[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, 5 deletions

diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index 176458f35316..0beb4c620962 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -291,17 +291,19 @@ invalid_datalen:
                            min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
         }
 
-        if (rhdr->flags & ISCSI_FLAG_CMD_UNDERFLOW) {
+        if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
+                           ISCSI_FLAG_CMD_OVERFLOW)) {
                 int res_count = be32_to_cpu(rhdr->residual_count);
 
-                if (res_count > 0 && res_count <= scsi_bufflen(sc))
+                if (res_count > 0 &&
+                    (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
+                     res_count <= scsi_bufflen(sc)))
                         scsi_set_resid(sc, res_count);
                 else
                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
-        } else if (rhdr->flags & ISCSI_FLAG_CMD_BIDI_UNDERFLOW)
+        } else if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
+                                  ISCSI_FLAG_CMD_BIDI_OVERFLOW))
                 sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
-        else if (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW)
-                scsi_set_resid(sc, be32_to_cpu(rhdr->residual_count));
 
 out:
         debug_scsi("done [sc %lx res %d itt 0x%x]\n",