target: Move task tag into struct se_cmd + support 64-bit tags

Simplify target core and target drivers by storing the task tag
a.k.a. command identifier inside struct se_cmd.

For several transports (e.g. SRP) tags are 64 bits wide.
Hence add support for 64-bit tags.

(Fix core_tmr_abort_task conversion spec warnings - nab)
(Fix up usb-gadget to use 16-bit tags - HCH + bart)

Signed-off-by: Bart Van Assche <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Andy Grover <[email protected]>
Cc: Sagi Grimberg <[email protected]>
Cc: <[email protected]>
Cc: Felipe Balbi <[email protected]>
Cc: Michael S. Tsirkin <[email protected]>
Cc: Juergen Gross <[email protected]>
Signed-off-by: Nicholas Bellinger <[email protected]>

drivers/target/iscsi/iscsi_target.c

@@ -1008,6 +1008,8 @@ int iscsit_setup_scsi_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
 	if (cmd->sense_reason)
 		goto attach_cmd;
 
+	/* only used for printks or comparing with ->ref_task_tag */
+	cmd->se_cmd.tag = (__force u32)cmd->init_task_tag;
 	cmd->sense_reason = target_setup_cmd_from_cdb(&cmd->se_cmd, hdr->cdb);
 	if (cmd->sense_reason) {
 		if (cmd->sense_reason == TCM_OUT_OF_RESOURCES) {

drivers/target/iscsi/iscsi_target_configfs.c

@@ -1692,14 +1692,6 @@ static char *iscsi_get_fabric_name(void)
 	return "iSCSI";
 }
 
-static u32 iscsi_get_task_tag(struct se_cmd *se_cmd)
-{
-	struct iscsi_cmd *cmd = container_of(se_cmd, struct iscsi_cmd, se_cmd);
-
-	/* only used for printks or comparism with ->ref_task_tag */
-	return (__force u32)cmd->init_task_tag;
-}
-
 static int iscsi_get_cmd_state(struct se_cmd *se_cmd)
 {
 	struct iscsi_cmd *cmd = container_of(se_cmd, struct iscsi_cmd, se_cmd);
@@ -1938,7 +1930,6 @@ const struct target_core_fabric_ops iscsi_ops = {
 	.write_pending			= lio_write_pending,
 	.write_pending_status		= lio_write_pending_status,
 	.set_default_node_attributes	= lio_set_default_node_attributes,
-	.get_task_tag			= iscsi_get_task_tag,
 	.get_cmd_state			= iscsi_get_cmd_state,
 	.queue_data_in			= lio_queue_data_in,
 	.queue_status			= lio_queue_status,

drivers/target/loopback/tcm_loop.c

@@ -165,6 +165,7 @@ static void tcm_loop_submission_work(struct work_struct *work)
 		transfer_length = scsi_bufflen(sc);
 	}
 
+	se_cmd->tag = tl_cmd->sc_cmd_tag;
 	rc = target_submit_cmd_map_sgls(se_cmd, tl_nexus->se_sess, sc->cmnd,
 			&tl_cmd->tl_sense_buf[0], tl_cmd->sc->device->lun,
 			transfer_length, TCM_SIMPLE_TAG,
@@ -597,14 +598,6 @@ static void tcm_loop_set_default_node_attributes(struct se_node_acl *se_acl)
 	return;
 }
 
-static u32 tcm_loop_get_task_tag(struct se_cmd *se_cmd)
-{
-	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
-			struct tcm_loop_cmd, tl_se_cmd);
-
-	return tl_cmd->sc_cmd_tag;
-}
-
 static int tcm_loop_get_cmd_state(struct se_cmd *se_cmd)
 {
 	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
@@ -1259,7 +1252,6 @@ static const struct target_core_fabric_ops loop_ops = {
 	.write_pending			= tcm_loop_write_pending,
 	.write_pending_status		= tcm_loop_write_pending_status,
 	.set_default_node_attributes	= tcm_loop_set_default_node_attributes,
-	.get_task_tag			= tcm_loop_get_task_tag,
 	.get_cmd_state			= tcm_loop_get_cmd_state,
 	.queue_data_in			= tcm_loop_queue_data_in,
 	.queue_status			= tcm_loop_queue_status,

drivers/target/sbp/sbp_target.c

@@ -1234,6 +1234,8 @@ static void sbp_handle_command(struct sbp_target_request *req)
 	pr_debug("sbp_handle_command ORB:0x%llx unpacked_lun:%d data_len:%d data_dir:%d\n",
 			req->orb_pointer, unpacked_lun, data_length, data_dir);
 
