[PATCH] loop.c doesn't fail init gracefully

From: BlaisorBlade <blaisorblade_spam@yahoo.it>

loop_init doesn't fail gracefully for two reasons:

1) If initialization of loop driver fails, we have an call to
   devfs_add("loop") without any devfs_remove; I add that.

2) On lwn.net 2.6 kernel docs, Jonathan Corbet says: "If you are calling
   add_disk() in your driver initialization routine, you should not fail
   the initialization process after the first call."

So I make loop.c conform to this request by moving add_disk after all
memory allocations.

drivers/block/loop.c

@@ -1027,14 +1027,18 @@ int __init loop_init(void)
 		sprintf(disk->devfs_name, "loop/%d", i);
 		disk->private_data = lo;
 		disk->queue = lo->lo_queue;
-		add_disk(disk);
 	}
+
+	/* We cannot fail after we call this, so another loop!*/
+	for (i = 0; i < max_loop; i++)
+		add_disk(disks[i]);
 	printk(KERN_INFO "loop: loaded (max %d devices)\n", max_loop);
 	return 0;
 
 out_mem4:
 	while (i--)
 		blk_put_queue(loop_dev[i].lo_queue);
+	devfs_remove("loop");
 	i = max_loop;
 out_mem3:
 	while (i--)