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Commit bdbb0a13 authored by Tejun Heo's avatar Tejun Heo Committed by Greg Kroah-Hartman
Browse files

s390: use device_remove_file_self() instead of device_schedule_callback() 



driver-core now supports synchrnous self-deletion of attributes and
the asynchrnous removal mechanism is scheduled for removal.  Use it
instead of device_schedule_callback().

* Conversions in arch/s390/pci/pci_sysfs.c and
  drivers/s390/block/dcssblk.c are straightforward.

* drivers/s390/cio/ccwgroup.c is a bit more tricky because
  ccwgroup_notifier() was (ab)using device_schedule_callback() to
  purely obtain a process context to kick off ungroup operation which
  may block from a notifier callback.

  Rename ccwgroup_ungroup_callback() to ccwgroup_ungroup() and make it
  take ccwgroup_device * instead.  The new function is now called
  directly from ccwgroup_ungroup_store().

  ccwgroup_notifier() chain is updated to explicitly bounce through
  ccwgroup_device->ungroup_work.  This also removes possible failure
  from memory pressure.

Only compile-tested.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Cc: linux-s390@vger.kernel.org
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent de1dee78

arch/s390/include/asm/ccwgroup.h

+1 −0
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ struct ccwgroup_device { 
	unsigned int count;

	struct device	dev;

	struct ccw_device *cdev[0];

	struct work_struct ungroup_work;

};



/**

arch/s390/pci/pci_sysfs.c

+8 −10
Original line number Diff line number Diff line
@@ -48,29 +48,27 @@ static ssize_t show_pfgid(struct device *dev, struct device_attribute *attr, 
}

static DEVICE_ATTR(pfgid, S_IRUGO, show_pfgid, NULL);



static void recover_callback(struct device *dev)

static ssize_t store_recover(struct device *dev, struct device_attribute *attr,

			     const char *buf, size_t count)

{

	struct pci_dev *pdev = to_pci_dev(dev);

	struct zpci_dev *zdev = get_zdev(pdev);

	int ret;



	if (!device_remove_file_self(dev, attr))

		return count;



	pci_stop_and_remove_bus_device(pdev);

	ret = zpci_disable_device(zdev);

	if (ret)

		return;

		return ret;



	ret = zpci_enable_device(zdev);

	if (ret)

		return;

		return ret;



	pci_rescan_bus(zdev->bus);

}



static ssize_t store_recover(struct device *dev, struct device_attribute *attr,

			     const char *buf, size_t count)

{

	int rc = device_schedule_callback(dev, recover_callback);

	return rc ? rc : count;

	return count;

}

static DEVICE_ATTR(recover, S_IWUSR, NULL, store_recover);

drivers/s390/block/dcssblk.c

+7 −7
Original line number Diff line number Diff line
@@ -304,12 +304,6 @@ dcssblk_load_segment(char *name, struct segment_info **seg_info) 
	return rc;

}



static void dcssblk_unregister_callback(struct device *dev)

{

	device_unregister(dev);

	put_device(dev);

}



/*

 * device attribute for switching shared/nonshared (exclusive)

 * operation (show + store)
@@ -397,7 +391,13 @@ dcssblk_shared_store(struct device *dev, struct device_attribute *attr, const ch 
	blk_cleanup_queue(dev_info->dcssblk_queue);

	dev_info->gd->queue = NULL;

	put_disk(dev_info->gd);

	rc = device_schedule_callback(dev, dcssblk_unregister_callback);

	up_write(&dcssblk_devices_sem);



	if (device_remove_file_self(dev, attr)) {

		device_unregister(dev);

		put_device(dev);

	}

	return rc;

out:

	up_write(&dcssblk_devices_sem);

	return rc;

drivers/s390/cio/ccwgroup.c

+16 −10
Original line number Diff line number Diff line
@@ -168,14 +168,12 @@ static ssize_t ccwgroup_online_show(struct device *dev, 
 * Provide an 'ungroup' attribute so the user can remove group devices no

 * longer needed or accidentially created. Saves memory :)

 */

static void ccwgroup_ungroup_callback(struct device *dev)

static void ccwgroup_ungroup(struct ccwgroup_device *gdev)

{

	struct ccwgroup_device *gdev = to_ccwgroupdev(dev);



	mutex_lock(&gdev->reg_mutex);

	if (device_is_registered(&gdev->dev)) {

		__ccwgroup_remove_symlinks(gdev);

		device_unregister(dev);

		device_unregister(&gdev->dev);

		__ccwgroup_remove_cdev_refs(gdev);

	}

	mutex_unlock(&gdev->reg_mutex);
@@ -195,10 +193,9 @@ static ssize_t ccwgroup_ungroup_store(struct device *dev, 
		rc = -EINVAL;

		goto out;

	}

	/* Note that we cannot unregister the device from one of its

	 * attribute methods, so we have to use this roundabout approach.

	 */

	rc = device_schedule_callback(dev, ccwgroup_ungroup_callback);



	if (device_remove_file_self(dev, attr))

		ccwgroup_ungroup(gdev);

out:

	if (rc) {

		if (rc != -EAGAIN)
@@ -224,6 +221,14 @@ static const struct attribute_group *ccwgroup_attr_groups[] = { 
	NULL,

};



static void ccwgroup_ungroup_workfn(struct work_struct *work)

{

	struct ccwgroup_device *gdev =

		container_of(work, struct ccwgroup_device, ungroup_work);



	ccwgroup_ungroup(gdev);

}



static void ccwgroup_release(struct device *dev)

{

	kfree(to_ccwgroupdev(dev));
@@ -323,6 +328,7 @@ int ccwgroup_create_dev(struct device *parent, struct ccwgroup_driver *gdrv, 
	atomic_set(&gdev->onoff, 0);

	mutex_init(&gdev->reg_mutex);

	mutex_lock(&gdev->reg_mutex);

	INIT_WORK(&gdev->ungroup_work, ccwgroup_ungroup_workfn);

	gdev->count = num_devices;

	gdev->dev.bus = &ccwgroup_bus_type;

	gdev->dev.parent = parent;
@@ -404,10 +410,10 @@ EXPORT_SYMBOL(ccwgroup_create_dev); 
static int ccwgroup_notifier(struct notifier_block *nb, unsigned long action,

			     void *data)

{

	struct device *dev = data;

	struct ccwgroup_device *gdev = to_ccwgroupdev(data);



	if (action == BUS_NOTIFY_UNBIND_DRIVER)

		device_schedule_callback(dev, ccwgroup_ungroup_callback);

		schedule_work(&gdev->ungroup_work);



	return NOTIFY_OK;

}