[ Upstream commit 2e3c18d0ada16f145087b2687afcad1748c0827c ]
syzbot is hitting flush_work() warning caused by commit 4d43d395fed12463 ("workqueue: Try to catch flush_work() without INIT_WORK().") [1]. Although that commit did not expect INIT_WORK(NULL) case, calling flush_work() without setting a valid callback should be avoided anyway. Fix this problem by setting a no-op callback instead of NULL.
[1] https://syzkaller.appspot.com/bug?id=e390366bc48bc82a7c668326e0663be3b91cbd2...
Signed-off-by: Tetsuo Handa penguin-kernel@I-love.SAKURA.ne.jp Reported-and-tested-by: syzbot syzbot+ba2a929dcf8e704c180e@syzkaller.appspotmail.com Cc: Tejun Heo tj@kernel.org Signed-off-by: Jens Axboe axboe@kernel.dk [sl: rename blk_timeout_work] Signed-off-by: Sasha Levin sashal@kernel.org --- block/blk-core.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/block/blk-core.c b/block/blk-core.c index eb8b52241453..33488b1426b7 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -980,6 +980,10 @@ static void blk_rq_timed_out_timer(struct timer_list *t) kblockd_schedule_work(&q->timeout_work); }
+static void blk_timeout_work_dummy(struct work_struct *work) +{ +} + /** * blk_alloc_queue_node - allocate a request queue * @gfp_mask: memory allocation flags @@ -1034,7 +1038,7 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id, timer_setup(&q->backing_dev_info->laptop_mode_wb_timer, laptop_mode_timer_fn, 0); timer_setup(&q->timeout, blk_rq_timed_out_timer, 0); - INIT_WORK(&q->timeout_work, NULL); + INIT_WORK(&q->timeout_work, blk_timeout_work_dummy); INIT_LIST_HEAD(&q->timeout_list); INIT_LIST_HEAD(&q->icq_list); #ifdef CONFIG_BLK_CGROUP