[PATCH] nvme-pci: fix sleeping function called from interrupt context

[Keith Busch]

On Mon, Dec 18, 2023 at 04:11:38PM +0100, Maurizio Lombardi wrote:
> p'a 15. 12. 2023 v 18:25 odes'ilatel Keith Busch <kbusch at kernel.org> napsal:
> > What async event occured to cause this? It looks like the only AEN
> > handling that cancels anything is the FW activation one, but that only
> > applies to fabrics, not pci. Still, that AEN hanlder sets the state to
> > "RESETTING", but we only cancel work when transitioning to "LIVE" from a
> > CONNECTING state.
> 
> It looks like the stack trace is a bit imprecise.
> It's not the call to nvme_change_ctrl_state() that triggers the error
> because, as
> you correctly noticed, moving the controller to the resetting state
> doesn't block.
> 
> The problem is the call to nvme_auth_stop().
> 
>         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)) {
>                         nvme_auth_stop(ctrl);     <----------------
>                         requeue = false;
>                         queue_work(nvme_wq, &ctrl->fw_act_work);
>                 }
> 
> void nvme_auth_stop(struct nvme_ctrl *ctrl)
> {
>         cancel_work_sync(&ctrl->dhchap_auth_work);
> }

Oh, got it; thank you for clarifying.

In that case, let's move the nvme_auth_stop() call to fw_act_work. The
AER handler doesn't depend on auth_work being sync'ed.