lightnvm: pblk: add trace events for pblk state changes

Add trace events for tracking pblk state changes.
Signed-off-by: Hans Holmberg <hans.holmberg@cnexlabs.com>
Signed-off-by: Matias Bjørling <mb@lightnvm.io>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/lightnvm/pblk-core.c

@@ -1503,6 +1503,7 @@ static void pblk_stop_writes(struct pblk *pblk, struct pblk_line *line)
 
 	pblk_set_space_limit(pblk);
 	pblk->state = PBLK_STATE_STOPPING;
+	trace_pblk_state(pblk_disk_name(pblk), pblk->state);
 }
 
 static void pblk_line_close_meta_sync(struct pblk *pblk)
@@ -1552,6 +1553,7 @@ void __pblk_pipeline_flush(struct pblk *pblk)
 		return;
 	}
 	pblk->state = PBLK_STATE_RECOVERING;
+	trace_pblk_state(pblk_disk_name(pblk), pblk->state);
 	spin_unlock(&l_mg->free_lock);
 
 	pblk_flush_writer(pblk);
@@ -1573,6 +1575,7 @@ void __pblk_pipeline_stop(struct pblk *pblk)
 
 	spin_lock(&l_mg->free_lock);
 	pblk->state = PBLK_STATE_STOPPED;
+	trace_pblk_state(pblk_disk_name(pblk), pblk->state);
 	l_mg->data_line = NULL;
 	l_mg->data_next = NULL;
 	spin_unlock(&l_mg->free_lock);

drivers/lightnvm/pblk-init.c

@@ -1109,6 +1109,7 @@ static void *pblk_init(struct nvm_tgt_dev *dev, struct gendisk *tdisk,
 	pblk->dev = dev;
 	pblk->disk = tdisk;
 	pblk->state = PBLK_STATE_RUNNING;
+	trace_pblk_state(pblk_disk_name(pblk), pblk->state);
 	pblk->gc.gc_enabled = 0;
 
 	if (!(geo->version == NVM_OCSSD_SPEC_12 ||

drivers/lightnvm/pblk-trace.h

@@ -25,6 +25,13 @@ struct ppa_addr;
 	{ PBLK_LINESTATE_CORRUPT,	"CORRUPT"	})
 
 
+#define show_pblk_state(state) __print_symbolic(state,		\
+	{ PBLK_STATE_RUNNING,		"RUNNING",	},	\
+	{ PBLK_STATE_STOPPING,		"STOPPING",	},	\
+	{ PBLK_STATE_RECOVERING,	"RECOVERING",	},	\
+	{ PBLK_STATE_STOPPED,		"STOPPED"	})
+
+
 TRACE_EVENT(pblk_chunk_state,
 
 	TP_PROTO(const char *name, struct ppa_addr *ppa, int state),
@@ -75,6 +82,27 @@ TRACE_EVENT(pblk_line_state,
 
 );
 
+TRACE_EVENT(pblk_state,
+
+	TP_PROTO(const char *name, int state),
+
+	TP_ARGS(name, state),
+
+	TP_STRUCT__entry(
+		__string(name, name)
+		__field(int, state);
+	),
+
+	TP_fast_assign(
+		__assign_str(name, name);
+		__entry->state = state;
+	),
+
+	TP_printk("dev=%s state=%s", __get_str(name),
+			show_pblk_state((int)__entry->state))
+
+);
+
 #endif /* !defined(_TRACE_PBLK_H) || defined(TRACE_HEADER_MULTI_READ) */
 
 /* This part must be outside protection */