[SCSI] target: add initial statistics

This patch adds a target_core_mib.c statistics conversion for
backend context struct se_subsystem_dev + struct se_device config_group
based statistics in target_core_device.c using CONFIGFS_EATTR()
based struct config_item_types from target_core_stat.c code.

The conversion from backend /proc/scsi_target/mib/ context output to configfs
default groups+attributes include scsi_dev, scsi_lu, and scsi_tgt_dev output
from within individual:

	/sys/kernel/config/target/core/$HBA/DEV/

The legacy procfs output now appear as individual configfs attributes under:

*) $HBA/$DEV/statistics/scsi_dev:

|-- indx
|-- inst
|-- ports
`-- role

*) $HBA/$DEV/statistics/scsi_lu:

|-- creation_time
|-- dev
|-- dev_type
|-- full_stat
|-- hs_num_cmds
|-- indx
|-- inst
|-- lu_name
|-- lun
|-- num_cmds
|-- prod
|-- read_mbytes
|-- resets
|-- rev
|-- state_bit
|-- status
|-- vend
`-- write_mbytes

*) $HBA/$DEV/statistics/scsi_tgt_dev:

|-- indx
|-- inst
|-- non_access_lus
|-- num_lus
|-- resets
`-- status

The conversion from backend /proc/scsi_target/mib/ context output to configfs
default groups+attributes include scsi_port, scsi_tgt_port and scsi_transport
output from within individual:

	/sys/kernel/config/target/fabric/$WWN/tpgt_$TPGT/lun/lun_$LUN_ID/statistics/

The legacy procfs output now appear as individual configfs attributes under:

*) fabric/$WWN/tpgt_$TPGT/lun/lun_$LUN_ID/statistics/scsi_port

|-- busy_count
|-- dev
|-- indx
|-- inst
`-- role

*) fabric/$WWN/tpgt_$TPGT/lun/lun_$LUN_ID/statistics/scsi_tgt_port

|-- dev
|-- hs_in_cmds
|-- in_cmds
|-- indx
|-- inst
|-- name
|-- port_index
|-- read_mbytes
`-- write_mbytes

*) fabric/$WWN/tpgt_$TPGT/lun/lun_$LUN_ID/statistics/scsi_transport

|-- dev_name
|-- device
|-- indx
`-- inst

The conversion from backend /proc/scsi_target/mib/ context output to configfs
default groups+attributes include scsi_att_intr_port and scsi_auth_intr output
from within individual:

	/sys/kernel/config/target/fabric/$WWN/tpgt_$TPGT/acls/$INITIATOR_WWN/lun_$LUN_ID/statistics/

The legacy procfs output now appear as individual configfs attributes under:

*) acls/$INITIATOR_WWN/lun_$LUN_ID/statistics/scsi_att_intr_port

|-- dev
|-- indx
|-- inst
|-- port
|-- port_auth_indx
`-- port_ident

*) acls/$INITIATOR_WWN/lun_$LUN_ID/statistics/scsi_auth_intr

|-- att_count
|-- creation_time
|-- dev
|-- dev_or_port
|-- hs_num_cmds
|-- indx
|-- inst
|-- intr_name
|-- map_indx
|-- num_cmds
|-- port
|-- read_mbytes
|-- row_status
`-- write_mbytes

Also, this includes adding struct target_fabric_configfs_template->
tfc_wwn_fabric_stats_cit and ->tfc_tpg_nacl_stat_cit respectively for
use during target_core_fabric_configfs.c:target_fabric_setup_cits()
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

drivers/target/Makefile

@@ -12,7 +12,8 @@ target_core_mod-y		:= target_core_configfs.o \
 				   target_core_transport.o \
 				   target_core_cdb.o \
 				   target_core_ua.o \
-				   target_core_rd.o
+				   target_core_rd.o \
+				   target_core_stat.o
 
 obj-$(CONFIG_TARGET_CORE)	+= target_core_mod.o
 

drivers/target/target_core_configfs.c

@@ -3,8 +3,8 @@
  *
  * This file contains ConfigFS logic for the Generic Target Engine project.
  *
- * Copyright (c) 2008-2010 Rising Tide Systems
- * Copyright (c) 2008-2010 Linux-iSCSI.org
+ * Copyright (c) 2008-2011 Rising Tide Systems
+ * Copyright (c) 2008-2011 Linux-iSCSI.org
  *
  * Nicholas A. Bellinger <nab@kernel.org>
  *
@@ -50,6 +50,7 @@
 #include "target_core_hba.h"
 #include "target_core_pr.h"
 #include "target_core_rd.h"
+#include "target_core_stat.h"
 
 static struct list_head g_tf_list;
 static struct mutex g_tf_lock;
@@ -2709,6 +2710,34 @@ static struct config_item_type target_core_alua_cit = {
 
