Commit 8bf450f3 authored by Waiman Long's avatar Waiman Long Committed by Tejun Heo
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cgroup/cpuset: Fix error handling in remote_partition_disable() 



When remote_partition_disable() is called to disable a remote partition,
it always sets the partition to an invalid partition state. It should
only do so if an error code (prs_err) has been set. Correct that and
add proper error code in places where remote_partition_disable() is
called due to error.

Fixes: 181c8e09 ("cgroup/cpuset: Introduce remote partition")
Signed-off-by: default avatarWaiman Long <longman@redhat.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 668e0416

kernel/cgroup/cpuset.c

+20 −9
Original line number Diff line number Diff line
@@ -1406,6 +1406,7 @@ static int remote_partition_enable(struct cpuset *cs, int new_prs, 
	list_add(&cs->remote_sibling, &remote_children);

	spin_unlock_irq(&callback_lock);

	update_unbound_workqueue_cpumask(isolcpus_updated);

	cs->prs_err = 0;



	/*

	 * Propagate changes in top_cpuset's effective_cpus down the hierarchy.
@@ -1436,9 +1437,11 @@ static void remote_partition_disable(struct cpuset *cs, struct tmpmasks *tmp) 
	list_del_init(&cs->remote_sibling);

	isolcpus_updated = partition_xcpus_del(cs->partition_root_state,

					       NULL, tmp->new_cpus);

	if (cs->prs_err)

		cs->partition_root_state = -cs->partition_root_state;

	if (!cs->prs_err)

		cs->prs_err = PERR_INVCPUS;

	else

		cs->partition_root_state = PRS_MEMBER;



	reset_partition_data(cs);

	spin_unlock_irq(&callback_lock);

	update_unbound_workqueue_cpumask(isolcpus_updated);
@@ -1471,8 +1474,10 @@ static void remote_cpus_update(struct cpuset *cs, struct cpumask *newmask, 


	WARN_ON_ONCE(!cpumask_subset(cs->effective_xcpus, subpartitions_cpus));



	if (cpumask_empty(newmask))

	if (cpumask_empty(newmask)) {

		cs->prs_err = PERR_CPUSEMPTY;

		goto invalidate;

	}



	adding   = cpumask_andnot(tmp->addmask, newmask, cs->effective_xcpus);

	deleting = cpumask_andnot(tmp->delmask, cs->effective_xcpus, newmask);
@@ -1482,10 +1487,15 @@ static void remote_cpus_update(struct cpuset *cs, struct cpumask *newmask, 
	 * not allocated to other partitions and there are effective_cpus

	 * left in the top cpuset.

	 */

	if (adding && (!capable(CAP_SYS_ADMIN) ||

		       cpumask_intersects(tmp->addmask, subpartitions_cpus) ||

		       cpumask_subset(top_cpuset.effective_cpus, tmp->addmask)))

	if (adding) {

		if (!capable(CAP_SYS_ADMIN))

			cs->prs_err = PERR_ACCESS;

		else if (cpumask_intersects(tmp->addmask, subpartitions_cpus) ||

			 cpumask_subset(top_cpuset.effective_cpus, tmp->addmask))

			cs->prs_err = PERR_NOCPUS;

		if (cs->prs_err)

			goto invalidate;

	}



	spin_lock_irq(&callback_lock);

	if (adding)
@@ -1601,7 +1611,7 @@ static bool prstate_housekeeping_conflict(int prstate, struct cpumask *new_cpus) 
 * The partcmd_update command is used by update_cpumasks_hier() with newmask

 * NULL and update_cpumask() with newmask set. The partcmd_invalidate is used

 * by update_cpumask() with NULL newmask. In both cases, the callers won't

 * check for error and so partition_root_state and prs_error will be updated

 * check for error and so partition_root_state and prs_err will be updated

 * directly.

 */

static int update_parent_effective_cpumask(struct cpuset *cs, int cmd,
@@ -3739,6 +3749,7 @@ static void cpuset_hotplug_update_tasks(struct cpuset *cs, struct tmpmasks *tmp) 


	if (remote && cpumask_empty(&new_cpus) &&

	    partition_is_populated(cs, NULL)) {

		cs->prs_err = PERR_HOTPLUG;

		remote_partition_disable(cs, tmp);

		compute_effective_cpumask(&new_cpus, cs, parent);

		remote = false;