From: Yafang Shao <laoar.shao@gmail.com>
To: ast@kernel.org, daniel@iogearbox.net, john.fastabend@gmail.com,
andrii@kernel.org, martin.lau@linux.dev, song@kernel.org,
yonghong.song@linux.dev, kpsingh@kernel.org, sdf@google.com,
haoluo@google.com, jolsa@kernel.org, tj@kernel.org,
lizefan.x@bytedance.com, hannes@cmpxchg.org,
yosryahmed@google.com, mkoutny@suse.com, sinquersw@gmail.com,
longman@redhat.com
Cc: cgroups@vger.kernel.org, bpf@vger.kernel.org,
oliver.sang@intel.com, Yafang Shao <laoar.shao@gmail.com>
Subject: [PATCH v3 bpf-next 01/11] cgroup: Remove unnecessary list_empty()
Date: Sun, 29 Oct 2023 06:14:28 +0000 [thread overview]
Message-ID: <20231029061438.4215-2-laoar.shao@gmail.com> (raw)
In-Reply-To: <20231029061438.4215-1-laoar.shao@gmail.com>
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(-)
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);
--
1.8.3.1
next prev parent reply other threads:[~2023-10-29 6:14 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-29 6:14 [PATCH v3 bpf-next 00/11] bpf, cgroup: Add BPF support for cgroup1 hierarchy Yafang Shao
2023-10-29 6:14 ` Yafang Shao [this message]
2023-11-09 21:09 ` [PATCH v3 bpf-next 01/11] cgroup: Remove unnecessary list_empty() Tejun Heo
2023-10-29 6:14 ` [PATCH v3 bpf-next 02/11] cgroup: Make operations on the cgroup root_list RCU safe Yafang Shao
2023-11-09 21:19 ` Tejun Heo
2023-10-29 6:14 ` [PATCH v3 bpf-next 03/11] cgroup: Eliminate the need for cgroup_mutex in proc_cgroup_show() Yafang Shao
2023-11-09 21:20 ` Tejun Heo
2023-10-29 6:14 ` [PATCH v3 bpf-next 04/11] cgroup: Add annotation for holding namespace_sem in current_cgns_cgroup_from_root() Yafang Shao
2023-11-09 21:22 ` Tejun Heo
2023-10-29 6:14 ` [PATCH v3 bpf-next 05/11] cgroup: Add a new helper for cgroup1 hierarchy Yafang Shao
2023-11-09 9:33 ` Hou Tao
2023-11-09 21:27 ` Tejun Heo
2023-11-09 23:30 ` Tejun Heo
2023-11-10 2:37 ` Yafang Shao
2023-10-29 6:14 ` [PATCH v3 bpf-next 06/11] bpf: Add a new kfunc " Yafang Shao
2023-10-30 9:00 ` kernel test robot
2023-10-30 11:35 ` Yafang Shao
2023-10-30 13:59 ` Jiri Olsa
2023-10-31 2:40 ` Yafang Shao
2023-10-31 4:22 ` David Marchevsky
2023-11-03 8:18 ` kernel test robot
2023-11-03 8:49 ` Yafang Shao
2023-11-05 6:22 ` [PATCH bpf-next] compiler-gcc: Ignore -Wmissing-prototypes warning for older GCC Yafang Shao
2023-11-05 8:24 ` Arnd Bergmann
2023-11-05 11:54 ` Yafang Shao
2023-11-05 13:01 ` Arnd Bergmann
2023-11-05 13:50 ` Yafang Shao
2023-11-06 3:18 ` [PATCH v2 bpf-next] compiler-gcc: Suppress -Wmissing-prototypes warning for all supported GCC Yafang Shao
2023-11-09 18:23 ` Alexei Starovoitov
2023-11-10 6:34 ` Arnd Bergmann
2023-11-10 7:48 ` Yafang Shao
2023-11-10 16:00 ` patchwork-bot+netdevbpf
2023-11-09 21:29 ` [PATCH v3 bpf-next 06/11] bpf: Add a new kfunc for cgroup1 hierarchy Tejun Heo
2023-10-29 6:14 ` [PATCH v3 bpf-next 07/11] selftests/bpf: Fix issues in setup_classid_environment() Yafang Shao
2023-10-29 6:14 ` [PATCH v3 bpf-next 08/11] selftests/bpf: Add parallel support for classid Yafang Shao
2023-10-29 6:14 ` [PATCH v3 bpf-next 09/11] selftests/bpf: Add a new cgroup helper get_classid_cgroup_id() Yafang Shao
2023-10-29 6:14 ` [PATCH v3 bpf-next 10/11] selftests/bpf: Add a new cgroup helper get_cgroup_hierarchy_id() Yafang Shao
2023-11-09 21:32 ` Tejun Heo
2023-11-10 2:40 ` Yafang Shao
2023-10-29 6:14 ` [PATCH v3 bpf-next 11/11] selftests/bpf: Add selftests for cgroup1 hierarchy Yafang Shao
2023-11-09 21:36 ` [PATCH v3 bpf-next 00/11] bpf, cgroup: Add BPF support " Tejun Heo
2023-11-09 23:06 ` Alexei Starovoitov
2023-11-09 23:28 ` Tejun Heo
2023-11-09 23:35 ` Alexei Starovoitov
2023-11-10 6:04 ` Yafang Shao
2023-11-10 17:05 ` Alexei Starovoitov
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