diff options
| -rw-r--r-- | net/sched/act_mirred.c | 78 |
1 files changed, 51 insertions, 27 deletions
diff --git a/net/sched/act_mirred.c b/net/sched/act_mirred.c index 7a045cc7fe3b..327be257033d 100644 --- a/net/sched/act_mirred.c +++ b/net/sched/act_mirred.c @@ -30,6 +30,7 @@ #include <net/tc_act/tc_mirred.h> static LIST_HEAD(mirred_list); +static DEFINE_SPINLOCK(mirred_list_lock); static bool tcf_mirred_is_act_redirect(int action) { @@ -62,13 +63,23 @@ static bool tcf_mirred_can_reinsert(int action) return false; } +static struct net_device *tcf_mirred_dev_dereference(struct tcf_mirred *m) +{ + return rcu_dereference_protected(m->tcfm_dev, + lockdep_is_held(&m->tcf_lock)); +} + static void tcf_mirred_release(struct tc_action *a) { struct tcf_mirred *m = to_mirred(a); struct net_device *dev; + spin_lock(&mirred_list_lock); list_del(&m->tcfm_list); - dev = rtnl_dereference(m->tcfm_dev); + spin_unlock(&mirred_list_lock); + + /* last reference to action, no need to lock */ + dev = rcu_dereference_protected(m->tcfm_dev, 1); if (dev) dev_put(dev); } @@ -128,22 +139,9 @@ static int tcf_mirred_init(struct net *net, struct nlattr *nla, NL_SET_ERR_MSG_MOD(extack, "Unknown mirred option"); return -EINVAL; } - if (parm->ifindex) { - dev = __dev_get_by_index(net, parm->ifindex); - if (dev == NULL) { - if (exists) - tcf_idr_release(*a, bind); - else - tcf_idr_cleanup(tn, parm->index); - return -ENODEV; - } - mac_header_xmit = dev_is_mac_header_xmit(dev); - } else { - dev = NULL; - } if (!exists) { - if (!dev) { + if (!parm->ifindex) { tcf_idr_cleanup(tn, parm->index); NL_SET_ERR_MSG_MOD(extack, "Specified device does not exist"); return -EINVAL; @@ -161,19 +159,31 @@ static int tcf_mirred_init(struct net *net, struct nlattr *nla, } m = to_mirred(*a); - ASSERT_RTNL(); + spin_lock(&m->tcf_lock); m->tcf_action = parm->action; m->tcfm_eaction = parm->eaction; - if (dev != NULL) { - if (ret != ACT_P_CREATED) - dev_put(rcu_dereference_protected(m->tcfm_dev, 1)); - dev_hold(dev); - rcu_assign_pointer(m->tcfm_dev, dev); + + if (parm->ifindex) { + dev = dev_get_by_index(net, parm->ifindex); + if (!dev) { + spin_unlock(&m->tcf_lock); + tcf_idr_release(*a, bind); + return -ENODEV; + } + mac_header_xmit = dev_is_mac_header_xmit(dev); + rcu_swap_protected(m->tcfm_dev, dev, + lockdep_is_held(&m->tcf_lock)); + if (dev) + dev_put(dev); m->tcfm_mac_header_xmit = mac_header_xmit; } + spin_unlock(&m->tcf_lock); if (ret == ACT_P_CREATED) { + spin_lock(&mirred_list_lock); list_add(&m->tcfm_list, &mirred_list); + spin_unlock(&mirred_list_lock); + tcf_idr_insert(tn, *a); } @@ -287,26 +297,33 @@ static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind, { unsigned char *b = skb_tail_pointer(skb); struct tcf_mirred *m = to_mirred(a); - struct net_device *dev = rtnl_dereference(m->tcfm_dev); struct tc_mirred opt = { .index = m->tcf_index, - .action = m->tcf_action, .refcnt = refcount_read(&m->tcf_refcnt) - ref, .bindcnt = atomic_read(&m->tcf_bindcnt) - bind, - .eaction = m->tcfm_eaction, - .ifindex = dev ? dev->ifindex : 0, }; + struct net_device *dev; struct tcf_t t; + spin_lock(&m->tcf_lock); + opt.action = m->tcf_action; + opt.eaction = m->tcfm_eaction; + dev = tcf_mirred_dev_dereference(m); + if (dev) + opt.ifindex = dev->ifindex; + if (nla_put(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt)) goto nla_put_failure; tcf_tm_dump(&t, &m->tcf_tm); if (nla_put_64bit(skb, TCA_MIRRED_TM, sizeof(t), &t, TCA_MIRRED_PAD)) goto nla_put_failure; + spin_unlock(&m->tcf_lock); + return skb->len; nla_put_failure: + spin_unlock(&m->tcf_lock); nlmsg_trim(skb, b); return -1; } @@ -337,15 +354,19 @@ static int mirred_device_event(struct notifier_block *unused, ASSERT_RTNL(); if (event == NETDEV_UNREGISTER) { + spin_lock(&mirred_list_lock); list_for_each_entry(m, &mirred_list, tcfm_list) { - if (rcu_access_pointer(m->tcfm_dev) == dev) { + spin_lock(&m->tcf_lock); + if (tcf_mirred_dev_dereference(m) == dev) { dev_put(dev); /* Note : no rcu grace period necessary, as * net_device are already rcu protected. */ RCU_INIT_POINTER(m->tcfm_dev, NULL); } + spin_unlock(&m->tcf_lock); } + spin_unlock(&mirred_list_lock); } return NOTIFY_DONE; @@ -358,10 +379,13 @@ static struct notifier_block mirred_device_notifier = { static struct net_device *tcf_mirred_get_dev(const struct tc_action *a) { struct tcf_mirred *m = to_mirred(a); - struct net_device *dev = rtnl_dereference(m->tcfm_dev); + struct net_device *dev; + rcu_read_lock(); + dev = rcu_dereference(m->tcfm_dev); if (dev) dev_hold(dev); + rcu_read_unlock(); return dev; } |