Commit d76123eb authored by Cornelia Huck's avatar Cornelia Huck Committed by Martin Schwidefsky
Browse files

[S390] cio: ccwgroup register vs. unregister. 



Introduce a mutex for struct ccwgroup to prevent simuntaneous
register/unregister on the same ccwgroup device.

Signed-off-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 82b7ac05

drivers/s390/cio/ccwgroup.c

+18 −15
Original line number Diff line number Diff line
@@ -75,8 +75,10 @@ static void ccwgroup_ungroup_callback(struct device *dev) 
{

	struct ccwgroup_device *gdev = to_ccwgroupdev(dev);



	mutex_lock(&gdev->reg_mutex);

	__ccwgroup_remove_symlinks(gdev);

	device_unregister(dev);

	mutex_unlock(&gdev->reg_mutex);

}



static ssize_t
@@ -173,7 +175,8 @@ ccwgroup_create(struct device *root, 
		return -ENOMEM;



	atomic_set(&gdev->onoff, 0);



	mutex_init(&gdev->reg_mutex);

	mutex_lock(&gdev->reg_mutex);

	for (i = 0; i < argc; i++) {

		gdev->cdev[i] = get_ccwdev_by_busid(cdrv, argv[i]);
@@ -183,12 +186,12 @@ ccwgroup_create(struct device *root, 
		    || gdev->cdev[i]->id.driver_info !=

		    gdev->cdev[0]->id.driver_info) {

			rc = -EINVAL;

			goto free_dev;

			goto error;

		}

		/* Don't allow a device to belong to more than one group. */

		if (gdev->cdev[i]->dev.driver_data) {

			rc = -EINVAL;

			goto free_dev;

			goto error;

		}

		gdev->cdev[i]->dev.driver_data = gdev;

	}
@@ -203,9 +206,8 @@ ccwgroup_create(struct device *root, 
			gdev->cdev[0]->dev.bus_id);



	rc = device_register(&gdev->dev);

	

	if (rc)

		goto free_dev;

		goto error;

	get_device(&gdev->dev);

	rc = device_create_file(&gdev->dev, &dev_attr_ungroup);
@@ -216,27 +218,21 @@ ccwgroup_create(struct device *root, 


	rc = __ccwgroup_create_symlinks(gdev);

	if (!rc) {

		mutex_unlock(&gdev->reg_mutex);

		put_device(&gdev->dev);

		return 0;

	}

	device_remove_file(&gdev->dev, &dev_attr_ungroup);

	device_unregister(&gdev->dev);

error:

	for (i = 0; i < argc; i++)

		if (gdev->cdev[i]) {

			put_device(&gdev->cdev[i]->dev);

			gdev->cdev[i]->dev.driver_data = NULL;

		}

	put_device(&gdev->dev);

	return rc;

free_dev:

	for (i = 0; i < argc; i++)

		if (gdev->cdev[i]) {

			if (gdev->cdev[i]->dev.driver_data == gdev)

				gdev->cdev[i]->dev.driver_data = NULL;

			put_device(&gdev->cdev[i]->dev);

		}

	kfree(gdev);

	mutex_unlock(&gdev->reg_mutex);

	put_device(&gdev->dev);

	return rc;

}
@@ -422,8 +418,12 @@ ccwgroup_driver_unregister (struct ccwgroup_driver *cdriver) 
	get_driver(&cdriver->driver);

	while ((dev = driver_find_device(&cdriver->driver, NULL, NULL,

					 __ccwgroup_match_all))) {

		__ccwgroup_remove_symlinks(to_ccwgroupdev(dev));

		struct ccwgroup_device *gdev = to_ccwgroupdev(dev);



		mutex_lock(&gdev->reg_mutex);

		__ccwgroup_remove_symlinks(gdev);

		device_unregister(dev);

		mutex_unlock(&gdev->reg_mutex);

		put_device(dev);

	}

	put_driver(&cdriver->driver);
@@ -444,8 +444,10 @@ __ccwgroup_get_gdev_by_cdev(struct ccw_device *cdev) 
	if (cdev->dev.driver_data) {

		gdev = (struct ccwgroup_device *)cdev->dev.driver_data;

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

			mutex_lock(&gdev->reg_mutex);

			if (device_is_registered(&gdev->dev))

				return gdev;

			mutex_unlock(&gdev->reg_mutex);

			put_device(&gdev->dev);

		}

		return NULL;
@@ -465,6 +467,7 @@ ccwgroup_remove_ccwdev(struct ccw_device *cdev) 
	if (gdev) {

		__ccwgroup_remove_symlinks(gdev);

		device_unregister(&gdev->dev);

		mutex_unlock(&gdev->reg_mutex);

		put_device(&gdev->dev);

	}

}

include/asm-s390/ccwgroup.h

+1 −0
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ struct ccwgroup_device { 
		CCWGROUP_ONLINE,

	} state;

	atomic_t onoff;

	struct mutex reg_mutex;

	unsigned int count;		/* number of attached slave devices */

	struct device	dev;		/* master device		    */

	struct ccw_device *cdev[0];	/* variable number, allocate as needed */