From: Geliang Tang <tanggeliang@kylinos.cn>

This patch is the second part of refactoring dump_addr().

With the help of get_addr(), only copy the address list to an id
bitmap while holding the lock, then release the lock immediately.

After that, without locking, walking the copied id bitmap to get
every copy of entry by using get_addr(), and send each one looply:

	lock();
	for_each_entry(entry)
		set_bit(bitmap);
	unlock();

	for_each_bit(bitmap) {
		copy = get_addr();
		send_nlmsg(copy);
	}

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 net/mptcp/pm_netlink.c   | 20 +++++++++++---------
 net/mptcp/pm_userspace.c | 23 ++++++++++++-----------
 2 files changed, 23 insertions(+), 20 deletions(-)

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 9d502ab4d91d..bcee83306e40 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -1866,8 +1866,9 @@ int mptcp_pm_nl_get_addr_doit(struct sk_buff *skb, struct genl_info *info)
 static int mptcp_pm_nl_dump_addr(struct sk_buff *msg,
 				 struct netlink_callback *cb)
 {
+	const struct genl_info *info = genl_info_dump(cb);
 	struct net *net = sock_net(msg->sk);
-	struct mptcp_pm_addr_entry *entry;
+	struct mptcp_pm_addr_entry entry;
 	struct mptcp_id_bitmap *bitmap;
 	struct pm_nl_pernet *pernet;
 	int id = cb->args[0];
@@ -1877,16 +1878,18 @@ static int mptcp_pm_nl_dump_addr(struct sk_buff *msg,
 	bitmap = (struct mptcp_id_bitmap *)cb->ctx;
 	pernet = pm_nl_get_pernet(net);
 
-	spin_lock_bh(&pernet->lock);
-	if (!id)
+	if (!id) {
+		spin_lock_bh(&pernet->lock);
 		bitmap_copy(bitmap->map, pernet->id_bitmap.map, MPTCP_PM_MAX_ADDR_ID + 1);
+		spin_unlock_bh(&pernet->lock);
+	}
+
 	for (i = id; i < MPTCP_PM_MAX_ADDR_ID + 1; i++) {
 		if (test_bit(i, bitmap->map)) {
-			entry = __lookup_addr_by_id(pernet, i);
-			if (!entry)
+			if (mptcp_pm_nl_get_addr(i, &entry, info))
 				break;
 
-			if (entry->addr.id <= id)
+			if (entry.addr.id <= id)
 				continue;
 
 			hdr = genlmsg_put(msg, NETLINK_CB(cb->skb).portid,
@@ -1895,16 +1898,15 @@ static int mptcp_pm_nl_dump_addr(struct sk_buff *msg,
 			if (!hdr)
 				break;
 
-			if (mptcp_nl_fill_addr(msg, entry) < 0) {
+			if (mptcp_nl_fill_addr(msg, &entry) < 0) {
 				genlmsg_cancel(msg, hdr);
 				break;
 			}
 
-			id = entry->addr.id;
+			id = entry.addr.id;
 			genlmsg_end(msg, hdr);
 		}
 	}
-	spin_unlock_bh(&pernet->lock);
 
 	cb->args[0] = id;
 	return msg->len;
diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
index 2f1afb719ecf..ad011a4fad4e 100644
--- a/net/mptcp/pm_userspace.c
+++ b/net/mptcp/pm_userspace.c
@@ -601,7 +601,7 @@ int mptcp_userspace_pm_dump_addr(struct sk_buff *msg,
 				 struct netlink_callback *cb)
 {
 	const struct genl_info *info = genl_info_dump(cb);
-	struct mptcp_pm_addr_entry *entry;
+	struct mptcp_pm_addr_entry entry;
 	struct mptcp_id_bitmap *bitmap;
 	struct mptcp_sock *msk;
 	int id = cb->args[0];
@@ -618,17 +618,20 @@ int mptcp_userspace_pm_dump_addr(struct sk_buff *msg,
 
 	sk = (struct sock *)msk;
 
-	lock_sock(sk);
-	spin_lock_bh(&msk->pm.lock);
-	if (!id)
+	if (!id) {
+		lock_sock(sk);
+		spin_lock_bh(&msk->pm.lock);
 		ret = mptcp_userspace_pm_set_bitmap(msk, bitmap);
+		spin_unlock_bh(&msk->pm.lock);
+		release_sock(sk);
+	}
+
 	for (i = id; i < MPTCP_PM_MAX_ADDR_ID + 1; i++) {
 		if (test_bit(i, bitmap->map)) {
-			entry = mptcp_userspace_pm_lookup_addr_by_id(msk, i);
-			if (!entry)
+			if (mptcp_userspace_pm_get_addr(i, &entry, info))
 				break;
 
-			if (id && entry->addr.id <= id)
+			if (id && entry.addr.id <= id)
 				continue;
 
 			hdr = genlmsg_put(msg, NETLINK_CB(cb->skb).portid,
@@ -637,18 +640,16 @@ int mptcp_userspace_pm_dump_addr(struct sk_buff *msg,
 			if (!hdr)
 				break;
 
-			if (mptcp_nl_fill_addr(msg, entry) < 0) {
+			if (mptcp_nl_fill_addr(msg, &entry) < 0) {
 				genlmsg_cancel(msg, hdr);
 				break;
 			}
 
-			id = entry->addr.id;
+			id = entry.addr.id;
 			genlmsg_end(msg, hdr);
 		}
 	}
 	cb->args[0] = id;
-	spin_unlock_bh(&msk->pm.lock);
-	release_sock(sk);
 	ret = msg->len;
 
 	sock_put(sk);
-- 
2.43.0