USB: allow usbstorage to have LUNS greater than 2Tb

Attached is a very small patch (several comment lines) and a one-line
coded change) that allows for USB storage devices that are larger than
2TB.

At the company where I work we need such support, and one of my
co-workers, Jane Liu, pointed out that SCSI low-layer drivers need to
specify what size CDBs they accept. After looking through the code it
became obvious that the current USB Storage code accepted the default of
12-byte CDBs, so I changed it to accept 16-byte CDBs. This allows our
device to work.

Signed-off-by: Richard Sharpe <rsharpe@richardsharpe.com>
Signed-off-by: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/usb/storage/usb.c b/drivers/usb/storage/usb.c
index 59181667066c..3451e8d03ab0 100644
--- a/drivers/usb/storage/usb.c
+++ b/drivers/usb/storage/usb.c
@@ -960,6 +960,10 @@ static int storage_probe(struct usb_interface *intf,
                 return -ENOMEM;
         }
 
+        /*
+         * Allow 16-byte CDBs and thus > 2TB
+         */
+        host->max_cmd_len = 16;
         us = host_to_us(host);
         memset(us, 0, sizeof(struct us_data));
         mutex_init(&(us->dev_mutex));