[SCSI] target: Remove procfs based target_core_mib.c code

This patch removes the legacy procfs based target_core_mib.c code,
and moves the necessary scsi_index_tables functions and defines into
target_core_transport.c and target_core_base.h code to allow existing
fabric independent statistics to function.

This includes the removal of a handful of 'atomic_t mib_ref_count'
counters used in struct se_node_acl, se_session and se_hba to prevent
removal while using seq_list procfs walking logic.

[jejb: fix up compile failures]
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

drivers/target/Makefile

@@ -13,8 +13,7 @@ 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_mib.o
+				   target_core_rd.o
 
 obj-$(CONFIG_TARGET_CORE)	+= target_core_mod.o
 

drivers/target/target_core_configfs.c

@@ -37,7 +37,6 @@
 #include <linux/parser.h>
 #include <linux/syscalls.h>
 #include <linux/configfs.h>
-#include <linux/proc_fs.h>
 
 #include <target/target_core_base.h>
 #include <target/target_core_device.h>
@@ -3022,7 +3021,6 @@ static int target_core_init_configfs(void)
 	struct config_group *target_cg, *hba_cg = NULL, *alua_cg = NULL;
 	struct config_group *lu_gp_cg = NULL;
 	struct configfs_subsystem *subsys;
-	struct proc_dir_entry *scsi_target_proc = NULL;
 	struct t10_alua_lu_gp *lu_gp;
 	int ret;
 
@@ -3128,21 +3126,10 @@ static int target_core_init_configfs(void)
 	if (core_dev_setup_virtual_lun0() < 0)
 		goto out;
 
-	scsi_target_proc = proc_mkdir("scsi_target", 0);
-	if (!(scsi_target_proc)) {
-		printk(KERN_ERR "proc_mkdir(scsi_target, 0) failed\n");
-		goto out;
-	}
-	ret = init_scsi_target_mib();
-	if (ret < 0)
-		goto out;
-
 	return 0;
 
 out:
 	configfs_unregister_subsystem(subsys);
-	if (scsi_target_proc)
-		remove_proc_entry("scsi_target", 0);
 	core_dev_release_virtual_lun0();
 	rd_module_exit();
 out_global:
@@ -3210,8 +3197,6 @@ static void target_core_exit_configfs(void)
 	printk(KERN_INFO "TARGET_CORE[0]: Released ConfigFS Fabric"
 			" Infrastructure\n");
 
-	remove_scsi_target_mib();
-	remove_proc_entry("scsi_target", 0);
 	core_dev_release_virtual_lun0();
 	rd_module_exit();
 	release_se_global();

drivers/target/target_core_device.c

@@ -867,9 +867,6 @@ static void se_dev_stop(struct se_device *dev)
 		}
 	}
 	spin_unlock(&hba->device_lock);
-
-	while (atomic_read(&hba->dev_mib_access_count))
-		cpu_relax();
 }
 
 int se_dev_check_online(struct se_device *dev)

drivers/target/target_core_mib.h

-#ifndef TARGET_CORE_MIB_H
-#define TARGET_CORE_MIB_H
-
-typedef enum {
-	SCSI_INST_INDEX,
-	SCSI_DEVICE_INDEX,
-	SCSI_AUTH_INTR_INDEX,
-	SCSI_INDEX_TYPE_MAX
-} scsi_index_t;
-
-struct scsi_index_table {
-	spinlock_t	lock;
-	u32 		scsi_mib_index[SCSI_INDEX_TYPE_MAX];
-} ____cacheline_aligned;
-
-/* SCSI Port stats */
-struct scsi_port_stats {
-	u64	cmd_pdus;
-	u64	tx_data_octets;
-	u64	rx_data_octets;
-} ____cacheline_aligned;
-
-extern int init_scsi_target_mib(void);
-extern void remove_scsi_target_mib(void);
-extern void init_scsi_index_table(void);
-extern u32 scsi_get_new_index(scsi_index_t);
-
-#endif   /*** TARGET_CORE_MIB_H ***/

drivers/target/target_core_tpg.c

@@ -275,7 +275,6 @@ struct se_node_acl *core_tpg_check_initiator_node_acl(
 	spin_lock_init(&acl->device_list_lock);
 	spin_lock_init(&acl->nacl_sess_lock);
 	atomic_set(&acl->acl_pr_ref_count, 0);
-	atomic_set(&acl->mib_ref_count, 0);
 	acl->queue_depth = TPG_TFO(tpg)->tpg_get_default_depth(tpg);
 	snprintf(acl->initiatorname, TRANSPORT_IQN_LEN, "%s", initiatorname);
 	acl->se_tpg = tpg;
@@ -318,12 +317,6 @@ void core_tpg_wait_for_nacl_pr_ref(struct se_node_acl *nacl)
 		cpu_relax();
 }
 
