target: Introduce a function that shows the command state

Introduce target_show_cmd() and use it where appropriate. If
transport_wait_for_tasks() takes too long, make it show the
state of the command it is waiting for.

(Add missing brackets around multi-line conditions - nab)

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Andy Grover <agrover@redhat.com>
Cc: David Disseldorp <ddiss@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/target/target_core_tmr.c

@@ -355,20 +355,10 @@ static void core_tmr_drain_state_list(
 		cmd = list_entry(drain_task_list.next, struct se_cmd, state_list);
 		list_del_init(&cmd->state_list);
 
-		pr_debug("LUN_RESET: %s cmd: %p"
-			" ITT/CmdSN: 0x%08llx/0x%08x, i_state: %d, t_state: %d"
-			"cdb: 0x%02x\n",
-			(preempt_and_abort_list) ? "Preempt" : "", cmd,
-			cmd->tag, 0,
-			cmd->se_tfo->get_cmd_state(cmd), cmd->t_state,
-			cmd->t_task_cdb[0]);
-		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->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);
+		target_show_cmd("LUN_RESET: ", cmd);
+		pr_debug("LUN_RESET: ITT[0x%08llx] - %s pr_res_key: 0x%016Lx\n",
+			 cmd->tag, (preempt_and_abort_list) ? "preempt" : "",
+			 cmd->pr_res_key);
 
 		/*
 		 * If the command may be queued onto a workqueue cancel it now.

drivers/target/target_core_transport.c

@@ -1704,15 +1704,9 @@ void transport_generic_request_failure(struct se_cmd *cmd,
 	if (transport_check_aborted_status(cmd, 1))
 		return;
 
-	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);
-	pr_debug("-----[ CMD_T_ACTIVE: %d CMD_T_STOP: %d CMD_T_SENT: %d\n",
-		(cmd->transport_state & CMD_T_ACTIVE) != 0,
-		(cmd->transport_state & CMD_T_STOP) != 0,
-		(cmd->transport_state & CMD_T_SENT) != 0);
+	pr_debug("-----[ Storage Engine Exception; sense_reason %d\n",
+		 sense_reason);
+	target_show_cmd("-----[ ", cmd);
 
 	/*
 	 * For SAM Task Attribute emulation for failed struct se_cmd
@@ -2705,6 +2699,108 @@ int target_put_sess_cmd(struct se_cmd *se_cmd)
 }
 EXPORT_SYMBOL(target_put_sess_cmd);
 
