s390/dasd: Store path configuration data during path handling

Currently, the configuration data for a path is retrieved during a path
verification and used only temporarily. If a path is newly added to the
I/O setup after a boot, no configuration data will be stored for this
particular path.
However, this data is required for later use and should be present for
a valid I/O path anyway. Store this data during the path verification so
that newly added paths can provide all information necessary.

[sth@linux.ibm.com: fix conf_data memleak]
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
Reviewed-by: Stefan Haberland <sth@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/s390/block/dasd_eckd.c

@@ -1007,6 +1007,11 @@ static void dasd_eckd_store_conf_data(struct dasd_device *device,
 	struct subchannel_id sch_id;
 
 	ccw_device_get_schid(device->cdev, &sch_id);
+	/*
+	 * path handling and read_conf allocate data
+	 * free it before replacing the pointer
+	 */
+	kfree(device->path[chp].conf_data);
 	device->path[chp].conf_data = conf_data;
 	device->path[chp].cssid = sch_id.cssid;
 	device->path[chp].ssid = sch_id.ssid;
@@ -1263,9 +1268,10 @@ static void do_path_verification_work(struct work_struct *work)
 	struct dasd_uid *uid;
 	__u8 path_rcd_buf[DASD_ECKD_RCD_DATA_SIZE];
 	__u8 lpm, opm, npm, ppm, epm, hpfpm, cablepm;
+	struct dasd_conf_data *conf_data;
 	unsigned long flags;
 	char print_uid[60];
-	int rc;
+	int rc, pos;
 
 	data = container_of(work, struct path_verification_work_data, worker);
 	device = data->device;
@@ -1395,6 +1401,14 @@ static void do_path_verification_work(struct work_struct *work)
 			}
 		}
 
+		conf_data = kzalloc(DASD_ECKD_RCD_DATA_SIZE, GFP_KERNEL);
+		if (conf_data) {
+			memcpy(conf_data, data->rcd_buffer,
+			       DASD_ECKD_RCD_DATA_SIZE);
+		}
+		pos = pathmask_to_pos(lpm);
+		dasd_eckd_store_conf_data(device, conf_data, pos);
+
 		/*
 		 * There is a small chance that a path is lost again between
 		 * above path verification and the following modification of