From: Tejun Heo <tj@kernel.org>
Date: Thu, 14 Nov 2019 14:46:51 -0800
Subject: [PATCH] cgroup: fix incorrect WARN_ON_ONCE() in cgroup_setup_root()
Git-commit: d7495343228f30d8206e92dccfd1c41adcfa142d
Patch-mainline: v5.5-rc1
References: bsc#1175995,jsc#SLE-15608
743210386c03 ("cgroup: use cgrp->kn->id as the cgroup ID") added WARN
which triggers if cgroup_id(root_cgrp) is not 1. This is fine on
64bit ino archs but on 32bit archs cgroup ID is ((gen << 32) | ino)
and gen starts at 1, so the root id is 0x1_0000_0001 instead of 1
always triggering the WARN.
What we wanna make sure is that the ino part is 1. Fix it.
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Fixes: 743210386c03 ("cgroup: use cgrp->kn->id as the cgroup ID")
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Hannes Reinecke <hare@suse.com>
---
kernel/cgroup/cgroup.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index c12dcf7dc432..53098c1d45e2 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -1966,7 +1966,7 @@ int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask)
goto exit_root_id;
}
root_cgrp->kn = root->kf_root->kn;
- WARN_ON_ONCE(cgroup_id(root_cgrp) != 1);
+ WARN_ON_ONCE(cgroup_ino(root_cgrp) != 1);
root_cgrp->ancestor_ids[0] = cgroup_id(root_cgrp);
ret = css_populate_dir(&root_cgrp->self);
--
2.16.4