bcachefs: Add a tracepoint for journal entry close

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/journal.c

@@ -184,6 +184,8 @@ static void __journal_entry_close(struct journal *j, unsigned closed_val)
 	/* Close out old buffer: */
 	buf->data->u64s		= cpu_to_le32(old.cur_entry_offset);
 
+	trace_journal_entry_close(c, vstruct_bytes(buf->data));
+
 	sectors = vstruct_blocks_plus(buf->data, c->block_bits,
 				      buf->u64s_reserved) << c->block_bits;
 	BUG_ON(sectors > buf->sectors);

fs/bcachefs/trace.h

@@ -188,6 +188,25 @@ DEFINE_EVENT(bch_fs, journal_entry_full,
 	TP_ARGS(c)
 );
 
+TRACE_EVENT(journal_entry_close,
+	TP_PROTO(struct bch_fs *c, unsigned bytes),
+	TP_ARGS(c, bytes),
+
+	TP_STRUCT__entry(
+		__field(dev_t,		dev			)
+		__field(u32,		bytes			)
+	),
+
+	TP_fast_assign(
+		__entry->dev			= c->dev;
+		__entry->bytes			= bytes;
+	),
+
+	TP_printk("%d,%d entry bytes %u",
+		  MAJOR(__entry->dev), MINOR(__entry->dev),
+		  __entry->bytes)
+);
+
 DEFINE_EVENT(bio, journal_write,
 	TP_PROTO(struct bio *bio),
 	TP_ARGS(bio)