[SCSI] bfa: Handle SCSI IO underrun case.

When IO is completed with underrun and with good SCSI status, check if
the transferred bytes against scsi_cmnd->underflow, which is set to
minimum number of bytes that must be transferred for this command, if
is less than required minimum, complete the IO with DID_ERROR.

Signed-off-by: Krishna Gudipati <kgudipat@brocade.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

1 files changed, 12 insertions, 2 deletions

diff --git a/drivers/scsi/bfa/bfad_im.c b/drivers/scsi/bfa/bfad_im.c
index cee3d89d1412..fb7aefaba129 100644
--- a/drivers/scsi/bfa/bfad_im.c
+++ b/drivers/scsi/bfa/bfad_im.c
@@ -43,11 +43,11 @@ bfa_cb_ioim_done(void *drv, struct bfad_ioim_s *dio,
         struct bfad_s         *bfad = drv;
         struct bfad_itnim_data_s *itnim_data;
         struct bfad_itnim_s *itnim;
+        u8         host_status = DID_OK;
 
         switch (io_status) {
         case BFI_IOIM_STS_OK:
                 bfa_trc(bfad, scsi_status);
-                cmnd->result = ScsiResult(DID_OK, scsi_status);
                 scsi_set_resid(cmnd, 0);
 
                 if (sns_len > 0) {
@@ -56,8 +56,18 @@ bfa_cb_ioim_done(void *drv, struct bfad_ioim_s *dio,
                                 sns_len = SCSI_SENSE_BUFFERSIZE;
                         memcpy(cmnd->sense_buffer, sns_info, sns_len);
                 }
-                if (residue > 0)
+                if (residue > 0) {
+                        bfa_trc(bfad, residue);
                         scsi_set_resid(cmnd, residue);
+                        if (!sns_len && (scsi_status == SAM_STAT_GOOD) &&
+                                (scsi_bufflen(cmnd) - residue) <
+                                        cmnd->underflow) {
+                                bfa_trc(bfad, 0);
+                                host_status = DID_ERROR;
+                        }
+                }
+                cmnd->result = ScsiResult(host_status, scsi_status);
+
                 break;
 
         case BFI_IOIM_STS_ABORTED: