On 2023/11/9 05:18, syzbot wrote: > syzbot has bisected this issue to: > > commit d78bfa1346ab1fe04d20aa45a0678d1fc866f37c > Author: Chengming Zhou <zhouchengming@xxxxxxxxxxxxx> > Date: Wed Sep 13 15:16:16 2023 +0000 > > block/null_blk: add queue_rqs() support > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=106414a8e80000 > start commit: 13d88ac54ddd Merge tag 'vfs-6.7.fsid' of git://git.kernel... > git tree: upstream > final oops: https://syzkaller.appspot.com/x/report.txt?x=126414a8e80000 > console output: https://syzkaller.appspot.com/x/log.txt?x=146414a8e80000 > kernel config: https://syzkaller.appspot.com/x/.config?x=beb32a598fd79db9 > dashboard link: https://syzkaller.appspot.com/bug?extid=fcc47ba2476570cbbeb0 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1465bb08e80000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13e7881f680000 > > Reported-by: syzbot+fcc47ba2476570cbbeb0@xxxxxxxxxxxxxxxxxxxxxxxxx > Fixes: d78bfa1346ab ("block/null_blk: add queue_rqs() support") > > For information about bisection process see: https://goo.gl/tpsmEJ#bisection CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION is enabled in the kernel config, so null_queue_rq() will return BLK_STS_RESOURCE or BLK_STS_DEV_RESOURCE for some requests, which have been marked as IN_FLIGHT status. Then null_queue_rqs() put these requests in the rqlist and return back, blk-mq will try to queue them individually once again, caused the warning "WARN_ON_ONCE(blk_mq_rq_state(rq) != MQ_RQ_IDLE)" in blk_mq_start_request(). So handling of return value of null_queue_rq() in null_queue_rqs() is wrong, maybe we should __blk_mq_requeue_request() for these requests, before adding them in the rqlist? Thanks!
