[POWERPC] iSeries: improve viodasd initialisation

On error, make sure that we undo all necessary operations.

This also gets rid of a must_check warning.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 36 insertions, 13 deletions

diff --git a/drivers/block/viodasd.c b/drivers/block/viodasd.c
index ec5a1b90a0a2..e19ba4ebcd4e 100644
--- a/drivers/block/viodasd.c
+++ b/drivers/block/viodasd.c
@@ -759,6 +759,8 @@ static struct vio_driver viodasd_driver = {
         }
 };
 
+static int need_delete_probe;
+
 /*
  * Initialize the whole device driver.  Handle module and non-module
  * versions
@@ -773,46 +775,67 @@ static int __init viodasd_init(void)
 
         if (viopath_hostLp == HvLpIndexInvalid) {
                 printk(VIOD_KERN_WARNING "invalid hosting partition\n");
-                return -EIO;
+                rc = -EIO;
+                goto early_fail;
         }
 
         printk(VIOD_KERN_INFO "vers " VIOD_VERS ", hosting partition %d\n",
                         viopath_hostLp);
 
         /* register the block device */
-        if (register_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME)) {
+        rc =  register_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
+        if (rc) {
                 printk(VIOD_KERN_WARNING
                                 "Unable to get major number %d for %s\n",
                                 VIODASD_MAJOR, VIOD_GENHD_NAME);
-                return -EIO;
+                goto early_fail;
         }
         /* Actually open the path to the hosting partition */
-        if (viopath_open(viopath_hostLp, viomajorsubtype_blockio,
-                                VIOMAXREQ + 2)) {
+        rc = viopath_open(viopath_hostLp, viomajorsubtype_blockio,
+                                VIOMAXREQ + 2);
+        if (rc) {
                 printk(VIOD_KERN_WARNING
                        "error opening path to host partition %d\n",
                        viopath_hostLp);
-                unregister_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
-                return -EIO;
+                goto unregister_blk;
         }
 
         /* Initialize our request handler */
         vio_setHandler(viomajorsubtype_blockio, handle_block_event);
 
         rc = vio_register_driver(&viodasd_driver);
-        if (rc == 0)
-                driver_create_file(&viodasd_driver.driver, &driver_attr_probe);
+        if (rc) {
+                printk(VIOD_KERN_WARNING "vio_register_driver failed\n");
+                goto unset_handler;
+        }
+
+        /*
+         * If this call fails, it just means that we cannot dynamically
+         * add virtual disks, but the driver will still work fine for
+         * all existing disk, so ignore the failure.
+         */
+        if (!driver_create_file(&viodasd_driver.driver, &driver_attr_probe))
+                need_delete_probe = 1;
+
+        return 0;
+
+unset_handler:
+        vio_clearHandler(viomajorsubtype_blockio);
+        viopath_close(viopath_hostLp, viomajorsubtype_blockio, VIOMAXREQ + 2);
+unregister_blk:
+        unregister_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
+early_fail:
         return rc;
 }
 module_init(viodasd_init);
 
-void viodasd_exit(void)
+void __exit viodasd_exit(void)
 {
-        driver_remove_file(&viodasd_driver.driver, &driver_attr_probe);
+        if (need_delete_probe)
+                driver_remove_file(&viodasd_driver.driver, &driver_attr_probe);
         vio_unregister_driver(&viodasd_driver);
         vio_clearHandler(viomajorsubtype_blockio);
-        unregister_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
         viopath_close(viopath_hostLp, viomajorsubtype_blockio, VIOMAXREQ + 2);
+        unregister_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
 }
-
 module_exit(viodasd_exit);