diff mbox series

[net,v3,1/3] bonding: restore IFF_MASTER/SLAVE flags on bond enslave ether type change

Message ID 20230315111842.1589296-2-razor@blackwall.org (mailing list archive)
State Accepted
Commit 9ec7eb60dcbcb6c41076defbc5df7bbd95ceaba5
Delegated to: Netdev Maintainers
Headers show
Series bonding: properly restore flags when bond changes ether type | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 21 this patch: 21
netdev/cc_maintainers fail 1 blamed authors not CCed: monis@Voltaire.COM; 1 maintainers not CCed: monis@Voltaire.COM
netdev/build_clang success Errors and warnings before: 18 this patch: 18
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 21 this patch: 21
netdev/checkpatch warning WARNING: 'muticast' may be misspelled - perhaps 'multicast'?
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Nikolay Aleksandrov March 15, 2023, 11:18 a.m. UTC
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>
---
v3: squashed patch 01 with the helper into this one, adjusted the
comment to be more explicit, no code changes

 drivers/net/bonding/bond_main.c | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 00646aa315c3..4bd911f9d3f9 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -1775,6 +1775,19 @@  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)
@@ -1866,10 +1879,8 @@  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);