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Miller" , Jakub Kicinski , Paolo Abeni Cc: Simon Horman , David Ahern , Kuniyuki Iwashima , netdev@vger.kernel.org, eric.dumazet@gmail.com, Eric Dumazet Content-Type: text/plain; charset="UTF-8" iproute2 can spend considerable amount of time in ll_init_map() or ll_link_get() to dump verbose netdev attributes, contributing to RTNL pressure. Add RTEXT_FILTER_TERSE_DUMP new flag so that rtnl_fill_ifinfo() limits its output to: - struct nlmsghdr - IFLA_IFNAME - IFLA_PROP_LIST We can later avoid using RTNL when RTEXT_FILTER_TERSE_DUMP is requested, as none of these attributes need RTNL. Signed-off-by: Eric Dumazet --- include/uapi/linux/rtnetlink.h | 1 + net/core/rtnetlink.c | 31 ++++++++++++++++++++++--------- 2 files changed, 23 insertions(+), 9 deletions(-) diff --git a/include/uapi/linux/rtnetlink.h b/include/uapi/linux/rtnetlink.h index dab9493c791b8465c6476990f42c4ee5ae82da2d..4b1dbd554e5c72c90d2416f7ade37956ad5472b7 100644 --- a/include/uapi/linux/rtnetlink.h +++ b/include/uapi/linux/rtnetlink.h @@ -840,6 +840,7 @@ enum { #define RTEXT_FILTER_CFM_CONFIG (1 << 5) #define RTEXT_FILTER_CFM_STATUS (1 << 6) #define RTEXT_FILTER_MST (1 << 7) +#define RTEXT_FILTER_TERSE_DUMP (1 << 8) /* End of information exported to user level */ diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index b613bb6e07df6586aa06e7a59c8384dcedffeeef..7a9a769d142b6826d7fb01b599a4d9e0ae09a97d 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -1295,7 +1295,12 @@ static noinline size_t if_nlmsg_size(const struct net_device *dev, size = NLMSG_ALIGN(sizeof(struct ifinfomsg)) + nla_total_size(IFNAMSIZ) /* IFLA_IFNAME */ - + nla_total_size(IFALIASZ) /* IFLA_IFALIAS */ + + rtnl_prop_list_size(dev); + + if (ext_filter_mask & RTEXT_FILTER_TERSE_DUMP) + return size; + + size += nla_total_size(IFALIASZ) /* IFLA_IFALIAS */ + nla_total_size(IFNAMSIZ) /* IFLA_QDISC */ + nla_total_size_64bit(sizeof(struct rtnl_link_ifmap)) + nla_total_size(MAX_ADDR_LEN) /* IFLA_ADDRESS */ @@ -1342,7 +1347,6 @@ static noinline size_t if_nlmsg_size(const struct net_device *dev, + nla_total_size(4) /* IFLA_CARRIER_DOWN_COUNT */ + nla_total_size(4) /* IFLA_MIN_MTU */ + nla_total_size(4) /* IFLA_MAX_MTU */ - + rtnl_prop_list_size(dev) + nla_total_size(MAX_ADDR_LEN) /* IFLA_PERM_ADDRESS */ + rtnl_devlink_port_size(dev) + rtnl_dpll_pin_size(dev) @@ -1940,15 +1944,18 @@ static int rtnl_fill_alt_ifnames(struct sk_buff *skb, struct netdev_name_node *name_node; int count = 0; + rcu_read_lock(); list_for_each_entry_rcu(name_node, &dev->name_node->list, list) { - if (nla_put_string(skb, IFLA_ALT_IFNAME, name_node->name)) + if (nla_put_string(skb, IFLA_ALT_IFNAME, name_node->name)) { + rcu_read_unlock(); return -EMSGSIZE; + } count++; } + rcu_read_unlock(); return count; } -/* RCU protected. */ static int rtnl_fill_prop_list(struct sk_buff *skb, const struct net_device *dev) { @@ -2071,13 +2078,20 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb, ifm->ifi_flags = netif_get_flags(dev); ifm->ifi_change = change; - if (tgt_netnsid >= 0 && nla_put_s32(skb, IFLA_TARGET_NETNSID, tgt_netnsid)) - goto nla_put_failure; - netdev_copy_name(dev, devname); if (nla_put_string(skb, IFLA_IFNAME, devname)) goto nla_put_failure; + if (rtnl_fill_prop_list(skb, dev)) + goto nla_put_failure; + + if (ext_filter_mask & RTEXT_FILTER_TERSE_DUMP) + goto end; + + if (tgt_netnsid >= 0 && + nla_put_s32(skb, IFLA_TARGET_NETNSID, tgt_netnsid)) + goto nla_put_failure; + if (nla_put_u32(skb, IFLA_TXQLEN, READ_ONCE(dev->tx_queue_len)) || nla_put_u8(skb, IFLA_OPERSTATE, netif_running(dev) ? READ_ONCE(dev->operstate) : @@ -2190,8 +2204,6 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb, goto nla_put_failure_rcu; if (rtnl_fill_link_ifmap(skb, dev)) goto nla_put_failure_rcu; - if (rtnl_fill_prop_list(skb, dev)) - goto nla_put_failure_rcu; rcu_read_unlock(); if (dev->dev.parent && @@ -2210,6 +2222,7 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb, if (rtnl_fill_dpll_pin(skb, dev)) goto nla_put_failure; +end: nlmsg_end(skb, nlh); return 0; -- 2.54.0.563.g4f69b47b94-goog