[PATCH v3 net-next 08/15] net: Remove rtnl_held of struct fib_dump_filter.

Kuniyuki Iwashima
2026-04-07T21:20:17Z

Commit 22e36ea9f5d7 ("inet: allow ip_valid_fib_dump_req() to
be called with RTNL or RCU") introduced the rtnl_held field in
struct fib_dump_filter to switch __dev_get_by_index() and
dev_get_by_index_rcu() depending on the caller's context.

This field served as an interim measure while we were incrementally
converting all callers of ip_valid_fib_dump_req() to RCU.

Now that all users (IPv4, IPv6, ipmr, ip6mr, and MPLS) have
been converted to RCU, the field is no longer necessary.

Let's remove it.

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
---
include/net/ip_fib.h | 1 -
net/ipv4/fib_frontend.c | 19 ++++++-------------
net/ipv4/ipmr.c | 4 +---
net/ipv6/ip6_fib.c | 1 -
net/ipv6/ip6mr.c | 4 +---
net/mpls/af_mpls.c | 6 ++----
6 files changed, 10 insertions(+), 25 deletions(-)

diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
index 318593743b6e..1142ffad7444 100644
--- a/include/net/ip_fib.h
+++ b/include/net/ip_fib.h
@@ -269,7 +269,6 @@ struct fib_dump_filter {
bool filter_set;
bool dump_routes;
bool dump_exceptions;
- bool rtnl_held;
unsigned char protocol;
unsigned char rt_type;
unsigned int flags;
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index 1dab44e13d3b..ceeb87b13b93 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -946,9 +946,6 @@ int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
struct rtmsg *rtm;
int err, i;

- if (filter->rtnl_held)
- ASSERT_RTNL();
-
rtm = nlmsg_payload(nlh, sizeof(*rtm));
if (!rtm) {
NL_SET_ERR_MSG(extack, "Invalid header for FIB dump request");
@@ -992,10 +989,8 @@ int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
break;
case RTA_OIF:
ifindex = nla_get_u32(tb[i]);
- if (filter->rtnl_held)
- filter->dev = __dev_get_by_index(net, ifindex);
- else
- filter->dev = dev_get_by_index_rcu(net, ifindex);
+
+ filter->dev = dev_get_by_index_rcu(net, ifindex);
if (!filter->dev)
return -ENODEV;
break;
@@ -1017,18 +1012,16 @@ EXPORT_SYMBOL_GPL(ip_valid_fib_dump_req);

static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
{
+ const struct nlmsghdr *nlh = cb->nlh;
+ struct net *net = sock_net(skb->sk);
struct fib_dump_filter filter = {
.dump_routes = true,
.dump_exceptions = true,
- .rtnl_held = false,
};
- const struct nlmsghdr *nlh = cb->nlh;
- struct net *net = sock_net(skb->sk);
- unsigned int h, s_h;
- unsigned int e = 0, s_e;
- struct fib_table *tb;
+ unsigned int e = 0, s_e, h, s_h;
struct hlist_head *head;
int dumped = 0, err = 0;
+ struct fib_table *tb;

rcu_read_lock();
if (cb->strict_check) {
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index 2566b4a1f80b..c0fc606b0ae9 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -2770,9 +2770,7 @@ static int ipmr_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,

static int ipmr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
{
- struct fib_dump_filter filter = {
- .rtnl_held = false,
- };
+ struct fib_dump_filter filter = {};
int err;

rcu_read_lock();
diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index b897b3c5023b..fc95738ded76 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -633,7 +633,6 @@ static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
struct rt6_rtnl_dump_arg arg = {
.filter.dump_exceptions = true,
.filter.dump_routes = true,
- .filter.rtnl_held = false,
};
const struct nlmsghdr *nlh = cb->nlh;
struct net *net = sock_net(skb->sk);
diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
index cd28bea8c11a..b9c048b6f1ca 100644
--- a/net/ipv6/ip6mr.c
+++ b/net/ipv6/ip6mr.c
@@ -2750,9 +2750,7 @@ static int ip6mr_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
static int ip6mr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
{
const struct nlmsghdr *nlh = cb->nlh;
- struct fib_dump_filter filter = {
- .rtnl_held = false,
- };
+ struct fib_dump_filter filter = {};
int err;

rcu_read_lock();
diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
index 26340a7306b5..ca504d9626cf 100644
--- a/net/mpls/af_mpls.c
+++ b/net/mpls/af_mpls.c
@@ -2221,12 +2221,10 @@ static bool mpls_rt_uses_dev(struct mpls_route *rt,

static int mpls_dump_routes(struct sk_buff *skb, struct netlink_callback *cb)
{
+ struct mpls_route __rcu **platform_label;
const struct nlmsghdr *nlh = cb->nlh;
struct net *net = sock_net(skb->sk);
- struct mpls_route __rcu **platform_label;
- struct fib_dump_filter filter = {
- .rtnl_held = false,
- };
+ struct fib_dump_filter filter = {};
unsigned int flags = NLM_F_MULTI;
size_t platform_labels;
unsigned int index;
--
2.53.0.1213.gd9a14994de-goog