Commit 4c75f877 authored by Keith Busch's avatar Keith Busch
Browse files

nvme: Prevent resets during paused controller state 



A paused controller is doing critical internal activation work in the
background. Prevent subsequent controller resets from occurring during
this period by setting the controller state to RESETTING first. A helper
function, nvme_try_sched_reset_work(), is introduced for these paths so
they may continue with scheduling the reset_work after they've completed
their uninterruptible critical section.

Tested-by: default avatarEdmund Nadolski <edmund.nadolski@intel.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarKeith Busch <kbusch@kernel.org>
parent 92b98e88

drivers/nvme/host/core.c

+25 −4
Original line number Diff line number Diff line
@@ -120,6 +120,21 @@ static void nvme_queue_scan(struct nvme_ctrl *ctrl) 
		queue_work(nvme_wq, &ctrl->scan_work);

}



/*

 * Use this function to proceed with scheduling reset_work for a controller

 * that had previously been set to the resetting state. This is intended for

 * code paths that can't be interrupted by other reset attempts. A hot removal

 * may prevent this from succeeding.

 */

static int nvme_try_sched_reset(struct nvme_ctrl *ctrl)

{

	if (ctrl->state != NVME_CTRL_RESETTING)

		return -EBUSY;

	if (!queue_work(nvme_reset_wq, &ctrl->reset_work))

		return -EBUSY;

	return 0;

}



int nvme_reset_ctrl(struct nvme_ctrl *ctrl)

{

	if (!nvme_change_ctrl_state(ctrl, NVME_CTRL_RESETTING))
@@ -3828,13 +3843,13 @@ static void nvme_fw_act_work(struct work_struct *work) 
		if (time_after(jiffies, fw_act_timeout)) {

			dev_warn(ctrl->device,

				"Fw activation timeout, reset controller\n");

			nvme_reset_ctrl(ctrl);

			break;

			nvme_try_sched_reset(ctrl);

			return;

		}

		msleep(100);

	}



	if (ctrl->state != NVME_CTRL_LIVE)

	if (!nvme_change_ctrl_state(ctrl, NVME_CTRL_LIVE))

		return;



	nvme_start_queues(ctrl);
@@ -3854,6 +3869,12 @@ static void nvme_handle_aen_notice(struct nvme_ctrl *ctrl, u32 result) 
		nvme_queue_scan(ctrl);

		break;

	case NVME_AER_NOTICE_FW_ACT_STARTING:

		/*

		 * We are (ab)using the RESETTING state to prevent subsequent

		 * recovery actions from interfering with the controller's

		 * firmware activation.

		 */

		if (nvme_change_ctrl_state(ctrl, NVME_CTRL_RESETTING))

			queue_work(nvme_wq, &ctrl->fw_act_work);

		break;

#ifdef CONFIG_NVME_MULTIPATH

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