From: Eric Dumazet <edumazet@google.com>
To: "David S . Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Paolo Abeni <pabeni@redhat.com>
Cc: netdev@vger.kernel.org, eric.dumazet@gmail.com,
Eric Dumazet <edumazet@google.com>,
Remi Denis-Courmont <courmisch@gmail.com>
Subject: [PATCH v2 net-next] phonet: no longer hold RTNL in route_dumpit()
Date: Tue, 7 May 2024 12:17:48 +0000 [thread overview]
Message-ID: <20240507121748.416287-1-edumazet@google.com> (raw)
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(-)
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;
}
--
2.45.0.rc1.225.g2a3ae87e7f-goog
next reply other threads:[~2024-05-07 12:17 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-07 12:17 Eric Dumazet [this message]
2024-05-08 12:40 ` [PATCH v2 net-next] phonet: no longer hold RTNL in route_dumpit() Simon Horman
2024-05-09 2:00 ` patchwork-bot+netdevbpf
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