Revert "driver core: check start node in klist_iter_init_node"

This reverts commit a15d49fd3094cff90e5410ca454a870e0a722fe1 as that
patch broke the build.

Cc: Hannes Reinecke <hare@suse.de>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

6 files changed, 46 insertions, 76 deletions

diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index 76aed01a8b2c..2bcef657a60c 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -296,13 +296,11 @@ int bus_for_each_dev(struct bus_type *bus, struct device *start,
         if (!bus)
                 return -EINVAL;
 
-        error = klist_iter_init_node(&bus->p->klist_devices, &i,
-                                     (start ? &start->p->knode_bus : NULL));
-        if (!error) {
-                while ((dev = next_device(&i)) && !error)
-                        error = fn(dev, data);
-                klist_iter_exit(&i);
-        }
+        klist_iter_init_node(&bus->p->klist_devices, &i,
+                             (start ? &start->p->knode_bus : NULL));
+        while ((dev = next_device(&i)) && !error)
+                error = fn(dev, data);
+        klist_iter_exit(&i);
         return error;
 }
 EXPORT_SYMBOL_GPL(bus_for_each_dev);
@@ -332,10 +330,8 @@ struct device *bus_find_device(struct bus_type *bus,
         if (!bus)
                 return NULL;
 
-        if (klist_iter_init_node(&bus->p->klist_devices, &i,
-                                 (start ? &start->p->knode_bus : NULL)) < 0)
-                return NULL;
-
+        klist_iter_init_node(&bus->p->klist_devices, &i,
+                             (start ? &start->p->knode_bus : NULL));
         while ((dev = next_device(&i)))
                 if (match(dev, data) && get_device(dev))
                         break;
@@ -388,9 +384,7 @@ struct device *subsys_find_device_by_id(struct bus_type *subsys, unsigned int id
                 return NULL;
 
         if (hint) {
-                if (klist_iter_init_node(&subsys->p->klist_devices, &i,
-                                         &hint->p->knode_bus) < 0)
-                        return NULL;
+                klist_iter_init_node(&subsys->p->klist_devices, &i, &hint->p->knode_bus);
                 dev = next_device(&i);
                 if (dev && dev->id == id && get_device(dev)) {
                         klist_iter_exit(&i);
@@ -452,13 +446,11 @@ int bus_for_each_drv(struct bus_type *bus, struct device_driver *start,
         if (!bus)
                 return -EINVAL;
 
-        error = klist_iter_init_node(&bus->p->klist_drivers, &i,
-                                     start ? &start->p->knode_bus : NULL);
-        if (!error) {
-                while ((drv = next_driver(&i)) && !error)
-                        error = fn(drv, data);
-                klist_iter_exit(&i);
-        }
+        klist_iter_init_node(&bus->p->klist_drivers, &i,
+                             start ? &start->p->knode_bus : NULL);
+        while ((drv = next_driver(&i)) && !error)
+                error = fn(drv, data);
+        klist_iter_exit(&i);
         return error;
 }
 EXPORT_SYMBOL_GPL(bus_for_each_drv);
@@ -1119,19 +1111,15 @@ EXPORT_SYMBOL_GPL(bus_sort_breadthfirst);
  * otherwise if it is NULL, the iteration starts at the beginning of
  * the list.
  */
-int subsys_dev_iter_init(struct subsys_dev_iter *iter, struct bus_type *subsys,
-                         struct device *start, const struct device_type *type)
+void subsys_dev_iter_init(struct subsys_dev_iter *iter, struct bus_type *subsys,
+                          struct device *start, const struct device_type *type)
 {
         struct klist_node *start_knode = NULL;
-        int error;
 
         if (start)
                 start_knode = &start->p->knode_bus;
-        error = klist_iter_init_node(&subsys->p->klist_devices, &iter->ki,
-                                     start_knode);
-        if (!error)
-                iter->type = type;
-        return error;
+        klist_iter_init_node(&subsys->p->klist_devices, &iter->ki, start_knode);
+        iter->type = type;
 }
 EXPORT_SYMBOL_GPL(subsys_dev_iter_init);
 
diff --git a/drivers/base/class.c b/drivers/base/class.c
index 23dbc661d4a0..03243d4002fd 100644
--- a/drivers/base/class.c
+++ b/drivers/base/class.c
@@ -301,20 +301,15 @@ void class_destroy(struct class *cls)
  * otherwise if it is NULL, the iteration starts at the beginning of
  * the list.
  */
-int class_dev_iter_init(struct class_dev_iter *iter, struct class *class,
-                        struct device *start, const struct device_type *type)
+void class_dev_iter_init(struct class_dev_iter *iter, struct class *class,
+                         struct device *start, const struct device_type *type)
 {
         struct klist_node *start_knode = NULL;
-        int error;
 
         if (start)
                 start_knode = &start->knode_class;
-        error = klist_iter_init_node(&class->p->klist_devices, &iter->ki,
-                                     start_knode);
-        if (!error)
-                iter->type = type;
-
-        return error;
+        klist_iter_init_node(&class->p->klist_devices, &iter->ki, start_knode);
+        iter->type = type;
 }
 EXPORT_SYMBOL_GPL(class_dev_iter_init);
 
@@ -392,15 +387,14 @@ int class_for_each_device(struct class *class, struct device *start,
                 return -EINVAL;
         }
 
