[PATCH 09/10] driver core: Implement tagged directory support for device classes.

Eric W. Biederman
2007-12-01T09:39:25Z

This patch enables tagging on every class directory if struct class
has tag_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 whose classes have tag_ops that they
work properly.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
drivers/base/class.c | 30 ++++++++++++++++++++++++---
drivers/base/core.c | 51 +++++++++++++++++++++++++----------------------
include/linux/device.h | 2 +
3 files changed, 55 insertions(+), 28 deletions(-)

diff --git a/drivers/base/class.c b/drivers/base/class.c
index c4f8843..ed9393d 100644
--- a/drivers/base/class.c
+++ b/drivers/base/class.c
@@ -135,6 +135,17 @@ static void remove_class_attrs(struct class * cls)
}
}

+static int class_setup_tagging(struct class *cls)
+{
+ const struct sysfs_tagged_dir_operations *tag_ops;
+
+ tag_ops = cls->tag_ops;
+ if (!tag_ops)
+ return 0;
+
+ return sysfs_enable_tagging(&cls->subsys.kobj, tag_ops);
+}
+
int class_register(struct class * cls)
{
int error;
@@ -160,11 +171,22 @@ int class_register(struct class * cls)
cls->subsys.kobj.ktype = &class_ktype;

error = kset_register(&cls->subsys);
- if (!error) {
- error = add_class_attrs(class_get(cls));
- class_put(cls);
- }
+ if (error)
+ goto out;
+
+ error = class_setup_tagging(cls);
+ if (error)
+ goto out_unregister;
+
+ error = add_class_attrs(cls);
+ if (error)
+ goto out_unregister;
+
+out:
return error;
+out_unregister:
+ kset_unregister(&cls->subsys);
+ goto out;
}

void class_unregister(struct class * cls)
diff --git a/drivers/base/core.c b/drivers/base/core.c
index a2c3d4e..f9d3fcf 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -600,16 +600,20 @@ static struct kobject *get_device_parent(struct device *dev,
return kobj;

/* or create a new class-directory at the parent device */
- k = kobject_create(dev->class->name, parent_kobj);
- if (!k)
+bser kobj = kobject_create(dev->class->name, parent_kobj);
+ if (!kobj)
return NULL;
- k->kset = &dev->class->class_dirs;
- retval = kobject_register(k);
+ kobj->kset = &dev->class->class_dirs;
+ retval = kobject_register(kobj);
if (retval < 0) {
- kfree(k);
+ kfree(kobj);
return NULL;
}
- return k;
+ /* If we created a new class-directory setup tagging */
+ if (kobj && dev->class->tag_ops)
+ sysfs_enable_tagging(k, dev->class->tag_ops);
+
+ return kobj;
}

if (parent)
@@ -758,7 +762,8 @@ static void device_remove_class_symlinks(struct device *dev)

if (dev->kobj.parent != &dev->class->subsys.kobj &&
dev->type != &part_type)
- sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
+ sysfs_delete_link(&dev->class->subsys.kobj,
+ &dev->kobj, dev->bus_id);
#else
if (dev->parent && dev->type != &part_type)
sysfs_remove_link(&dev->kobj, "device");
@@ -1223,6 +1228,15 @@ int device_rename(struct device *dev, char *new_name)
strlcpy(old_device_name, dev->bus_id, BUS_ID_SIZE);
strlcpy(dev->bus_id, new_name, BUS_ID_SIZE);

+#ifndef CONFIG_SYSFS_DEPRECATED
+ 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;
+ }
+#endif
+
error = kobject_rename(&dev->kobj, new_name);
if (error) {
strlcpy(dev->bus_id, old_device_name, BUS_ID_SIZE);
@@ -1231,24 +1245,13 @@ int device_rename(struct device *dev, char *new_name)

#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);
- }
- }
-#else
- 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) {
- dev_err(dev, "%s: sysfs_create_symlink failed (%d)\n",
- __FUNCTION__, error);
- }
+ if (new_class_name)
+ error = sysfs_rename_link(&dev->parent->kobj,
+ &dev->kobj,
+ old_class_name,
+ new_class_name);
}
#endif

diff --git a/include/linux/device.h b/include/linux/device.h
index ed38712..80ba08f 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -187,6 +187,8 @@ struct class {

int (*suspend)(struct device *, pm_message_t state);
int (*resume)(struct device *);
+
+ const struct sysfs_tagged_dir_operations *tag_ops;
};

extern int __must_check class_register(struct class *);
--
1.5.3.rc6.17.g1911