From: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Date: Fri, 1 Nov 2019 14:46:38 +0200
Subject: net: bridge: fdb: avoid two atomic bitops in
 br_fdb_external_learn_add()
Patch-mainline: v5.5-rc1
Git-commit: 31f1155bdc26aabd8de4bdf25e1c9ce9dbb21ff5
References: bsc#1154353

If we setup the fdb flags prior to calling fdb_create() we can avoid
two atomic bitops when learning a new entry.

Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 net/bridge/br_fdb.c |    9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

--- a/net/bridge/br_fdb.c
+++ b/net/bridge/br_fdb.c
@@ -1113,14 +1113,15 @@ int br_fdb_external_learn_add(struct net
 
 	fdb = br_fdb_find(br, addr, vid);
 	if (!fdb) {
-		fdb = fdb_create(br, p, addr, vid, 0);
+		unsigned long flags = BIT(BR_FDB_ADDED_BY_EXT_LEARN);
+
+		if (swdev_notify)
+			flags |= BIT(BR_FDB_ADDED_BY_USER);
+		fdb = fdb_create(br, p, addr, vid, flags);
 		if (!fdb) {
 			err = -ENOMEM;
 			goto err_unlock;
 		}
-		if (swdev_notify)
-			set_bit(BR_FDB_ADDED_BY_USER, &fdb->flags);
-		set_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags);
 		fdb_notify(br, fdb, RTM_NEWNEIGH, swdev_notify);
 	} else {
 		fdb->updated = jiffies;