Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@xxxxxxx>
---
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 b09ed08d0782..1eff4afa4019 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -1329,7 +1329,25 @@ 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_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_disk->queue->blk_trace);
+ bte = rcu_dereference(bio->bi_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_disk->queue, bio, ta, 0);
}
static void blk_add_trace_bio_frontmerge(void *ignore, struct bio *bio)
--
2.22.1
