[SCSI] scsi_dh: add generic SPC-3 alua handler

Signed-off-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NChandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

drivers/scsi/device_handler/Kconfig

@@ -30,3 +30,11 @@ config SCSI_DH_EMC
 	depends on SCSI_DH
 	help
 	If you have a EMC CLARiiON select y. Otherwise, say N.
+
+config SCSI_DH_ALUA
+	tristate "SPC-3 ALUA Device Handler (EXPERIMENTAL)"
+	depends on SCSI_DH && EXPERIMENTAL
+	help
+	  SCSI Device handler for generic SPC-3 Asymmetric Logical Unit
+	  Access (ALUA).
+

drivers/scsi/device_handler/Makefile

@@ -5,3 +5,4 @@ obj-$(CONFIG_SCSI_DH)		+= scsi_dh.o
 obj-$(CONFIG_SCSI_DH_RDAC)	+= scsi_dh_rdac.o
 obj-$(CONFIG_SCSI_DH_HP_SW)	+= scsi_dh_hp_sw.o
 obj-$(CONFIG_SCSI_DH_EMC)	+= scsi_dh_emc.o
+obj-$(CONFIG_SCSI_DH_ALUA)	+= scsi_dh_alua.o

include/scsi/scsi.h

@@ -106,6 +106,7 @@
 #define VARIABLE_LENGTH_CMD   0x7f
 #define REPORT_LUNS           0xa0
 #define MAINTENANCE_IN        0xa3
+#define MAINTENANCE_OUT       0xa4
 #define MOVE_MEDIUM           0xa5
 #define EXCHANGE_MEDIUM       0xa6
 #define READ_12               0xa8
@@ -125,6 +126,8 @@
 #define	SAI_READ_CAPACITY_16  0x10
 /* values for maintenance in */
 #define MI_REPORT_TARGET_PGS  0x0a
+/* values for maintenance out */
+#define MO_SET_TARGET_PGS     0x0a
 
 /* Values for T10/04-262r7 */
 #define	ATA_16		      0x85	/* 16-byte pass-thru */