We got a reference of the io scheduler module in blk_mq_elv_switch_none to prevent the module from being removed. We need to put that reference back once we are done. Signed-off-by: Jinlong Chen <chenjinlong2016@xxxxxxxxxxx> --- --- Changes in v2: - reword the commit message because the patch is for blk-mq precisely block/blk-mq.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/block/blk-mq.c b/block/blk-mq.c index 8070b6c10e8d..8dfe3bf3e599 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -4595,6 +4595,13 @@ static void blk_mq_elv_switch_back(struct list_head *head, mutex_lock(&q->sysfs_lock); elevator_switch(q, t); + /** + * We got a reference of the io scheduler module in + * blk_mq_elv_switch_none to prevent the module from + * being removed. We need to put that reference back + * once we are done. + */ + module_put(t->elevator_owner); mutex_unlock(&q->sysfs_lock); } -- 2.34.1