[PATCH net-next 07/11] net: make netdev netlink ops hold netdev_lock()
From: Jakub Kicinski <kuba@kernel.org>
Date: 2025-01-14 03:51:35
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
In prep for dropping rtnl_lock, start locking netdev->lock in netlink genl ops. We need to be using netdev->up instead of flags & IFF_UP. We can remove the RCU lock protection for the NAPI since NAPI list is protected by netdev->lock already. Signed-off-by: Jakub Kicinski <kuba@kernel.org> --- net/core/dev.h | 1 - net/core/dev.c | 3 ++- net/core/netdev-genl.c | 46 +++++++++++++++++++++++------------------- 3 files changed, 27 insertions(+), 23 deletions(-)
diff --git a/net/core/dev.h b/net/core/dev.h
index ef37e2dd44f4..a5b166bbd169 100644
--- a/net/core/dev.h
+++ b/net/core/dev.h@@ -23,7 +23,6 @@ struct sd_flow_limit { extern int netdev_flow_limit_table_len; -struct napi_struct *netdev_napi_by_id(struct net *net, unsigned int napi_id); struct napi_struct * netdev_napi_by_id_lock(struct net *net, unsigned int napi_id); struct net_device *dev_get_by_napi_id(unsigned int napi_id);
diff --git a/net/core/dev.c b/net/core/dev.c
index cf3bf8a906b6..1151baaedf4d 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c@@ -767,7 +767,8 @@ static struct napi_struct *napi_by_id(unsigned int napi_id) } /* must be called under rcu_read_lock(), as we dont take a reference */ -struct napi_struct *netdev_napi_by_id(struct net *net, unsigned int napi_id) +static struct napi_struct * +netdev_napi_by_id(struct net *net, unsigned int napi_id) { struct napi_struct *napi;
diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c
index c59619a2ec23..810a446ab62c 100644
--- a/net/core/netdev-genl.c
+++ b/net/core/netdev-genl.c@@ -167,7 +167,7 @@ netdev_nl_napi_fill_one(struct sk_buff *rsp, struct napi_struct *napi, void *hdr; pid_t pid; - if (!(napi->dev->flags & IFF_UP)) + if (!napi->dev->up) return 0; hdr = genlmsg_iput(rsp, info);
@@ -230,17 +230,16 @@ int netdev_nl_napi_get_doit(struct sk_buff *skb, struct genl_info *info) return -ENOMEM; rtnl_lock(); - rcu_read_lock(); - napi = netdev_napi_by_id(genl_info_net(info), napi_id); + napi = netdev_napi_by_id_lock(genl_info_net(info), napi_id); if (napi) { err = netdev_nl_napi_fill_one(rsp, napi, info); + netdev_unlock(napi->dev); } else { NL_SET_BAD_ATTR(info->extack, info->attrs[NETDEV_A_NAPI_ID]); err = -ENOENT; } - rcu_read_unlock(); rtnl_unlock(); if (err) {
@@ -266,7 +265,7 @@ netdev_nl_napi_dump_one(struct net_device *netdev, struct sk_buff *rsp, unsigned int prev_id; int err = 0; - if (!(netdev->flags & IFF_UP)) + if (!netdev->up) return err; prev_id = UINT_MAX;
@@ -303,13 +302,15 @@ int netdev_nl_napi_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb) rtnl_lock(); if (ifindex) { - netdev = __dev_get_by_index(net, ifindex); - if (netdev) + netdev = netdev_get_by_index_lock(net, ifindex); + if (netdev) { err = netdev_nl_napi_dump_one(netdev, skb, info, ctx); - else + netdev_unlock(netdev); + } else { err = -ENODEV; + } } else { - for_each_netdev_dump(net, netdev, ctx->ifindex) { + for_each_netdev_lock_scoped(net, netdev, ctx->ifindex) { err = netdev_nl_napi_dump_one(netdev, skb, info, ctx); if (err < 0) break;
@@ -358,17 +359,16 @@ int netdev_nl_napi_set_doit(struct sk_buff *skb, struct genl_info *info) napi_id = nla_get_u32(info->attrs[NETDEV_A_NAPI_ID]); rtnl_lock(); - rcu_read_lock(); - napi = netdev_napi_by_id(genl_info_net(info), napi_id); + napi = netdev_napi_by_id_lock(genl_info_net(info), napi_id); if (napi) { err = netdev_nl_napi_set_config(napi, info); + netdev_unlock(napi->dev); } else { NL_SET_BAD_ATTR(info->extack, info->attrs[NETDEV_A_NAPI_ID]); err = -ENOENT; } - rcu_read_unlock(); rtnl_unlock(); return err;
@@ -442,7 +442,7 @@ netdev_nl_queue_fill(struct sk_buff *rsp, struct net_device *netdev, u32 q_idx, { int err; - if (!(netdev->flags & IFF_UP)) + if (!netdev->up) return -ENOENT; err = netdev_nl_queue_validate(netdev, q_idx, q_type);
@@ -474,11 +474,13 @@ int netdev_nl_queue_get_doit(struct sk_buff *skb, struct genl_info *info) rtnl_lock(); - netdev = __dev_get_by_index(genl_info_net(info), ifindex); - if (netdev) + netdev = netdev_get_by_index_lock(genl_info_net(info), ifindex); + if (netdev) { err = netdev_nl_queue_fill(rsp, netdev, q_id, q_type, info); - else + netdev_unlock(netdev); + } else { err = -ENODEV; + } rtnl_unlock();
@@ -499,7 +501,7 @@ netdev_nl_queue_dump_one(struct net_device *netdev, struct sk_buff *rsp, { int err = 0; - if (!(netdev->flags & IFF_UP)) + if (!netdev->up) return err; for (; ctx->rxq_idx < netdev->real_num_rx_queues; ctx->rxq_idx++) {
@@ -532,13 +534,15 @@ int netdev_nl_queue_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb) rtnl_lock(); if (ifindex) { - netdev = __dev_get_by_index(net, ifindex); - if (netdev) + netdev = netdev_get_by_index_lock(net, ifindex); + if (netdev) { err = netdev_nl_queue_dump_one(netdev, skb, info, ctx); - else + netdev_unlock(netdev); + } else { err = -ENODEV; + } } else { - for_each_netdev_dump(net, netdev, ctx->ifindex) { + for_each_netdev_lock_scoped(net, netdev, ctx->ifindex) { err = netdev_nl_queue_dump_one(netdev, skb, info, ctx); if (err < 0) break;
--
2.47.1