nvme: Remove ADMIN_ONLY state

The admin only state was intended to fence off actions that don't
apply to a non-IO capable controller. The only actual user of this is
the scan_work, and pci was the only transport to ever set this state.
The consequence of having this state is placing an additional burden on
every other action that applies to both live and admin only controllers.

Remove the admin only state and place the admin only burden on the only
place that actually cares: scan_work.

This also prepares to make it easier to temporarily pause a LIVE state
so that we don't need to remember which state the controller had been in
prior to the pause.
Tested-by: Edmund Nadolski <edmund.nadolski@intel.com>
Reviewed-by: James Smart <james.smart@broadcom.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>

drivers/nvme/host/core.c

@@ -116,7 +116,7 @@ static void nvme_queue_scan(struct nvme_ctrl *ctrl)
 	/*
 	 * Only new queue scan work when admin and IO queues are both alive
 	 */
-	if (ctrl->state == NVME_CTRL_LIVE)
+	if (ctrl->state == NVME_CTRL_LIVE && ctrl->tagset)
 		queue_work(nvme_wq, &ctrl->scan_work);
 }
 
@@ -137,8 +137,7 @@ int nvme_reset_ctrl_sync(struct nvme_ctrl *ctrl)
 	ret = nvme_reset_ctrl(ctrl);
 	if (!ret) {
 		flush_work(&ctrl->reset_work);
-		if (ctrl->state != NVME_CTRL_LIVE &&
-		    ctrl->state != NVME_CTRL_ADMIN_ONLY)
+		if (ctrl->state != NVME_CTRL_LIVE)
 			ret = -ENETRESET;
 	}
 
@@ -315,15 +314,6 @@ bool nvme_change_ctrl_state(struct nvme_ctrl *ctrl,
 
 	old_state = ctrl->state;
 	switch (new_state) {
-	case NVME_CTRL_ADMIN_ONLY:
-		switch (old_state) {
-		case NVME_CTRL_CONNECTING:
-			changed = true;
-			/* FALLTHRU */
-		default:
-			break;
-		}
-		break;
 	case NVME_CTRL_LIVE:
 		switch (old_state) {
 		case NVME_CTRL_NEW:
@@ -339,7 +329,6 @@ bool nvme_change_ctrl_state(struct nvme_ctrl *ctrl,
 		switch (old_state) {
 		case NVME_CTRL_NEW:
 		case NVME_CTRL_LIVE:
-		case NVME_CTRL_ADMIN_ONLY:
 			changed = true;
 			/* FALLTHRU */
 		default:
@@ -359,7 +348,6 @@ bool nvme_change_ctrl_state(struct nvme_ctrl *ctrl,
 	case NVME_CTRL_DELETING:
 		switch (old_state) {
 		case NVME_CTRL_LIVE:
-		case NVME_CTRL_ADMIN_ONLY:
 		case NVME_CTRL_RESETTING:
 		case NVME_CTRL_CONNECTING:
 			changed = true;
@@ -2873,7 +2861,6 @@ static int nvme_dev_open(struct inode *inode, struct file *file)
 
 	switch (ctrl->state) {
 	case NVME_CTRL_LIVE:
-	case NVME_CTRL_ADMIN_ONLY:
 		break;
 	default:
 		return -EWOULDBLOCK;
@@ -3167,7 +3154,6 @@ static ssize_t nvme_sysfs_show_state(struct device *dev,
 	static const char *const state_name[] = {
 		[NVME_CTRL_NEW]		= "new",
 		[NVME_CTRL_LIVE]	= "live",
-		[NVME_CTRL_ADMIN_ONLY]	= "only-admin",
 		[NVME_CTRL_RESETTING]	= "resetting",
 		[NVME_CTRL_CONNECTING]	= "connecting",
 		[NVME_CTRL_DELETING]	= "deleting",
@@ -3678,11 +3664,10 @@ static void nvme_scan_work(struct work_struct *work)
 	struct nvme_id_ctrl *id;
 	unsigned nn;
 
