| Message ID | 20240507121748.416287-1-edumazet@google.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 58a4ff5d77b187086eb12d41d613749420947f19 |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [v2,net-next] phonet: no longer hold RTNL in route_dumpit() | expand |
On Tue, May 07, 2024 at 12:17:48PM +0000, Eric Dumazet wrote: > route_dumpit() already relies on RCU, RTNL is not needed. > > Also change return value at the end of a dump. > This allows NLMSG_DONE to be appended to the current > skb at the end of a dump, saving a couple of recvmsg() > system calls. > > Signed-off-by: Eric Dumazet <edumazet@google.com> > Cc: Remi Denis-Courmont <courmisch@gmail.com> > --- > v2: break;; -> break; (Jakub) Reviewed-by: Simon Horman <horms@kernel.org>
Hello: This patch was applied to netdev/net-next.git (main) by Jakub Kicinski <kuba@kernel.org>: On Tue, 7 May 2024 12:17:48 +0000 you wrote: > route_dumpit() already relies on RCU, RTNL is not needed. > > Also change return value at the end of a dump. > This allows NLMSG_DONE to be appended to the current > skb at the end of a dump, saving a couple of recvmsg() > system calls. > > [...] Here is the summary with links: - [v2,net-next] phonet: no longer hold RTNL in route_dumpit() https://git.kernel.org/netdev/net-next/c/58a4ff5d77b1 You are awesome, thank you!
diff --git a/net/phonet/pn_netlink.c b/net/phonet/pn_netlink.c index 59aebe29689077bfa77d37516aea4617fe3b8a50..92245fdfa846cb8b9747764a3330e17d8c6b1f16 100644 --- a/net/phonet/pn_netlink.c +++ b/net/phonet/pn_netlink.c @@ -178,7 +178,7 @@ static int fill_route(struct sk_buff *skb, struct net_device *dev, u8 dst, rtm->rtm_type = RTN_UNICAST; rtm->rtm_flags = 0; if (nla_put_u8(skb, RTA_DST, dst) || - nla_put_u32(skb, RTA_OIF, dev->ifindex)) + nla_put_u32(skb, RTA_OIF, READ_ONCE(dev->ifindex))) goto nla_put_failure; nlmsg_end(skb, nlh); return 0; @@ -263,6 +263,7 @@ static int route_doit(struct sk_buff *skb, struct nlmsghdr *nlh, static int route_dumpit(struct sk_buff *skb, struct netlink_callback *cb) { struct net *net = sock_net(skb->sk); + int err = 0; u8 addr; rcu_read_lock(); @@ -272,16 +273,16 @@ static int route_dumpit(struct sk_buff *skb, struct netlink_callback *cb) if (!dev) continue; - if (fill_route(skb, dev, addr << 2, NETLINK_CB(cb->skb).portid, - cb->nlh->nlmsg_seq, RTM_NEWROUTE) < 0) - goto out; + err = fill_route(skb, dev, addr << 2, + NETLINK_CB(cb->skb).portid, + cb->nlh->nlmsg_seq, RTM_NEWROUTE); + if (err < 0) + break; } - -out: rcu_read_unlock(); cb->args[0] = addr; - return skb->len; + return err; } int __init phonet_netlink_register(void) @@ -301,6 +302,6 @@ int __init phonet_netlink_register(void) rtnl_register_module(THIS_MODULE, PF_PHONET, RTM_DELROUTE, route_doit, NULL, 0); rtnl_register_module(THIS_MODULE, PF_PHONET, RTM_GETROUTE, - NULL, route_dumpit, 0); + NULL, route_dumpit, RTNL_FLAG_DUMP_UNLOCKED); return 0; }
route_dumpit() already relies on RCU, RTNL is not needed. Also change return value at the end of a dump. This allows NLMSG_DONE to be appended to the current skb at the end of a dump, saving a couple of recvmsg() system calls. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Remi Denis-Courmont <courmisch@gmail.com> --- v2: break;; -> break; (Jakub) --- net/phonet/pn_netlink.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-)