target: Add per device xcopy_lun for copy offload I/O

This patch adds a se_device->xcopy_lun that is used for local
copy offload I/O, instead of allocating + initializing a pseudo
se_lun for each received EXTENDED_COPY operation.

Also, move declaration of struct se_lun + struct se_port_stat_grps
ahead of struct se_device.
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/target/target_core_device.c

@@ -1409,6 +1409,7 @@ static void scsi_dump_inquiry(struct se_device *dev)
 struct se_device *target_alloc_device(struct se_hba *hba, const char *name)
 {
 	struct se_device *dev;
+	struct se_lun *xcopy_lun;
 
 	dev = hba->transport->alloc_device(hba, name);
 	if (!dev)
@@ -1471,6 +1472,14 @@ struct se_device *target_alloc_device(struct se_hba *hba, const char *name)
 	dev->dev_attrib.fabric_max_sectors = DA_FABRIC_MAX_SECTORS;
 	dev->dev_attrib.optimal_sectors = DA_FABRIC_MAX_SECTORS;
 
+	xcopy_lun = &dev->xcopy_lun;
+	xcopy_lun->lun_se_dev = dev;
+	init_completion(&xcopy_lun->lun_shutdown_comp);
+	INIT_LIST_HEAD(&xcopy_lun->lun_acl_list);
+	spin_lock_init(&xcopy_lun->lun_acl_lock);
+	spin_lock_init(&xcopy_lun->lun_sep_lock);
+	init_completion(&xcopy_lun->lun_ref_comp);
+
 	return dev;
 }
 

drivers/target/target_core_xcopy.c

@@ -401,9 +401,6 @@ static void xcopy_pt_release_cmd(struct se_cmd *se_cmd)
 	struct xcopy_pt_cmd *xpt_cmd = container_of(se_cmd,
 				struct xcopy_pt_cmd, se_cmd);
 
-	if (xpt_cmd->remote_port)
-		kfree(se_cmd->se_lun);
-
 	kfree(xpt_cmd);
 }
 
@@ -568,21 +565,10 @@ static int target_xcopy_init_pt_lun(
 		return 0;
 	}
 
-	pt_cmd->se_lun = kzalloc(sizeof(struct se_lun), GFP_KERNEL);
-	if (!pt_cmd->se_lun) {
-		pr_err("Unable to allocate pt_cmd->se_lun\n");
-		return -ENOMEM;
-	}
-	init_completion(&pt_cmd->se_lun->lun_shutdown_comp);
-	INIT_LIST_HEAD(&pt_cmd->se_lun->lun_acl_list);
-	spin_lock_init(&pt_cmd->se_lun->lun_acl_lock);
-	spin_lock_init(&pt_cmd->se_lun->lun_sep_lock);
-	init_completion(&pt_cmd->se_lun->lun_ref_comp);
-
+	pt_cmd->se_lun = &se_dev->xcopy_lun;
 	pt_cmd->se_dev = se_dev;
 
 	pr_debug("Setup emulated se_dev: %p from se_dev\n", pt_cmd->se_dev);
-	pt_cmd->se_lun->lun_se_dev = se_dev;
 	pt_cmd->se_cmd_flags |= SCF_SE_LUN_CMD | SCF_CMD_XCOPY_PASSTHROUGH;
 
 	pr_debug("Setup emulated se_dev: %p to pt_cmd->se_lun->lun_se_dev\n",
@@ -653,8 +639,6 @@ static int target_xcopy_setup_pt_cmd(
 	return 0;
 
 out:
-	if (remote_port == true)
-		kfree(cmd->se_lun);
 	return ret;
 }
 

include/target/target_core_base.h

@@ -627,6 +627,34 @@ struct se_dev_attrib {
 	struct config_group da_group;
 };
 
+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 {
+#define SE_LUN_LINK_MAGIC			0xffff7771
+	u32			lun_link_magic;
+	/* See transport_lun_status_table */
+	enum transport_lun_status_table lun_status;
+	u32			lun_access;
+	u32			lun_flags;
+	u32			unpacked_lun;
+	atomic_t		lun_acl_count;
+	spinlock_t		lun_acl_lock;
+	spinlock_t		lun_sep_lock;
+	struct completion	lun_shutdown_comp;
+	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_stat_grps port_stat_grps;
+	struct completion	lun_ref_comp;
+	struct percpu_ref	lun_ref;
+};
+
 struct se_dev_stat_grps {
 	struct config_group stat_group;
 	struct config_group scsi_dev_group;
@@ -710,6 +738,7 @@ struct se_device {
 	struct se_subsystem_api *transport;
 	/* Linked list for struct se_hba struct se_device list */
 	struct list_head	dev_list;
+	struct se_lun		xcopy_lun;
 };
 
 struct se_hba {
@@ -729,34 +758,6 @@ struct se_hba {
 	struct se_subsystem_api *transport;
 };
 
-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 {
-#define SE_LUN_LINK_MAGIC			0xffff7771
-	u32			lun_link_magic;
-	/* See transport_lun_status_table */
-	enum transport_lun_status_table lun_status;
-	u32			lun_access;
-	u32			lun_flags;
-	u32			unpacked_lun;
-	atomic_t		lun_acl_count;
-	spinlock_t		lun_acl_lock;
-	spinlock_t		lun_sep_lock;
-	struct completion	lun_shutdown_comp;
-	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_stat_grps port_stat_grps;
-	struct completion	lun_ref_comp;
-	struct percpu_ref	lun_ref;
-};
-
 struct scsi_port_stats {
        u64     cmd_pdus;
        u64     tx_data_octets;