Skip to content

Commit

Permalink
driver core: core: move to use class_to_subsys()
Browse files Browse the repository at this point in the history 
There are a number of places in core.c that need access to the private
subsystem structure of struct class, so move them to use
class_to_subsys() instead of accessing it directly.

This requires exporting class_to_subsys() out of class.c, but keeping it
local to the driver core.

Reviewed-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230331093318.82288-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  • Loading branch information
Greg Kroah-Hartman committed Mar 31, 2023
1 parent 6332a6c commit 7d90e81
Show file tree
Hide file tree
Showing 3 changed files with 81 additions and 44 deletions.
2 changes: 2 additions & 0 deletions drivers/base/base.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -73,6 +73,8 @@ static inline void subsys_put(struct subsys_private *sp)
kset_put(&sp->subsys);
}

struct subsys_private *class_to_subsys(const struct class *class);

struct driver_private {
struct kobject kobj;
struct klist klist_devices;
Expand Down
2 changes: 1 addition & 1 deletion drivers/base/class.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -39,7 +39,7 @@ static struct kset *class_kset;
* NULL. A call to subsys_put() must be done when finished with the pointer in
* order for it to be properly freed.
*/
static struct subsys_private *class_to_subsys(const struct class *class)
struct subsys_private *class_to_subsys(const struct class *class)
{
struct subsys_private *sp = NULL;
struct kobject *kobj;
Expand Down
121 changes: 78 additions & 43 deletions drivers/base/core.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -3149,8 +3149,8 @@ static const struct kobj_type class_dir_ktype = {
.child_ns_type = class_dir_child_ns_type
};

static struct kobject *
class_dir_create_and_add(const struct class *class, struct kobject *parent_kobj)
static struct kobject *class_dir_create_and_add(struct subsys_private *sp,
struct kobject *parent_kobj)
{
struct class_dir *dir;
int retval;
Expand All @@ -3159,12 +3159,12 @@ class_dir_create_and_add(const struct class *class, struct kobject *parent_kobj)
if (!dir)
return ERR_PTR(-ENOMEM);

dir->class = class;
dir->class = sp->class;
kobject_init(&dir->kobj, &class_dir_ktype);

dir->kobj.kset = &class->p->glue_dirs;
dir->kobj.kset = &sp->glue_dirs;

retval = kobject_add(&dir->kobj, parent_kobj, "%s", class->name);
retval = kobject_add(&dir->kobj, parent_kobj, "%s", sp->class->name);
if (retval < 0) {
kobject_put(&dir->kobj);
return ERR_PTR(retval);
Expand All @@ -3177,9 +3177,10 @@ static DEFINE_MUTEX(gdp_mutex);
static struct kobject *get_device_parent(struct device *dev,
struct device *parent)
{
struct subsys_private *sp = class_to_subsys(dev->class);
struct kobject *kobj = NULL;

if (dev->class) {
if (sp) {
struct kobject *parent_kobj;
struct kobject *k;

Expand All @@ -3190,30 +3191,34 @@ static struct kobject *get_device_parent(struct device *dev,
*/
if (parent == NULL)
parent_kobj = virtual_device_parent(dev);
else if (parent->class && !dev->class->ns_type)
else if (parent->class && !dev->class->ns_type) {
subsys_put(sp);
return &parent->kobj;
else
} else {
parent_kobj = &parent->kobj;
}

mutex_lock(&gdp_mutex);

/* find our class-directory at the parent and reference it */
spin_lock(&dev->class->p->glue_dirs.list_lock);
list_for_each_entry(k, &dev->class->p->glue_dirs.list, entry)
spin_lock(&sp->glue_dirs.list_lock);
list_for_each_entry(k, &sp->glue_dirs.list, entry)
if (k->parent == parent_kobj) {
kobj = kobject_get(k);
break;
}
spin_unlock(&dev->class->p->glue_dirs.list_lock);
spin_unlock(&sp->glue_dirs.list_lock);
if (kobj) {
mutex_unlock(&gdp_mutex);
subsys_put(sp);
return kobj;
}

/* or create a new class-directory at the parent device */
k = class_dir_create_and_add(dev->class, parent_kobj);
k = class_dir_create_and_add(sp, parent_kobj);
/* do not emit an uevent for this simple "glue" directory */
mutex_unlock(&gdp_mutex);
subsys_put(sp);
return k;
}

Expand All @@ -3236,10 +3241,23 @@ static struct kobject *get_device_parent(struct device *dev,
static inline bool live_in_glue_dir(struct kobject *kobj,
struct device *dev)
{
if (!kobj || !dev->class ||
kobj->kset != &dev->class->p->glue_dirs)
struct subsys_private *sp;
bool retval;

if (!kobj || !dev->class)
return false;
return true;

sp = class_to_subsys(dev->class);
if (!sp)
return false;

if (kobj->kset == &sp->glue_dirs)
retval = true;
else
retval = false;

subsys_put(sp);
return retval;
}

static inline struct kobject *get_glue_dir(struct device *dev)
Expand Down Expand Up @@ -3336,6 +3354,7 @@ static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
static int device_add_class_symlinks(struct device *dev)
{
struct device_node *of_node = dev_of_node(dev);
struct subsys_private *sp;
int error;

if (of_node) {
Expand All @@ -3345,12 +3364,11 @@ static int device_add_class_symlinks(struct device *dev)
/* An error here doesn't warrant bringing down the device */
}

if (!dev->class)
sp = class_to_subsys(dev->class);
if (!sp)
return 0;

error = sysfs_create_link(&dev->kobj,
&dev->class->p->subsys.kobj,
"subsystem");
error = sysfs_create_link(&dev->kobj, &sp->subsys.kobj, "subsystem");
if (error)
goto out_devnode;

