From 0fd7bac6b6157eed6cf0cb86a1e88ba29e57c033 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 21 Dec 2011 07:11:44 +0000 Subject: net: relax rcvbuf limits skb->truesize might be big even for a small packet. Its even bigger after commit 87fb4b7b533 (net: more accurate skb truesize) and big MTU. We should allow queueing at least one packet per receiver, even with a low RCVBUF setting. Reported-by: Michal Simek Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- include/net/sock.h | 4 +++- net/core/sock.c | 6 +----- net/packet/af_packet.c | 6 ++---- 3 files changed, 6 insertions(+), 10 deletions(-) diff --git a/include/net/sock.h b/include/net/sock.h index abb6e0f0c3c..32e39371fba 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -637,12 +637,14 @@ static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb) /* * Take into account size of receive queue and backlog queue + * Do not take into account this skb truesize, + * to allow even a single big packet to come. */ static inline bool sk_rcvqueues_full(const struct sock *sk, const struct sk_buff *skb) { unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc); - return qsize + skb->truesize > sk->sk_rcvbuf; + return qsize > sk->sk_rcvbuf; } /* The per-socket spinlock must be held here. */ diff --git a/net/core/sock.c b/net/core/sock.c index 4ed7b1d12f5..b23f174ab84 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -288,11 +288,7 @@ int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) unsigned long flags; struct sk_buff_head *list = &sk->sk_receive_queue; - /* Cast sk->rcvbuf to unsigned... It's pointless, but reduces - number of warnings when compiling with -W --ANK - */ - if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >= - (unsigned)sk->sk_rcvbuf) { + if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) { atomic_inc(&sk->sk_drops); trace_sock_rcvqueue_full(sk, skb); return -ENOMEM; diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 82a6f34d39d..3891702b81d 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -1630,8 +1630,7 @@ static int packet_rcv(struct sk_buff *skb, struct net_device *dev, if (snaplen > res) snaplen = res; - if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >= - (unsigned)sk->sk_rcvbuf) + if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) goto drop_n_acct; if (skb_shared(skb)) { @@ -1762,8 +1761,7 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, if (po->tp_version <= TPACKET_V2) { if (macoff + snaplen > po->rx_ring.frame_size) { if (po->copy_thresh && - atomic_read(&sk->sk_rmem_alloc) + skb->truesize - < (unsigned)sk->sk_rcvbuf) { + atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) { if (skb_shared(skb)) { copy_skb = skb_clone(skb, GFP_ATOMIC); } else { -- cgit v1.2.3