scsi: zfcp: Fix sysfs roll-back on error in zfcp_adapter_enqueue()

When zfcp_adapter_enqueue() fails to create the zfcp_sysfs_adapter_attrs
group, it calls zfcp_adapter_unregister() to tear down the adapter state
again. This then unconditionally attempts to remove the
zfcp_sysfs_adapter_attrs group, resulting in a "group not found" WARN from
sysfs code.

Avoid this by copying most of zfcp_adapter_unregister() into the error
path, allowing for more fine-granular roll-back. Then skip the sysfs
tear-down steps if we haven't progressed this far in the initialization.

Link: https://lore.kernel.org/r/790922cc3af075795fff9a4b787e6bda19bdb3be.1618417667.git.bblock@linux.ibm.comReviewed-by: Benjamin Block <bblock@linux.ibm.com>
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/s390/scsi/zfcp_aux.c

@@ -418,7 +418,7 @@ struct zfcp_adapter *zfcp_adapter_enqueue(struct ccw_device *ccw_device)
 		goto failed;
 
 	if (zfcp_diag_sysfs_setup(adapter))
-		goto failed;
+		goto err_diag_sysfs;
 
 	/* report size limit per scatter-gather segment */
 	adapter->ccw_device->dev.dma_parms = &adapter->dma_parms;
@@ -427,8 +427,24 @@ struct zfcp_adapter *zfcp_adapter_enqueue(struct ccw_device *ccw_device)
 
 	return adapter;
 
+err_diag_sysfs:
+	sysfs_remove_group(&ccw_device->dev.kobj, &zfcp_sysfs_adapter_attrs);
 failed:
-	zfcp_adapter_unregister(adapter);
+	/* TODO: make this more fine-granular */
+	cancel_delayed_work_sync(&adapter->scan_work);
+	cancel_work_sync(&adapter->stat_work);
+	cancel_work_sync(&adapter->ns_up_work);
+	cancel_work_sync(&adapter->version_change_lost_work);
+	zfcp_destroy_adapter_work_queue(adapter);
+
+	zfcp_fc_wka_ports_force_offline(adapter->gs);
+	zfcp_scsi_adapter_unregister(adapter);
+
+	zfcp_erp_thread_kill(adapter);
+	zfcp_dbf_adapter_unregister(adapter);
+	zfcp_qdio_destroy(adapter->qdio);
+
+	zfcp_ccw_adapter_put(adapter); /* final put to release */
 	return ERR_PTR(-ENOMEM);
 }