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>

6 files changed, 210 insertions, 3 deletions

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 1cd4e71916f8..6c4348245d1f 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/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);
diff --git a/tools/testing/selftests/drivers/net/bonding/Makefile b/tools/testing/selftests/drivers/net/bonding/Makefile
index 6b8d2e2f23c2..0f3921908b07 100644
--- a/tools/testing/selftests/drivers/net/bonding/Makefile
+++ b/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 \
diff --git a/tools/testing/selftests/drivers/net/bonding/lag_lib.sh b/tools/testing/selftests/drivers/net/bonding/lag_lib.sh
index 16c7fb858ac1..2a268b17b61f 100644
--- a/tools/testing/selftests/drivers/net/bonding/lag_lib.sh
+++ b/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 ($2) bond recovery"
+	lag_reset_network
+}
diff --git a/tools/testing/selftests/drivers/net/bonding/mode-1-recovery-updelay.sh b/tools/testing/selftests/drivers/net/bonding/mode-1-recovery-updelay.sh
new file mode 100755
index 000000000000..ad4c845a4ac7
--- /dev/null
+++ b/tools/testing/selftests/drivers/net/bonding/mode-1-recovery-updelay.sh
@@ -0,0 +1,45 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+
+# Regression Test:
+#  When the bond is configured with down/updelay and the link state of
+#  slave members flaps if there are no remaining members up the bond
+#  should immediately select a member to bring up. (from bonding.txt
+#  section 13.1 paragraph 4)
+#
+#  +-------------+       +-----------+
+#  | client      |       | switch    |
+#  |             |       |           |
+#  |    +--------| link1 |-----+     |
+#  |    |        +-------+     |     |
+#  |    |        |       |     |     |
+#  |    |        +-------+     |     |
+#  |    | bond   | link2 | Br0 |     |
+#  +-------------+       +-----------+
+#     172.20.2.1           172.20.2.2
+
+
+REQUIRE_MZ=no
+REQUIRE_JQ=no
+NUM_NETIFS=0
+lib_dir=$(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"
diff --git a/tools/testing/selftests/drivers/net/bonding/mode-2-recovery-updelay.sh b/tools/testing/selftests/drivers/net/bonding/mode-2-recovery-updelay.sh
new file mode 100755
index 000000000000..2330d37453f9
--- /dev/null
+++ b/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"
diff --git a/tools/testing/selftests/drivers/net/bonding/settings b/tools/testing/selftests/drivers/net/bonding/settings
index 867e118223cd..6091b45d226b 100644
--- a/tools/testing/selftests/drivers/net/bonding/settings
+++ b/tools/testing/selftests/drivers/net/bonding/settings
@@ -1 +1 @@
-timeout=60
+timeout=120