[PATCH] s390: tape operation abortion leads to panic

When a request is aborted because of a signal, we currently stop the request
via csh, but we do not wait for the interrupt of csh in any case.  We free the
request structure and therefore when the interrupt for the csh operation is
presented, the request object is no longer valid and an invalid callback
pointer is used.

To fix this wait until the interrupt for csh arrives and until
wait_event_interruptible() does not return -ERESTARTSYS.
Signed-off-by: Michael Holzheu <holzheu@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/s390/char/tape_core.c

@@ -1015,7 +1015,7 @@ tape_do_io_interruptible(struct tape_device *device,
 				wq,
 				(request->callback == NULL)
 			);
-		} while (rc != -ERESTARTSYS);
+		} while (rc == -ERESTARTSYS);
 
 		DBF_EVENT(3, "IO stopped on %08x\n", device->cdev_id);
 		rc = -ERESTARTSYS;