+	/* only used for printk until we do TMRs */
+	req->se_cmd.tag = req->orb_pointer;
 	if (target_submit_cmd(&req->se_cmd, sess->se_sess, req->cmd_buf,
 			      req->sense_buf, unpacked_lun, data_length,
 			      TCM_SIMPLE_TAG, data_dir, 0))
@@ -1768,15 +1770,6 @@ static void sbp_set_default_node_attrs(struct se_node_acl *nacl)
 	return;
 }
 
-static u32 sbp_get_task_tag(struct se_cmd *se_cmd)
-{
-	struct sbp_target_request *req = container_of(se_cmd,
-			struct sbp_target_request, se_cmd);
-
-	/* only used for printk until we do TMRs */
-	return (u32)req->orb_pointer;
-}
-
 static int sbp_get_cmd_state(struct se_cmd *se_cmd)
 {
 	return 0;
@@ -2377,7 +2370,6 @@ static const struct target_core_fabric_ops sbp_ops = {
 	.write_pending			= sbp_write_pending,
 	.write_pending_status		= sbp_write_pending_status,
 	.set_default_node_attributes	= sbp_set_default_node_attrs,
-	.get_task_tag			= sbp_get_task_tag,
 	.get_cmd_state			= sbp_get_cmd_state,
 	.queue_data_in			= sbp_queue_data_in,
 	.queue_status			= sbp_queue_status,

drivers/target/target_core_configfs.c

@@ -374,10 +374,6 @@ static int target_fabric_tf_ops_check(const struct target_core_fabric_ops *tfo)
 		pr_err("Missing tfo->set_default_node_attributes()\n");
 		return -EINVAL;
 	}
-	if (!tfo->get_task_tag) {
-		pr_err("Missing tfo->get_task_tag()\n");
-		return -EINVAL;
-	}
 	if (!tfo->get_cmd_state) {
 		pr_err("Missing tfo->get_cmd_state()\n");
 		return -EINVAL;

drivers/target/target_core_tmr.c

@@ -117,7 +117,7 @@ void core_tmr_abort_task(
 {
 	struct se_cmd *se_cmd;
 	unsigned long flags;
-	int ref_tag;
+	u64 ref_tag;
 
 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
 	list_for_each_entry(se_cmd, &se_sess->sess_cmd_list, se_cmd_list) {
@@ -129,16 +129,17 @@ void core_tmr_abort_task(
 		if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
 			continue;
 
-		ref_tag = se_cmd->se_tfo->get_task_tag(se_cmd);
+		ref_tag = se_cmd->tag;
 		if (tmr->ref_task_tag != ref_tag)
 			continue;
 
-		printk("ABORT_TASK: Found referenced %s task_tag: %u\n",
+		printk("ABORT_TASK: Found referenced %s task_tag: %llu\n",
 			se_cmd->se_tfo->get_fabric_name(), ref_tag);
 
 		spin_lock(&se_cmd->t_state_lock);
 		if (se_cmd->transport_state & CMD_T_COMPLETE) {
-			printk("ABORT_TASK: ref_tag: %u already complete, skipping\n", ref_tag);
+			printk("ABORT_TASK: ref_tag: %llu already complete,"
+			       " skipping\n", ref_tag);
 			spin_unlock(&se_cmd->t_state_lock);
 			spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
 			goto out;
@@ -157,14 +158,14 @@ void core_tmr_abort_task(
 		transport_cmd_finish_abort(se_cmd, true);
 
 		printk("ABORT_TASK: Sending TMR_FUNCTION_COMPLETE for"
-				" ref_tag: %d\n", ref_tag);
+				" ref_tag: %llu\n", ref_tag);
 		tmr->response = TMR_FUNCTION_COMPLETE;
 		return;
 	}
 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
 
 out:
-	printk("ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: %d\n",
+	printk("ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: %lld\n",
 			tmr->ref_task_tag);
 	tmr->response = TMR_TASK_DOES_NOT_EXIST;
 }
@@ -289,16 +290,16 @@ static void core_tmr_drain_state_list(
 		list_del(&cmd->state_list);
 