-void core_tpg_wait_for_mib_ref(struct se_node_acl *nacl)
-{
-	while (atomic_read(&nacl->mib_ref_count) != 0)
-		cpu_relax();
-}
-
 void core_tpg_clear_object_luns(struct se_portal_group *tpg)
 {
 	int i, ret;
@@ -480,7 +473,6 @@ int core_tpg_del_initiator_node_acl(
 	spin_unlock_bh(&tpg->session_lock);
 
 	core_tpg_wait_for_nacl_pr_ref(acl);
-	core_tpg_wait_for_mib_ref(acl);
 	core_clear_initiator_node_from_tpg(acl, tpg);
 	core_free_device_list_for_node(acl, tpg);
 
@@ -701,6 +693,8 @@ EXPORT_SYMBOL(core_tpg_register);
 
 int core_tpg_deregister(struct se_portal_group *se_tpg)
 {
+	struct se_node_acl *nacl, *nacl_tmp;
+
 	printk(KERN_INFO "TARGET_CORE[%s]: Deallocating %s struct se_portal_group"
 		" for endpoint: %s Portal Tag %u\n",
 		(se_tpg->se_tpg_type == TRANSPORT_TPG_TYPE_NORMAL) ?
@@ -714,6 +708,25 @@ int core_tpg_deregister(struct se_portal_group *se_tpg)
 
 	while (atomic_read(&se_tpg->tpg_pr_ref_count) != 0)
 		cpu_relax();
+	/*
+	 * Release any remaining demo-mode generated se_node_acl that have
+	 * not been released because of TFO->tpg_check_demo_mode_cache() == 1
+	 * in transport_deregister_session().
+	 */
+	spin_lock_bh(&se_tpg->acl_node_lock);
+	list_for_each_entry_safe(nacl, nacl_tmp, &se_tpg->acl_node_list,
+			acl_list) {
+		list_del(&nacl->acl_list);
+		se_tpg->num_node_acls--;
+		spin_unlock_bh(&se_tpg->acl_node_lock);
+
+		core_tpg_wait_for_nacl_pr_ref(nacl);
+		core_free_device_list_for_node(nacl, se_tpg);
+		TPG_TFO(se_tpg)->tpg_release_fabric_acl(se_tpg, nacl);
+
+		spin_lock_bh(&se_tpg->acl_node_lock);
+	}
+	spin_unlock_bh(&se_tpg->acl_node_lock);
 
 	if (se_tpg->se_tpg_type == TRANSPORT_TPG_TYPE_NORMAL)
 		core_tpg_release_virtual_lun0(se_tpg);

drivers/target/target_core_transport.c

@@ -379,6 +379,40 @@ void release_se_global(void)
 	se_global = NULL;
 }
 
+/* SCSI statistics table index */
+static struct scsi_index_table scsi_index_table;
+
+/*
+ * Initialize the index table for allocating unique row indexes to various mib
+ * tables.
+ */
+void init_scsi_index_table(void)
+{
+	memset(&scsi_index_table, 0, sizeof(struct scsi_index_table));
+	spin_lock_init(&scsi_index_table.lock);
+}
+
+/*
+ * Allocate a new row index for the entry type specified
+ */
+u32 scsi_get_new_index(scsi_index_t type)
+{
+	u32 new_index;
+
+	if ((type < 0) || (type >= SCSI_INDEX_TYPE_MAX)) {
+		printk(KERN_ERR "Invalid index type %d\n", type);
+		return -EINVAL;
+	}
+
+	spin_lock(&scsi_index_table.lock);
+	new_index = ++scsi_index_table.scsi_mib_index[type];
+	if (new_index == 0)
+		new_index = ++scsi_index_table.scsi_mib_index[type];
+	spin_unlock(&scsi_index_table.lock);
+
+	return new_index;
+}
+
 void transport_init_queue_obj(struct se_queue_obj *qobj)
 {
 	atomic_set(&qobj->queue_cnt, 0);
@@ -437,7 +471,6 @@ struct se_session *transport_init_session(void)
 	}
 	INIT_LIST_HEAD(&se_sess->sess_list);
 	INIT_LIST_HEAD(&se_sess->sess_acl_list);
-	atomic_set(&se_sess->mib_ref_count, 0);
 
