From patchwork Tue Aug 15 17:30:20 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Julian Anastasov X-Patchwork-Id: 13354023 X-Patchwork-Delegate: kuba@kernel.org Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3420117ABF for ; Tue, 15 Aug 2023 17:32:34 +0000 (UTC) Received: from mg.ssi.bg (mg.ssi.bg [193.238.174.37]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3D36A1BDC; Tue, 15 Aug 2023 10:32:32 -0700 (PDT) Received: from mg.bb.i.ssi.bg (localhost [127.0.0.1]) by mg.bb.i.ssi.bg (Proxmox) with ESMTP id D75C1FDFF; Tue, 15 Aug 2023 20:32:30 +0300 (EEST) Received: from ink.ssi.bg (ink.ssi.bg [193.238.174.40]) by mg.bb.i.ssi.bg (Proxmox) with ESMTPS id BEB30FF4A; Tue, 15 Aug 2023 20:32:30 +0300 (EEST) Received: from ja.ssi.bg (unknown [213.16.62.126]) by ink.ssi.bg (Postfix) with ESMTPSA id 896383C07C8; Tue, 15 Aug 2023 20:32:16 +0300 (EEST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=ssi.bg; s=ink; t=1692120736; bh=P48NNIbmKmKcUAIbpzuvb8YDGYAzwDxo+kEi4DdF/5U=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=vbBpwtdjeDK5byZZ4+xvrDb5EMI7c2hTio/JeihI4XY3rfIF7lq6AYiW7LV1DNzeS bmeYGSbygNRvc9qYiDF4W+4TXvgVJw60FezAjOutdVfyr9fVYY5qdHdLpA9vmgIJ2M SwuAAgKOZtBTgs/HnWbo8nqW7UVfFImFjCBqiL+Y= Received: from ja.home.ssi.bg (localhost.localdomain [127.0.0.1]) by ja.ssi.bg (8.17.1/8.17.1) with ESMTP id 37FHWG6i168619; Tue, 15 Aug 2023 20:32:16 +0300 Received: (from root@localhost) by ja.home.ssi.bg (8.17.1/8.17.1/Submit) id 37FHWGLT168618; Tue, 15 Aug 2023 20:32:16 +0300 From: Julian Anastasov To: Simon Horman Cc: lvs-devel@vger.kernel.org, netfilter-devel@vger.kernel.org, netdev@vger.kernel.org, "Paul E . McKenney" , rcu@vger.kernel.org, Dust Li , Jiejian Wu , Jiri Wiesner Subject: [PATCH RFC net-next 03/14] ipvs: some service readers can use RCU Date: Tue, 15 Aug 2023 20:30:20 +0300 Message-ID: <20230815173031.168344-4-ja@ssi.bg> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230815173031.168344-1-ja@ssi.bg> References: <20230815173031.168344-1-ja@ssi.bg> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: kuba@kernel.org X-Patchwork-State: RFC 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 --- 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 e5ae4fac8ec9..276fdc31e938 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); @@ -3314,9 +3312,9 @@ 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) || @@ -3370,9 +3368,9 @@ 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) { @@ -3383,7 +3381,7 @@ 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) { @@ -3394,7 +3392,7 @@ 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; @@ -3450,13 +3448,11 @@ 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 */ @@ -3583,7 +3579,7 @@ 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)) @@ -3595,7 +3591,7 @@ 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) { @@ -3608,7 +3604,7 @@ 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; } @@ -3914,9 +3910,12 @@ 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; @@ -4036,7 +4035,7 @@ 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) @@ -4104,7 +4103,7 @@ 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; }