From: James Chapman Date: Sun, 29 Apr 2012 21:48:46 +0000 (+0000) Subject: l2tp: fix locking of 64-bit counters for smp X-Git-Tag: next-20120503~56^2~12 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=5de7aee5413cdfe6f96289a84a5ad22b1314e873;p=karo-tx-linux.git l2tp: fix locking of 64-bit counters for smp L2TP uses 64-bit counters but since these are not updated atomically, we need to make them safe for smp. This patch addresses that. Signed-off-by: James Chapman Signed-off-by: David S. Miller --- diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c index 0ca9bc39150f..f1bfae3e1ba6 100644 --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -330,8 +330,10 @@ static void l2tp_recv_queue_skb(struct l2tp_session *session, struct sk_buff *sk struct sk_buff *skbp; struct sk_buff *tmp; u32 ns = L2TP_SKB_CB(skb)->ns; + struct l2tp_stats *sstats; spin_lock_bh(&session->reorder_q.lock); + sstats = &session->stats; skb_queue_walk_safe(&session->reorder_q, skbp, tmp) { if (L2TP_SKB_CB(skbp)->ns > ns) { __skb_queue_before(&session->reorder_q, skbp, skb); @@ -339,7 +341,9 @@ static void l2tp_recv_queue_skb(struct l2tp_session *session, struct sk_buff *sk "%s: pkt %hu, inserted before %hu, reorder_q len=%d\n", session->name, ns, L2TP_SKB_CB(skbp)->ns, skb_queue_len(&session->reorder_q)); - session->stats.rx_oos_packets++; + u64_stats_update_begin(&sstats->syncp); + sstats->rx_oos_packets++; + u64_stats_update_end(&sstats->syncp); goto out; } } @@ -356,16 +360,23 @@ static void l2tp_recv_dequeue_skb(struct l2tp_session *session, struct sk_buff * { struct l2tp_tunnel *tunnel = session->tunnel; int length = L2TP_SKB_CB(skb)->length; + struct l2tp_stats *tstats, *sstats; /* We're about to requeue the skb, so return resources * to its current owner (a socket receive buffer). */ skb_orphan(skb); - tunnel->stats.rx_packets++; - tunnel->stats.rx_bytes += length; - session->stats.rx_packets++; - session->stats.rx_bytes += length; + tstats = &tunnel->stats; + u64_stats_update_begin(&tstats->syncp); + sstats = &session->stats; + u64_stats_update_begin(&sstats->syncp); + tstats->rx_packets++; + tstats->rx_bytes += length; + sstats->rx_packets++; + sstats->rx_bytes += length; + u64_stats_update_end(&tstats->syncp); + u64_stats_update_end(&sstats->syncp); if (L2TP_SKB_CB(skb)->has_seq) { /* Bump our Nr */ @@ -396,6 +407,7 @@ static void l2tp_recv_dequeue(struct l2tp_session *session) { struct sk_buff *skb; struct sk_buff *tmp; + struct l2tp_stats *sstats; /* If the pkt at the head of the queue has the nr that we * expect to send up next, dequeue it and any other @@ -403,10 +415,13 @@ static void l2tp_recv_dequeue(struct l2tp_session *session) */ start: spin_lock_bh(&session->reorder_q.lock); + sstats = &session->stats; skb_queue_walk_safe(&session->reorder_q, skb, tmp) { if (time_after(jiffies, L2TP_SKB_CB(skb)->expires)) { - session->stats.rx_seq_discards++; - session->stats.rx_errors++; + u64_stats_update_begin(&sstats->syncp); + sstats->rx_seq_discards++; + sstats->rx_errors++; + u64_stats_update_end(&sstats->syncp); PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, "%s: oos pkt %u len %d discarded (too old), " "waiting for %u, reorder_q_len=%d\n", @@ -558,6 +573,7 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, struct l2tp_tunnel *tunnel = session->tunnel; int offset; u32 ns, nr; + struct l2tp_stats *sstats = &session->stats; /* The ref count is increased since we now hold a pointer to * the session. Take care to decrement the refcnt when exiting @@ -573,7 +589,9 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, PRINTK(tunnel->debug, L2TP_MSG_DATA, KERN_INFO, "%s: cookie mismatch (%u/%u). Discarding.