src/patches/suse-2.6.27.25/patches.fixes/scsi-retry-TASK_ABORTED

   1 Subject: scsi_error: TASK ABORTED status handling improvement
   2 From: Vladislav Bolkhovitin <vst@vlnb.net>
   3 Date: Fri Nov 7 11:21:03 2008 -0600:
   4 Git: ab2d67aa39bc63a60fba748b27cf4d962d0dc7f8
   5
   6 This patch improves handling of TASK ABORTED status by Linux SCSI
   7 mid-layer. Currently, command returned with this status considered
   8 failed and returned to upper layers. It leads to additional error
   9 recovery load on file systems and block layer, which sometimes can
  10 cause undesired side effects, like I/O errors and file systems
  11 corruptions. See http://lkml.org/lkml/2008/11/1/38, for instance.
  12
  13 From other side, TASK ABORTED status is returned by SCSI target if the
  14 corresponding command was aborted by another initiator and the target
  15 has TAS bit set in the control mode page. So, in the majority of cases
  16 commands with TASK ABORTED status should be simply retried. In other
  17 cases, maybe_retry path will not retry if no retries are allowed.
  18
  19 This patch implement suggestion by James Bottomley from
  20 http://marc.info/?l=linux-scsi&m=121932916906009&w=2.
  21
  22 Signed-off-by: Vladislav Bolkhovitin <vst@vlnb.net>
  23 Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
  24 Signed-off-by: Hannes Reinecke <hare@suse.de>
  25
  26 ---
  27  drivers/scsi/scsi_error.c |    3 ++-
  28  1 file changed, 2 insertions(+), 1 deletion(-)
  29
  30 --- a/drivers/scsi/scsi_error.c
  31 +++ b/drivers/scsi/scsi_error.c
  32 @@ -1486,8 +1486,9 @@ int scsi_decide_disposition(struct scsi_
  33                 return ADD_TO_MLQUEUE;
  34         case GOOD:
  35         case COMMAND_TERMINATED:
  36 -       case TASK_ABORTED:
  37                 return SUCCESS;
  38 +       case TASK_ABORTED:
  39 +               goto maybe_retry;
  40         case CHECK_CONDITION:
  41                 rtn = scsi_check_sense(scmd);
  42                 if (rtn == NEEDS_RETRY)