Merge branch 'bonding-fix-bond-recovery-in-mode-2'

Jonathan Toppins says:

====================
bonding: fix bond recovery in mode 2

When a bond is configured with a non-zero updelay and in mode 2 the bond
never recovers after all slaves lose link. The first patch adds
selftests that demonstrate the issue and the second patch fixes the
issue by ignoring the updelay when there are no usable slaves.
====================

Link: https://lore.kernel.org/r/cover.1669147951.git.jtoppins@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/bonding/bond_main.c

@@ -2529,7 +2529,16 @@ static int bond_miimon_inspect(struct bonding *bond)
 	struct slave *slave;
 	bool ignore_updelay;
 
-	ignore_updelay = !rcu_dereference(bond->curr_active_slave);
+	if (BOND_MODE(bond) == BOND_MODE_ACTIVEBACKUP) {
+		ignore_updelay = !rcu_dereference(bond->curr_active_slave);
+	} else {
+		struct bond_up_slave *usable_slaves;
+
+		usable_slaves = rcu_dereference(bond->usable_slaves);
+
+		if (usable_slaves && usable_slaves->count == 0)
+			ignore_updelay = true;
+	}
 
 	bond_for_each_slave_rcu(bond, slave, iter) {
 		bond_propose_link_state(slave, BOND_LINK_NOCHANGE);

tools/testing/selftests/drivers/net/bonding/Makefile

@@ -5,7 +5,9 @@ TEST_PROGS := \
 	bond-arp-interval-causes-panic.sh \
 	bond-break-lacpdu-tx.sh \
 	bond-lladdr-target.sh \
-	dev_addr_lists.sh
+	dev_addr_lists.sh \
+	mode-1-recovery-updelay.sh \
+	mode-2-recovery-updelay.sh
 
 TEST_FILES := \
 	lag_lib.sh \

tools/testing/selftests/drivers/net/bonding/lag_lib.sh

@@ -1,6 +1,8 @@
 #!/bin/bash
 # SPDX-License-Identifier: GPL-2.0
 
+NAMESPACES=""
+
 # Test that a link aggregation device (bonding, team) removes the hardware
 # addresses that it adds on its underlying devices.
 test_LAG_cleanup()
@@ -59,3 +61,107 @@ test_LAG_cleanup()
 
 	log_test "$driver cleanup mode $mode"
 }
+
+# Build a generic 2 node net namespace with 2 connections
+# between the namespaces
+#
+#  +-----------+       +-----------+
+#  | node1     |       | node2     |
+#  |           |       |           |
+#  |           |       |           |
+#  |      eth0 +-------+ eth0      |
+#  |           |       |           |
+#  |      eth1 +-------+ eth1      |
+#  |           |       |           |
+#  +-----------+       +-----------+
+lag_setup2x2()
+{
+	local state=${1:-down}
+	local namespaces="lag_node1 lag_node2"
+
+	# create namespaces
+	for n in ${namespaces}; do
+		ip netns add ${n}
+	done
+
+	# wire up namespaces
+	ip link add name lag1 type veth peer name lag1-end
+	ip link set dev lag1 netns lag_node1 $state name eth0
+	ip link set dev lag1-end netns lag_node2 $state name eth0
+
+	ip link add name lag1 type veth peer name lag1-end
+	ip link set dev lag1 netns lag_node1 $state name eth1
+	ip link set dev lag1-end netns lag_node2 $state name eth1
+
+	NAMESPACES="${namespaces}"
+}
+
+# cleanup all lag related namespaces and remove the bonding module
+lag_cleanup()
+{
+	for n in ${NAMESPACES}; do
+		ip netns delete ${n} >/dev/null 2>&1 || true
+	done
+	modprobe -r bonding
+}
+
+SWITCH="lag_node1"
+CLIENT="lag_node2"
+CLIENTIP="172.20.2.1"
+SWITCHIP="172.20.2.2"
+
+lag_setup_network()
+{
+	lag_setup2x2 "down"
+
+	# create switch
+	ip netns exec ${SWITCH} ip link add br0 up type bridge
+	ip netns exec ${SWITCH} ip link set eth0 master br0 up
+	ip netns exec ${SWITCH} ip link set eth1 master br0 up
+	ip netns exec ${SWITCH} ip addr add ${SWITCHIP}/24 dev br0
+}
+
+lag_reset_network()
+{
+	ip netns exec ${CLIENT} ip link del bond0
+	ip netns exec ${SWITCH} ip link set eth0 up
+	ip netns exec ${SWITCH} ip link set eth1 up
+}
+
+create_bond()
+{
+	# create client
+	ip netns exec ${CLIENT} ip link set eth0 down
+	ip netns exec ${CLIENT} ip link set eth1 down
+
+	ip netns exec ${CLIENT} ip link add bond0 type bond $@
+	ip netns exec ${CLIENT} ip link set eth0 master bond0
+	ip netns exec ${CLIENT} ip link set eth1 master bond0
+	ip netns exec ${CLIENT} ip link set bond0 up
+	ip netns exec ${CLIENT} ip addr add ${CLIENTIP}/24 dev bond0
+}
+
+test_bond_recovery()
+{
+	RET=0
+
+	create_bond $@
+
+	# verify connectivity
+	ip netns exec ${CLIENT} ping ${SWITCHIP} -c 2 >/dev/null 2>&1
+	check_err $? "No connectivity"
+
+	# force the links of the bond down
+	ip netns exec ${SWITCH} ip link set eth0 down
+	sleep 2
+	ip netns exec ${SWITCH} ip link set eth0 up
+	ip netns exec ${SWITCH} ip link set eth1 down
+
+	# re-verify connectivity
+	ip netns exec ${CLIENT} ping ${SWITCHIP} -c 2 >/dev/null 2>&1
+
+	local rc=$?
+	check_err $rc "Bond failed to recover"
+	log_test "$1 ($2) bond recovery"
+	lag_reset_network
+}

