driver core: revert "device" link creation check
[cascardo/linux.git] / drivers / base / core.c
index b78fc1e..e6738bc 100644 (file)
@@ -180,10 +180,12 @@ static int dev_uevent(struct kset *kset, struct kobject *kobj, char **envp,
                        const char *path;
 
                        path = kobject_get_path(&parent->kobj, GFP_KERNEL);
-                       add_uevent_var(envp, num_envp, &i,
-                                      buffer, buffer_size, &length,
-                                      "PHYSDEVPATH=%s", path);
-                       kfree(path);
+                       if (path) {
+                               add_uevent_var(envp, num_envp, &i,
+                                              buffer, buffer_size, &length,
+                                              "PHYSDEVPATH=%s", path);
+                               kfree(path);
+                       }
 
                        add_uevent_var(envp, num_envp, &i,
                                       buffer, buffer_size, &length,
@@ -301,13 +303,31 @@ out:
 static ssize_t store_uevent(struct device *dev, struct device_attribute *attr,
                            const char *buf, size_t count)
 {
-       if (memcmp(buf, "add", 3) != 0)
-               dev_err(dev, "uevent: unsupported action-string; this will "
-                       "be ignored in a future kernel version");
+       size_t len = count;
+       enum kobject_action action;
+
+       if (len && buf[len-1] == '\n')
+               len--;
+
+       for (action = 0; action < KOBJ_MAX; action++) {
+               if (strncmp(kobject_actions[action], buf, len) != 0)
+                       continue;
+               if (kobject_actions[action][len] != '\0')
+                       continue;
+               kobject_uevent(&dev->kobj, action);
+               goto out;
+       }
+
+       dev_err(dev, "uevent: unsupported action-string; this will "
+                    "be ignored in a future kernel version\n");
        kobject_uevent(&dev->kobj, KOBJ_ADD);
+out:
        return count;
 }
 
+static struct device_attribute uevent_attr =
+       __ATTR(uevent, S_IRUGO | S_IWUSR, show_uevent, store_uevent);
+
 static int device_add_attributes(struct device *dev,
                                 struct device_attribute *attrs)
 {
@@ -421,6 +441,9 @@ static ssize_t show_dev(struct device *dev, struct device_attribute *attr,
        return print_dev_t(buf, dev->devt);
 }
 
+static struct device_attribute devt_attr =
+       __ATTR(dev, S_IRUGO, show_dev, NULL);
+
 /*
  *     devices_subsys - structure to be registered with kobject core.
  */
@@ -635,6 +658,81 @@ static int setup_parent(struct device *dev, struct device *parent)
        return 0;
 }
 
+static int device_add_class_symlinks(struct device *dev)
+{
+       int error;
+
+       if (!dev->class)
+               return 0;
+       error = sysfs_create_link(&dev->kobj, &dev->class->subsys.kobj,
+                                 "subsystem");
+       if (error)
+               goto out;
+       /*
+        * If this is not a "fake" compatible device, then create the
+        * symlink from the class to the device.
+        */
+       if (dev->kobj.parent != &dev->class->subsys.kobj) {
+               error = sysfs_create_link(&dev->class->subsys.kobj, &dev->kobj,
+                                         dev->bus_id);
+               if (error)
+                       goto out_subsys;
+       }
+       if (dev->parent) {
+               error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
+                                         "device");
+               if (error)
+                       goto out_busid;
+#ifdef CONFIG_SYSFS_DEPRECATED
+               {
+                       char * class_name = make_class_name(dev->class->name,
+                                                               &dev->kobj);
+                       if (class_name)
+                               error = sysfs_create_link(&dev->parent->kobj,
+                                                       &dev->kobj, class_name);
+                       kfree(class_name);
+                       if (error)
+                               goto out_device;
+               }
+#endif
+       }
+       return 0;
+
+#ifdef CONFIG_SYSFS_DEPRECATED
+out_device:
+       if (dev->parent)
+               sysfs_remove_link(&dev->kobj, "device");
+#endif
+out_busid:
+       if (dev->kobj.parent != &dev->class->subsys.kobj)
+               sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
+out_subsys:
+       sysfs_remove_link(&dev->kobj, "subsystem");
+out:
+       return error;
+}
+
+static void device_remove_class_symlinks(struct device *dev)
+{
+       if (!dev->class)
+               return;
+       if (dev->parent) {
+#ifdef CONFIG_SYSFS_DEPRECATED
+               char *class_name;
+
+               class_name = make_class_name(dev->class->name, &dev->kobj);
+               if (class_name) {
+                       sysfs_remove_link(&dev->parent->kobj, class_name);
+                       kfree(class_name);
+               }
+#endif
+               sysfs_remove_link(&dev->kobj, "device");
+       }
+       if (dev->kobj.parent != &dev->class->subsys.kobj)
+               sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
+       sysfs_remove_link(&dev->kobj, "subsystem");
+}
+
 /**
  *     device_add - add device to device hierarchy.
  *     @dev:   device.
@@ -649,7 +747,6 @@ static int setup_parent(struct device *dev, struct device *parent)
 int device_add(struct device *dev)
 {
        struct device *parent = NULL;
-       char *class_name = NULL;
        struct class_interface *class_intf;
        int error = -EINVAL;
 
