: TASK ABORTED status handling improvement

This patch improves handling of TASK ABORTED status by Linux SCSI mid-layer. Currently, command returned with this status considered failed and returned to upper layers. It leads to additional error recovery load on file systems and block layer, which sometimes can cause undesired side effects, like I/O errors and file systems corruptions. See
http://lkml.org/lkml/2008/11/1/38, for instance.

command was aborted by another initiator and the target has TAS bit set in the control mode page. So, in the majority of cases commands with TASK ABORTED status should be simply retried. In other cases, maybe_retry path will not retry if no retries are allowed.

This patch implement suggestion by James Bottomley from http://marc.info/?l=linux-scsi&m=121932916906009&w=2.

 scsi_error.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff -upr linux-2.6.27.2/drivers/scsi/scsi_error.c linux-2.6.27.2/drivers/scsi/scsi_error.c
@@ -1408,8 +1408,9 @@ int scsi_decide_disposition(struct scsi_
 		return ADD_TO_MLQUEUE;
 	case GOOD:
 	case COMMAND_TERMINATED:
-	case TASK_ABORTED:
 		return SUCCESS;
+	case TASK_ABORTED:
+		goto maybe_retry;
 	case CHECK_CONDITION:
 		rtn = scsi_check_sense(scmd);
 		if (rtn == NEEDS_RETRY)