Network Drop Monitor: Adding kfree_skb_clean for non-drops and modifying end-of-line points for skbs
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
include/linux/skbuff.h | 4 +++-
net/core/datagram.c | 2 +-
net/core/skbuff.c | 22 ++++++++++++++++++++++
net/ipv4/arp.c | 2 +-
net/ipv4/udp.c | 2 +-
net/packet/af_packet.c | 2 +-
6 files changed, 29 insertions(+), 5 deletions(-)
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 1f659e8..1fbab2a 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -421,6 +421,7 @@
#endif
extern void kfree_skb(struct sk_buff *skb);
+extern void consume_skb(struct sk_buff *skb);
extern void __kfree_skb(struct sk_buff *skb);
extern struct sk_buff *__alloc_skb(unsigned int size,
gfp_t priority, int fclone, int node);
@@ -459,7 +460,8 @@
extern int skb_cow_data(struct sk_buff *skb, int tailbits,
struct sk_buff **trailer);
extern int skb_pad(struct sk_buff *skb, int pad);
-#define dev_kfree_skb(a) kfree_skb(a)
+#define dev_kfree_skb(a) consume_skb(a)
+#define dev_consume_skb(a) kfree_skb_clean(a)
extern void skb_over_panic(struct sk_buff *skb, int len,
void *here);
extern void skb_under_panic(struct sk_buff *skb, int len,
diff --git a/net/core/datagram.c b/net/core/datagram.c
index 5e2ac0c..d0de644 100644
--- a/net/core/datagram.c
+++ b/net/core/datagram.c
@@ -208,7 +208,7 @@
void skb_free_datagram(struct sock *sk, struct sk_buff *skb)
{
- kfree_skb(skb);
+ consume_skb(skb);
sk_mem_reclaim_partial(sk);
}
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index e5e2111..6acbf9e 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -65,6 +65,7 @@
#include <asm/uaccess.h>
#include <asm/system.h>
+#include <trace/skb.h>
#include "kmap_skb.h"
@@ -442,11 +443,32 @@
smp_rmb();
else if (likely(!atomic_dec_and_test(&skb->users)))
return;
+ trace_kfree_skb(skb, __builtin_return_address(0));
__kfree_skb(skb);
}
EXPORT_SYMBOL(kfree_skb);
/**
+ * consume_skb - free an skbuff
+ * @skb: buffer to free
+ *
+ * Drop a ref to the buffer and free it if the usage count has hit zero
+ * Functions identically to kfree_skb, but kfree_skb assumes that the frame
+ * is being dropped after a failure and notes that
+ */
+void consume_skb(struct sk_buff *skb)
+{
+ if (unlikely(!skb))
+ return;
+ if (likely(atomic_read(&skb->users) == 1))
+ smp_rmb();
+ else if (likely(!atomic_dec_and_test(&skb->users)))
+ return;
+ __kfree_skb(skb);
+}
+EXPORT_SYMBOL(consume_skb);
+
+/**
* skb_recycle_check - check if skb can be reused for receive
* @skb: buffer
* @skb_size: minimum receive buffer size
diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
index 3d67d1ff..9c22032 100644
--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c
@@ -892,7 +892,7 @@
out:
if (in_dev)
in_dev_put(in_dev);
- kfree_skb(skb);
+ consume_skb(skb);
return 0;
}
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 4bd178a..05b7abb 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1184,7 +1184,7 @@
sk = sknext;
} while (sknext);
} else
- kfree_skb(skb);
+ consume_skb(skb);
spin_unlock(&hslot->lock);
return 0;
}
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index d8cc006..74776de 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -584,7 +584,7 @@
skb->len = skb_len;
}
drop:
- kfree_skb(skb);
+ consume_skb(skb);
return 0;
}