+static const char *data_dir_name(enum dma_data_direction d)
+{
+	switch (d) {
+	case DMA_BIDIRECTIONAL:	return "BIDI";
+	case DMA_TO_DEVICE:	return "WRITE";
+	case DMA_FROM_DEVICE:	return "READ";
+	case DMA_NONE:		return "NONE";
+	}
+
+	return "(?)";
+}
+
+static const char *cmd_state_name(enum transport_state_table t)
+{
+	switch (t) {
+	case TRANSPORT_NO_STATE:	return "NO_STATE";
+	case TRANSPORT_NEW_CMD:		return "NEW_CMD";
+	case TRANSPORT_WRITE_PENDING:	return "WRITE_PENDING";
+	case TRANSPORT_PROCESSING:	return "PROCESSING";
+	case TRANSPORT_COMPLETE:	return "COMPLETE";
+	case TRANSPORT_ISTATE_PROCESSING:
+					return "ISTATE_PROCESSING";
+	case TRANSPORT_COMPLETE_QF_WP:	return "COMPLETE_QF_WP";
+	case TRANSPORT_COMPLETE_QF_OK:	return "COMPLETE_QF_OK";
+	case TRANSPORT_COMPLETE_QF_ERR:	return "COMPLETE_QF_ERR";
+	}
+
+	return "(?)";
+}
+
+static void target_append_str(char **str, const char *txt)
+{
+	char *prev = *str;
+
+	*str = *str ? kasprintf(GFP_ATOMIC, "%s,%s", *str, txt) :
+		kstrdup(txt, GFP_ATOMIC);
+	kfree(prev);
+}
+
+/*
+ * Convert a transport state bitmask into a string. The caller is
+ * responsible for freeing the returned pointer.
+ */
+static char *target_ts_to_str(u32 ts)
+{
+	char *str = NULL;
+
+	if (ts & CMD_T_ABORTED)
+		target_append_str(&str, "aborted");
+	if (ts & CMD_T_ACTIVE)
+		target_append_str(&str, "active");
+	if (ts & CMD_T_COMPLETE)
+		target_append_str(&str, "complete");
+	if (ts & CMD_T_SENT)
+		target_append_str(&str, "sent");
+	if (ts & CMD_T_STOP)
+		target_append_str(&str, "stop");
+	if (ts & CMD_T_FABRIC_STOP)
+		target_append_str(&str, "fabric_stop");
+
+	return str;
+}
+
+static const char *target_tmf_name(enum tcm_tmreq_table tmf)
+{
+	switch (tmf) {
+	case TMR_ABORT_TASK:		return "ABORT_TASK";
+	case TMR_ABORT_TASK_SET:	return "ABORT_TASK_SET";
+	case TMR_CLEAR_ACA:		return "CLEAR_ACA";
+	case TMR_CLEAR_TASK_SET:	return "CLEAR_TASK_SET";
+	case TMR_LUN_RESET:		return "LUN_RESET";
+	case TMR_TARGET_WARM_RESET:	return "TARGET_WARM_RESET";
+	case TMR_TARGET_COLD_RESET:	return "TARGET_COLD_RESET";
+	case TMR_UNKNOWN:		break;
+	}
+	return "(?)";
+}
+
+void target_show_cmd(const char *pfx, struct se_cmd *cmd)
+{
+	char *ts_str = target_ts_to_str(cmd->transport_state);
+	const u8 *cdb = cmd->t_task_cdb;
+	struct se_tmr_req *tmf = cmd->se_tmr_req;
+
+	if (!(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
+		pr_debug("%scmd %#02x:%#02x with tag %#llx dir %s i_state %d t_state %s len %d refcnt %d transport_state %s\n",
+			 pfx, cdb[0], cdb[1], cmd->tag,
+			 data_dir_name(cmd->data_direction),
+			 cmd->se_tfo->get_cmd_state(cmd),
+			 cmd_state_name(cmd->t_state), cmd->data_length,
+			 kref_read(&cmd->cmd_kref), ts_str);
+	} else {
+		pr_debug("%stmf %s with tag %#llx ref_task_tag %#llx i_state %d t_state %s refcnt %d transport_state %s\n",
+			 pfx, target_tmf_name(tmf->function), cmd->tag,
+			 tmf->ref_task_tag, cmd->se_tfo->get_cmd_state(cmd),
+			 cmd_state_name(cmd->t_state),
+			 kref_read(&cmd->cmd_kref), ts_str);
+	}
+	kfree(ts_str);
+}
+EXPORT_SYMBOL(target_show_cmd);
+
 /* target_sess_cmd_list_set_waiting - Flag all commands in
  *         sess_cmd_list to complete cmd_wait_comp.  Set
  *         sess_tearing_down so no more commands are queued.
@@ -2849,13 +2945,13 @@ __transport_wait_for_tasks(struct se_cmd *cmd, bool fabric_stop,
 
 	cmd->transport_state |= CMD_T_STOP;
 
-	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);
+	target_show_cmd("wait_for_tasks: Stopping ", cmd);
 
 	spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
 
-	wait_for_completion(&cmd->t_transport_stop_comp);
+	while (!wait_for_completion_timeout(&cmd->t_transport_stop_comp,
+					    180 * HZ))
+		target_show_cmd("wait for tasks: ", cmd);
 
 	spin_lock_irqsave(&cmd->t_state_lock, *flags);
 	cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);

include/target/target_core_fabric.h

@@ -160,6 +160,7 @@ int	target_get_sess_cmd(struct se_cmd *, bool);
 int	target_put_sess_cmd(struct se_cmd *);
 void	target_sess_cmd_list_set_waiting(struct se_session *);
 void	target_wait_for_sess_cmds(struct se_session *);
+void	target_show_cmd(const char *pfx, struct se_cmd *cmd);
 
 int	core_alua_check_nonop_delay(struct se_cmd *);