We should move the list operation after validation. Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx> --- block/blk-throttle.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 0649bce..f1bcb5c 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -423,12 +423,13 @@ static void throtl_qnode_add_bio(struct bio *bio, struct throtl_qnode *qn, */ static struct bio *throtl_peek_queued(struct list_head *queued) { - struct throtl_qnode *qn = list_first_entry(queued, struct throtl_qnode, node); + struct throtl_qnode *qn; struct bio *bio; if (list_empty(queued)) return NULL; + qn = list_first_entry(queued, struct throtl_qnode, node); bio = bio_list_peek(&qn->bios); WARN_ON_ONCE(!bio); return bio; @@ -451,12 +452,13 @@ static struct bio *throtl_peek_queued(struct list_head *queued) static struct bio *throtl_pop_queued(struct list_head *queued, struct throtl_grp **tg_to_put) { - struct throtl_qnode *qn = list_first_entry(queued, struct throtl_qnode, node); + struct throtl_qnode *qn; struct bio *bio; if (list_empty(queued)) return NULL; + qn = list_first_entry(queued, struct throtl_qnode, node); bio = bio_list_pop(&qn->bios); WARN_ON_ONCE(!bio); -- 1.8.3.1