[PATCH 155/196] Driver core: fix class glue dir cleanup logic

Greg Kroah-Hartman
2008-01-25T08:34:45Z

From: Kay Sievers <kay.sievers@vrfy.org>

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the parent relationship is no longer valid, and composing the path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>
---
drivers/base/core.c | 206 +++++++++++++++++++++++----------------------------
1 files changed, 94 insertions(+), 112 deletions(-)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 22fdf32..13cae18 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -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"
@@ -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)
{
@@ -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;

@@ -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)
@@ -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:
@@ -706,8 +741,9 @@ 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);
@@ -715,11 +751,18 @@ static void device_remove_class_symlinks(struct device *dev)
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");
}

@@ -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:
@@ -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 */
@@ -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);
@@ -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);
}

/**
--
1.5.3.8