 /* End functions for struct config_item_type target_core_alua_cit */
 
+/* Start functions for struct config_item_type target_core_stat_cit */
+
+static struct config_group *target_core_stat_mkdir(
+	struct config_group *group,
+	const char *name)
+{
+	return ERR_PTR(-ENOSYS);
+}
+
+static void target_core_stat_rmdir(
+	struct config_group *group,
+	struct config_item *item)
+{
+	return;
+}
+
+static struct configfs_group_operations target_core_stat_group_ops = {
+	.make_group		= &target_core_stat_mkdir,
+	.drop_item		= &target_core_stat_rmdir,
+};
+
+static struct config_item_type target_core_stat_cit = {
+	.ct_group_ops		= &target_core_stat_group_ops,
+	.ct_owner		= THIS_MODULE,
+};
+
+/* End functions for struct config_item_type target_core_stat_cit */
+
 /* Start functions for struct config_item_type target_core_hba_cit */
 
 static struct config_group *target_core_make_subdev(
@@ -2721,10 +2750,12 @@ static struct config_group *target_core_make_subdev(
 	struct config_item *hba_ci = &group->cg_item;
 	struct se_hba *hba = item_to_hba(hba_ci);
 	struct config_group *dev_cg = NULL, *tg_pt_gp_cg = NULL;
+	struct config_group *dev_stat_grp = NULL;
+	int errno = -ENOMEM, ret;
 
-	if (mutex_lock_interruptible(&hba->hba_access_mutex))
-		return NULL;
-
+	ret = mutex_lock_interruptible(&hba->hba_access_mutex);
+	if (ret)
+		return ERR_PTR(ret);
 	/*
 	 * Locate the struct se_subsystem_api from parent's struct se_hba.
 	 */
@@ -2754,7 +2785,7 @@ static struct config_group *target_core_make_subdev(
 	se_dev->se_dev_hba = hba;
 	dev_cg = &se_dev->se_dev_group;
 
-	dev_cg->default_groups = kzalloc(sizeof(struct config_group) * 6,
+	dev_cg->default_groups = kzalloc(sizeof(struct config_group) * 7,
 			GFP_KERNEL);
 	if (!(dev_cg->default_groups))
 		goto out;
@@ -2786,13 +2817,17 @@ static struct config_group *target_core_make_subdev(
 			&target_core_dev_wwn_cit);
 	config_group_init_type_name(&se_dev->t10_alua.alua_tg_pt_gps_group,
 			"alua", &target_core_alua_tg_pt_gps_cit);
+	config_group_init_type_name(&se_dev->dev_stat_grps.stat_group,
+			"statistics", &target_core_stat_cit);
+
 	dev_cg->default_groups[0] = &se_dev->se_dev_attrib.da_group;
 	dev_cg->default_groups[1] = &se_dev->se_dev_pr_group;
 	dev_cg->default_groups[2] = &se_dev->t10_wwn.t10_wwn_group;
 	dev_cg->default_groups[3] = &se_dev->t10_alua.alua_tg_pt_gps_group;
-	dev_cg->default_groups[4] = NULL;
+	dev_cg->default_groups[4] = &se_dev->dev_stat_grps.stat_group;
+	dev_cg->default_groups[5] = NULL;
 	/*
-	 * Add core/$HBA/$DEV/alua/tg_pt_gps/default_tg_pt_gp
+	 * Add core/$HBA/$DEV/alua/default_tg_pt_gp
 	 */
 	tg_pt_gp = core_alua_allocate_tg_pt_gp(se_dev, "default_tg_pt_gp", 1);
 	if (!(tg_pt_gp))
@@ -2812,6 +2847,17 @@ static struct config_group *target_core_make_subdev(
 	tg_pt_gp_cg->default_groups[0] = &tg_pt_gp->tg_pt_gp_group;
 	tg_pt_gp_cg->default_groups[1] = NULL;
 	T10_ALUA(se_dev)->default_tg_pt_gp = tg_pt_gp;
+	/*
+	 * Add core/$HBA/$DEV/statistics/ default groups
+	 */
+	dev_stat_grp = &DEV_STAT_GRP(se_dev)->stat_group;
+	dev_stat_grp->default_groups = kzalloc(sizeof(struct config_group) * 4,
+				GFP_KERNEL);
+	if (!dev_stat_grp->default_groups) {
+		printk(KERN_ERR "Unable to allocate dev_stat_grp->default_groups\n");
+		goto out;
+	}
+	target_stat_setup_dev_default_groups(se_dev);
 
