[Devel] [PATCH rh7] ve/drivers: Do not forget to release mismatched device found

[Vladimir Davydov]

On Thu, Jul 09, 2015 at 12:49:25PM +0300, Cyrill Gorcunov wrote:
[...]
> --- linux-pcs7.git.orig/drivers/base/core.c
> +++ linux-pcs7.git/drivers/base/core.c
> @@ -1838,15 +1838,12 @@ EXPORT_SYMBOL_GPL(device_destroy);
>  
>  void device_destroy_namespace(struct class *class, dev_t devt, void *ns)
>  {
> -	struct device *dev = NULL;
> +	struct device *dev = NULL, *prev = NULL;
>  
> -	for (;;) {
> -		dev = class_find_device(class, dev, &devt, __match_devt);
> -		if (!dev)
> -			break;
> -		if (!class->namespace ||
> -		    (class->namespace(dev) == ns))
> -			break;
> +	for (dev = class_find_device(class, dev, &devt, __match_devt);
> +	     dev && (class->namespace && class->namespace(dev) != ns);) {
> +		prev = dev, dev = class_find_device(class, dev, &devt, __match_devt);
> +		put_device(prev);
>  	}
>  
>  	if (dev) {
> 

I think class_find_device is already capable of doing this. It just
needs a bit tweaked match function. Something like this, may be?
---
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 6583bece847f..6b0e8139269a 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -1836,19 +1836,28 @@ void device_destroy(struct class *class, dev_t devt)
 }
 EXPORT_SYMBOL_GPL(device_destroy);
 
-void device_destroy_namespace(struct class *class, dev_t devt, void *ns)
+struct __match_devt_ns_arg {
+	dev_t devt;
+	void *ns;
+};
+
+static int __match_devt_ns(struct device *dev, const void *data)
 {
-	struct device *dev = NULL;
+	const __match_devt_ns_arg *arg = data;
 
-	for (;;) {
-		dev = class_find_device(class, dev, &devt, __match_devt);
-		if (!dev)
-			break;
-		if (!class->namespace ||
-		    (class->namespace(dev) == ns))
-			break;
-	}
+	return dev->devt == arg->devt &&
+		(!dev->class->namespace || dev->class->namespace(dev) == ns);
+}
+
+void device_destroy_namespace(struct class *class, dev_t devt, void *ns)
+{
+	struct __match_devt_ns_arg arg = {
+		.devt = devt,
+		.ns = ns,
+	};
+	struct device *dev;
 
+	dev = class_find_device(class, NULL, &arg, __match_devt_ns);
 	if (dev) {
 		put_device(dev);
 		device_unregister(dev);