From 2b632970da4f288e6dbdc826c34fbf74f40ec94c Mon Sep 17 00:00:00 2001 From: James Smart Date: Wed, 25 Oct 2017 16:43:17 -0700 Subject: [PATCH] nvme-fc: add dev_loss_tmo timeout and remoteport resume support When a remoteport is unregistered (connectivity lost), the following actions are taken: - the remoteport is marked DELETED - the time when dev_loss_tmo would expire is set in the remoteport - all controllers on the remoteport are reset. After a controller resets, it will stall in a RECONNECTING state waiting for one of the following: - the controller will continue to attempt reconnect per max_retries and reconnect_delay. As no remoteport connectivity, the reconnect attempt will immediately fail. If max reconnects has not been reached, a new reconnect_delay timer will be schedule. If the current time plus another reconnect_delay exceeds when dev_loss_tmo expires on the remote port, then the reconnect_delay will be shortend to schedule no later than when dev_loss_tmo expires. If max reconnect attempts are reached (e.g. ctrl_loss_tmo reached) or dev_loss_tmo ix exceeded without connectivity, the controller is deleted. - the remoteport is re-registered prior to dev_loss_tmo expiring. The resume of the remoteport will immediately attempt to reconnect each of its suspended controllers. Signed-off-by: James Smart Reviewed-by: Hannes Reinecke [hch: updated to use nvme_delete_ctrl] Signed-off-by: Christoph Hellwig --- drivers/nvme/host/fc.c | 280 +++++++++++++++++++++++++++++++++++------ 1 file changed, 240 insertions(+), 40 deletions(-) diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c index b64cc1002452..113c30be7276 100644 --- a/drivers/nvme/host/fc.c +++ b/drivers/nvme/host/fc.c @@ -138,6 +138,7 @@ struct nvme_fc_rport { struct nvme_fc_lport *lport; spinlock_t lock; struct kref ref; + unsigned long dev_loss_end; } __aligned(sizeof(u64)); /* alignment for other things alloc'd with */ enum nvme_fcctrl_flags { @@ -528,6 +529,102 @@ nvme_fc_rport_get(struct nvme_fc_rport *rport) return kref_get_unless_zero(&rport->ref); } +static void +nvme_fc_resume_controller(struct nvme_fc_ctrl *ctrl) +{ + switch (ctrl->ctrl.state) { + case NVME_CTRL_NEW: + case NVME_CTRL_RECONNECTING: + /* + * As all reconnects were suppressed, schedule a + * connect. + */ + dev_info(ctrl->ctrl.device, + "NVME-FC{%d}: connectivity re-established. " + "Attempting reconnect\n", ctrl->cnum); + + queue_delayed_work(nvme_wq, &ctrl->connect_work, 0); + break; + + case NVME_CTRL_RESETTING: + /* + * Controller is already in the process of terminating the + * association. No need to do anything further. The reconnect + * step will naturally occur after the reset completes. + */ + break; + + default: + /* no action to take - let it delete */ + break; + } +} + +static struct nvme_fc_rport * +nvme_fc_attach_to_suspended_rport(struct nvme_fc_lport *lport, + struct nvme_fc_port_info *pinfo) +{ + struct nvme_fc_rport *rport; + struct nvme_fc_ctrl *ctrl; + unsigned long flags; + + spin_lock_irqsave(&nvme_fc_lock, flags); + + list_for_each_entry(rport, &lport->endp_list, endp_list) { + if (rport->remoteport.node_name != pinfo->node_name || + rport->remoteport.port_name != pinfo->port_name) + continue; + + if (!nvme_fc_rport_get(rport)) { + rport = ERR_PTR(-ENOLCK); + goto out_done; + } + + spin_unlock_irqrestore(&nvme_fc_lock, flags); + + spin_lock_irqsave(&rport->lock, flags); + + /* has it been unregistered */ + if (rport->remoteport.port_state != FC_OBJSTATE_DELETED) { + /* means lldd called us twice */ + spin_unlock_irqrestore(&rport->lock, flags); + nvme_fc_rport_put(rport); + return ERR_PTR(-ESTALE); + } + + rport->remoteport.port_state = FC_OBJSTATE_ONLINE; + rport->dev_loss_end = 0; + + /* + * kick off a reconnect attempt on all associations to the + * remote port. A successful reconnects will resume i/o. + */ + list_for_each_entry(ctrl, &rport->ctrl_list, ctrl_list) + nvme_fc_resume_controller(ctrl); + + spin_unlock_irqrestore(&rport->lock, flags); + + return rport; + } + + rport = NULL; + +out_done: + spin_unlock_irqrestore(&nvme_fc_lock, flags); + + return