Driver Core: add ability for class_find_device to start in middle of list

This mirrors the functionality that driver_find_device has as well.

We add a start variable, and all callers of the function are fixed up at
the same time.

The block layer will be using this new functionality in a follow-on
patch.


Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

2 files changed, 14 insertions, 10 deletions

diff --git a/drivers/base/class.c b/drivers/base/class.c
index 2eb7048..3918d0e 100644
--- a/drivers/base/class.c
+++ b/drivers/base/class.c
@@ -302,6 +302,7 @@ EXPORT_SYMBOL_GPL(class_for_each_device);
 /**
  * class_find_device - device iterator for locating a particular device
  * @class: the class we're iterating
+ * @start: Device to begin with
  * @data: data for the match function
  * @match: function to check device
  *
@@ -319,8 +320,9 @@ EXPORT_SYMBOL_GPL(class_for_each_device);
  * re-acquired in @match, otherwise it will self-deadlocking. For
  * example, calls to add or remove class members would be verboten.
  */
-struct device *class_find_device(struct class *class, void *data,
-				   int (*match)(struct device *, void *))
+struct device *class_find_device(struct class *class, struct device *start,
+				 void *data,
+				 int (*match)(struct device *, void *))
 {
 	struct device *dev;
 	int found = 0;
@@ -330,15 +332,17 @@ struct device *class_find_device(struct class *class, void *data,
 
 	down(&class->sem);
 	list_for_each_entry(dev, &class->devices, node) {
+		if (start) {
+			if (start == dev)
+				start = NULL;
+			continue;
+		}
 		dev = get_device(dev);
-		if (dev) {
-			if (match(dev, data)) {
-				found = 1;
-				break;
-			} else
-				put_device(dev);
-		} else
+		if (match(dev, data)) {
+			found = 1;
 			break;
+		} else
+			put_device(dev);
 	}
 	up(&class->sem);
 
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 9ae28aa..9f05de6 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -1289,7 +1289,7 @@ void device_destroy(struct class *class, dev_t devt)
 {
 	struct device *dev;
 
-	dev = class_find_device(class, &devt, __match_devt);
+	dev = class_find_device(class, NULL, &devt, __match_devt);
 	if (dev) {
 		put_device(dev);
 		device_unregister(dev);