 	return se_sess;
 }
@@ -546,12 +579,6 @@ void transport_deregister_session(struct se_session *se_sess)
 		transport_free_session(se_sess);
 		return;
 	}
-	/*
-	 * Wait for possible reference in drivers/target/target_core_mib.c:
-	 * scsi_att_intr_port_seq_show()
-	 */
-	while (atomic_read(&se_sess->mib_ref_count) != 0)
-		cpu_relax();
 
 	spin_lock_bh(&se_tpg->session_lock);
 	list_del(&se_sess->sess_list);
@@ -574,7 +601,6 @@ void transport_deregister_session(struct se_session *se_sess)
 				spin_unlock_bh(&se_tpg->acl_node_lock);
 
 				core_tpg_wait_for_nacl_pr_ref(se_nacl);
-				core_tpg_wait_for_mib_ref(se_nacl);
 				core_free_device_list_for_node(se_nacl, se_tpg);
 				TPG_TFO(se_tpg)->tpg_release_fabric_acl(se_tpg,
 						se_nacl);

include/target/target_core_base.h

@@ -8,7 +8,6 @@
 #include <scsi/scsi_cmnd.h>
 #include <net/sock.h>
 #include <net/tcp.h>
-#include "target_core_mib.h"
 
 #define TARGET_CORE_MOD_VERSION		"v4.0.0-rc6"
 #define SHUTDOWN_SIGS	(sigmask(SIGKILL)|sigmask(SIGINT)|sigmask(SIGABRT))
@@ -195,6 +194,21 @@ typedef enum {
 	SAM_TASK_ATTR_EMULATED
 } t10_task_attr_index_t;
 
+/*
+ * Used for target SCSI statistics
+ */
+typedef enum {
+	SCSI_INST_INDEX,
+	SCSI_DEVICE_INDEX,
+	SCSI_AUTH_INTR_INDEX,
+	SCSI_INDEX_TYPE_MAX
+} scsi_index_t;
+
+struct scsi_index_table {
+	spinlock_t	lock;
+	u32		scsi_mib_index[SCSI_INDEX_TYPE_MAX];
+} ____cacheline_aligned;
+
 struct se_cmd;
 
 struct t10_alua {
@@ -578,8 +592,6 @@ struct se_node_acl {
 	spinlock_t		stats_lock;
 	/* Used for PR SPEC_I_PT=1 and REGISTER_AND_MOVE */
 	atomic_t		acl_pr_ref_count;
-	/* Used for MIB access */
-	atomic_t		mib_ref_count;
 	struct se_dev_entry	*device_list;
 	struct se_session	*nacl_sess;
 	struct se_portal_group *se_tpg;
@@ -595,8 +607,6 @@ struct se_node_acl {
 } ____cacheline_aligned;
 
 struct se_session {
-	/* Used for MIB access */
-	atomic_t		mib_ref_count;
 	u64			sess_bin_isid;
 	struct se_node_acl	*se_node_acl;
 	struct se_portal_group *se_tpg;
@@ -806,7 +816,6 @@ struct se_hba {
 	/* Virtual iSCSI devices attached. */
 	u32			dev_count;
 	u32			hba_index;
-	atomic_t		dev_mib_access_count;
 	atomic_t		load_balance_queue;
 	atomic_t		left_queue_depth;
 	/* Maximum queue depth the HBA can handle. */
@@ -845,6 +854,12 @@ struct se_lun {
 
 #define SE_LUN(c)		((struct se_lun *)(c)->se_lun)
 
+struct scsi_port_stats {
+       u64     cmd_pdus;
+       u64     tx_data_octets;
+       u64     rx_data_octets;
+} ____cacheline_aligned;
+
 struct se_port {
 	/* RELATIVE TARGET PORT IDENTIFER */
 	u16		sep_rtpi;

include/target/target_core_transport.h

@@ -111,6 +111,8 @@ struct se_subsystem_api;
 
 extern int init_se_global(void);
 extern void release_se_global(void);
+extern void init_scsi_index_table(void);
+extern u32 scsi_get_new_index(scsi_index_t);
 extern void transport_init_queue_obj(struct se_queue_obj *);
 extern int transport_subsystem_check_init(void);
 extern int transport_subsystem_register(struct se_subsystem_api *);