we
could introduce a __u8 flags member to xdp_mem_info and move flags
head_frag and pfmemalloc into this area.
Signed-off-by: Ilias Apalodimas <ilias.apalodi...@linaro.org>
Signed-off-by: Jesper Dangaard Brouer <bro...@redhat.com>
---
include/linux/skbuff.h | 6 +++++-
include/net/xdp.h | 1 +
net/core/skbuff.c | 7 +++++++
net/core/xdp.c | 6 ++++++
4 files changed, 19 insertions(+), 1 deletion(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 7dcfb5591dc3..95dac0ba6947 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -40,6 +40,7 @@
#include <linux/in6.h>
#include <linux/if_packet.h>
#include <net/flow.h>
+#include <net/xdp.h>
/* The interface for checksum offload between the stack and networking drivers
* is as follows...
@@ -744,6 +745,10 @@ struct sk_buff {
head_frag:1,
xmit_more:1,
pfmemalloc:1;
+ /* TODO: Future idea, extend mem_info with __u8 flags, and
+ * move bits head_frag and pfmemalloc there.
+ */
+ struct xdp_mem_info mem_info;
/* fields enclosed in headers_start/headers_end are copied
* using a single memcpy() in __copy_skb_header()
@@ -827,7 +832,6 @@ struct sk_buff {
#ifdef CONFIG_NETWORK_SECMARK
__u32 secmark;
#endif
-
union {
__u32 mark;
__u32 reserved_tailroom;
diff --git a/include/net/xdp.h b/include/net/xdp.h
index 5c33b9e0efab..4a0ca7a3d5e5 100644
--- a/include/net/xdp.h
+++ b/include/net/xdp.h
@@ -128,6 +128,7 @@ struct xdp_frame *convert_to_xdp_frame(struct xdp_buff *xdp)
void xdp_return_frame(struct xdp_frame *xdpf);
void xdp_return_frame_rx_napi(struct xdp_frame *xdpf);
void xdp_return_buff(struct xdp_buff *xdp);
+void xdp_return_skb_page(void *data, struct xdp_mem_info *mem_info);
int xdp_rxq_info_reg(struct xdp_rxq_info *xdp_rxq,
struct net_device *dev, u32 queue_index);
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index b4ee5c8b928f..71aca186e44c 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -70,6 +70,7 @@
#include <net/checksum.h>
#include <net/ip6_checksum.h>
#include <net/xfrm.h>
+#include <net/page_pool.h>
#include <linux/uaccess.h>
#include <trace/events/skb.h>
@@ -544,6 +545,11 @@ static void skb_free_head(struct sk_buff *skb)
{
unsigned char *head = skb->head;
+ if (skb->mem_info.type == MEM_TYPE_PAGE_POOL) {
+ xdp_return_skb_page(head, &skb->mem_info);
+ return;
+ }
+
if (skb->head_frag)
skb_free_frag(head);
else
@@ -859,6 +865,7 @@ static struct sk_buff *__skb_clone(struct sk_buff *n,
struct sk_buff *skb)
n->nohdr = 0;
n->peeked = 0;
C(pfmemalloc);
+ C(mem_info);
n->destructor = NULL;
C(tail);
C(end);
diff --git a/net/core/xdp.c b/net/core/xdp.c
index e79526314864..1703be4c2611 100644
--- a/net/core/xdp.c
+++ b/net/core/xdp.c
@@ -379,6 +379,12 @@ void xdp_return_buff(struct xdp_buff *xdp)
}
EXPORT_SYMBOL_GPL(xdp_return_buff);
+void xdp_return_skb_page(void *data, struct xdp_mem_info *mem_info)
+{
+ __xdp_return(data, mem_info, false, 0);
+}
+EXPORT_SYMBOL(xdp_return_skb_page);
+
int xdp_attachment_query(struct xdp_attachment_info *info,
struct netdev_bpf *bpf)
{
