usb: storage: fix module reference for scsi host

While accessing a unusual usb storage (ums-alauda, ums-cypress, ...),
the module reference count is not incremented.  Because these drivers
allocate scsi hosts with usb_stor_host_template defined in usb-storage
module.  So these drivers always can be unloaded.

This fixes it by preparing scsi host template which is initialized
at module_init() for each ums-* driver.  In order to minimize the
difference in ums-* drivers, introduce module_usb_stor_driver() helper
macro which is same as module_usb_driver() except that it also
initializes scsi host template.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Vinayak Holikatti <vinholikatti@gmail.com>
Cc: Dolev Raviv <draviv@codeaurora.org>
Cc: Sujit Reddy Thumma <sthumma@codeaurora.org>
Cc: Subhash Jadavani <subhashj@codeaurora.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Cc: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Hannes Reinecke <hare@suse.de>
Cc: linux-usb@vger.kernel.org
Cc: usb-storage@lists.one-eyed-alien.net
Cc: linux-scsi@vger.kernel.org
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/storage/jumpshot.c

@@ -56,7 +56,9 @@
 #include "transport.h"
 #include "protocol.h"
 #include "debug.h"
+#include "scsiglue.h"
 
+#define DRV_NAME "ums-jumpshot"
 
 MODULE_DESCRIPTION("Driver for Lexar \"Jumpshot\" Compact Flash reader");
 MODULE_AUTHOR("Jimmie Mayfield <mayfield+usb@sackheads.org>");
@@ -647,6 +649,8 @@ static int jumpshot_transport(struct scsi_cmnd *srb, struct us_data *us)
 	return USB_STOR_TRANSPORT_FAILED;
 }
 
+static struct scsi_host_template jumpshot_host_template;
+
 static int jumpshot_probe(struct usb_interface *intf,
 			 const struct usb_device_id *id)
 {
@@ -654,7 +658,8 @@ static int jumpshot_probe(struct usb_interface *intf,
 	int result;
 
 	result = usb_stor_probe1(&us, intf, id,
-			(id - jumpshot_usb_ids) + jumpshot_unusual_dev_list);
+			(id - jumpshot_usb_ids) + jumpshot_unusual_dev_list,
+			&jumpshot_host_template);
 	if (result)
 		return result;
 
@@ -668,7 +673,7 @@ static int jumpshot_probe(struct usb_interface *intf,
 }
 
 static struct usb_driver jumpshot_driver = {
-	.name =		"ums-jumpshot",
+	.name =		DRV_NAME,
 	.probe =	jumpshot_probe,
 	.disconnect =	usb_stor_disconnect,
 	.suspend =	usb_stor_suspend,
@@ -681,4 +686,4 @@ static struct usb_driver jumpshot_driver = {
 	.no_dynamic_id = 1,
 };
 
-module_usb_driver(jumpshot_driver);
+module_usb_stor_driver(jumpshot_driver, jumpshot_host_template, DRV_NAME);