SCSI: sd: Reshuffle init_sd to avoid crash

commit afd5e34 upstream.

scsi_register_driver will register a prep_fn() function, which
in turn migh need to use the sd_cdp_pool for DIF.
Which hasn't been initialised at this point, leading to
a crash. So reshuffle the init_sd() and exit_sd() paths
to have the driver registered last.

Signed-off-by: Joel D. Diaz <joeldiaz@us.ibm.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Cc: CAI Qian <caiqian@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/scsi/sd.c

@@ -2826,10 +2826,6 @@ static int __init init_sd(void)
 	if (err)
 		goto err_out;
 
-	err = scsi_register_driver(&sd_template.gendrv);
-	if (err)
-		goto err_out_class;
-
 	sd_cdb_cache = kmem_cache_create("sd_ext_cdb", SD_EXT_CDB_SIZE,
 					 0, 0, NULL);
 	if (!sd_cdb_cache) {
@@ -2843,8 +2839,15 @@ static int __init init_sd(void)
 		goto err_out_cache;
 	}
 
+	err = scsi_register_driver(&sd_template.gendrv);
+	if (err)
+		goto err_out_driver;
+
 	return 0;
 
+err_out_driver:
+	mempool_destroy(sd_cdb_pool);
+
 err_out_cache:
 	kmem_cache_destroy(sd_cdb_cache);
 
@@ -2867,10 +2870,10 @@ static void __exit exit_sd(void)
 
 	SCSI_LOG_HLQUEUE(3, printk("exit_sd: exiting sd driver\n"));
 
+	scsi_unregister_driver(&sd_template.gendrv);
 	mempool_destroy(sd_cdb_pool);
 	kmem_cache_destroy(sd_cdb_cache);
 
-	scsi_unregister_driver(&sd_template.gendrv);
 	class_unregister(&sd_disk_class);
 
 	for (i = 0; i < SD_MAJORS; i++)