ANDROID: kernel: cgroup: cpuset: Clear cpus_requested for empty buf
update_cpumask had a special case for empty buf which
did not update cpus_requested. This change reduces
differences (only to parsing) in empty/non-empty codepaths
to make them consistent.
Bug: 120444281
Fixes: 4803def4e0b2 ("ANDROID: cpuset: Make cpusets restore on hotplug")
Test: check that writes to /dev/cpuset/background/tasks
Test: work as expected, e.g.:
Test: echo $$ > /dev/cpuset/background/tasks
Test: echo > /dev/cpuset/background/tasks
Signed-off-by: Roman Kiryanov <rkir@google.com>
Change-Id: I49d320ea046636ec38bd23f053317abc59f64f8e
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index e0d05cf..428c8e5 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -957,24 +957,24 @@
return -EACCES;
/*
- * An empty cpus_allowed is ok only if the cpuset has no tasks.
+ * An empty cpus_requested is ok only if the cpuset has no tasks.
* Since cpulist_parse() fails on an empty mask, we special case
* that parsing. The validate_change() call ensures that cpusets
* with tasks have cpus.
*/
if (!*buf) {
- cpumask_clear(trialcs->cpus_allowed);
+ cpumask_clear(trialcs->cpus_requested);
} else {
retval = cpulist_parse(buf, trialcs->cpus_requested);
if (retval < 0)
return retval;
-
- if (!cpumask_subset(trialcs->cpus_requested, cpu_present_mask))
- return -EINVAL;
-
- cpumask_and(trialcs->cpus_allowed, trialcs->cpus_requested, cpu_active_mask);
}
+ if (!cpumask_subset(trialcs->cpus_requested, cpu_present_mask))
+ return -EINVAL;
+
+ cpumask_and(trialcs->cpus_allowed, trialcs->cpus_requested, cpu_active_mask);
+
/* Nothing to do if the cpus didn't change */
if (cpumask_equal(cs->cpus_requested, trialcs->cpus_requested))
return 0;