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

[Kuniyuki Iwashima <kuniyu@google.com>]

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