\n", tunnel->name, tunnel->tunnel_id, session->session_id); - session->stats.rx_cookie_discards++; + u64_stats_update_begin(&sstats->syncp); + sstats->rx_cookie_discards++; + u64_stats_update_end(&sstats->syncp); goto discard; } ptr += session->peer_cookie_len; @@ -642,7 +660,9 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, PRINTK(session->debug, L2TP_MSG_SEQ, KERN_WARNING, "%s: recv data has no seq numbers when required. " "Discarding\n", session->name); - session->stats.rx_seq_discards++; + u64_stats_update_begin(&sstats->syncp); + sstats->rx_seq_discards++; + u64_stats_update_end(&sstats->syncp); goto discard; } @@ -661,7 +681,9 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, PRINTK(session->debug, L2TP_MSG_SEQ, KERN_WARNING, "%s: recv data has no seq numbers when required. " "Discarding\n", session->name); - session->stats.rx_seq_discards++; + u64_stats_update_begin(&sstats->syncp); + sstats->rx_seq_discards++; + u64_stats_update_end(&sstats->syncp); goto discard; } } @@ -715,7 +737,9 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, * packets */ if (L2TP_SKB_CB(skb)->ns != session->nr) { - session->stats.rx_seq_discards++; + u64_stats_update_begin(&sstats->syncp); + sstats->rx_seq_discards++; + u64_stats_update_end(&sstats->syncp); PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, "%s: oos pkt %u len %d discarded, " "waiting for %u, reorder_q_len=%d\n", @@ -742,7 +766,9 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, return; discard: - session->stats.rx_errors++; + u64_stats_update_begin(&sstats->syncp); + sstats->rx_errors++; + u64_stats_update_end(&sstats->syncp); kfree_skb(skb); if (session->deref) @@ -768,6 +794,7 @@ static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb, int offset; u16 version; int length; + struct l2tp_stats *tstats; if (tunnel->sock && l2tp_verify_udp_checksum(tunnel->sock, skb)) goto discard_bad_csum; @@ -860,7 +887,10 @@ static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb, discard_bad_csum: LIMIT_NETDEBUG("%s: UDP: bad checksum\n", tunnel->name); UDP_INC_STATS_USER(tunnel->l2tp_net, UDP_MIB_INERRORS, 0); - tunnel->stats.rx_errors++; + tstats = &tunnel->stats; + u64_stats_update_begin(&tstats->syncp); + tstats->rx_errors++; + u64_stats_update_end(&tstats->syncp); kfree_skb(skb); return 0; @@ -986,6 +1016,7 @@ static int l2tp_xmit_core(struct l2tp_session *session, struct sk_buff *skb, struct l2tp_tunnel *tunnel = session->tunnel; unsigned int len = skb->len; int error; + struct l2tp_stats *tstats, *sstats; /* Debug */ if (session->send_seq) @@ -1022,15 +1053,21 @@ static int l2tp_xmit_core(struct l2tp_session *session, struct sk_buff *skb, error = ip_queue_xmit(skb, fl); /* Update stats */ + tstats = &tunnel->stats; + u64_stats_update_begin(&tstats->syncp); + sstats = &session->stats; + u64_stats_update_begin(&sstats->syncp); if (error >= 0) { - tunnel->stats.tx_packets++; - tunnel->stats.tx_bytes += len; - session->stats.tx_packets++; - session->stats.tx_bytes += len; + tstats->tx_packets++; + tstats->tx_bytes += len; + sstats->tx_packets++; + sstats->tx_bytes += len; } else { - tunnel->stats.tx_errors++; - session->stats.tx_errors++; + tstats->tx_errors++; + sstats->tx_errors++; } + u64_stats_update_end(&tstats->syncp); + u64_stats_update_end(&sstats->syncp); return 0; } diff --git a/net/l2tp/l2tp_core.h b/net/l2tp/l2tp_core.h index 09e4a38b4f43..a8c943bf4140 100644 --- a/net/l2tp/l2tp_core.h +++ b/net/l2tp/l2tp_core.h @@ -45,6 +45,7 @@ struct l2tp_stats { u64 rx_oos_packets; u64 rx_errors; u64 rx_cookie_discards; + struct u64_stats_sync syncp; }; struct l2tp_tunnel; diff --git a/net/l2tp/l2tp_netlink.c b/net/l2tp/l2tp_netlink.c index bc8c3348f835..1dbb9772fc45 100644 --- a/net/l2tp/l2tp_netlink.c +++ b/net/l2tp/l2tp_netlink.c @@ -225,6 +225,8 @@ static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 pid, u32 seq, int flags, struct nlattr *nest; struct sock *sk = NULL; struct inet_sock *inet; + struct l2tp_stats stats; + unsigned int start; hdr = genlmsg_put(skb, pid, seq, &l2tp_nl_family, flags, L2TP_CMD_TUNNEL_GET); @@ -242,16 +244,28 @@ static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 pid, u32 seq, int flags, if (nest == NULL) goto nla_put_failure; - if (nla_put_u64(skb, L2TP_ATTR_TX_PACKETS, tunnel->stats.tx_packets) || - nla_put_u64(skb, L2TP_ATTR_TX_BYTES, tunnel->stats.tx_bytes) || - nla_put_u64(skb, L2TP_ATTR_TX_ERRORS, tunnel->stats.tx_errors) || - nla_put_u64(skb, L2TP_ATTR_RX_PACKETS, tunnel->stats.rx_packets) || - nla_put_u64(skb, L2TP_ATTR_RX_BYTES, tunnel->stats.rx_bytes) || + do { + start = u64_stats_fetch_begin(&tunnel->stats.syncp); + stats.tx_packets = tunnel->stats.tx_packets; + stats.tx_bytes = tunnel->stats.tx_bytes; + stats.tx_errors = tunnel->stats.tx_errors; + stats.rx_packets = tunnel->stats.rx_packets; + stats.rx_bytes = tunnel->stats.rx_bytes; + stats.rx_errors = tunnel->stats.rx_errors; + stats.rx_seq_discards = tunnel->stats.rx_seq_discards; + stats.rx_oos_packets = tunnel->stats.rx_oos_packets; + } while (u64_stats_fetch_retry(&tunnel->stats.syncp, start)); + + if (nla_put_u64(skb, L2TP_ATTR_TX_PACKETS, stats.tx_packets) || + nla_put_u64(skb, L2TP_ATTR_TX_BYTES, stats.tx_bytes) || + nla_put_u64(skb, L2TP_ATTR_TX_ERRORS, stats.tx_errors) || + nla_put_u64(skb, L2TP_ATTR_RX_PACKETS, stats.rx_packets) || + nla_put_u64(skb, L2TP_ATTR_RX_BYTES, stats.rx_bytes) || nla_put_u64(skb, L2TP_ATTR_RX_SEQ_DISCARDS, - tunnel->stats.rx_seq_discards) || + stats.rx_seq_discards) || nla_put_u64(skb, L2TP_ATTR_RX_OOS_PACKETS, - tunnel->stats.rx_oos_packets) || - nla_put_u64(skb, L2TP_ATTR_RX_ERRORS, tunnel->stats.rx_errors)) + stats.rx_oos_packets) || + nla_put_u64(skb, L2TP_ATTR_RX_ERRORS, stats.rx_errors)) goto nla_put_failure; nla_nest_end(skb, nest); @@ -563,6 +577,8 @@ static int l2tp_nl_session_send(struct sk_buff *skb, u32 pid, u32 seq, int flags struct nlattr *nest; struct l2tp_tunnel *tunnel = session->tunnel; struct sock *sk = NULL; + struct l2tp_stats stats; + unsigned int start; sk = tunnel->sock; @@ -600,19 +616,33 @@ static int l2tp_nl_session_send(struct sk_buff *skb, u32 pid, u32 seq, int flags (session->reorder_timeout && nla_put_msecs(skb, L2TP_ATTR_RECV_TIMEOUT, session->reorder_timeout))) goto nla_put_failure; + nest = nla_nest_start(skb, L2TP_ATTR_STATS); if (nest == NULL) goto nla_put_failure; - if (nla_put_u64(skb, L2TP_ATTR_TX_PACKETS, session->stats.tx_packets) || - nla_put_u64(skb, L2TP_ATTR_TX_BYTES, session->stats.tx_bytes) || - nla_put_u64(skb, L2TP_ATTR_TX_ERRORS, session->stats.tx_errors) || - nla_put_u64(skb, L2TP_ATTR_RX_PACKETS, session->stats.rx_packets) || - nla_put_u64(skb, L2TP_ATTR_RX_BYTES, session->stats.rx_bytes) || + + do { + start = u64_stats_fetch_begin(&session->stats.syncp); + stats.tx_packets = session->stats.tx_packets; + stats.tx_bytes = session->stats.tx_bytes; + stats.tx_errors = session->stats.tx_errors; + stats.rx_packets = session->stats.rx_packets; + stats.rx_bytes = session->stats.rx_bytes; + stats.rx_errors = session->stats.rx_errors; + stats.rx_seq_discards = session->stats.rx_seq_discards; + stats.rx_oos_packets = session->stats.rx_oos_packets; + } while (u64_stats_fetch_retry(&session->stats.syncp, start)); + + if (nla_put_u64(skb, L2TP_ATTR_TX_PACKETS, stats.tx_packets) || + nla_put_u64(skb, L2TP_ATTR_TX_BYTES, stats.tx_bytes) || + nla_put_u64(skb, L2TP_ATTR_TX_ERRORS, stats.tx_errors) || + nla_put_u64(skb, L2TP_ATTR_RX_PACKETS, stats.rx_packets) || + nla_put_u64(skb, L2TP_ATTR_RX_BYTES, stats.rx_bytes) || nla_put_u64(skb, L2TP_ATTR_RX_SEQ_DISCARDS, - session->stats.rx_seq_discards) || + stats.rx_seq_discards) || nla_put_u64(skb, L2TP_ATTR_RX_OOS_PACKETS, - session->stats.rx_oos_packets) || - nla_put_u64(skb, L2TP_ATTR_RX_ERRORS, session->stats.rx_errors)) + stats.rx_oos_packets) || + nla_put_u64(skb, L2TP_ATTR_RX_ERRORS, stats.rx_errors)) goto nla_put_failure; nla_nest_end(skb, nest);