Some places walk the services under mutex but they can just use RCU: * ip_vs_dst_event() uses ip_vs_forget_dev() which uses its own lock to modify dest * ip_vs_genl_dump_services(): ip_vs_genl_fill_service() just fills skb * ip_vs_genl_parse_service(): move RCU lock to callers ip_vs_genl_set_cmd(), ip_vs_genl_dump_dests() and ip_vs_genl_get_cmd() * ip_vs_genl_dump_dests(): just fill skb Signed-off-by: Julian Anastasov <ja@xxxxxx> --- net/netfilter/ipvs/ip_vs_ctl.c | 47 +++++++++++++++++----------------- 1 file changed, 23 insertions(+), 24 deletions(-) diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c index 071106b08ae1..73c66b5d89a6 100644 --- a/net/netfilter/ipvs/ip_vs_ctl.c +++ b/net/netfilter/ipvs/ip_vs_ctl.c @@ -1758,23 +1758,21 @@ static int ip_vs_dst_event(struct notifier_block *this, unsigned long event, if (event != NETDEV_DOWN || !ipvs) return NOTIFY_DONE; IP_VS_DBG(3, "%s() dev=%s\n", __func__, dev->name); - mutex_lock(&ipvs->service_mutex); + rcu_read_lock(); for (idx = 0; idx < IP_VS_SVC_TAB_SIZE; idx++) { - hlist_for_each_entry(svc, &ipvs->svc_table[idx], s_list) { - list_for_each_entry(dest, &svc->destinations, - n_list) { + hlist_for_each_entry_rcu(svc, &ipvs->svc_table[idx], s_list) + list_for_each_entry_rcu(dest, &svc->destinations, + n_list) ip_vs_forget_dev(dest, dev); - } - } - hlist_for_each_entry(svc, &ipvs->svc_fwm_table[idx], f_list) { - list_for_each_entry(dest, &svc->destinations, - n_list) { + hlist_for_each_entry_rcu(svc, &ipvs->svc_fwm_table[idx], f_list) + list_for_each_entry_rcu(dest, &svc->destinations, + n_list) ip_vs_forget_dev(dest, dev); - } - } } + rcu_read_unlock(); + mutex_lock(&ipvs->service_mutex); spin_lock_bh(&ipvs->dest_trash_lock); list_for_each_entry(dest, &ipvs->dest_trash, t_list) { ip_vs_forget_dev(dest, dev); @@ -3316,9 +3314,9 @@ static int ip_vs_genl_fill_service(struct sk_buff *skb, goto nla_put_failure; } - sched = rcu_dereference_protected(svc->scheduler, 1); + sched = rcu_dereference(svc->scheduler); sched_name = sched ? sched->name : "none"; - pe = rcu_dereference_protected(svc->pe, 1); + pe = rcu_dereference(svc->pe); if (nla_put_string(skb, IPVS_SVC_ATTR_SCHED_NAME, sched_name) || (pe && nla_put_string(skb, IPVS_SVC_ATTR_PE_NAME, pe->name)) || nla_put(skb, IPVS_SVC_ATTR_FLAGS, sizeof(flags), &flags) || @@ -3372,9 +3370,9 @@ static int ip_vs_genl_dump_services(struct sk_buff *skb, struct net *net = sock_net(skb->sk); struct netns_ipvs *ipvs = net_ipvs(net); - mutex_lock(&ipvs->service_mutex); + rcu_read_lock(); for (i = 0; i < IP_VS_SVC_TAB_SIZE; i++) { - hlist_for_each_entry(svc, &ipvs->svc_table[i], s_list) { + hlist_for_each_entry_rcu(svc, &ipvs->svc_table[i], s_list) { if (++idx <= start) continue; if (ip_vs_genl_dump_service(skb, svc, cb) < 0) { @@ -3385,7 +3383,7 @@ static int ip_vs_genl_dump_services(struct sk_buff *skb, } for (i = 0; i < IP_VS_SVC_TAB_SIZE; i++) { - hlist_for_each_entry(svc, &ipvs->svc_fwm_table[i], f_list) { + hlist_for_each_entry_rcu(svc, &ipvs->svc_fwm_table[i], f_list) { if (++idx <= start) continue; if (ip_vs_genl_dump_service(skb, svc, cb) < 0) { @@ -3396,7 +3394,7 @@ static int ip_vs_genl_dump_services(struct sk_buff *skb, } nla_put_failure: - mutex_unlock(&ipvs->service_mutex); + rcu_read_unlock(); cb->args[0] = idx; return skb->len; @@ -3452,13 +3450,11 @@ static int ip_vs_genl_parse_service(struct netns_ipvs *ipvs, usvc->fwmark = 0; } - rcu_read_lock(); if (usvc->fwmark) svc = __ip_vs_svc_fwm_find(ipvs, usvc->af, usvc->fwmark); else svc = __ip_vs_service_find(ipvs, usvc->af, usvc->protocol, &usvc->addr, usvc->port); - rcu_read_unlock(); *ret_svc = svc; /* If a full entry was requested, check for the additional fields */ @@ -3585,7 +3581,7 @@ static int ip_vs_genl_dump_dests(struct sk_buff *skb, struct net *net = sock_net(skb->sk); struct netns_ipvs *ipvs = net_ipvs(net); - mutex_lock(&ipvs->service_mutex); + rcu_read_lock(); /* Try to find the service for which to dump destinations */ if (nlmsg_parse_deprecated(cb->nlh, GENL_HDRLEN, attrs, IPVS_CMD_ATTR_MAX, ip_vs_cmd_policy, cb->extack)) @@ -3597,7 +3593,7 @@ static int ip_vs_genl_dump_dests(struct sk_buff *skb, goto out_err; /* Dump the destinations */ - list_for_each_entry(dest, &svc->destinations, n_list) { + list_for_each_entry_rcu(dest, &svc->destinations, n_list) { if (++idx <= start) continue; if (ip_vs_genl_dump_dest(skb, dest, cb) < 0) { @@ -3610,7 +3606,7 @@ static int ip_vs_genl_dump_dests(struct sk_buff *skb, cb->args[0] = idx; out_err: - mutex_unlock(&ipvs->service_mutex); + rcu_read_unlock(); return skb->len; } @@ -3916,9 +3912,12 @@ static int ip_vs_genl_set_cmd(struct sk_buff *skb, struct genl_info *info) if (cmd == IPVS_CMD_NEW_SERVICE || cmd == IPVS_CMD_SET_SERVICE) need_full_svc = true; + /* We use function that requires RCU lock */ + rcu_read_lock(); ret = ip_vs_genl_parse_service(ipvs, &usvc, info->attrs[IPVS_CMD_ATTR_SERVICE], need_full_svc, &svc); + rcu_read_unlock(); if (ret) goto out; @@ -4038,7 +4037,7 @@ static int ip_vs_genl_get_cmd(struct sk_buff *skb, struct genl_info *info) if (!msg) return -ENOMEM; - mutex_lock(&ipvs->service_mutex); + rcu_read_lock(); reply = genlmsg_put_reply(msg, info, &ip_vs_genl_family, 0, reply_cmd); if (reply == NULL) @@ -4106,7 +4105,7 @@ static int ip_vs_genl_get_cmd(struct sk_buff *skb, struct genl_info *info) out_err: nlmsg_free(msg); out: - mutex_unlock(&ipvs->service_mutex); + rcu_read_unlock(); return ret; } -- 2.44.0