cgroup: kselftest: relax fs_spec checks

On my laptop most memcg kselftests were being skipped because it claimed
cgroup v2 hierarchy wasn't mounted, but this isn't correct.  Instead, it
seems current systemd HEAD mounts it with the name "cgroup2" instead of
"cgroup":

    % grep cgroup /proc/mounts
    cgroup2 /sys/fs/cgroup cgroup2 rw,nosuid,nodev,noexec,relatime,nsdelegate 0 0

I can't think of a reason to need to check fs_spec explicitly
since it's arbitrary, so we can just rely on fs_vfstype.

After these changes, `make TARGETS=cgroup kselftest` actually runs the
cgroup v2 tests in more cases.

Link: http://lkml.kernel.org/r/20190723210737.GA487@chrisdown.name
Signed-off-by: Chris Down <chris@chrisdown.name>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/tools/testing/selftests/cgroup/cgroup_util.c b/tools/testing/selftests/cgroup/cgroup_util.c
index 4c223266299aa7c90c1288bcbed7fd891f802f3d..bdb69599c4bdc2526943cf9a690e1ef0697872dd 100644 (file)
--- a/tools/testing/selftests/cgroup/cgroup_util.c
+++ b/tools/testing/selftests/cgroup/cgroup_util.c
@@ -191,8 +191,7 @@ int cg_find_unified_root(char *root, size_t len)
                strtok(NULL, delim);
                strtok(NULL, delim);
 
-               if (strcmp(fs, "cgroup") == 0 &&
-                   strcmp(type, "cgroup2") == 0) {
+               if (strcmp(type, "cgroup2") == 0) {
                        strncpy(root, mount, len);
                        return 0;
                }