fcp: Do not interpret check condition as underrun

This patch avoids that the FCoE initiator sends a REC message after
having received a SCSI response with non-zero status and non-zero
DATA IN buffer length.
Signed-off-by: NBart Van Assche <bvanassche@acm.org>
Cc: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>

drivers/scsi/libfc/fc_fcp.c

@@ -902,7 +902,8 @@ static void fc_fcp_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
 	/*
 	 * Check for missing or extra data frames.
 	 */
-	if (unlikely(fsp->xfer_len != expected_len)) {
+	if (unlikely(fsp->cdb_status == SAM_STAT_GOOD &&
+		     fsp->xfer_len != expected_len)) {
 		if (fsp->xfer_len < expected_len) {
 			/*
 			 * Some data may be queued locally,
@@ -955,12 +956,11 @@ static void fc_fcp_complete_locked(struct fc_fcp_pkt *fsp)
 		 * Test for transport underrun, independent of response
 		 * underrun status.
 		 */
-		if (fsp->xfer_len < fsp->data_len && !fsp->io_status &&
+		if (fsp->cdb_status == SAM_STAT_GOOD &&
+		    fsp->xfer_len < fsp->data_len && !fsp->io_status &&
 		    (!(fsp->scsi_comp_flags & FCP_RESID_UNDER) ||
-		     fsp->xfer_len < fsp->data_len - fsp->scsi_resid)) {
+		     fsp->xfer_len < fsp->data_len - fsp->scsi_resid))
 			fsp->status_code = FC_DATA_UNDRUN;
-			fsp->io_status = 0;
-		}
 	}
 
 	seq = fsp->seq_ptr;