[PATCH 2/3] [TCM/PR]: Convert REGISTER_AND_MOVE use new configfs dependency wrappers

["Nicholas A. Bellinger" <nab@linux-iscsi.org>]

From: Nicholas Bellinger <nab@linux-iscsi.org>

This patch converts core_scsi3_emulate_pro_register_and_move() to use
the new demo-mode safe configfs dependency wrappers in 9c8e057ee5 instead of
using direct calls to configfs_depend_item() and configfs_undepend_item() which
originally require explict NodeACLs for REGISTER_AND_MOVE to function.

This patch also adds the *pr_ref_count + 1 references for TPG, NodeACL and MappedLUN
structures used by REGISTER_AND_MOVE, which are dropped when REGISTER_AND_MOVE
is complete by core_scsi3_tpg_undepend_item(), core_scsi3_nodeacl_undepend_item() and
core_scsi3_lunacl_undepend_item() respectively.

Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
---
 drivers/target/target_core_pr.c |   62 +++++++++++++++++++++++---------------
 1 files changed, 37 insertions(+), 25 deletions(-)

diff --git a/drivers/target/target_core_pr.c b/drivers/target/target_core_pr.c
index 03f40e3..6211d59 100644
--- a/drivers/target/target_core_pr.c
+++ b/drivers/target/target_core_pr.c
@@ -2842,7 +2842,7 @@ static int core_scsi3_emulate_pro_register_and_move(
 	unsigned char *buf = (unsigned char *)T_TASK(cmd)->t_task_buf;
 	unsigned char *initiator_str;
 	char *iport_ptr = NULL, dest_iport[64];
-	u32 tid_len;
+	u32 tid_len, tmp_tid_len;
 	int new_reg = 0, type, scope, ret;
 	unsigned short rtpi;
 	unsigned char proto_ident;
@@ -2923,13 +2923,17 @@ static int core_scsi3_emulate_pro_register_and_move(
 		dest_tf_ops = TPG_TFO(dest_se_tpg);
 		if (!(dest_tf_ops))
 			continue;
+
+		atomic_inc(&dest_se_tpg->tpg_pr_ref_count);
+		smp_mb__after_atomic_inc();
 		spin_unlock(&dev->se_port_lock);
 
-		ret = configfs_depend_item(dest_tf_ops->tf_subsys,
-				&dest_se_tpg->tpg_group.cg_item);
+		ret = core_scsi3_tpg_depend_item(dest_se_tpg);
 		if (ret != 0) {
-			printk(KERN_ERR "configfs_depend_item() failed for"
-				" dest_se_tpg->tpg_group\n");
+			printk(KERN_ERR "core_scsi3_tpg_depend_item() failed"
+				" for dest_se_tpg\n");
+			atomic_dec(&dest_se_tpg->tpg_pr_ref_count);
+			smp_mb__after_atomic_dec();
 			core_scsi3_put_pr_reg(pr_reg);
 			return PYX_TRANSPORT_LU_COMM_FAILURE;
 		}
@@ -2968,7 +2972,7 @@ static int core_scsi3_emulate_pro_register_and_move(
 		goto out;
 	}
 	initiator_str = dest_tf_ops->tpg_parse_pr_out_transport_id(
-			(const char *)&buf[24], NULL, &iport_ptr);
+			(const char *)&buf[24], &tmp_tid_len, &iport_ptr);
 	if (!(initiator_str)) {
 		printk(KERN_ERR "SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
 			" initiator_str from Transport ID\n");
@@ -2999,8 +3003,13 @@ static int core_scsi3_emulate_pro_register_and_move(
 	/*
 	 * Locate the destination se_node_acl_t from the received Transport ID
 	 */
-	dest_node_acl = core_tpg_get_initiator_node_acl(dest_se_tpg,
+	spin_lock_bh(&dest_se_tpg->acl_node_lock);
+	dest_node_acl = __core_tpg_get_initiator_node_acl(dest_se_tpg,
 				initiator_str);
+	atomic_inc(&dest_node_acl->acl_pr_ref_count);
+	smp_mb__after_atomic_inc();
+	spin_unlock_bh(&dest_se_tpg->acl_node_lock);
+
 	if (!(dest_node_acl)) {
 		printk(KERN_ERR "Unable to locate %s dest_node_acl for"
 			" TransportID%s\n", dest_tf_ops->get_fabric_name(),
@@ -3008,11 +3017,12 @@ static int core_scsi3_emulate_pro_register_and_move(
 		ret = PYX_TRANSPORT_INVALID_PARAMETER_LIST;
 		goto out;
 	}
-	ret = configfs_depend_item(dest_tf_ops->tf_subsys,
-				&dest_node_acl->acl_group.cg_item);
+	ret = core_scsi3_nodeacl_depend_item(dest_node_acl);
 	if (ret != 0) {
-		printk(KERN_ERR "configfs_depend_item() failed for"
-			" dest_node_acl->acl_group\n");
+		printk(KERN_ERR "core_scsi3_nodeacl_depend_item() for"
+			" dest_node_acl\n");
+		atomic_dec(&dest_node_acl->acl_pr_ref_count);
+		smp_mb__after_atomic_dec();
 		ret = PYX_TRANSPORT_LU_COMM_FAILURE;
 		dest_node_acl = NULL;
 		goto out;
@@ -3056,8 +3066,7 @@ static int core_scsi3_emulate_pro_register_and_move(
 	}
 	/*
 	 * Locate the se_dev_entry_t pointer for the matching RELATIVE TARGET
-	 * PORT IDENTIFIER.  core_get_se_deve_from_rtpi() will call
-	 * configfs_item_depend() on deve->se_lun_acl->se_lun_group.cg_item
+	 * PORT IDENTIFIER.
 	 */
 	dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl, rtpi);
 	if (!(dest_se_deve)) {
@@ -3066,6 +3075,15 @@ static int core_scsi3_emulate_pro_register_and_move(
 		ret = PYX_TRANSPORT_INVALID_PARAMETER_LIST;
 		goto out;
 	}
+	
+	ret = core_scsi3_lunacl_depend_item(dest_se_deve);
+	if (ret < 0) {
+		printk(KERN_ERR "core_scsi3_lunacl_depend_item() failed\n");
+		atomic_dec(&dest_se_deve->pr_ref_count);
+		smp_mb__after_atomic_dec();
+		ret = PYX_TRANSPORT_LU_COMM_FAILURE;
+		goto out;
+	}
 #if 0
 	printk(KERN_INFO "SPC-3 PR REGISTER_AND_MOVE: Located %s node %s LUN"
 		" ACL for dest_se_deve->mapped_lun: %u\n",
@@ -3201,12 +3219,9 @@ static int core_scsi3_emulate_pro_register_and_move(
 	 * It is now safe to release configfs group dependencies for destination
 	 * of Transport ID Initiator Device/Port Identifier
 	 */
-	configfs_undepend_item(dest_tf_ops->tf_subsys,
-			&dest_se_deve->se_lun_acl->se_lun_group.cg_item);
-	configfs_undepend_item(dest_tf_ops->tf_subsys,
-			&dest_node_acl->acl_group.cg_item);
-	configfs_undepend_item(dest_tf_ops->tf_subsys,
-			&dest_se_tpg->tpg_group.cg_item);
+	core_scsi3_lunacl_undepend_item(dest_se_deve);
+	core_scsi3_nodeacl_undepend_item(dest_node_acl);
+	core_scsi3_tpg_undepend_item(dest_se_tpg);
 	/*
 	 * h) If the UNREG bit is set to one, unregister (see 5.7.11.3) the I_T
 	 * nexus on which PERSISTENT RESERVE OUT command was received.
@@ -3241,13 +3256,10 @@ static int core_scsi3_emulate_pro_register_and_move(
 	return 0;
 out:
 	if (dest_se_deve)
-		configfs_undepend_item(dest_tf_ops->tf_subsys,
-			&dest_se_deve->se_lun_acl->se_lun_group.cg_item);
+		core_scsi3_lunacl_undepend_item(dest_se_deve);
 	if (dest_node_acl)
-		configfs_undepend_item(dest_tf_ops->tf_subsys,
-				&dest_node_acl->acl_group.cg_item);
-	configfs_undepend_item(dest_tf_ops->tf_subsys,
-			&dest_se_tpg->tpg_group.cg_item);
+		core_scsi3_nodeacl_undepend_item(dest_node_acl);
+	core_scsi3_tpg_undepend_item(dest_se_tpg);
 	core_scsi3_put_pr_reg(pr_reg);
 	return ret;
 }
-- 
1.5.6.5