From: Nikolay Aleksandrov <razor@blackwall.org>
Date: Wed, 15 Mar 2023 13:18:40 +0200
Subject: [PATCH] bonding: restore IFF_MASTER/SLAVE flags on bond enslave ether
type change
References: bsc#1012628
Patch-mainline: 6.2.8
Git-commit: 9ec7eb60dcbcb6c41076defbc5df7bbd95ceaba5
[ Upstream commit 9ec7eb60dcbcb6c41076defbc5df7bbd95ceaba5 ]
Add bond_ether_setup helper which is used to fix ether_setup() calls in the
bonding driver. It takes care of both IFF_MASTER and IFF_SLAVE flags, the
former is always restored and the latter only if it was set.
If the bond enslaves non-ARPHRD_ETHER device (changes its type), then
releases it and enslaves ARPHRD_ETHER device (changes back) then we
use ether_setup() to restore the bond device type but it also resets its
flags and removes IFF_MASTER and IFF_SLAVE[1]. Use the bond_ether_setup
helper to restore both after such transition.
[1] reproduce (nlmon is non-ARPHRD_ETHER):
$ ip l add nlmon0 type nlmon
$ ip l add bond2 type bond mode active-backup
$ ip l set nlmon0 master bond2
$ ip l set nlmon0 nomaster
$ ip l add bond1 type bond
(we use bond1 as ARPHRD_ETHER device to restore bond2's mode)
$ ip l set bond1 master bond2
$ ip l sh dev bond2
37: bond2: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
link/ether be:d7:c5:40:5b:cc brd ff:ff:ff:ff:ff:ff promiscuity 0 minmtu 68 maxmtu 1500
(notice bond2's IFF_MASTER is missing)
Fixes: e36b9d16c6a6 ("bonding: clean muticast addresses when device changes type")
Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
drivers/net/bonding/bond_main.c | 19 +++++++++++++++----
1 file changed, 15 insertions(+), 4 deletions(-)
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 0363ce59..ef7ae8c9 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -1773,6 +1773,19 @@ void bond_lower_state_changed(struct slave *slave)
slave_err(bond_dev, slave_dev, "Error: %s\n", errmsg); \
} while (0)
+/* The bonding driver uses ether_setup() to convert a master bond device
+ * to ARPHRD_ETHER, that resets the target netdevice's flags so we always
+ * have to restore the IFF_MASTER flag, and only restore IFF_SLAVE if it was set
+ */
+static void bond_ether_setup(struct net_device *bond_dev)
+{
+ unsigned int slave_flag = bond_dev->flags & IFF_SLAVE;
+
+ ether_setup(bond_dev);
+ bond_dev->flags |= IFF_MASTER | slave_flag;
+ bond_dev->priv_flags &= ~IFF_TX_SKB_SHARING;
+}
+
/* enslave device <slave> to bond device <master> */
int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev,
struct netlink_ext_ack *extack)
@@ -1864,10 +1877,8 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev,
if (slave_dev->type != ARPHRD_ETHER)
bond_setup_by_slave(bond_dev, slave_dev);
- else {
- ether_setup(bond_dev);
- bond_dev->priv_flags &= ~IFF_TX_SKB_SHARING;
- }
+ else
+ bond_ether_setup(bond_dev);
call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE,
bond_dev);
--
2.35.3