From ead2ceb0ec9f85cff19c43b5cdb2f8a054484431 Mon Sep 17 00:00:00 2001 From: Neil Horman Date: Wed, 11 Mar 2009 09:49:55 +0000 Subject: [PATCH] Network Drop Monitor: Adding kfree_skb_clean for non-drops and modifying end-of-line points for skbs Signed-off-by: Neil Horman 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 --- 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(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 1f659e8c2b88..1fbab2ae613c 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -421,6 +421,7 @@ extern void skb_dma_unmap(struct device *dev, struct sk_buff *skb, #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_to_sgvec(struct sk_buff *skb, 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 5e2ac0c4b07c..d0de644b378d 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -208,7 +208,7 @@ struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags, 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 e5e2111a397d..6acbf9e79eb1 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -65,6 +65,7 @@ #include #include +#include #include "kmap_skb.h" @@ -442,10 +443,31 @@ void kfree_skb(struct sk_buff *skb) 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 diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c index 3d67d1ffed77..9c220323f353 100644 --- a/net/ipv4/arp.c +++ b/net/ipv4/arp.c @@ -892,7 +892,7 @@ static int arp_process(struct sk_buff *skb) 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 4bd178a111d5..05b7abb99f69 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1184,7 +1184,7 @@ static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb, 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 d8cc006fac45..74776de523ec 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -584,7 +584,7 @@ drop_n_restore: skb->len = skb_len; } drop: - kfree_skb(skb); + consume_skb(skb); return 0; } -- 2.30.2