diff mbox series

[RFC,16/39] blktrace: update blk_add_trace_bio_backmerge()

Message ID 20210225070231.21136-17-chaitanya.kulkarni@wdc.com (mailing list archive)
State New, archived
Headers show
Series blktrace: add block trace extension support | expand

Commit Message

Chaitanya Kulkarni Feb. 25, 2021, 7:02 a.m. UTC 
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
---
 kernel/trace/blktrace.c | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)
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Patch

diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index e3210951f1f0..1ebaffb6a3d2 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -1325,8 +1325,25 @@  static void blk_add_trace_bio_complete(void *ignore,
 
 static void blk_add_trace_bio_backmerge(void *ignore, struct bio *bio)
 {
-	blk_add_trace_bio(bio->bi_bdev->bd_disk->queue, bio, BLK_TA_BACKMERGE,
-			0);
+	u64 ta = 0;
+	struct blk_trace *bt;
+	struct blk_trace_ext *bte;
+
+	rcu_read_lock();
+	bt = rcu_dereference(bio->bi_bdev->bd_disk->queue->blk_trace);
+	bte = rcu_dereference(bio->bi_bdev->bd_disk->queue->blk_trace_ext);
+	if (likely(!bt) && likely(!bte)) {
+		rcu_read_unlock();
+		return;
+	}
+
+	if (bt) {
+		ta = BLK_TA_BACKMERGE;
+	} else if (bte) {
+		ta = BLK_TA_BACKMERGE_EXT;
+	}
+	rcu_read_unlock();
+	blk_add_trace_bio(bio->bi_bdev->bd_disk->queue, bio, ta, 0);
 }
 
 static void blk_add_trace_bio_frontmerge(void *ignore, struct bio *bio)