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[S390] cio: ccwgroup register vs. unregister.

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

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Cornelia Huck 2007-04-27 16:01:37 +02:00 committed by Martin Schwidefsky
parent 82b7ac058f
commit d76123eb35
2 changed files with 19 additions and 15 deletions
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33
drivers/s390/cio/ccwgroup.c
View File

@ -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);
}
}

1
include/asm-s390/ccwgroup.h
View File

@ -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 */