mpls_dev_get() uses rcu_dereference_rtnl() to fetch dev->mpls_ptr. We will replace RTNL with a dedicated mutex to protect the field. Then, we will use rcu_dereference_protected() for clarity. Let's add mpls_dev_rcu() for the RCU reader. Signed-off-by: Kuniyuki Iwashima --- net/mpls/af_mpls.c | 12 ++++++------ net/mpls/internal.h | 5 +++++ net/mpls/mpls_iptunnel.c | 2 +- 3 files changed, 12 insertions(+), 7 deletions(-) diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c index efc6c7da5766..10130b90c439 100644 --- a/net/mpls/af_mpls.c +++ b/net/mpls/af_mpls.c @@ -136,7 +136,7 @@ void mpls_stats_inc_outucastpkts(struct net *net, struct mpls_dev *mdev; if (skb->protocol == htons(ETH_P_MPLS_UC)) { - mdev = mpls_dev_get(dev); + mdev = mpls_dev_rcu(dev); if (mdev) MPLS_INC_STATS_LEN(mdev, skb->len, tx_packets, @@ -358,7 +358,7 @@ static int mpls_forward(struct sk_buff *skb, struct net_device *dev, /* Careful this entire function runs inside of an rcu critical section */ - mdev = mpls_dev_get(dev); + mdev = mpls_dev_rcu(dev); if (!mdev) goto drop; @@ -467,7 +467,7 @@ static int mpls_forward(struct sk_buff *skb, struct net_device *dev, return 0; tx_err: - out_mdev = out_dev ? mpls_dev_get(out_dev) : NULL; + out_mdev = out_dev ? mpls_dev_rcu(out_dev) : NULL; if (out_mdev) MPLS_INC_STATS(out_mdev, tx_errors); goto drop; @@ -1118,7 +1118,7 @@ static int mpls_fill_stats_af(struct sk_buff *skb, struct mpls_dev *mdev; struct nlattr *nla; - mdev = mpls_dev_get(dev); + mdev = mpls_dev_rcu(dev); if (!mdev) return -ENODATA; @@ -1138,7 +1138,7 @@ static size_t mpls_get_stats_af_size(const struct net_device *dev) { struct mpls_dev *mdev; - mdev = mpls_dev_get(dev); + mdev = mpls_dev_rcu(dev); if (!mdev) return 0; @@ -1341,7 +1341,7 @@ static int mpls_netconf_dump_devconf(struct sk_buff *skb, rcu_read_lock(); for_each_netdev_dump(net, dev, ctx->ifindex) { - mdev = mpls_dev_get(dev); + mdev = mpls_dev_rcu(dev); if (!mdev) continue; err = mpls_netconf_fill_devconf(skb, mdev, diff --git a/net/mpls/internal.h b/net/mpls/internal.h index e491427ea08a..080e82010022 100644 --- a/net/mpls/internal.h +++ b/net/mpls/internal.h @@ -185,6 +185,11 @@ static inline struct mpls_entry_decoded mpls_entry_decode(struct mpls_shim_hdr * return result; } +static inline struct mpls_dev *mpls_dev_rcu(const struct net_device *dev) +{ + return rcu_dereference(dev->mpls_ptr); +} + static inline struct mpls_dev *mpls_dev_get(const struct net_device *dev) { return rcu_dereference_rtnl(dev->mpls_ptr); diff --git a/net/mpls/mpls_iptunnel.c b/net/mpls/mpls_iptunnel.c index cfbab7b2fec7..1a1a0eb5b787 100644 --- a/net/mpls/mpls_iptunnel.c +++ b/net/mpls/mpls_iptunnel.c @@ -153,7 +153,7 @@ static int mpls_xmit(struct sk_buff *skb) return LWTUNNEL_XMIT_DONE; drop: - out_mdev = out_dev ? mpls_dev_get(out_dev) : NULL; + out_mdev = out_dev ? mpls_dev_rcu(out_dev) : NULL; if (out_mdev) MPLS_INC_STATS(out_mdev, tx_errors); kfree_skb(skb); -- 2.51.1.851.g4ebd6896fd-goog