s390/dasd: check for device error pointer within state change interrupts
Check if the device pointer is valid. Just a sanity check since we already
are in the int handler of the device.
Signed-off-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index 0e3fdfd..f3099c8 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -1712,8 +1712,11 @@
/* check for for attention message */
if (scsw_dstat(&irb->scsw) & DEV_STAT_ATTENTION) {
device = dasd_device_from_cdev_locked(cdev);
- device->discipline->check_attention(device, irb->esw.esw1.lpum);
- dasd_put_device(device);
+ if (!IS_ERR(device)) {
+ device->discipline->check_attention(device,
+ irb->esw.esw1.lpum);
+ dasd_put_device(device);
+ }
}
if (!cqr)