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Driver core: fix class glue dir cleanup logic
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We should remove the glue directory between the class and the bus
device _after_ we sent out the 'remove' event for the device, otherwise
the parent relationship is no longer valid, and composing the path
with deleted sysfs entries will not work.

Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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Kay Sievers authored and Greg Kroah-Hartman committed Jan 25, 2008
1 parent ef2c517 commit da231fd
Showing 1 changed file with 94 additions and 112 deletions.
206 changes: 94 additions & 112 deletions drivers/base/core.c
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Original file line number Diff line number Diff line change
Expand Up @@ -18,7 +18,7 @@
#include <linux/string.h>
#include <linux/kdev_t.h>
#include <linux/notifier.h>

#include <linux/genhd.h>
#include <asm/semaphore.h>

#include "base.h"
Expand Down Expand Up @@ -538,22 +538,20 @@ void device_initialize(struct device *dev)
}

#ifdef CONFIG_SYSFS_DEPRECATED
static struct kobject * get_device_parent(struct device *dev,
struct device *parent)
static struct kobject *get_device_parent(struct device *dev,
struct device *parent)
{
/*
* Set the parent to the class, not the parent device
* for topmost devices in class hierarchy.
* This keeps sysfs from having a symlink to make old
* udevs happy
*/
/* class devices without a parent live in /sys/class/<classname>/ */
if (dev->class && (!parent || parent->class != dev->class))
return &dev->class->subsys.kobj;
/* all other devices keep their parent */
else if (parent)
return &parent->kobj;

return NULL;
}

static inline void cleanup_device_parent(struct device *dev) {}
#else
static struct kobject *virtual_device_parent(struct device *dev)
{
Expand All @@ -566,8 +564,8 @@ static struct kobject *virtual_device_parent(struct device *dev)
return virtual_dir;
}

static struct kobject * get_device_parent(struct device *dev,
struct device *parent)
static struct kobject *get_device_parent(struct device *dev,
struct device *parent)
{
int retval;

Expand Down Expand Up @@ -618,6 +616,34 @@ static struct kobject * get_device_parent(struct device *dev,
return &parent->kobj;
return NULL;
}

static void cleanup_device_parent(struct device *dev)
{
struct device *d;
int other = 0;

if (!dev->class)
return;

/* see if we live in a parent class directory */
if (dev->kobj.parent->kset != &dev->class->class_dirs)
return;

/* if we are the last child of our class, delete the directory */
down(&dev->class->sem);
list_for_each_entry(d, &dev->class->devices, node) {
if (d == dev)
continue;
if (d->kobj.parent == dev->kobj.parent) {
other = 1;
break;
}
}
if (!other)
kobject_del(dev->kobj.parent);
kobject_put(dev->kobj.parent);
up(&dev->class->sem);
}
#endif

static int setup_parent(struct device *dev, struct device *parent)
Expand All @@ -637,65 +663,74 @@ static int device_add_class_symlinks(struct device *dev)

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.
*/

#ifdef CONFIG_SYSFS_DEPRECATED
/* stacked class devices need a symlink in the class directory */
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) {
#ifdef CONFIG_SYSFS_DEPRECATED
{
struct device *parent = dev->parent;
char *class_name;

/*
* In old sysfs stacked class devices had 'device'
* link pointing to real device instead of parent
*/
while (parent->class && !parent->bus && parent->parent)
parent = parent->parent;

error = sysfs_create_link(&dev->kobj,
&parent->kobj,
"device");
if (error)
goto out_busid;
struct device *parent = dev->parent;
char *class_name;

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;
}
#else
error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
/*
* stacked class devices have the 'device' link
* pointing to the bus device instead of the parent
*/
while (parent->class && !parent->bus && parent->parent)
parent = parent->parent;

error = sysfs_create_link(&dev->kobj,
&parent->kobj,
"device");
if (error)
goto out_busid;
#endif

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;
}
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);
#else
/* link in the class directory pointing to the device */
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;
}
return 0;

out_busid:
sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
#endif

out_subsys:
sysfs_remove_link(&dev->kobj, "subsystem");
out:
Expand All @@ -706,20 +741,28 @@ static void device_remove_class_symlinks(struct device *dev)
{
if (!dev->class)
return;
if (dev->parent) {

#ifdef CONFIG_SYSFS_DEPRECATED
if (dev->parent) {
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);
#else
if (dev->parent)
sysfs_remove_link(&dev->kobj, "device");

sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
#endif

sysfs_remove_link(&dev->kobj, "subsystem");
}

Expand Down Expand Up @@ -830,26 +873,6 @@ int device_add(struct device *dev)
SymlinkError:
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
* 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);
if (parent) {
#ifdef CONFIG_SYSFS_DEPRECATED
char *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");
}
}
ueventattrError:
device_remove_file(dev, &uevent_attr);
attrError:
Expand Down Expand Up @@ -932,23 +955,7 @@ void device_del(struct device * dev)
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
* 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);
if (parent) {
#ifdef CONFIG_SYSFS_DEPRECATED
char *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");
}
device_remove_class_symlinks(dev);

down(&dev->class->sem);
/* notify any interfaces that the device is now gone */
Expand All @@ -958,31 +965,6 @@ void device_del(struct device * dev)
/* remove the device from the class list */
list_del_init(&dev->node);
up(&dev->class->sem);

/* If we live in a parent class-directory, unreference it */
if (dev->kobj.parent->kset == &dev->class->class_dirs) {
struct device *d;
int other = 0;

/*
* if we are the last child of our class, delete
* our class-directory at this parent
*/
down(&dev->class->sem);
list_for_each_entry(d, &dev->class->devices, node) {
if (d == dev)
continue;
if (d->kobj.parent == dev->kobj.parent) {
other = 1;
break;
}
}
if (!other)
kobject_del(dev->kobj.parent);

kobject_put(dev->kobj.parent);
up(&dev->class->sem);
}
}
device_remove_file(dev, &uevent_attr);
device_remove_attrs(dev);
Expand All @@ -1004,9 +986,9 @@ void device_del(struct device * dev)
blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
BUS_NOTIFY_DEL_DEVICE, dev);
kobject_uevent(&dev->kobj, KOBJ_REMOVE);
cleanup_device_parent(dev);
kobject_del(&dev->kobj);
if (parent)
put_device(parent);
put_device(parent);
}

/**
Expand Down

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