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>

1 files changed, 4 insertions, 14 deletions

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 9649a42e..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();