[PATCH] sched,debug: fix dentry leak in update_sched_domain_debugfs

[Major Chen]

update_sched_domain_debugfs() uses debugfs_lookup() to find wanted dentry(which has
been created by debugfs_create_dir() before), but not call dput() to return this dentry
back. This result in dentry leak even debugfs_remove() is called.
 
Signed-off-by: major.chen <major.chen@xxxxxxxxxxx>
---
 kernel/sched/debug.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)
 
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index bb3d63b..4ffea2d 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -412,11 +412,14 @@ void update_sched_domain_debugfs(void)
 
         for_each_cpu(cpu, sd_sysctl_cpus) {
                 struct sched_domain *sd;
-                struct dentry *d_cpu;
+                struct dentry *d_cpu, *d_lookup;
                 char buf[32];
 
                 snprintf(buf, sizeof(buf), "cpu%d", cpu);
-                debugfs_remove(debugfs_lookup(buf, sd_dentry));
+                d_lookup = debugfs_lookup(buf, sd_dentry);
+                debugfs_remove(d_lookup);
+                if (!IS_ERR_OR_NULL(d_lookup))
+                        dput(d_lookup);
                 d_cpu = debugfs_create_dir(buf, sd_dentry);
 
                 i = 0;
-- 
2.7.4