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 9f427aa5e942..84d22df8687e 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -1342,7 +1342,25 @@ static void blk_add_trace_bio_backmerge(void *ignore, struct request *rq, struct bio *bio) { - blk_add_trace_bio(q, bio, BLK_TA_BACKMERGE, 0); + u64 ta = 0; + struct blk_trace *bt; + struct blk_trace_ext *bte; + + rcu_read_lock(); + bt = rcu_dereference(q->blk_trace); + bte = rcu_dereference(q->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(q, bio, ta, 0); } static void blk_add_trace_bio_frontmerge(void *ignore, -- 2.22.1