From ebiederm@xmission.com Fri Jul 20 23:21:18 2007 From: ebiederm@xmission.com (Eric W. Biederman) Date: Wed, 18 Jul 2007 22:47:27 -0600 Subject: [PATCH 4/4] driver core: Implement shadow directory support for device classes. To: Greg KH Cc: Greg KH , Dave Hansen , Benjamin Thery , Linux Containers , Tejun Heo Message-ID: This patch enables shadowing on every class directory if struct class has shadow_ops. In addition device_del and device_rename were modified to use sysfs_delete_link and sysfs_rename_link respectively to ensure when these operations happen on devices whos classes have shadow operations that they work properly. Signed-off-by: Eric W. Biederman Cc: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- drivers/base/class.c | 30 ++++++++++++++++++++++++++---- drivers/base/core.c | 45 ++++++++++++++++++++++++--------------------- include/linux/device.h | 2 ++ 3 files changed, 52 insertions(+), 25 deletions(-) --- a/drivers/base/class.c +++ b/drivers/base/class.c @@ -134,6 +134,17 @@ static void remove_class_attrs(struct cl } } +static int class_setup_shadowing(struct class *cls) +{ + const struct shadow_dir_operations *shadow_ops; + + shadow_ops = cls->shadow_ops; + if (!shadow_ops) + return 0; + + return sysfs_enable_shadowing(&cls->subsys.kobj, shadow_ops); +} + int class_register(struct class * cls) { int error; @@ -152,11 +163,22 @@ int class_register(struct class * cls) subsys_set_kset(cls, class_subsys); error = subsystem_register(&cls->subsys); - if (!error) { - error = add_class_attrs(class_get(cls)); - class_put(cls); - } + if (error) + goto out; + + error = class_setup_shadowing(cls); + if (error) + goto out_unregister; + + error = add_class_attrs(cls); + if (error) + goto out_unregister; + +out: return error; +out_unregister: + subsystem_unregister(&cls->subsys); + goto out; } void class_unregister(struct class * cls) --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -645,8 +645,14 @@ static struct kobject * get_device_paren return kobj; /* or create a new class-directory at the parent device */ - return kobject_kset_add_dir(&dev->class->class_dirs, + kobj = kobject_kset_add_dir(&dev->class->class_dirs, parent_kobj, dev->class->name); + + /* If we created a new class-directory setup shadowing */ + if (kobj && dev->class->shadow_ops) + sysfs_enable_shadowing(kobj, dev->class->shadow_ops); + + return kobj; } if (parent) @@ -843,8 +849,8 @@ int device_add(struct device *dev) /* If this is not a "fake" compatible device, remove the * symlink from the class to the device. */ if (dev->kobj.parent != &dev->class->subsys.kobj) - sysfs_remove_link(&dev->class->subsys.kobj, - dev->bus_id); + sysfs_delete_link(&dev->class->subsys.kobj, + &dev->kobj, dev->bus_id); if (parent && parent->bus) { #ifdef CONFIG_SYSFS_DEPRECATED char *class_name = make_class_name(dev->class->name, @@ -1241,6 +1247,13 @@ int device_rename(struct device *dev, ch strlcpy(old_device_name, dev->bus_id, BUS_ID_SIZE); strlcpy(dev->bus_id, new_name, BUS_ID_SIZE); + if (dev->class && (dev->kobj.parent != &dev->class->subsys.kobj)) { + error = sysfs_rename_link(&dev->class->subsys.kobj, + &dev->kobj, old_device_name, new_name); + if (error) + goto out; + } + error = kobject_rename(&dev->kobj, new_name); if (error) { strlcpy(dev->bus_id, old_device_name, BUS_ID_SIZE); @@ -1249,27 +1262,17 @@ int device_rename(struct device *dev, ch #ifdef CONFIG_SYSFS_DEPRECATED if (old_class_name) { + error = -ENOMEM; new_class_name = make_class_name(dev->class->name, &dev->kobj); - if (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 (!new_class_name) + goto out; - if (dev->class) { - 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); - } + error = sysfs_rename_link(&dev->parent->kobj, &dev->kobj, + old_class_name, new_class_name); + if (error) + goto out; } +#endif out: put_device(dev); --- a/include/linux/device.h +++ b/include/linux/device.h @@ -200,6 +200,8 @@ struct class { int (*suspend)(struct device *, pm_message_t state); int (*resume)(struct device *); + + const struct shadow_dir_operations *shadow_ops; }; extern int __must_check class_register(struct class *);