 		pr_debug("LUN_RESET: %s cmd: %p"
-			" ITT/CmdSN: 0x%08x/0x%08x, i_state: %d, t_state: %d"
+			" ITT/CmdSN: 0x%08llx/0x%08x, i_state: %d, t_state: %d"
 			"cdb: 0x%02x\n",
 			(preempt_and_abort_list) ? "Preempt" : "", cmd,
-			cmd->se_tfo->get_task_tag(cmd), 0,
+			cmd->tag, 0,
 			cmd->se_tfo->get_cmd_state(cmd), cmd->t_state,
 			cmd->t_task_cdb[0]);
-		pr_debug("LUN_RESET: ITT[0x%08x] - pr_res_key: 0x%016Lx"
+		pr_debug("LUN_RESET: ITT[0x%08llx] - pr_res_key: 0x%016Lx"
 			" -- CMD_T_ACTIVE: %d"
 			" CMD_T_STOP: %d CMD_T_SENT: %d\n",
-			cmd->se_tfo->get_task_tag(cmd), cmd->pr_res_key,
+			cmd->tag, cmd->pr_res_key,
 			(cmd->transport_state & CMD_T_ACTIVE) != 0,
 			(cmd->transport_state & CMD_T_STOP) != 0,
 			(cmd->transport_state & CMD_T_SENT) != 0);

drivers/target/target_core_transport.c

@@ -600,9 +600,8 @@ static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists,
 	 * this command for frontend exceptions.
 	 */
 	if (cmd->transport_state & CMD_T_STOP) {
-		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
-			__func__, __LINE__,
-			cmd->se_tfo->get_task_tag(cmd));
+		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
+			__func__, __LINE__, cmd->tag);
 
 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 
@@ -1155,6 +1154,8 @@ target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
 /*
  * Used by fabric modules containing a local struct se_cmd within their
  * fabric dependent per I/O descriptor.
+ *
+ * Preserves the value of @cmd->tag.
  */
 void transport_init_se_cmd(
 	struct se_cmd *cmd,
@@ -1380,6 +1381,8 @@ transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
  * @sgl_prot: struct scatterlist memory protection information
  * @sgl_prot_count: scatterlist count for protection information
  *
+ * Task tags are supported if the caller has set @se_cmd->tag.
+ *
  * Returns non zero to signal active I/O shutdown failure.  All other
  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
  * but still return zero here.
@@ -1512,6 +1515,8 @@ EXPORT_SYMBOL(target_submit_cmd_map_sgls);
  * @data_dir: DMA data direction
  * @flags: flags for command submission from target_sc_flags_tables
  *
+ * Task tags are supported if the caller has set @se_cmd->tag.
+ *
  * Returns non zero to signal active I/O shutdown failure.  All other
  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
  * but still return zero here.
@@ -1639,9 +1644,8 @@ void transport_generic_request_failure(struct se_cmd *cmd,
 {
 	int ret = 0;
 
-	pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08x"
-		" CDB: 0x%02x\n", cmd, cmd->se_tfo->get_task_tag(cmd),
-		cmd->t_task_cdb[0]);
+	pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08llx"
+		" CDB: 0x%02x\n", cmd, cmd->tag, cmd->t_task_cdb[0]);
 	pr_debug("-----[ i_state: %d t_state: %d sense_reason: %d\n",
 		cmd->se_tfo->get_cmd_state(cmd),
 		cmd->t_state, sense_reason);
@@ -1849,9 +1853,8 @@ void target_execute_cmd(struct se_cmd *cmd)
 	 */
 	spin_lock_irq(&cmd->t_state_lock);
 	if (cmd->transport_state & CMD_T_STOP) {
-		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
-			__func__, __LINE__,
-			cmd->se_tfo->get_task_tag(cmd));
+		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
+			__func__, __LINE__, cmd->tag);
 
 		spin_unlock_irq(&cmd->t_state_lock);
 		complete_all(&cmd->t_transport_stop_comp);
@@ -2658,10 +2661,8 @@ bool transport_wait_for_tasks(struct se_cmd *cmd)
 
 	cmd->transport_state |= CMD_T_STOP;
 
-	pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08x"
-		" i_state: %d, t_state: %d, CMD_T_STOP\n",
-		cmd, cmd->se_tfo->get_task_tag(cmd),
-		cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
+	pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08llx i_state: %d, t_state: %d, CMD_T_STOP\n",
+		cmd, cmd->tag, cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
 
 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 
@@ -2670,9 +2671,8 @@ bool transport_wait_for_tasks(struct se_cmd *cmd)
 	spin_lock_irqsave(&cmd->t_state_lock, flags);
 	cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
 
-	pr_debug("wait_for_tasks: Stopped wait_for_completion("
-		"&cmd->t_transport_stop_comp) for ITT: 0x%08x\n",
-		cmd->se_tfo->get_task_tag(cmd));
+	pr_debug("wait_for_tasks: Stopped wait_for_completion(&cmd->t_transport_stop_comp) for ITT: 0x%08llx\n",
+		cmd->tag);
 
