Re: [PATCH v2 03/14] nvmet: Implement CCR nvme command

Mohamed Khalfella
2026-02-03T18:40:49Z

On Tue 2026-02-03 04:19:50 +0100, Hannes Reinecke wrote:
> On 1/30/26 23:34, Mohamed Khalfella wrote:
> > @@ -1501,6 +1516,38 @@ struct nvmet_ctrl *nvmet_ctrl_find_get(const char *subsysnqn,
> > return ctrl;
> > }
> >
> > +struct nvmet_ctrl *nvmet_ctrl_find_get_ccr(struct nvmet_subsys *subsys,
> > + const char *hostnqn, u8 ciu,
> > + u16 cntlid, u64 cirn)
> > +{
> > + struct nvmet_ctrl *ctrl;
> > + bool found = false;
> > +
> > + mutex_lock(&subsys->lock);
> > + list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) {
> > + if (ctrl->cntlid != cntlid)
> > + continue;
> > + if (strncmp(ctrl->hostnqn, hostnqn, NVMF_NQN_SIZE))
> > + continue;
> > +
> Why do we compare the hostnqn here, too? To my understanding the host
> NQN is tied to the controller, so the controller ID should be sufficient
> here.

We got cntlid from CCR nvme command and we do not trust the value sent by
the host. We check hostnqn to confirm that host is actually connected to
the impacted controller. A host should not be allowed to reset a
controller connected to another host.

> > @@ -1740,12 +1788,35 @@ struct nvmet_ctrl *nvmet_alloc_ctrl(struct nvmet_alloc_ctrl_args *args)
> > }
> > EXPORT_SYMBOL_GPL(nvmet_alloc_ctrl);
> >
> > +static void nvmet_ctrl_complete_pending_ccr(struct nvmet_ctrl *ctrl)
> > +{
> > + struct nvmet_subsys *subsys = ctrl->subsys;
> > + struct nvmet_ctrl *sctrl;
> > + struct nvmet_ccr *ccr;
> > +
> > + mutex_lock(&ctrl->lock);
> > + nvmet_ctrl_cleanup_ccrs(ctrl, true);
> > + mutex_unlock(&ctrl->lock);
> > +
> > + list_for_each_entry(sctrl, &subsys->ctrls, subsys_entry) {
> > + mutex_lock(&sctrl->lock);
> > + list_for_each_entry(ccr, &sctrl->ccr_list, entry) {
> > + if (ccr->ctrl == ctrl) {
> > + ccr->ctrl = NULL;
> > + break;
> > + }
> > + }
> > + mutex_unlock(&sctrl->lock);
> > + }
> > +}
> > +
>
> Maybe add documentation here that the first CCR cleanup is for clearing
> CCRs issued from this controller, and the second is for CCRs issued _to_
> this controller.
>

Good point. Will do that.