diff options
| -rw-r--r-- | drivers/s390/cio/ccwgroup.c | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/drivers/s390/cio/ccwgroup.c b/drivers/s390/cio/ccwgroup.c index 17fa009d995..918e6fce257 100644 --- a/drivers/s390/cio/ccwgroup.c +++ b/drivers/s390/cio/ccwgroup.c @@ -91,15 +91,23 @@ ccwgroup_ungroup_store(struct device *dev, struct device_attribute *attr, const gdev = to_ccwgroupdev(dev); - if (gdev->state != CCWGROUP_OFFLINE) - return -EINVAL; - + /* Prevent concurrent online/offline processing and ungrouping. */ + if (atomic_cmpxchg(&gdev->onoff, 0, 1) != 0) + return -EAGAIN; + if (gdev->state != CCWGROUP_OFFLINE) { + 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 (rc) - count = rc; +out: + if (rc) { + /* Release onoff "lock" when ungrouping failed. */ + atomic_set(&gdev->onoff, 0); + return rc; + } return count; } |