null_blk: add tracepoint helpers for zoned mode

This patch adds two new tracpoints for null_blk_zoned.c that allows us
to trace report-zones, zone-mgmt-op and zone-write operations which has
direct effect on the zone condition state machine.

Also, we update drivers/block/Makefile so that new null_blk related
tracefiles can be compiled.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 21 insertions, 0 deletions

diff --git a/drivers/block/null_blk_trace.c b/drivers/block/null_blk_trace.c
new file mode 100644
index 000000000000..f246e7bff698
--- /dev/null
+++ b/drivers/block/null_blk_trace.c
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * null_blk trace related helpers.
+ *
+ * Copyright (C) 2020 Western Digital Corporation or its affiliates.
+ */
+#include "null_blk_trace.h"
+
+/*
+ * Helper to use for all null_blk traces to extract disk name.
+ */
+const char *nullb_trace_disk_name(struct trace_seq *p, char *name)
+{
+	const char *ret = trace_seq_buffer_ptr(p);
+
+	if (name && *name)
+		trace_seq_printf(p, "disk=%s, ", name);
+	trace_seq_putc(p, 0);
+
+	return ret;
+}