 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 
@@ -2974,8 +2974,8 @@ int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
 	if (!send_status || !(cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS))
 		return 1;
 
-	pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB: 0x%02x ITT: 0x%08x\n",
-		 cmd->t_task_cdb[0], cmd->se_tfo->get_task_tag(cmd));
+	pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB: 0x%02x ITT: 0x%08llx\n",
+		 cmd->t_task_cdb[0], cmd->tag);
 
 	cmd->se_cmd_flags &= ~SCF_SEND_DELAYED_TAS;
 	cmd->scsi_status = SAM_STAT_TASK_ABORTED;
@@ -3014,9 +3014,8 @@ void transport_send_task_abort(struct se_cmd *cmd)
 
 	transport_lun_remove_cmd(cmd);
 
-	pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x,"
-		" ITT: 0x%08x\n", cmd->t_task_cdb[0],
-		cmd->se_tfo->get_task_tag(cmd));
+	pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x, ITT: 0x%08llx\n",
+		 cmd->t_task_cdb[0], cmd->tag);
 
 	trace_target_cmd_complete(cmd);
 	cmd->se_tfo->queue_status(cmd);

drivers/target/target_core_xcopy.c

@@ -359,11 +359,6 @@ static char *xcopy_pt_get_fabric_name(void)
         return "xcopy-pt";
 }
 
-static u32 xcopy_pt_get_tag(struct se_cmd *se_cmd)
-{
-        return 0;
-}
-
 static int xcopy_pt_get_cmd_state(struct se_cmd *se_cmd)
 {
         return 0;
@@ -424,7 +419,6 @@ static int xcopy_pt_queue_status(struct se_cmd *se_cmd)
 
 static const struct target_core_fabric_ops xcopy_pt_tfo = {
 	.get_fabric_name	= xcopy_pt_get_fabric_name,
-	.get_task_tag		= xcopy_pt_get_tag,
 	.get_cmd_state		= xcopy_pt_get_cmd_state,
 	.release_cmd		= xcopy_pt_release_cmd,
 	.check_stop_free	= xcopy_pt_check_stop_free,
@@ -575,6 +569,7 @@ static int target_xcopy_setup_pt_cmd(
 	xpt_cmd->xcopy_op = xop;
 	target_xcopy_setup_pt_port(xpt_cmd, xop, remote_port);
 
+	cmd->tag = 0;
 	sense_rc = target_setup_cmd_from_cdb(cmd, cdb);
 	if (sense_rc) {
 		ret = -EINVAL;

drivers/target/tcm_fc/tcm_fc.h

@@ -157,7 +157,6 @@ int ft_queue_status(struct se_cmd *);
 int ft_queue_data_in(struct se_cmd *);
 int ft_write_pending(struct se_cmd *);
 int ft_write_pending_status(struct se_cmd *);
-u32 ft_get_task_tag(struct se_cmd *);
 int ft_get_cmd_state(struct se_cmd *);
 void ft_queue_tm_resp(struct se_cmd *);
 void ft_aborted_task(struct se_cmd *);

drivers/target/tcm_fc/tfc_cmd.c

@@ -247,15 +247,6 @@ int ft_write_pending(struct se_cmd *se_cmd)
 	return 0;
 }
 
-u32 ft_get_task_tag(struct se_cmd *se_cmd)
-{
-	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
-
-	if (cmd->aborted)
-		return ~0;
-	return fc_seq_exch(cmd->seq)->rxid;
-}
-
 int ft_get_cmd_state(struct se_cmd *se_cmd)
 {
 	return 0;
@@ -568,6 +559,7 @@ static void ft_send_work(struct work_struct *work)
 	}
 
 	fc_seq_exch(cmd->seq)->lp->tt.seq_set_resp(cmd->seq, ft_recv_seq, cmd);
+	cmd->se_cmd.tag = fc_seq_exch(cmd->seq)->rxid;
 	/*
 	 * Use a single se_cmd->cmd_kref as we expect to release se_cmd
 	 * directly from ft_check_stop_free callback in response path.

drivers/target/tcm_fc/tfc_conf.c

@@ -468,7 +468,6 @@ static const struct target_core_fabric_ops ft_fabric_ops = {
 	.write_pending =		ft_write_pending,
 	.write_pending_status =		ft_write_pending_status,
 	.set_default_node_attributes =	ft_set_default_node_attr,
-	.get_task_tag =			ft_get_task_tag,
 	.get_cmd_state =		ft_get_cmd_state,
 	.queue_data_in =		ft_queue_data_in,
 	.queue_status =			ft_queue_status,