From: Joseph Qi <qijiang.qj@xxxxxxxxxxxxxxx>
Since throtl_rb_first may return NULL, so it should check tg first and
then use it.
Signed-off-by: Joseph Qi <qijiang.qj@xxxxxxxxxxxxxxx>
---
block/blk-throttle.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index a7285bf..c1d2c5b 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -1201,7 +1201,7 @@ static int throtl_select_dispatch(struct throtl_service_queue *parent_sq)
while (1) {
struct throtl_grp *tg = throtl_rb_first(parent_sq);
- struct throtl_service_queue *sq = &tg->service_queue;
+ struct throtl_service_queue *sq;
if (!tg)
break;
@@ -1213,6 +1213,7 @@ static int throtl_select_dispatch(struct throtl_service_queue *parent_sq)
nr_disp += throtl_dispatch_tg(tg);
+ sq = &tg->service_queue;
if (sq->nr_queued[0] || sq->nr_queued[1])
tg_update_disptime(tg);
--
1.9.4