-        error = class_dev_iter_init(&iter, class, start, NULL);
-        if (!error) {
-                while ((dev = class_dev_iter_next(&iter))) {
-                        error = fn(dev, data);
-                        if (error)
-                                break;
-                }
-                class_dev_iter_exit(&iter);
+        class_dev_iter_init(&iter, class, start, NULL);
+        while ((dev = class_dev_iter_next(&iter))) {
+                error = fn(dev, data);
+                if (error)
+                        break;
         }
+        class_dev_iter_exit(&iter);
+
         return error;
 }
 EXPORT_SYMBOL_GPL(class_for_each_device);
@@ -440,9 +434,7 @@ struct device *class_find_device(struct class *class, struct device *start,
                 return NULL;
         }
 
-        if (class_dev_iter_init(&iter, class, start, NULL) < 0)
-                return NULL;
-
+        class_dev_iter_init(&iter, class, start, NULL);
         while ((dev = class_dev_iter_next(&iter))) {
                 if (match(dev, data)) {
                         get_device(dev);
diff --git a/drivers/base/driver.c b/drivers/base/driver.c
index 16f6dd2c4403..3ec3896c83a6 100644
--- a/drivers/base/driver.c
+++ b/drivers/base/driver.c
@@ -49,13 +49,11 @@ int driver_for_each_device(struct device_driver *drv, struct device *start,
         if (!drv)
                 return -EINVAL;
 
-        error = klist_iter_init_node(&drv->p->klist_devices, &i,
-                                     start ? &start->p->knode_driver : NULL);
-        if (!error) {
-                while ((dev = next_device(&i)) && !error)
-                        error = fn(dev, data);
-                klist_iter_exit(&i);
-        }
+        klist_iter_init_node(&drv->p->klist_devices, &i,
+                             start ? &start->p->knode_driver : NULL);
+        while ((dev = next_device(&i)) && !error)
+                error = fn(dev, data);
+        klist_iter_exit(&i);
         return error;
 }
 EXPORT_SYMBOL_GPL(driver_for_each_device);
@@ -85,10 +83,8 @@ struct device *driver_find_device(struct device_driver *drv,
         if (!drv)
                 return NULL;
 
-        if (klist_iter_init_node(&drv->p->klist_devices, &i,
-                                 (start ? &start->p->knode_driver : NULL)) < 0)
-                return NULL;
-
+        klist_iter_init_node(&drv->p->klist_devices, &i,
+                             (start ? &start->p->knode_driver : NULL));
         while ((dev = next_device(&i)))
                 if (match(dev, data) && get_device(dev))
                         break;
diff --git a/include/linux/device.h b/include/linux/device.h
index 50429b911b21..5ad17cccdd71 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -128,7 +128,7 @@ struct subsys_dev_iter {
         struct klist_iter               ki;
         const struct device_type        *type;
 };
-int subsys_dev_iter_init(struct subsys_dev_iter *iter,
+void subsys_dev_iter_init(struct subsys_dev_iter *iter,
                          struct bus_type *subsys,
                          struct device *start,
                          const struct device_type *type);
@@ -380,10 +380,10 @@ int class_compat_create_link(struct class_compat *cls, struct device *dev,
 void class_compat_remove_link(struct class_compat *cls, struct device *dev,
                               struct device *device_link);
 
-extern int class_dev_iter_init(struct class_dev_iter *iter,
-                               struct class *class,
-                               struct device *start,
-                               const struct device_type *type);
+extern void class_dev_iter_init(struct class_dev_iter *iter,
+                                struct class *class,
+                                struct device *start,
+                                const struct device_type *type);
 extern struct device *class_dev_iter_next(struct class_dev_iter *iter);
 extern void class_dev_iter_exit(struct class_dev_iter *iter);
 
diff --git a/include/linux/klist.h b/include/linux/klist.h
index 9f633230f189..a370ce57cf1d 100644
--- a/include/linux/klist.h
+++ b/include/linux/klist.h
@@ -60,7 +60,7 @@ struct klist_iter {
 
 
 extern void klist_iter_init(struct klist *k, struct klist_iter *i);
-extern int klist_iter_init_node(struct klist *k, struct klist_iter *i,
+extern void klist_iter_init_node(struct klist *k, struct klist_iter *i,
                                  struct klist_node *n);
 extern void klist_iter_exit(struct klist_iter *i);
 extern struct klist_node *klist_next(struct klist_iter *i);
diff --git a/lib/klist.c b/lib/klist.c
index a2741a7d9784..0874e41609a6 100644
--- a/lib/klist.c
+++ b/lib/klist.c
@@ -278,19 +278,13 @@ EXPORT_SYMBOL_GPL(klist_node_attached);
  * Similar to klist_iter_init(), but starts the action off with @n,
  * instead of with the list head.
  */
-int klist_iter_init_node(struct klist *k, struct klist_iter *i,
-                         struct klist_node *n)
+void klist_iter_init_node(struct klist *k, struct klist_iter *i,
+                          struct klist_node *n)
 {
-        if (n) {
-                kref_get(&n->n_ref);
-                if (!n->n_klist) {
-                        kref_put(&n->n_ref);
-                        return -ENODEV;
-                }
-        }
         i->i_klist = k;
         i->i_cur = n;
-        return 0;
+        if (n)
+                kref_get(&n->n_ref);
 }
 EXPORT_SYMBOL_GPL(klist_iter_init_node);