setup_hierarchy() mounts a bpffs on /sys/fs/bpf with setup_bpffs(), and
then sets up the cgroups with setup_cgroups(), which moves the test into
a private mount namespace.
The bpffs thus lands in the mount namespace that test_progs shares with
the tests running in parallel, on top of the bpffs already there, and
hides what they pin. cleanup_bpffs() later runs in the private mount
namespace and can't unmount it, so it stays there for good.
bpftool_maps_access then fails to pin an iterator because
/sys/fs/bpf/test_bpftool_map doesn't exist anymore, and bpftool_metadata
can't find the program it pinned in /sys/fs/bpf/test_metadata.
Set up the cgroups first, so that the bpffs is mounted in the private
mount namespace.
Fixes: 88886309d2e8 ("selftests/bpf: add a selftest for cgroup hierarchical
stats collection")
Signed-off-by: Qiliang Yuan <[email protected]>
---
tools/testing/selftests/bpf/prog_tests/cgroup_hierarchical_stats.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/cgroup_hierarchical_stats.c
b/tools/testing/selftests/bpf/prog_tests/cgroup_hierarchical_stats.c
index 3bd27d2ea668c..ad19d6d41918a 100644
--- a/tools/testing/selftests/bpf/prog_tests/cgroup_hierarchical_stats.c
+++ b/tools/testing/selftests/bpf/prog_tests/cgroup_hierarchical_stats.c
@@ -151,7 +151,7 @@ static void cleanup_cgroups(void)
/* Sets up cgroup hiearchary, returns 0 on success. */
static int setup_hierarchy(void)
{
- return setup_bpffs() || setup_cgroups();
+ return setup_cgroups() || setup_bpffs();
}
static void destroy_hierarchy(void)
--
2.43.0
