scsi: add DID_REQUEUE to the error handling

We have a DID_IMM_RETRY to require a retry at once, but we could do with
a DID_REQUEUE to instruct the mid-layer to treat this command in the
same manner as QUEUE_FULL or BUSY (i.e. halt the submission until
another command returns ... or the queue pressure builds if there are no
outstanding commands).

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

2 files changed, 5 insertions, 0 deletions

diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 13bac93fc397..203a0812508a 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -1306,6 +1306,9 @@ int scsi_decide_disposition(struct scsi_cmnd *scmd)
         case DID_IMM_RETRY:
                 return NEEDS_RETRY;
 
+        case DID_REQUEUE:
+                return ADD_TO_MLQUEUE;
+
         case DID_ERROR:
                 if (msg_byte(scmd->result) == COMMAND_COMPLETE &&
                     status_byte(scmd->result) == RESERVATION_CONFLICT)
diff --git a/include/scsi/scsi.h b/include/scsi/scsi.h
index 3507b3d7c0eb..659ecf48fb4a 100644
--- a/include/scsi/scsi.h
+++ b/include/scsi/scsi.h
@@ -295,6 +295,8 @@ struct scsi_lun {
 #define DID_PASSTHROUGH 0x0a    /* Force command past mid-layer            */
 #define DID_SOFT_ERROR  0x0b    /* The low level driver just wish a retry  */
 #define DID_IMM_RETRY   0x0c    /* Retry without decrementing retry count  */
+#define DID_REQUEUE     0x0d    /* Requeue command (no immediate retry) also
+                                 * without decrementing the retry count    */
 #define DRIVER_OK       0x00    /* Driver status                           */
 
 /*