[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>

1 files changed, 66 insertions, 10 deletions

diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c
index a38fec4acceb..a5f44a6e6e1d 100644
--- a/drivers/target/target_core_configfs.c
+++ b/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 @@ out:
                 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 @@ out:
         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;