Staging: hv: Add support for >2 TB LUN in storage driver.

commit cf55f4a8 upstream.

If a LUN larger than 2 TB is attached to a Linux VM on Hyper-V, we currently
report a maximum size of 2 TB. This patch resolves the issue in hv_storvsc.
Thanks to Robert Scheck <robert.scheck@etes.de> for reporting the issue.
Reported-by: Robert Scheck <robert.scheck@etes.de>
Signed-off-by: Mike Sterling <mike.sterling@microsoft.com>
Signed-off-by: K.Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/hv/hyperv_storage.h

@@ -218,6 +218,7 @@ struct vstor_packet {
 #define STORVSC_MAX_LUNS_PER_TARGET			64
 #define STORVSC_MAX_TARGETS				1
 #define STORVSC_MAX_CHANNELS				1
+#define STORVSC_MAX_CMD_LEN				16
 
 struct hv_storvsc_request;
 

drivers/staging/hv/storvsc_drv.c

@@ -701,6 +701,8 @@ static int storvsc_probe(struct hv_device *device)
 	host->max_id = STORVSC_MAX_TARGETS;
 	/* max # of channels */
 	host->max_channel = STORVSC_MAX_CHANNELS - 1;
+	/* max cmd length */
+	host->max_cmd_len = STORVSC_MAX_CMD_LEN;
 
 	/* Register the HBA and start the scsi bus scan */
 	ret = scsi_add_host(host, &device->device);