diff mbox series

[v3,bpf-next,01/11] cgroup: Remove unnecessary list_empty()

Message ID 20231029061438.4215-2-laoar.shao@gmail.com (mailing list archive)
State Changes Requested
Delegated to: BPF
Headers show
Series bpf, cgroup: Add BPF support for cgroup1 hierarchy | expand

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bpf/vmtest-bpf-next-PR success PR summary
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netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1371 this patch: 1371
netdev/cc_maintainers success CCed 5 of 5 maintainers
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Commit Message

Yafang Shao Oct. 29, 2023, 6:14 a.m. UTC 
The root hasn't been removed from the root_list, so the list can't be NULL.
However, if it had been removed, attempting to destroy it once more is not
possible. Let's replace this with WARN_ON_ONCE() for clarity.

Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
---
 kernel/cgroup/cgroup.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

Comments

Tejun Heo Nov. 9, 2023, 9:09 p.m. UTC | #1 
On Sun, Oct 29, 2023 at 06:14:28AM +0000, Yafang Shao wrote:
> The root hasn't been removed from the root_list, so the list can't be NULL.
> However, if it had been removed, attempting to destroy it once more is not
> possible. Let's replace this with WARN_ON_ONCE() for clarity.
> 
> Signed-off-by: Yafang Shao <laoar.shao@gmail.com>

Acked-by: Tejun Heo <tj@kernel.org>
diff mbox series

Patch

diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 1fb7f56..3053d42 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -1345,10 +1345,9 @@  static void cgroup_destroy_root(struct cgroup_root *root)
 
 	spin_unlock_irq(&css_set_lock);
 
-	if (!list_empty(&root->root_list)) {
-		list_del(&root->root_list);
-		cgroup_root_count--;
-	}
+	WARN_ON_ONCE(list_empty(&root->root_list));
+	list_del(&root->root_list);
+	cgroup_root_count--;
 
 	cgroup_favor_dynmods(root, false);
 	cgroup_exit_root_id(root);