[PATCH 3/3] BLIST_ATTACH_PQ3 flags

[Kurt Garloff <garloff@suse.de>]

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From: Kurt Garloff <garloff@suse.de>
Subject: Tolerate PQ 3 at LUN 0 for scanning
Patch-mainline: 
References: 158532

Some devices report a peripheral qualifier of 3 for LUN 0; with the original
code, we would still try a REPORT_LUNS scan (if SCSI level is >= 3 or if we 
have the BLIST_REPORTLUNS2 passed in), but NOT any sequential scan.
Also, the device at LUN 0 (which is not connected according to the PQ) is not
registered with the OS.

Unfortunately, SANs exist that are SCSI-2 and do NOT support REPORT_LUNS, but
report a unknown device with PQ 3 on LUN 0. We still need to scan them, and
most probably we even need BLIST_SPARSELUN (and BLIST_LARGELUN). See the bug
reference for an infamous example.

This is patch 3/3:
3. Implement the blacklist flag BLIST_ATTACH_PQ3 that makes the scsi
   scanning code register PQ3 devices and continues scanning; only sg
   will attach thanks to scsi_bus_match().

Acked-by: 
Signed-off-by: Kurt Garloff <garloff@suse.de>

Index: linux-2.6.16/drivers/scsi/scsi_scan.c
===================================================================
--- linux-2.6.16.orig/drivers/scsi/scsi_scan.c
+++ linux-2.6.16/drivers/scsi/scsi_scan.c
@@ -888,7 +888,7 @@ static int scsi_probe_and_add_lun(struct
 	/*
 	 * result contains valid SCSI INQUIRY data.
 	 */
-	if ((result[0] >> 5) == 3) {
+	if (((result[0] >> 5) == 3) && !(bflags & BLIST_ATTACH_PQ3)) {
 		/*
 		 * For a Peripheral qualifier 3 (011b), the SCSI
 		 * spec says: The device server is not capable of
Index: linux-2.6.16/drivers/scsi/scsi_devinfo.c
===================================================================
--- linux-2.6.16.orig/drivers/scsi/scsi_devinfo.c
+++ linux-2.6.16/drivers/scsi/scsi_devinfo.c
@@ -155,6 +155,8 @@ static struct {
 	{"HITACHI", "DF400", "*", BLIST_SPARSELUN},
 	{"HITACHI", "DF500", "*", BLIST_SPARSELUN},
 	{"HITACHI", "DF600", "*", BLIST_SPARSELUN},
+	{"HITACHI", "DISK-SUBSYSTEM", "*", BLIST_ATTACH_PQ3 | BLIST_SPARSELUN | BLIST_LARGELUN},
+	{"HITACHI", "OPEN-E", "*", BLIST_ATTACH_PQ3 | BLIST_SPARSELUN | BLIST_LARGELUN},
 	{"HP", "A6189A", NULL, BLIST_SPARSELUN | BLIST_LARGELUN},	/* HP VA7400 */
 	{"HP", "OPEN-", "*", BLIST_SPARSELUN | BLIST_LARGELUN}, /* HP XP Arrays */
 	{"HP", "NetRAID-4M", NULL, BLIST_FORCELUN},
Index: linux-2.6.16/include/scsi/scsi_devinfo.h
===================================================================
--- linux-2.6.16.orig/include/scsi/scsi_devinfo.h
+++ linux-2.6.16/include/scsi/scsi_devinfo.h
@@ -28,4 +28,5 @@
 #define BLIST_NO_ULD_ATTACH	0x100000 /* device is actually for RAID config */
 #define BLIST_SELECT_NO_ATN	0x200000 /* select without ATN */
 #define BLIST_RETRY_HWERROR	0x400000 /* retry HARDWARE_ERROR */
+#define BLIST_ATTACH_PQ3	0x800000 /* Scan: Attach to PQ3 devices */
 #endif
-- 
Kurt Garloff, Head Architect Linux R&D, Novell Inc.

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