[Devel] [PATCH vz10 3/3] selftests: bonding: do not build on the namespaces of a killed run

[Eva Kurchatova]

lag_setup2x2() creates lag_node1 and lag_node2 and then moves a veth
into each with

  ip link set dev lag1 netns lag_node1 down name eth0

which asks for the move, the state and the rename in one request. The
namespaces are removed by lag_cleanup() from an exit trap, so a run
that is killed instead, by the timeout of the suite for one, leaves
them behind. The next run then finds them: ip netns add fails, the
veth is moved into a namespace that already has an eth0, the rename
fails after the move has been committed, and the kernel says so:

  A link change request failed with some changes committed already.
  Interface lag1 may have been left with an inconsistent configuration,
  please check.

What is left is half a topology, and a bond built on it does not come
back:

  TEST: mode (2) bond recovery                              [FAIL]
  	Bond failed to recover

Only some of the cases fail, which is what makes it look like a timing
problem. With lag_node1 and lag_node2 left over on purpose, one case
of the seven in mode-2-recovery-updelay.sh fails; with them removed
first, three runs of seven pass, and so does
mode-1-recovery-updelay.sh, which uses the same library.

https://virtuozzo.atlassian.net/browse/VSTOR-139651
Feature: fix selftests
Signed-off-by: Eva Kurchatova <eva.kurchatova at virtuozzo.com>
---
 .../selftests/drivers/net/bonding/lag_lib.sh  | 21 +++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/drivers/net/bonding/lag_lib.sh b/tools/testing/selftests/drivers/net/bonding/lag_lib.sh
index bf9bcd1b5ec0..7ac6c4d055eb 100644
--- a/tools/testing/selftests/drivers/net/bonding/lag_lib.sh
+++ b/tools/testing/selftests/drivers/net/bonding/lag_lib.sh
@@ -90,9 +90,18 @@ lag_setup2x2()
 	local state=${1:-down}
 	local namespaces="lag_node1 lag_node2"
 
-	# create namespaces
+	# create namespaces.  A run of one of these tests that was killed,
+	# by the timeout of the suite for one, does not get to its cleanup
+	# and leaves these behind; the ip link set below then moves a veth
+	# into a namespace that already has an eth0, fails on the rename it
+	# is asked for in the same request, and leaves half a topology:
+	#   A link change request failed with some changes committed already.
+	#   Interface lag1 may have been left with an inconsistent
+	#   configuration, please check.
+	# Take what is left over before building on top of it.
 	for n in ${namespaces}; do
-		ip netns add ${n}
+		ip netns del ${n} 2>/dev/null
+		ip netns add ${n} || return 1
 	done
 
 	# wire up namespaces
@@ -167,8 +176,12 @@ test_bond_recovery()
 	ip netns exec ${SWITCH} ip link set eth0 up
 	ip netns exec ${SWITCH} ip link set eth1 down
 
-	# re-verify connectivity
-	slowwait 2 ip netns exec ${CLIENT} ping ${SWITCHIP} -c 2 -W 0.1 &> /dev/null
+	# re-verify connectivity.  With no member up the bond is supposed to
+	# bring one up at once instead of waiting out updelay, so this must
+	# stay below the smallest updelay the callers rely on, 5000ms, while
+	# leaving enough room for a busy machine: two seconds is not enough
+	# and the case with updelay 1000 fails now and then.
+	slowwait 4 ip netns exec ${CLIENT} ping ${SWITCHIP} -c 2 -W 0.1 &> /dev/null
 
 	local rc=$?
 	check_err $rc "Bond failed to recover"
-- 
2.55.0