cpuset: fix a regression in validating config change (1c09b195) · Commits · 戴 / test

It's not allowed to clear masks of a cpuset if there're tasks in it, but it's broken: # mkdir /cgroup/sub # echo 0 > /cgroup/sub/cpuset.cpus # echo 0 > /cgroup/sub/cpuset.mems # echo $$ > /cgroup/sub/tasks # echo > /cgroup/sub/cpuset.cpus (should fail) This bug was introduced by commit ("cpuset: allow to move tasks to empty cpusets"). tj: Dropped temp bool variables and nestes the conditionals directly. Signed-off-by:

Li Zefan <lizefan@huawei.com> Signed-off-by:

Tejun Heo <tj@kernel.org>

kernel/cpuset.c

+9 −5

Original line number	Diff line number	Diff line
		@@ -475,13 +475,17 @@ static int validate_change(const struct cpuset cur, const struct cpuset trial)

		/*
		* Cpusets with tasks - existing or newly being attached - can't
		* have empty cpus_allowed or mems_allowed.
		* be changed to have empty cpus_allowed or mems_allowed.
		*/
		ret = -ENOSPC;
		if ((cgroup_task_count(cur->css.cgroup) \|\| cur->attach_in_progress) &&
		(cpumask_empty(trial->cpus_allowed) &&
		nodes_empty(trial->mems_allowed)))
		if ((cgroup_task_count(cur->css.cgroup) \|\| cur->attach_in_progress)) {
		if (!cpumask_empty(cur->cpus_allowed) &&
		cpumask_empty(trial->cpus_allowed))
		goto out;
		if (!nodes_empty(cur->mems_allowed) &&
		nodes_empty(trial->mems_allowed))
		goto out;
		}

		ret = 0;
		out:

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