Hi ming On 05/11/2018 08:29 PM, Ming Lei wrote: > +static void nvme_eh_done(struct nvme_eh_work *eh_work, int result) > +{ > + struct nvme_dev *dev = eh_work->dev; > + bool top_eh; > + > + spin_lock(&dev->eh_lock); > + top_eh = list_is_last(&eh_work->list, &dev->eh_head); > + dev->nested_eh--; > + > + /* Fail controller if the top EH can't recover it */ > + if (!result) > + wake_up_all(&dev->eh_wq); > + else if (top_eh) { > + dev->ctrl_failed = true; > + nvme_eh_sched_fail_ctrl(dev); > + wake_up_all(&dev->eh_wq); > + } > + > + list_del(&eh_work->list); > + spin_unlock(&dev->eh_lock); > + > + dev_info(dev->ctrl.device, "EH %d: state %d, eh_done %d, top eh %d\n", > + eh_work->seq, dev->ctrl.state, result, top_eh); > + wait_event(dev->eh_wq, nvme_eh_reset_done(dev)); decrease the nested_eh before it exits, another new EH will have confusing seq number. please refer to following log: [ 1342.961869] nvme nvme0: Abort status: 0x0 [ 1342.961878] nvme nvme0: Abort status: 0x0 [ 1343.148341] nvme nvme0: EH 0: after shutdown, top eh: 1 [ 1403.828484] nvme nvme0: I/O 21 QID 0 timeout, disable controller [ 1403.828603] nvme nvme0: EH 1: before shutdown ... waring logs are ignored here [ 1403.984731] nvme nvme0: EH 0: state 4, eh_done -4, top eh 0 // EH0 go to wait [ 1403.984786] nvme nvme0: EH 1: after shutdown, top eh: 1 [ 1464.856290] nvme nvme0: I/O 22 QID 0 timeout, disable controller // timeout again in EH 1 [ 1464.856411] nvme nvme0: EH 1: before shutdown // a new EH has a 1 seq number Is it expected that the new EH has seq number 1 instead of 2 ? Thanks Jianchao