From: Li Zefan <lizefan@huawei.com>
Date: Tue, 13 Aug 2013 02:05:59 +0000 (+0800)
Subject: cpuset: fix the return value of cpuset_write_u64()
X-Git-Url: http://git.mmlx.us/?a=commitdiff_plain;h=9fa6018620ff121a3d892394021d4285636b7cd5;p=linux-edison.git

cpuset: fix the return value of cpuset_write_u64()

commit a903f0865a190f8778c73df1a810ea6e25e5d7cf upstream.

Writing to this file always returns -ENODEV:

  # echo 1 > cpuset.memory_pressure_enabled
  -bash: echo: write error: No such device

Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 64b3f791bbe..6948e9476b4 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -1502,11 +1502,13 @@ static int cpuset_write_u64(struct cgroup *cgrp, struct cftype *cft, u64 val)
 {
 	struct cpuset *cs = cgroup_cs(cgrp);
 	cpuset_filetype_t type = cft->private;
-	int retval = -ENODEV;
+	int retval = 0;
 
 	mutex_lock(&cpuset_mutex);
-	if (!is_cpuset_online(cs))
+	if (!is_cpuset_online(cs)) {
+		retval = -ENODEV;
 		goto out_unlock;
+	}
 
 	switch (type) {
 	case FILE_CPU_EXCLUSIVE: