[SCSI] iscsi: Prettify resid handling and some extra checks

  - Check to see that OVERFLOW is not negative indicating
    a bug.
  - Unify handling of UNDERFLOW and OVERFLOW to the same
    code.
  - Also handle BIDI_OVERFLOW.

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

1 files changed, 7 insertions, 9 deletions

diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index 1b540e03f5bf..fd88777df28b 100644
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -507,22 +507,20 @@ iscsi_data_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
         }
 
         if (rhdr->flags & ISCSI_FLAG_DATA_STATUS) {
+                sc->result = (DID_OK << 16) | rhdr->cmd_status;
                 conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
-                if (rhdr->flags & ISCSI_FLAG_DATA_UNDERFLOW) {
+                if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
+                                   ISCSI_FLAG_DATA_OVERFLOW)) {
                         int res_count = be32_to_cpu(rhdr->residual_count);
 
                         if (res_count > 0 &&
-                            res_count <= scsi_bufflen(sc)) {
+                            (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
+                             res_count <= scsi_bufflen(sc)))
                                 scsi_set_resid(sc, res_count);
-                                sc->result = (DID_OK << 16) | rhdr->cmd_status;
-                        } else
+                        else
                                 sc->result = (DID_BAD_TARGET << 16) |
                                         rhdr->cmd_status;
-                } else if (rhdr->flags & ISCSI_FLAG_DATA_OVERFLOW) {
-                        scsi_set_resid(sc, be32_to_cpu(rhdr->residual_count));
-                        sc->result = (DID_OK << 16) | rhdr->cmd_status;
-                } else
-                        sc->result = (DID_OK << 16) | rhdr->cmd_status;
+                }
         }
 
         conn->datain_pdus_cnt++;