From 893f139b9a6c00c097b9082a90f3041cfb3a0d20 Mon Sep 17 00:00:00 2001 From: Jarno Rajahalme Date: Mon, 5 May 2014 15:22:25 -0700 Subject: [PATCH] openvswitch: Minimize ovs_flow_cmd_new|set critical sections. Signed-off-by: Jarno Rajahalme Signed-off-by: Pravin B Shelar --- net/openvswitch/datapath.c | 192 ++++++++++++++++++++++--------------- 1 file changed, 116 insertions(+), 76 deletions(-) diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c index 22665a6144fc..6bc9d94c8df2 100644 --- a/net/openvswitch/datapath.c +++ b/net/openvswitch/datapath.c @@ -796,8 +796,7 @@ static int ovs_flow_cmd_new(struct sk_buff *skb, struct genl_info *info) { struct nlattr **a = info->attrs; struct ovs_header *ovs_header = info->userhdr; - struct sw_flow_key key, masked_key; - struct sw_flow *flow; + struct sw_flow *flow, *new_flow; struct sw_flow_mask mask; struct sk_buff *reply; struct datapath *dp; @@ -805,61 +804,77 @@ static int ovs_flow_cmd_new(struct sk_buff *skb, struct genl_info *info) struct sw_flow_match match; int error; - /* Extract key. */ + /* Must have key and actions. */ error = -EINVAL; if (!a[OVS_FLOW_ATTR_KEY]) goto error; + if (!a[OVS_FLOW_ATTR_ACTIONS]) + goto error; - ovs_match_init(&match, &key, &mask); + /* Most of the time we need to allocate a new flow, do it before + * locking. + */ + new_flow = ovs_flow_alloc(); + if (IS_ERR(new_flow)) { + error = PTR_ERR(new_flow); + goto error; + } + + /* Extract key. */ + ovs_match_init(&match, &new_flow->unmasked_key, &mask); error = ovs_nla_get_match(&match, a[OVS_FLOW_ATTR_KEY], a[OVS_FLOW_ATTR_MASK]); if (error) - goto error; + goto err_kfree_flow; - /* Validate actions. */ - error = -EINVAL; - if (!a[OVS_FLOW_ATTR_ACTIONS]) - goto error; + ovs_flow_mask_key(&new_flow->key, &new_flow->unmasked_key, &mask); + /* Validate actions. */ acts = ovs_nla_alloc_flow_actions(nla_len(a[OVS_FLOW_ATTR_ACTIONS])); error = PTR_ERR(acts); if (IS_ERR(acts)) - goto error; + goto err_kfree_flow; - ovs_flow_mask_key(&masked_key, &key, &mask); - error = ovs_nla_copy_actions(a[OVS_FLOW_ATTR_ACTIONS], - &masked_key, 0, &acts); + error = ovs_nla_copy_actions(a[OVS_FLOW_ATTR_ACTIONS], &new_flow->key, + 0, &acts); if (error) { OVS_NLERR("Flow actions may not be safe on all matching packets.\n"); - goto err_kfree; + goto err_kfree_acts; + } + + reply = ovs_flow_cmd_alloc_info(acts, info, false); + if (IS_ERR(reply)) { + error = PTR_ERR(reply); + goto err_kfree_acts; } ovs_lock(); dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex); - error = -ENODEV; - if (!dp) + if (unlikely(!dp)) { + error = -ENODEV; goto err_unlock_ovs; - + } /* Check if this is a duplicate flow */ - flow = ovs_flow_tbl_lookup(&dp->table, &key); - if (!flow) { - /* Allocate flow. */ - flow = ovs_flow_alloc(); - if (IS_ERR(flow)) { - error = PTR_ERR(flow); - goto err_unlock_ovs; - } - - flow->key = masked_key; - flow->unmasked_key = key; - rcu_assign_pointer(flow->sf_acts, acts); + flow = ovs_flow_tbl_lookup(&dp->table, &new_flow->unmasked_key); + if (likely(!flow)) { + rcu_assign_pointer(new_flow->sf_acts, acts); /* Put flow in bucket. */ - error = ovs_flow_tbl_insert(&dp->table, flow, &mask); - if (error) { + error = ovs_flow_tbl_insert(&dp->table, new_flow, &mask); + if (unlikely(error)) { acts = NULL; - goto err_flow_free; + goto err_unlock_ovs; } + + if (unlikely(reply)) { + error = ovs_flow_cmd_fill_info(new_flow, + ovs_header->dp_ifindex, + reply, info->snd_portid, + info->snd_seq, 0, + OVS_FLOW_CMD_NEW); + BUG_ON(error < 0); + } + ovs_unlock(); } else { struct sw_flow_actions *old_acts; @@ -869,39 +884,45 @@ static int ovs_flow_cmd_new(struct sk_buff *skb, struct genl_info *info) * request. We also accept NLM_F_EXCL in case that bug ever * gets fixed. */ - error = -EEXIST; - if (info->nlhdr->nlmsg_flags & (NLM_F_CREATE | NLM_F_EXCL)) + if (unlikely(info->nlhdr->nlmsg_flags & (NLM_F_CREATE + | NLM_F_EXCL))) { + error = -EEXIST; goto err_unlock_ovs; - + } /* The unmasked key has to be the same for flow updates. */ - if (!ovs_flow_cmp_unmasked_key(flow, &match)) + if (unlikely(!ovs_flow_cmp_unmasked_key(flow, &match))) { + error = -EEXIST; goto err_unlock_ovs; - + } /* Update actions. */ old_acts = ovsl_dereference(flow->sf_acts); rcu_assign_pointer(flow->sf_acts, acts); - ovs_nla_free_flow_actions(old_acts); - } - reply = ovs_flow_cmd_build_info(flow, ovs_header->dp_ifindex, - info, OVS_FLOW_CMD_NEW, false); - ovs_unlock(); + if (unlikely(reply)) { + error = ovs_flow_cmd_fill_info(flow, + ovs_header->dp_ifindex, + reply, info->snd_portid, + info->snd_seq, 0, + OVS_FLOW_CMD_NEW); + BUG_ON(error < 0); + } + ovs_unlock(); - if (reply) { - if (!IS_ERR(reply)) - ovs_notify(&dp_flow_genl_family, reply, info); - else - netlink_set_err(sock_net(skb->sk)->genl_sock, 0, 0, - PTR_ERR(reply)); + ovs_nla_free_flow_actions(old_acts); + ovs_flow_free(new_flow, false); } + + if (reply) + ovs_notify(&dp_flow_genl_family, reply, info); return 0; -err_flow_free: - ovs_flow_free(flow, false); err_unlock_ovs: ovs_unlock(); -err_kfree: + kfree_skb(reply); +err_kfree_acts: kfree(acts); +err_kfree_flow: + ovs_flow_free(new_flow, false); error: return error; } @@ -915,7 +936,7 @@ static int ovs_flow_cmd_set(struct sk_buff *skb, struct genl_info *info) struct sw_flow_mask mask; struct sk_buff *reply = NULL; struct datapath *dp; - struct sw_flow_actions *acts = NULL; + struct sw_flow_actions *old_acts = NULL, *acts = NULL; struct sw_flow_match match; int error; @@ -942,56 +963,75 @@ static int ovs_flow_cmd_set(struct sk_buff *skb, struct genl_info *info) &masked_key, 0, &acts); if (error) { OVS_NLERR("Flow actions may not be safe on all matching packets.\n"); - goto err_kfree; + goto err_kfree_acts; + } + } + + /* Can allocate before locking if have acts. */ + if (acts) { + reply = ovs_flow_cmd_alloc_info(acts, info, false); + if (IS_ERR(reply)) { + error = PTR_ERR(reply); + goto err_kfree_acts; } } ovs_lock(); dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex); - error = -ENODEV; - if (!dp) + if (unlikely(!dp)) { + error = -ENODEV; goto err_unlock_ovs; - + } /* Check that the flow exists. */ flow = ovs_flow_tbl_lookup(&dp->table, &key); - error = -ENOENT; - if (!flow) + if (unlikely(!flow)) { + error = -ENOENT; goto err_unlock_ovs; - + } /* The unmasked key has to be the same for flow updates. */ - error = -EEXIST; - if (!ovs_flow_cmp_unmasked_key(flow, &match)) + if (unlikely(!ovs_flow_cmp_unmasked_key(flow, &match))) { + error = -EEXIST; goto err_unlock_ovs; - + } /* Update actions, if present. */ - if (acts) { - struct sw_flow_actions *old_acts; - + if (likely(acts)) { old_acts = ovsl_dereference(flow->sf_acts); rcu_assign_pointer(flow->sf_acts, acts); - ovs_nla_free_flow_actions(old_acts); + + if (unlikely(reply)) { + error = ovs_flow_cmd_fill_info(flow, + ovs_header->dp_ifindex, + reply, info->snd_portid, + info->snd_seq, 0, + OVS_FLOW_CMD_NEW); + BUG_ON(error < 0); + } + } else { + /* Could not alloc without acts before locking. */ + reply = ovs_flow_cmd_build_info(flow, ovs_header->dp_ifindex, + info, OVS_FLOW_CMD_NEW, false); + if (unlikely(IS_ERR(reply))) { + error = PTR_ERR(reply); + goto err_unlock_ovs; + } } - reply = ovs_flow_cmd_build_info(flow, ovs_header->dp_ifindex, - info, OVS_FLOW_CMD_NEW, false); /* Clear stats. */ if (a[OVS_FLOW_ATTR_CLEAR]) ovs_flow_stats_clear(flow); ovs_unlock(); - if (reply) { - if (!IS_ERR(reply)) - ovs_notify(&dp_flow_genl_family, reply, info); - else - genl_set_err(&dp_flow_genl_family, sock_net(skb->sk), 0, - 0, PTR_ERR(reply)); - } + if (reply) + ovs_notify(&dp_flow_genl_family, reply, info); + if (old_acts) + ovs_nla_free_flow_actions(old_acts); return 0; err_unlock_ovs: ovs_unlock(); -err_kfree: + kfree_skb(reply); +err_kfree_acts: kfree(acts); error: return error; -- 2.30.2