[RFC PATCH 09/39] blktrace: update blk_add_trace_rq_insert()

From: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
To: linux-btrace@vger.kernel.org
Subject: [RFC PATCH 09/39] blktrace: update blk_add_trace_rq_insert()
Date: Thu, 05 Nov 2020 02:40:08 +0000	[thread overview]
Message-ID: <20201105024038.5831-10-chaitanya.kulkarni@wdc.com> (raw)

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
---
 kernel/trace/blktrace.c | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 9ac46e08979a..152ca769ce5b 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -1144,7 +1144,25 @@ static void blk_add_trace_rq(struct request *rq, int error,
 static void blk_add_trace_rq_insert(void *ignore,
 				    struct request_queue *q, struct request *rq)
 {
-	blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_INSERT,
+	u64 ta = 0;
+	struct blk_trace *bt;
+	struct blk_trace_ext *bte;
+
+	rcu_read_lock();
+	bt = rcu_dereference(rq->q->blk_trace);
+	bte = rcu_dereference(rq->q->blk_trace_ext);
+	if (likely(!bt) && likely(!bte)) {
+		rcu_read_unlock();
+		return;
+	}
+
+	if (bt) {
+		ta = BLK_TA_INSERT;
+	} else if (bte) {
+		ta = BLK_TA_INSERT_EXT;
+	}
+	rcu_read_unlock();
+	blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), ta,
 			 blk_trace_request_get_cgid(q, rq));
 }
 
-- 
2.22.1