@@ -679,63 +776,27 @@ int device_add(struct device *dev)
                blocking_notifier_call_chain(&dev->bus->bus_notifier,
                                             BUS_NOTIFY_ADD_DEVICE, dev);
 
-       dev->uevent_attr.attr.name = "uevent";
-       dev->uevent_attr.attr.mode = S_IRUGO | S_IWUSR;
-       if (dev->driver)
-               dev->uevent_attr.attr.owner = dev->driver->owner;
-       dev->uevent_attr.store = store_uevent;
-       dev->uevent_attr.show = show_uevent;
-       error = device_create_file(dev, &dev->uevent_attr);
+       error = device_create_file(dev, &uevent_attr);
        if (error)
                goto attrError;
 
        if (MAJOR(dev->devt)) {
-               struct device_attribute *attr;
-               attr = kzalloc(sizeof(*attr), GFP_KERNEL);
-               if (!attr) {
-                       error = -ENOMEM;
-                       goto ueventattrError;
-               }
-               attr->attr.name = "dev";
-               attr->attr.mode = S_IRUGO;
-               if (dev->driver)
-                       attr->attr.owner = dev->driver->owner;
-               attr->show = show_dev;
-               error = device_create_file(dev, attr);
-               if (error) {
-                       kfree(attr);
+               error = device_create_file(dev, &devt_attr);
+               if (error)
                        goto ueventattrError;
-               }
-
-               dev->devt_attr = attr;
        }
 
-       if (dev->class) {
-               sysfs_create_link(&dev->kobj, &dev->class->subsys.kobj,
-                                 "subsystem");
-               /* If this is not a "fake" compatible device, then create the
-                * symlink from the class to the device. */
-               if (dev->kobj.parent != &dev->class->subsys.kobj)
-                       sysfs_create_link(&dev->class->subsys.kobj,
-                                         &dev->kobj, dev->bus_id);
-               if (parent) {
-                       sysfs_create_link(&dev->kobj, &dev->parent->kobj,
-                                                       "device");
-#ifdef CONFIG_SYSFS_DEPRECATED
-                       class_name = make_class_name(dev->class->name,
-                                                       &dev->kobj);
-                       if (class_name)
-                               sysfs_create_link(&dev->parent->kobj,
-                                                 &dev->kobj, class_name);
-#endif
-               }
-       }
-
-       if ((error = device_add_attrs(dev)))
+       error = device_add_class_symlinks(dev);
+       if (error)
+               goto SymlinkError;
+       error = device_add_attrs(dev);
+       if (error)
                goto AttrsError;
-       if ((error = device_pm_add(dev)))
+       error = device_pm_add(dev);
+       if (error)
                goto PMError;
-       if ((error = bus_add_device(dev)))
+       error = bus_add_device(dev);
+       if (error)
                goto BusError;
        kobject_uevent(&dev->kobj, KOBJ_ADD);
        bus_attach_device(dev);
@@ -754,7 +815,6 @@ int device_add(struct device *dev)
                up(&dev->class->sem);
        }
  Done:
-       kfree(class_name);
        put_device(dev);
        return error;
  BusError:
@@ -765,10 +825,10 @@ int device_add(struct device *dev)
                                             BUS_NOTIFY_DEL_DEVICE, dev);
        device_remove_attrs(dev);
  AttrsError:
-       if (dev->devt_attr) {
-               device_remove_file(dev, dev->devt_attr);
-               kfree(dev->devt_attr);
-       }
+       device_remove_class_symlinks(dev);
+ SymlinkError:
+       if (MAJOR(dev->devt))
+               device_remove_file(dev, &devt_attr);
 
