From 4bd33b568855f5483a6c6d7e4706ef507ab8586b Mon Sep 17 00:00:00 2001
From: Janosch Frank <frankja@linux.vnet.ibm.com>
Date: Wed, 14 Oct 2015 12:37:35 +0200
Subject: KVM: Remove unnecessary debugfs dentry references

KVM creates debugfs files to export VM statistics to userland. To be
able to remove them on kvm exit it tracks the files' dentries.

Since their parent directory is also tracked and since each parent
direntry knows its children we can easily remove them by using
debugfs_remove_recursive(kvm_debugfs_dir). Therefore we don't
need the extra tracking in the kvm_stats_debugfs_item anymore.

Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Reviewed-By: Sascha Silbe <silbe@linux.vnet.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index a754fc0..590c46e 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1016,7 +1016,6 @@ struct kvm_stats_debugfs_item {
 	const char *name;
 	int offset;
 	enum kvm_stat_kind kind;
-	struct dentry *dentry;
 };
 extern struct kvm_stats_debugfs_item debugfs_entries[];
 extern struct dentry *kvm_debugfs_dir;
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 9649a42..be3cef1 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -3447,10 +3447,9 @@ static int kvm_init_debug(void)
 		goto out;
 
 	for (p = debugfs_entries; p->name; ++p) {
-		p->dentry = debugfs_create_file(p->name, 0444, kvm_debugfs_dir,
-						(void *)(long)p->offset,
-						stat_fops[p->kind]);
-		if (p->dentry == NULL)
+		if (!debugfs_create_file(p->name, 0444, kvm_debugfs_dir,
+					 (void *)(long)p->offset,
+					 stat_fops[p->kind]))
 			goto out_dir;
 	}
 
@@ -3462,15 +3461,6 @@ out:
 	return r;
 }
 
-static void kvm_exit_debug(void)
-{
-	struct kvm_stats_debugfs_item *p;
-
-	for (p = debugfs_entries; p->name; ++p)
-		debugfs_remove(p->dentry);
-	debugfs_remove(kvm_debugfs_dir);
-}
-
 static int kvm_suspend(void)
 {
 	if (kvm_usage_count)
@@ -3628,7 +3618,7 @@ EXPORT_SYMBOL_GPL(kvm_init);
 
 void kvm_exit(void)
 {
-	kvm_exit_debug();
+	debugfs_remove_recursive(kvm_debugfs_dir);
 	misc_deregister(&kvm_dev);
 	kmem_cache_destroy(kvm_vcpu_cache);
 	kvm_async_pf_deinit();
-- 
cgit v0.10.2