tools/testing/selftests/drivers/net/bonding/mode-1-recovery-updelay.sh

@@ -0,0 +1,45 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+
+# Regression Test:
+#  When the bond is configured with down/updelay and the link state of
+#  slave members flaps if there are no remaining members up the bond
+#  should immediately select a member to bring up. (from bonding.txt
+#  section 13.1 paragraph 4)
+#
+#  +-------------+       +-----------+
+#  | client      |       | switch    |
+#  |             |       |           |
+#  |    +--------| link1 |-----+     |
+#  |    |        +-------+     |     |
+#  |    |        |       |     |     |
+#  |    |        +-------+     |     |
+#  |    | bond   | link2 | Br0 |     |
+#  +-------------+       +-----------+
+#     172.20.2.1           172.20.2.2
+
+
+REQUIRE_MZ=no
+REQUIRE_JQ=no
+NUM_NETIFS=0
+lib_dir=$(dirname "$0")
+source "$lib_dir"/net_forwarding_lib.sh
+source "$lib_dir"/lag_lib.sh
+
+cleanup()
+{
+	lag_cleanup
+}
+
+trap cleanup 0 1 2
+
+lag_setup_network
+test_bond_recovery mode 1 miimon 100 updelay 0
+test_bond_recovery mode 1 miimon 100 updelay 200
+test_bond_recovery mode 1 miimon 100 updelay 500
+test_bond_recovery mode 1 miimon 100 updelay 1000
+test_bond_recovery mode 1 miimon 100 updelay 2000
+test_bond_recovery mode 1 miimon 100 updelay 5000
+test_bond_recovery mode 1 miimon 100 updelay 10000
+
+exit "$EXIT_STATUS"

tools/testing/selftests/drivers/net/bonding/mode-2-recovery-updelay.sh

@@ -0,0 +1,45 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+
+# Regression Test:
+#  When the bond is configured with down/updelay and the link state of
+#  slave members flaps if there are no remaining members up the bond
+#  should immediately select a member to bring up. (from bonding.txt
+#  section 13.1 paragraph 4)
+#
+#  +-------------+       +-----------+
+#  | client      |       | switch    |
+#  |             |       |           |
+#  |    +--------| link1 |-----+     |
+#  |    |        +-------+     |     |
+#  |    |        |       |     |     |
+#  |    |        +-------+     |     |
+#  |    | bond   | link2 | Br0 |     |
+#  +-------------+       +-----------+
+#     172.20.2.1           172.20.2.2
+
+
+REQUIRE_MZ=no
+REQUIRE_JQ=no
+NUM_NETIFS=0
+lib_dir=$(dirname "$0")
+source "$lib_dir"/net_forwarding_lib.sh
+source "$lib_dir"/lag_lib.sh
+
+cleanup()
+{
+	lag_cleanup
+}
+
+trap cleanup 0 1 2
+
+lag_setup_network
+test_bond_recovery mode 2 miimon 100 updelay 0
+test_bond_recovery mode 2 miimon 100 updelay 200
+test_bond_recovery mode 2 miimon 100 updelay 500
+test_bond_recovery mode 2 miimon 100 updelay 1000
+test_bond_recovery mode 2 miimon 100 updelay 2000
+test_bond_recovery mode 2 miimon 100 updelay 5000
+test_bond_recovery mode 2 miimon 100 updelay 10000
+
+exit "$EXIT_STATUS"

tools/testing/selftests/drivers/net/bonding/settings

@@ -1 +1 @@
-timeout=60
+timeout=120