        if (dev->class) {
                sysfs_remove_link(&dev->kobj, "subsystem");
@@ -790,7 +850,7 @@ int device_add(struct device *dev)
                }
        }
  ueventattrError:
-       device_remove_file(dev, &dev->uevent_attr);
+       device_remove_file(dev, &uevent_attr);
  attrError:
        kobject_uevent(&dev->kobj, KOBJ_REMOVE);
        kobject_del(&dev->kobj);
@@ -867,10 +927,8 @@ void device_del(struct device * dev)
 
        if (parent)
                klist_del(&dev->knode_parent);
-       if (dev->devt_attr) {
-               device_remove_file(dev, dev->devt_attr);
-               kfree(dev->devt_attr);
-       }
+       if (MAJOR(dev->devt))
+               device_remove_file(dev, &devt_attr);
        if (dev->class) {
                sysfs_remove_link(&dev->kobj, "subsystem");
                /* If this is not a "fake" compatible device, remove the
@@ -924,7 +982,7 @@ void device_del(struct device * dev)
                        up(&dev->class->sem);
                }
        }
-       device_remove_file(dev, &dev->uevent_attr);
+       device_remove_file(dev, &uevent_attr);
        device_remove_attrs(dev);
        bus_remove_device(dev);
 
@@ -1153,7 +1211,7 @@ int device_rename(struct device *dev, char *new_name)
 {
        char *old_class_name = NULL;
        char *new_class_name = NULL;
-       char *old_symlink_name = NULL;
+       char *old_device_name = NULL;
        int error;
 
        dev = get_device(dev);
@@ -1167,42 +1225,49 @@ int device_rename(struct device *dev, char *new_name)
                old_class_name = make_class_name(dev->class->name, &dev->kobj);
 #endif
 
-       if (dev->class) {
-               old_symlink_name = kmalloc(BUS_ID_SIZE, GFP_KERNEL);
-               if (!old_symlink_name) {
-                       error = -ENOMEM;
-                       goto out_free_old_class;
-               }
-               strlcpy(old_symlink_name, dev->bus_id, BUS_ID_SIZE);
+       old_device_name = kmalloc(BUS_ID_SIZE, GFP_KERNEL);
+       if (!old_device_name) {
+               error = -ENOMEM;
+               goto out;
        }
-
+       strlcpy(old_device_name, dev->bus_id, BUS_ID_SIZE);
        strlcpy(dev->bus_id, new_name, BUS_ID_SIZE);
 
        error = kobject_rename(&dev->kobj, new_name);
+       if (error) {
+               strlcpy(dev->bus_id, old_device_name, BUS_ID_SIZE);
+               goto out;
+       }
 
 #ifdef CONFIG_SYSFS_DEPRECATED
        if (old_class_name) {
                new_class_name = make_class_name(dev->class->name, &dev->kobj);
                if (new_class_name) {
-                       sysfs_create_link(&dev->parent->kobj, &dev->kobj,
-                                         new_class_name);
+                       error = sysfs_create_link(&dev->parent->kobj,
+                                                 &dev->kobj, new_class_name);
+                       if (error)
+                               goto out;
                        sysfs_remove_link(&dev->parent->kobj, old_class_name);
                }
        }
 #endif
 
        if (dev->class) {
-               sysfs_remove_link(&dev->class->subsys.kobj,
-                                 old_symlink_name);
-               sysfs_create_link(&dev->class->subsys.kobj, &dev->kobj,
-                                 dev->bus_id);
+               sysfs_remove_link(&dev->class->subsys.kobj, old_device_name);
+               error = sysfs_create_link(&dev->class->subsys.kobj, &dev->kobj,
+                                         dev->bus_id);
+               if (error) {
+                       /* Uh... how to unravel this if restoring can fail? */
+                       dev_err(dev, "%s: sysfs_create_symlink failed (%d)\n",
+                               __FUNCTION__, error);
+               }
        }
+out:
        put_device(dev);
 
        kfree(new_class_name);
-       kfree(old_symlink_name);
- out_free_old_class:
        kfree(old_class_name);
+       kfree(old_device_name);
 
        return error;
 }