From: Jakub Kicinski <kuba@kernel•org>
To: davem@davemloft•net
Cc: netdev@vger•kernel.org, edumazet@google•com, pabeni@redhat•com,
andrew+netdev@lunn•ch, horms@kernel•org, sdf@fomichev•me,
hramamurthy@google•com, kuniyu@amazon•com, jdamato@fastly•com,
Jakub Kicinski <kuba@kernel•org>
Subject: [PATCH net-next v2 6/8] netdev: depend on netdev->lock for xdp features
Date: Tue, 8 Apr 2025 12:59:53 -0700 [thread overview]
Message-ID: <20250408195956.412733-7-kuba@kernel.org> (raw)
In-Reply-To: <20250408195956.412733-1-kuba@kernel.org>
Writes to XDP features are now protected by netdev->lock.
Other things we report are based on ops which don't change
once device has been registered. It is safe to stop taking
rtnl_lock, and depend on netdev->lock instead.
Reviewed-by: Joe Damato <jdamato@fastly•com>
Acked-by: Stanislav Fomichev <sdf@fomichev•me>
Signed-off-by: Jakub Kicinski <kuba@kernel•org>
---
net/core/netdev-genl.c | 26 ++++++++++++--------------
1 file changed, 12 insertions(+), 14 deletions(-)
diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c
index 7ef9b0191936..8c58261de969 100644
--- a/net/core/netdev-genl.c
+++ b/net/core/netdev-genl.c
@@ -38,6 +38,8 @@ netdev_nl_dev_fill(struct net_device *netdev, struct sk_buff *rsp,
u64 xdp_rx_meta = 0;
void *hdr;
+ netdev_assert_locked(netdev); /* note: rtnl_lock may not be held! */
+
hdr = genlmsg_iput(rsp, info);
if (!hdr)
return -EMSGSIZE;
@@ -122,15 +124,14 @@ int netdev_nl_dev_get_doit(struct sk_buff *skb, struct genl_info *info)
if (!rsp)
return -ENOMEM;
- rtnl_lock();
-
- netdev = __dev_get_by_index(genl_info_net(info), ifindex);
- if (netdev)
- err = netdev_nl_dev_fill(netdev, rsp, info);
- else
+ netdev = netdev_get_by_index_lock(genl_info_net(info), ifindex);
+ if (!netdev) {
err = -ENODEV;
+ goto err_free_msg;
+ }
- rtnl_unlock();
+ err = netdev_nl_dev_fill(netdev, rsp, info);
+ netdev_unlock(netdev);
if (err)
goto err_free_msg;
@@ -146,18 +147,15 @@ int netdev_nl_dev_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
{
struct netdev_nl_dump_ctx *ctx = netdev_dump_ctx(cb);
struct net *net = sock_net(skb->sk);
- struct net_device *netdev;
- int err = 0;
+ int err;
- rtnl_lock();
- for_each_netdev_dump(net, netdev, ctx->ifindex) {
+ for_each_netdev_lock_scoped(net, netdev, ctx->ifindex) {
err = netdev_nl_dev_fill(netdev, skb, genl_info_dump(cb));
if (err < 0)
- break;
+ return err;
}
- rtnl_unlock();
- return err;
+ return 0;
}
static int
--
2.49.0
next prev parent reply other threads:[~2025-04-08 20:00 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-04-08 19:59 [PATCH net-next v2 0/8] net: depend on instance lock for queue related netlink ops Jakub Kicinski
2025-04-08 19:59 ` [PATCH net-next v2 1/8] net: avoid potential race between netdev_get_by_index_lock() and netns switch Jakub Kicinski
2025-04-08 19:59 ` [PATCH net-next v2 2/8] net: designate XSK pool pointers in queues as "ops protected" Jakub Kicinski
2025-04-08 19:59 ` [PATCH net-next v2 3/8] netdev: add "ops compat locking" helpers Jakub Kicinski
2025-04-08 19:59 ` [PATCH net-next v2 4/8] netdev: don't hold rtnl_lock over nl queue info get when possible Jakub Kicinski
2025-04-08 19:59 ` [PATCH net-next v2 5/8] xdp: double protect netdev->xdp_flags with netdev->lock Jakub Kicinski
2025-04-08 22:15 ` Harshitha Ramamurthy
2025-04-09 18:40 ` Martin KaFai Lau
2025-04-08 19:59 ` Jakub Kicinski [this message]
2025-04-10 17:10 ` [PATCH net-next v2 6/8] netdev: depend on netdev->lock for xdp features Kuniyuki Iwashima
2025-04-11 2:10 ` Jakub Kicinski
2025-04-11 2:23 ` Jakub Kicinski
2025-04-11 17:41 ` Stanislav Fomichev
2025-04-11 19:19 ` Jakub Kicinski
2025-04-11 2:36 ` Kuniyuki Iwashima
2025-04-08 19:59 ` [PATCH net-next v2 7/8] docs: netdev: break down the instance locking info per ops struct Jakub Kicinski
2025-04-09 2:59 ` Joe Damato
2025-04-10 6:01 ` Jacob Keller
2025-04-10 16:08 ` Jakub Kicinski
2025-04-10 22:35 ` Keller, Jacob E
2025-04-10 23:39 ` Jakub Kicinski
2025-04-11 21:26 ` Jacob Keller
2025-04-08 19:59 ` [PATCH net-next v2 8/8] netdev: depend on netdev->lock for qstats in ops locked drivers Jakub Kicinski
2025-04-10 5:23 ` Jacob Keller
2025-04-10 23:46 ` Jakub Kicinski
2025-04-11 21:29 ` Jacob Keller
2025-04-10 0:40 ` [PATCH net-next v2 0/8] net: depend on instance lock for queue related netlink ops patchwork-bot+netdevbpf
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