From: Jesse Larrew <jlarrew@redhat.com>
Date: Fri, 15 May 2009 09:48:59 -0400
Subject: [scsi] retry for NOT_READY condition
Message-id: 20090515134859.GA13809@squad5-lp1.lab.bos.redhat.com
O-Subject: Re: [PATCH RHEL5.4 10/11 BZ489582] Retry for NOT_READY condition
Bugzilla: 489582
RH-Acked-by: Mike Christie <mchristi@redhat.com>

RHBZ#:
======
https://bugzilla.redhat.com/show_bug.cgi?id=489582

Description:
===========
This is a bug fix for all archs.

During device discovery, read capacity fails with 0x020401 and sets the
device size to 0. As a result, any I/O submitted to this path gets
killed at sd_prep_fn with BLKPREP_KILL.

NEED_RETRY in scsi_decide_disposition does not give sufficient time for the
device to become ready. This patch implements retry logic for 0x020401.

RHEL Version Found:
================
RHEL 5.3

kABI Status:
============
No symbols were harmed.

Brew:
=====
Built on all platforms.
http://brewweb.devel.redhat.com/brew/taskinfo?taskID=1800889

Upstream Status:
================
This patch has been submitted upstream but is not yet accepted:
https://www.redhat.com/archives/dm-devel/2009-April/msg00367.html

Test Status:
============
This patch has been tested by Babu Moger at LSI (Babu.Moger@lsi.com).

===============================================================

Jesse Larrew
IBM Onsite Partner
978-392-3183
jlarrew@redhat.com

Proposed Patch:
===============
This patch is based on 2.6.18-136.el5.

diff --git a/drivers/scsi/device_handler/scsi_dh_rdac.c b/drivers/scsi/device_handler/scsi_dh_rdac.c
index 9009bae..6f18bcd 100644
--- a/drivers/scsi/device_handler/scsi_dh_rdac.c
+++ b/drivers/scsi/device_handler/scsi_dh_rdac.c
@@ -564,6 +564,12 @@ static int rdac_check_sense(struct scsi_device *sdev,
 	struct rdac_dh_data *h = get_rdac_data(sdev);
 	switch (sense_hdr->sense_key) {
 	case NOT_READY:
+		if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x01)
+			/* LUN Not Ready - Logical Unit Not Ready and is in
+			* the process of becoming ready
+			* Just retry.
+			*/
+			return SCSI_MLQUEUE_DEVICE_BUSY2;
 		if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x81)
 			/* LUN Not Ready - Storage firmware incompatible
 			 * Manual code synchonisation required.