rport; +} + +static inline void +__nvme_fc_set_dev_loss_tmo(struct nvme_fc_rport *rport, + struct nvme_fc_port_info *pinfo) +{ + if (pinfo->dev_loss_tmo) + rport->remoteport.dev_loss_tmo = pinfo->dev_loss_tmo; + else + rport->remoteport.dev_loss_tmo = NVME_FC_DEFAULT_DEV_LOSS_TMO; +} + /** * nvme_fc_register_remoteport - transport entry point called by an * LLDD to register the existence of a NVME @@ -554,22 +651,45 @@ nvme_fc_register_remoteport(struct nvme_fc_local_port *localport, unsigned long flags; int ret, idx; + if (!nvme_fc_lport_get(lport)) { + ret = -ESHUTDOWN; + goto out_reghost_failed; + } + + /* + * look to see if there is already a remoteport that is waiting + * for a reconnect (within dev_loss_tmo) with the same WWN's. + * If so, transition to it and reconnect. + */ + newrec = nvme_fc_attach_to_suspended_rport(lport, pinfo); + + /* found an rport, but something about its state is bad */ + if (IS_ERR(newrec)) { + ret = PTR_ERR(newrec); + goto out_lport_put; + + /* found existing rport, which was resumed */ + } else if (newrec) { + nvme_fc_lport_put(lport); + __nvme_fc_set_dev_loss_tmo(newrec, pinfo); + nvme_fc_signal_discovery_scan(lport, newrec); + *portptr = &newrec->remoteport; + return 0; + } + + /* nothing found - allocate a new remoteport struct */ + newrec = kmalloc((sizeof(*newrec) + lport->ops->remote_priv_sz), GFP_KERNEL); if (!newrec) { ret = -ENOMEM; - goto out_reghost_failed; - } - - if (!nvme_fc_lport_get(lport)) { - ret = -ESHUTDOWN; - goto out_kfree_rport; + goto out_lport_put; } idx = ida_simple_get(&lport->endp_cnt, 0, 0, GFP_KERNEL); if (idx < 0) { ret = -ENOSPC; - goto out_lport_put; + goto out_kfree_rport; } INIT_LIST_HEAD(&newrec->endp_list); @@ -587,11 +707,7 @@ nvme_fc_register_remoteport(struct nvme_fc_local_port *localport, newrec->remoteport.port_id = pinfo->port_id; newrec->remoteport.port_state = FC_OBJSTATE_ONLINE; newrec->remoteport.port_num = idx; - /* a registration value of dev_loss_tmo=0 results in the default */ - if (pinfo->dev_loss_tmo) - newrec->remoteport.dev_loss_tmo = pinfo->dev_loss_tmo; - else - newrec->remoteport.dev_loss_tmo = NVME_FC_DEFAULT_DEV_LOSS_TMO; + __nvme_fc_set_dev_loss_tmo(newrec, pinfo); spin_lock_irqsave(&nvme_fc_lock, flags); list_add_tail(&newrec->endp_list, &lport->endp_list); @@ -602,10 +718,10 @@ nvme_fc_register_remoteport(struct nvme_fc_local_port *localport, *portptr = &newrec->remoteport; return 0; -out_lport_put: - nvme_fc_lport_put(lport); out_kfree_rport: kfree(newrec); +out_lport_put: + nvme_fc_lport_put(lport); out_reghost_failed: *portptr = NULL; return ret; @@ -636,6 +752,58 @@ nvme_fc_abort_lsops(struct nvme_fc_rport *rport) return 0; } +static void +nvme_fc_ctrl_connectivity_loss(struct nvme_fc_ctrl *ctrl) +{ + dev_info(ctrl->ctrl.device, + "NVME-FC{%d}: controller connectivity lost. Awaiting " + "Reconnect", ctrl->cnum); + + switch (ctrl->ctrl.state) { + case NVME_CTRL_NEW: + case NVME_CTRL_LIVE: + /* + * Schedule a controller reset. The reset will terminate the + * association and schedule the reconnect timer. Reconnects + * will be attempted until either the ctlr_loss_tmo + * (max_retries * connect_delay) expires or the remoteport's + * dev_loss_tmo expires. + */ + if (nvme_reset_ctrl(&ctrl->ctrl)) { + dev_warn(ctrl->ctrl.device, + "NVME-FC{%d}: Couldn't schedule reset. " + "Deleting controller.\n", + ctrl->cnum); + nvme_delete_ctrl(&ctrl->ctrl); + } + break; + + case NVME_CTRL_RECONNECTING: + /* + * The association has already been terminated and the + * controller is attempting reconnects. No need to do anything + * futher. Reconnects will be attempted until either the + * ctlr_loss_tmo (max_retries * connect_delay) expires or the + * remoteport's dev_loss_tmo expires. + */ + break; + + case NVME_CTRL_RESETTING: + /* + * Controller is already in the process of terminating the + * association. No need to do anything further. The reconnect + * step will kick in naturally after the association is + * terminated. + */ + break; + + case NVME_CTRL_DELETING: + default: + /* no action to take - let