 	printk(KERN_INFO "Target_Core_ConfigFS: Allocated struct se_subsystem_dev:"
 		" %p se_dev_su_ptr: %p\n", se_dev, se_dev->se_dev_su_ptr);
@@ -2823,6 +2869,8 @@ static struct config_group *target_core_make_subdev(
 		core_alua_free_tg_pt_gp(T10_ALUA(se_dev)->default_tg_pt_gp);
 		T10_ALUA(se_dev)->default_tg_pt_gp = NULL;
 	}
+	if (dev_stat_grp)
+		kfree(dev_stat_grp->default_groups);
 	if (tg_pt_gp_cg)
 		kfree(tg_pt_gp_cg->default_groups);
 	if (dev_cg)
@@ -2832,7 +2880,7 @@ static struct config_group *target_core_make_subdev(
 	kfree(se_dev);
 unlock:
 	mutex_unlock(&hba->hba_access_mutex);
-	return NULL;
+	return ERR_PTR(errno);
 }
 
 static void target_core_drop_subdev(
@@ -2844,7 +2892,7 @@ static void target_core_drop_subdev(
 	struct se_hba *hba;
 	struct se_subsystem_api *t;
 	struct config_item *df_item;
-	struct config_group *dev_cg, *tg_pt_gp_cg;
+	struct config_group *dev_cg, *tg_pt_gp_cg, *dev_stat_grp;
 	int i;
 
 	hba = item_to_hba(&se_dev->se_dev_hba->hba_group.cg_item);
@@ -2856,6 +2904,14 @@ static void target_core_drop_subdev(
 	list_del(&se_dev->g_se_dev_list);
 	spin_unlock(&se_global->g_device_lock);
 
+	dev_stat_grp = &DEV_STAT_GRP(se_dev)->stat_group;
+	for (i = 0; dev_stat_grp->default_groups[i]; i++) {
+		df_item = &dev_stat_grp->default_groups[i]->cg_item;
+		dev_stat_grp->default_groups[i] = NULL;
+		config_item_put(df_item);
+	}
+	kfree(dev_stat_grp->default_groups);
+
 	tg_pt_gp_cg = &T10_ALUA(se_dev)->alua_tg_pt_gps_group;
 	for (i = 0; tg_pt_gp_cg->default_groups[i]; i++) {
 		df_item = &tg_pt_gp_cg->default_groups[i]->cg_item;

drivers/target/target_core_stat.h

+#ifndef TARGET_CORE_STAT_H
+#define TARGET_CORE_STAT_H
+
+extern void target_stat_setup_dev_default_groups(struct se_subsystem_dev *);
+extern void target_stat_setup_port_default_groups(struct se_lun *);
+extern void target_stat_setup_mappedlun_default_groups(struct se_lun_acl *);
+
+#endif   /*** TARGET_CORE_STAT_H ***/

include/target/target_core_base.h

@@ -601,7 +601,8 @@ struct se_node_acl {
 	struct config_group	acl_attrib_group;
 	struct config_group	acl_auth_group;
 	struct config_group	acl_param_group;
-	struct config_group	*acl_default_groups[4];
+	struct config_group	acl_fabric_stat_group;
+	struct config_group	*acl_default_groups[5];
 	struct list_head	acl_list;
 	struct list_head	acl_sess_list;
 } ____cacheline_aligned;
@@ -622,6 +623,12 @@ struct se_device;
 struct se_transform_info;
 struct scatterlist;
 
+struct se_ml_stat_grps {
+	struct config_group	stat_group;
+	struct config_group	scsi_auth_intr_group;
+	struct config_group	scsi_att_intr_port_group;
+};
+
 struct se_lun_acl {
 	char			initiatorname[TRANSPORT_IQN_LEN];
 	u32			mapped_lun;
@@ -629,8 +636,11 @@ struct se_lun_acl {
 	struct se_lun		*se_lun;
 	struct list_head	lacl_list;
 	struct config_group	se_lun_group;
+	struct se_ml_stat_grps	ml_stat_grps;
 }  ____cacheline_aligned;
 
+#define ML_STAT_GRPS(lacl)	(&(lacl)->ml_stat_grps)
+
 struct se_dev_entry {
 	bool			def_pr_registered;
 	/* See transport_lunflags_table */
@@ -693,6 +703,13 @@ struct se_dev_attrib {
 	struct config_group da_group;
 } ____cacheline_aligned;
 
+struct se_dev_stat_grps {
+	struct config_group stat_group;
+	struct config_group scsi_dev_group;
+	struct config_group scsi_tgt_dev_group;
+	struct config_group scsi_lu_group;
+};
+
 struct se_subsystem_dev {
 /* Used for struct se_subsystem_dev-->se_dev_alias, must be less than PAGE_SIZE */
 #define SE_DEV_ALIAS_LEN		512
@@ -716,11 +733,14 @@ struct se_subsystem_dev {
 	struct config_group se_dev_group;
 	/* For T10 Reservations */
 	struct config_group se_dev_pr_group;
+	/* For target_core_stat.c groups */
+	struct se_dev_stat_grps dev_stat_grps;
 } ____cacheline_aligned;
 
 #define T10_ALUA(su_dev)	(&(su_dev)->t10_alua)
 #define T10_RES(su_dev)		(&(su_dev)->t10_reservation)
 #define T10_PR_OPS(su_dev)	(&(su_dev)->t10_reservation.pr_ops)
+#define DEV_STAT_GRP(dev)	(&(dev)->dev_stat_grps)
 
 struct se_device {
 	/* Set to 1 if thread is NOT sleeping on thread_sem */
@@ -834,6 +854,13 @@ struct se_hba {
 
 #define SE_HBA(dev)		((dev)->se_hba)
 
+struct se_port_stat_grps {
+	struct config_group stat_group;
+	struct config_group scsi_port_group;
+	struct config_group scsi_tgt_port_group;
+	struct config_group scsi_transport_group;
+};
+
 struct se_lun {
 	/* See transport_lun_status_table */
 	enum transport_lun_status_table lun_status;
@@ -848,11 +875,13 @@ struct se_lun {
 	struct list_head	lun_cmd_list;
 	struct list_head	lun_acl_list;
 	struct se_device	*lun_se_dev;
+	struct se_port		*lun_sep;
 	struct config_group	lun_group;
-	struct se_port	*lun_sep;
+	struct se_port_stat_grps port_stat_grps;
 } ____cacheline_aligned;
 
 #define SE_LUN(cmd)		((cmd)->se_lun)
+#define PORT_STAT_GRP(lun)	(&(lun)->port_stat_grps)
 
 struct scsi_port_stats {
        u64     cmd_pdus;
@@ -924,6 +953,8 @@ struct se_portal_group {
 struct se_wwn {
 	struct target_fabric_configfs *wwn_tf;
 	struct config_group	wwn_group;
+	struct config_group	*wwn_default_groups[2];
+	struct config_group	fabric_stat_group;
 } ____cacheline_aligned;
 
 struct se_global {

include/target/target_core_configfs.h

@@ -14,10 +14,12 @@ extern void target_fabric_configfs_deregister(struct target_fabric_configfs *);
 struct target_fabric_configfs_template {
 	struct config_item_type tfc_discovery_cit;
 	struct config_item_type	tfc_wwn_cit;
+	struct config_item_type tfc_wwn_fabric_stats_cit;
 	struct config_item_type tfc_tpg_cit;
 	struct config_item_type tfc_tpg_base_cit;
 	struct config_item_type tfc_tpg_lun_cit;
 	struct config_item_type tfc_tpg_port_cit;
+	struct config_item_type tfc_tpg_port_stat_cit;
 	struct config_item_type tfc_tpg_np_cit;
 	struct config_item_type tfc_tpg_np_base_cit;
 	struct config_item_type tfc_tpg_attrib_cit;
@@ -27,7 +29,9 @@ struct target_fabric_configfs_template {
 	struct config_item_type tfc_tpg_nacl_attrib_cit;
 	struct config_item_type tfc_tpg_nacl_auth_cit;
 	struct config_item_type tfc_tpg_nacl_param_cit;
+	struct config_item_type tfc_tpg_nacl_stat_cit;
 	struct config_item_type tfc_tpg_mappedlun_cit;
+	struct config_item_type tfc_tpg_mappedlun_stat_cit;
 };
 
 struct target_fabric_configfs {