[S390] cio: prevent purging of CCW devices in the online state

[~andy/linux] / drivers / s390 / cio / device.c

diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index df14c51f653224d37b6ac29c87ad4a778f2b2af9..8e04c00cf0ad10d522128b97e33cefcf3b870adf 100644 (file)
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -541,15 +541,24 @@ static ssize_t online_store (struct device *dev, struct device_attribute *attr,
        int force, ret;
        unsigned long i;
 
-       if (!dev_fsm_final_state(cdev) &&
-           cdev->private->state != DEV_STATE_DISCONNECTED)
-               return -EAGAIN;
+       /* Prevent conflict between multiple on-/offline processing requests. */
        if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
                return -EAGAIN;
+       /* Prevent conflict between internal I/Os and on-/offline processing. */
+       if (!dev_fsm_final_state(cdev) &&
+           cdev->private->state != DEV_STATE_DISCONNECTED) {
+               ret = -EAGAIN;
+               goto out_onoff;
+       }
+       /* Prevent conflict between pending work and on-/offline processing.*/
+       if (work_pending(&cdev->private->todo_work)) {
+               ret = -EAGAIN;
+               goto out_onoff;
+       }
 
        if (cdev->drv && !try_module_get(cdev->drv->driver.owner)) {
-               atomic_set(&cdev->private->onoff, 0);
-               return -EINVAL;
+               ret = -EINVAL;
+               goto out_onoff;
        }
        if (!strncmp(buf, "force\n", count)) {
                force = 1;
@@ -574,6 +583,7 @@ static ssize_t online_store (struct device *dev, struct device_attribute *attr,
 out:
        if (cdev->drv)
                module_put(cdev->drv->driver.owner);
+out_onoff:
        atomic_set(&cdev->private->onoff, 0);
        return (ret < 0) ? ret : count;
 }
@@ -1311,10 +1321,12 @@ static int purge_fn(struct device *dev, void *data)
 
        spin_lock_irq(cdev->ccwlock);
        if (is_blacklisted(id->ssid, id->devno) &&
-           (cdev->private->state == DEV_STATE_OFFLINE)) {
+           (cdev->private->state == DEV_STATE_OFFLINE) &&
+           (atomic_cmpxchg(&cdev->private->onoff, 0, 1) == 0)) {
                CIO_MSG_EVENT(3, "ccw: purging 0.%x.%04x\n", id->ssid,
                              id->devno);
                ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
+               atomic_set(&cdev->private->onoff, 0);
        }
        spin_unlock_irq(cdev->ccwlock);
        /* Abort loop in case of pending signal. */