[SCSI] iscsi: Some fixes in preparation for bidirectional support - exp_datasn

This patch fixes handling of expected datasn/r2tsn as received from
target. It is done according to: T10 rfc3720 section 3.2.2.3. Data Sequencing.

. unify expected datasn/r2tsn into one counter
. calculate than check expected datasn/r2tsn. On error print a message
  and fail the request. (TODO use iscsi retransmits)
. remove the FIXME   ;)
. avoid zero length memset

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/scsi/iscsi_tcp.h b/drivers/scsi/iscsi_tcp.h
index 32736831790e..f909edbf61ee 100644
--- a/drivers/scsi/iscsi_tcp.h
+++ b/drivers/scsi/iscsi_tcp.h
@@ -152,7 +152,7 @@ struct iscsi_tcp_cmd_task {
         struct scatterlist      *sg;                    /* per-cmd SG list  */
         struct scatterlist      *bad_sg;                /* assert statement */
         int                     sg_count;               /* SG's to process  */
-        uint32_t                exp_r2tsn;
+        uint32_t                exp_datasn;             /* expected target's R2TSN/DataSN */
         int                     data_offset;
         struct iscsi_r2t_info   *r2t;                   /* in progress R2T    */
         struct iscsi_queue      r2tpool;