From 32affa5578f0e6b9abef3623d3976395afbd265c Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 11 Apr 2024 13:33:40 +0000 Subject: fib: rules: no longer hold RTNL in fib_nl_dumprule() - fib rules are already RCU protected, RTNL is not needed to get them. - Fix return value at the end of a dump, so that NLMSG_DONE can be appended to current skb, saving one recvmsg() system call. Signed-off-by: Eric Dumazet Reviewed-by: David Ahern Link: https://lore.kernel.org/r/20240411133340.1332796-1-edumazet@google.com Signed-off-by: Jakub Kicinski --- net/core/fib_rules.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) diff --git a/net/core/fib_rules.c b/net/core/fib_rules.c index 3f933ffcefc3..6ebffbc63236 100644 --- a/net/core/fib_rules.c +++ b/net/core/fib_rules.c @@ -1142,10 +1142,10 @@ static int fib_nl_dumprule(struct sk_buff *skb, struct netlink_callback *cb) const struct nlmsghdr *nlh = cb->nlh; struct net *net = sock_net(skb->sk); struct fib_rules_ops *ops; - int idx = 0, family; + int err, idx = 0, family; if (cb->strict_check) { - int err = fib_valid_dumprule_req(nlh, cb->extack); + err = fib_valid_dumprule_req(nlh, cb->extack); if (err < 0) return err; @@ -1158,17 +1158,17 @@ static int fib_nl_dumprule(struct sk_buff *skb, struct netlink_callback *cb) if (ops == NULL) return -EAFNOSUPPORT; - dump_rules(skb, cb, ops); - - return skb->len; + return dump_rules(skb, cb, ops); } + err = 0; rcu_read_lock(); list_for_each_entry_rcu(ops, &net->rules_ops, list) { if (idx < cb->args[0] || !try_module_get(ops->owner)) goto skip; - if (dump_rules(skb, cb, ops) < 0) + err = dump_rules(skb, cb, ops); + if (err < 0) break; cb->args[1] = 0; @@ -1178,7 +1178,7 @@ skip: rcu_read_unlock(); cb->args[0] = idx; - return skb->len; + return err; } static void notify_rule_change(int event, struct fib_rule *rule, @@ -1293,7 +1293,8 @@ static int __init fib_rules_init(void) int err; rtnl_register(PF_UNSPEC, RTM_NEWRULE, fib_nl_newrule, NULL, 0); rtnl_register(PF_UNSPEC, RTM_DELRULE, fib_nl_delrule, NULL, 0); - rtnl_register(PF_UNSPEC, RTM_GETRULE, NULL, fib_nl_dumprule, 0); + rtnl_register(PF_UNSPEC, RTM_GETRULE, NULL, fib_nl_dumprule, + RTNL_FLAG_DUMP_UNLOCKED); err = register_pernet_subsys(&fib_rules_net_ops); if (err < 0) -- cgit