it delete */ + break; + } +} + /** * nvme_fc_unregister_remoteport - transport entry point called by an * LLDD to deregister/remove a previously @@ -665,15 +833,31 @@ nvme_fc_unregister_remoteport(struct nvme_fc_remote_port *portptr) } portptr->port_state = FC_OBJSTATE_DELETED; - /* tear down all associations to the remote port */ - list_for_each_entry(ctrl, &rport->ctrl_list, ctrl_list) - nvme_delete_ctrl(&ctrl->ctrl); + rport->dev_loss_end = jiffies + (portptr->dev_loss_tmo * HZ); + + list_for_each_entry(ctrl, &rport->ctrl_list, ctrl_list) { + /* if dev_loss_tmo==0, dev loss is immediate */ + if (!portptr->dev_loss_tmo) { + dev_warn(ctrl->ctrl.device, + "NVME-FC{%d}: controller connectivity lost. " + "Deleting controller.\n", + ctrl->cnum); + nvme_delete_ctrl(&ctrl->ctrl); + } else + nvme_fc_ctrl_connectivity_loss(ctrl); + } spin_unlock_irqrestore(&rport->lock, flags); nvme_fc_abort_lsops(rport); + /* + * release the reference, which will allow, if all controllers + * go away, which should only occur after dev_loss_tmo occurs, + * for the rport to be torn down. + */ nvme_fc_rport_put(rport); + return 0; } EXPORT_SYMBOL_GPL(nvme_fc_unregister_remoteport); @@ -700,7 +884,6 @@ nvme_fc_set_remoteport_devloss(struct nvme_fc_remote_port *portptr, u32 dev_loss_tmo) { struct nvme_fc_rport *rport = remoteport_to_rport(portptr); - struct nvme_fc_ctrl *ctrl; unsigned long flags; spin_lock_irqsave(&rport->lock, flags); @@ -2676,28 +2859,43 @@ nvme_fc_delete_ctrl(struct nvme_ctrl *nctrl) static void nvme_fc_reconnect_or_delete(struct nvme_fc_ctrl *ctrl, int status) { + struct nvme_fc_rport *rport = ctrl->rport; + struct nvme_fc_remote_port *portptr = &rport->remoteport; + unsigned long recon_delay = ctrl->ctrl.opts->reconnect_delay * HZ; + bool recon = true; + if (ctrl->ctrl.state != NVME_CTRL_RECONNECTING) return; - dev_info(ctrl->ctrl.device, - "NVME-FC{%d}: reset: Reconnect attempt failed (%d)\n", - ctrl->cnum, status); - - if (nvmf_should_reconnect(&ctrl->ctrl)) { - /* Only schedule the reconnect if the remote port is online */ - if (ctrl->rport->remoteport.port_state != FC_OBJSTATE_ONLINE) - return; - + if (portptr->port_state == FC_OBJSTATE_ONLINE) dev_info(ctrl->ctrl.device, - "NVME-FC{%d}: Reconnect attempt in %d seconds.\n", - ctrl->cnum, ctrl->ctrl.opts->reconnect_delay); - queue_delayed_work(nvme_wq, &ctrl->connect_work, - ctrl->ctrl.opts->reconnect_delay * HZ); + "NVME-FC{%d}: reset: Reconnect attempt failed (%d)\n", + ctrl->cnum, status); + else if (time_after_eq(jiffies, rport->dev_loss_end)) + recon = false; + + if (recon && nvmf_should_reconnect(&ctrl->ctrl)) { + if (portptr->port_state == FC_OBJSTATE_ONLINE) + dev_info(ctrl->ctrl.device, + "NVME-FC{%d}: Reconnect attempt in %ld " + "seconds\n", + ctrl->cnum, recon_delay / HZ); + else if (time_after(jiffies + recon_delay, rport->dev_loss_end)) + recon_delay = rport->dev_loss_end - jiffies; + + queue_delayed_work(nvme_wq, &ctrl->connect_work, recon_delay); } else { - dev_warn(ctrl->ctrl.device, + if (portptr->port_state == FC_OBJSTATE_ONLINE) + dev_warn(ctrl->ctrl.device, "NVME-FC{%d}: Max reconnect attempts (%d) " "reached. Removing controller\n", ctrl->cnum, ctrl->ctrl.nr_reconnects); + else + dev_warn(ctrl->ctrl.device, + "NVME-FC{%d}: dev_loss_tmo (%d) expired " + "while waiting for remoteport connectivity. " + "Removing controller\n", ctrl->cnum, + portptr->dev_loss_tmo); WARN_ON(nvme_delete_ctrl(&ctrl->ctrl)); } } @@ -2721,15 +2919,17 @@ nvme_fc_reset_ctrl_work(struct work_struct *work) return; } - if (ctrl->rport->remoteport.port_state == FC_OBJSTATE_ONLINE) { + if (ctrl->rport->remoteport.port_state == FC_OBJSTATE_ONLINE) ret = nvme_fc_create_association(ctrl); - if (ret) - nvme_fc_reconnect_or_delete(ctrl, ret); - else - dev_info(ctrl->ctrl.device, - "NVME-FC{%d}: controller reset complete\n", - ctrl->cnum); - } + else + ret = -ENOTCONN; + + if (ret) + nvme_fc_reconnect_or_delete(ctrl, ret); + else + dev_info(ctrl->ctrl.device, + "NVME-FC{%d}: controller reset complete\n", + ctrl->cnum); } static const struct nvme_ctrl_ops nvme_fc_ctrl_ops = {