Expand All @@ -3362,35 +3380,37 @@ static int device_add_class_symlinks(struct device *dev)
}

/* link in the class directory pointing to the device */
error = sysfs_create_link(&dev->class->p->subsys.kobj,
&dev->kobj, dev_name(dev));
error = sysfs_create_link(&sp->subsys.kobj, &dev->kobj, dev_name(dev));
if (error)
goto out_device;

return 0;
goto exit;

out_device:
sysfs_remove_link(&dev->kobj, "device");

out_subsys:
sysfs_remove_link(&dev->kobj, "subsystem");
out_devnode:
sysfs_remove_link(&dev->kobj, "of_node");
exit:
subsys_put(sp);
return error;
}

static void device_remove_class_symlinks(struct device *dev)
{
struct subsys_private *sp = class_to_subsys(dev->class);

if (dev_of_node(dev))
sysfs_remove_link(&dev->kobj, "of_node");

if (!dev->class)
if (!sp)
return;

if (dev->parent && device_is_not_partition(dev))
sysfs_remove_link(&dev->kobj, "device");
sysfs_remove_link(&dev->kobj, "subsystem");
sysfs_delete_link(&dev->class->p->subsys.kobj, &dev->kobj, dev_name(dev));
sysfs_delete_link(&sp->subsys.kobj, &dev->kobj, dev_name(dev));
subsys_put(sp);
}

/**
Expand Down Expand Up @@ -3499,6 +3519,7 @@ static int device_private_init(struct device *dev)
*/
int device_add(struct device *dev)
{
struct subsys_private *sp;
struct device *parent;
struct kobject *kobj;
struct class_interface *class_intf;
Expand Down Expand Up @@ -3627,18 +3648,18 @@ int device_add(struct device *dev)
klist_add_tail(&dev->p->knode_parent,
&parent->p->klist_children);

if (dev->class) {
mutex_lock(&dev->class->p->mutex);
sp = class_to_subsys(dev->class);
if (sp) {
mutex_lock(&sp->mutex);
/* tie the class to the device */
klist_add_tail(&dev->p->knode_class,
&dev->class->p->klist_devices);
klist_add_tail(&dev->p->knode_class, &sp->klist_devices);

/* notify any interfaces that the device is here */
list_for_each_entry(class_intf,
&dev->class->p->interfaces, node)
list_for_each_entry(class_intf, &sp->interfaces, node)
if (class_intf->add_dev)
class_intf->add_dev(dev, class_intf);
mutex_unlock(&dev->class->p->mutex);
mutex_unlock(&sp->mutex);
subsys_put(sp);
}
done:
put_device(dev);
Expand Down Expand Up @@ -3758,6 +3779,7 @@ EXPORT_SYMBOL_GPL(kill_device);
*/
void device_del(struct device *dev)
{
struct subsys_private *sp;
struct device *parent = dev->parent;
struct kobject *glue_dir = NULL;
struct class_interface *class_intf;
Expand All @@ -3784,18 +3806,20 @@ void device_del(struct device *dev)
device_remove_sys_dev_entry(dev);
device_remove_file(dev, &dev_attr_dev);
}
if (dev->class) {

sp = class_to_subsys(dev->class);
if (sp) {
device_remove_class_symlinks(dev);

mutex_lock(&dev->class->p->mutex);
mutex_lock(&sp->mutex);
/* notify any interfaces that the device is now gone */
list_for_each_entry(class_intf,
&dev->class->p->interfaces, node)
list_for_each_entry(class_intf, &sp->interfaces, node)
if (class_intf->remove_dev)
class_intf->remove_dev(dev, class_intf);
/* remove the device from the class list */
klist_del(&dev->p->knode_class);
mutex_unlock(&dev->class->p->mutex);
mutex_unlock(&sp->mutex);
subsys_put(sp);
}
device_remove_file(dev, &dev_attr_uevent);
device_remove_attrs(dev);
Expand Down Expand Up @@ -4458,9 +4482,16 @@ int device_rename(struct device *dev, const char *new_name)
}

if (dev->class) {
error = sysfs_rename_link_ns(&dev->class->p->subsys.kobj,
kobj, old_device_name,
struct subsys_private *sp = class_to_subsys(dev->class);

if (!sp) {
error = -EINVAL;
goto out;
}

error = sysfs_rename_link_ns(&sp->subsys.kobj, kobj, old_device_name,
new_name, kobject_namespace(kobj));
subsys_put(sp);
if (error)
goto out;
}
Expand Down Expand Up @@ -4643,6 +4674,7 @@ int device_change_owner(struct device *dev, kuid_t kuid, kgid_t kgid)
{
int error;
struct kobject *kobj = &dev->kobj;
struct subsys_private *sp;

dev = get_device(dev);
if (!dev)
Expand Down Expand Up @@ -4685,10 +4717,13 @@ int device_change_owner(struct device *dev, kuid_t kuid, kgid_t kgid)
* directory entry for @dev to @kuid/@kgid. This ensures that the
* symlink shows the same permissions as its target.
*/
error = sysfs_link_change_owner(&dev->class->p->subsys.kobj, &dev->kobj,
dev_name(dev), kuid, kgid);
if (error)
sp = class_to_subsys(dev->class);
if (!sp) {
error = -EINVAL;
goto out;
}
error = sysfs_link_change_owner(&sp->subsys.kobj, &dev->kobj, dev_name(dev), kuid, kgid);
subsys_put(sp);

out:
put_device(dev);
Expand Down

0 comments on commit 7d90e81

Please sign in to comment.