block/sx8: add error handling support for add_disk()

We never checked for errors on add_disk() as this function
returned void. Now that this is fixed, use the shiny new
error handling.

A completion is used to notify the initial probe what is
happening and so we must defer error handling on completion.
Do this by remembering the error and using the shared cleanup
function.

The tags are shared and so are hanlded later for the
driver already.

Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/sx8.c

@@ -297,6 +297,7 @@ struct carm_host {
 
 	struct work_struct		fsm_task;
 
+	int probe_err;
 	struct completion		probe_comp;
 };
 
@@ -1181,8 +1182,11 @@ static void carm_fsm_task (struct work_struct *work)
 				struct gendisk *disk = port->disk;
 
 				set_capacity(disk, port->capacity);
-				add_disk(disk);
-				activated++;
+				host->probe_err = add_disk(disk);
+				if (!host->probe_err)
+					activated++;
+				else
+					break;
 			}
 
 		printk(KERN_INFO DRV_NAME "(%s): %d ports activated\n",
@@ -1192,11 +1196,9 @@ static void carm_fsm_task (struct work_struct *work)
 		reschedule = 1;
 		break;
 	}
-
 	case HST_PROBE_FINISHED:
 		complete(&host->probe_comp);
 		break;
-
 	case HST_ERROR:
 		/* FIXME: TODO */
 		break;
@@ -1507,7 +1509,10 @@ static int carm_init_one (struct pci_dev *pdev, const struct pci_device_id *ent)
 		goto err_out_free_irq;
 
 	DPRINTK("waiting for probe_comp\n");
+	host->probe_err = -ENODEV;
 	wait_for_completion(&host->probe_comp);
+	if (host->probe_err)
+		goto err_out_free_irq;
 
 	printk(KERN_INFO "%s: pci %s, ports %d, io %llx, irq %u, major %d\n",
 	       host->name, pci_name(pdev), (int) CARM_MAX_PORTS,