-	if (ctrl->state != NVME_CTRL_LIVE)
+	/* No tagset on a live ctrl means IO queues could not created */
+	if (ctrl->state != NVME_CTRL_LIVE || !ctrl->tagset)
 		return;
 
-	WARN_ON_ONCE(!ctrl->tagset);
-
 	if (test_and_clear_bit(NVME_AER_NOTICE_NS_CHANGED, &ctrl->events)) {
 		dev_info(ctrl->device, "rescanning namespaces.\n");
 		nvme_clear_changed_ns_log(ctrl);

drivers/nvme/host/fabrics.h

@@ -182,8 +182,7 @@ bool nvmf_ip_options_match(struct nvme_ctrl *ctrl,
 static inline bool nvmf_check_ready(struct nvme_ctrl *ctrl, struct request *rq,
 		bool queue_live)
 {
-	if (likely(ctrl->state == NVME_CTRL_LIVE ||
-		   ctrl->state == NVME_CTRL_ADMIN_ONLY))
+	if (likely(ctrl->state == NVME_CTRL_LIVE))
 		return true;
 	return __nvmf_check_ready(ctrl, rq, queue_live);
 }

drivers/nvme/host/nvme.h

@@ -161,7 +161,6 @@ static inline u16 nvme_req_qid(struct request *req)
 enum nvme_ctrl_state {
 	NVME_CTRL_NEW,
 	NVME_CTRL_LIVE,
-	NVME_CTRL_ADMIN_ONLY,    /* Only admin queue live */
 	NVME_CTRL_RESETTING,
 	NVME_CTRL_CONNECTING,
 	NVME_CTRL_DELETING,

drivers/nvme/host/pci.c

@@ -2263,10 +2263,7 @@ static bool __nvme_disable_io_queues(struct nvme_dev *dev, u8 opcode)
 	return true;
 }
 
-/*
- * return error value only when tagset allocation failed
- */
-static int nvme_dev_add(struct nvme_dev *dev)
+static void nvme_dev_add(struct nvme_dev *dev)
 {
 	int ret;
 
@@ -2296,7 +2293,7 @@ static int nvme_dev_add(struct nvme_dev *dev)
 		if (ret) {
 			dev_warn(dev->ctrl.device,
 				"IO queues tagset allocation failed %d\n", ret);
-			return ret;
+			return;
 		}
 		dev->ctrl.tagset = &dev->tagset;
 	} else {
@@ -2307,7 +2304,6 @@ static int nvme_dev_add(struct nvme_dev *dev)
 	}
 
 	nvme_dbbuf_set(dev);
-	return 0;
 }
 
 static int nvme_pci_enable(struct nvme_dev *dev)
@@ -2527,7 +2523,6 @@ static void nvme_reset_work(struct work_struct *work)
 		container_of(work, struct nvme_dev, ctrl.reset_work);
 	bool was_suspend = !!(dev->ctrl.ctrl_config & NVME_CC_SHN_NORMAL);
 	int result;
-	enum nvme_ctrl_state new_state = NVME_CTRL_LIVE;
 
 	if (WARN_ON(dev->ctrl.state != NVME_CTRL_RESETTING)) {
 		result = -ENODEV;
@@ -2621,14 +2616,11 @@ static void nvme_reset_work(struct work_struct *work)
 		dev_warn(dev->ctrl.device, "IO queues not created\n");
 		nvme_kill_queues(&dev->ctrl);
 		nvme_remove_namespaces(&dev->ctrl);
-		new_state = NVME_CTRL_ADMIN_ONLY;
 		nvme_free_tagset(dev);
 	} else {
 		nvme_start_queues(&dev->ctrl);
 		nvme_wait_freeze(&dev->ctrl);
-		/* hit this only when allocate tagset fails */
-		if (nvme_dev_add(dev))
-			new_state = NVME_CTRL_ADMIN_ONLY;
+		nvme_dev_add(dev);
 		nvme_unfreeze(&dev->ctrl);
 	}
 
@@ -2636,9 +2628,9 @@ static void nvme_reset_work(struct work_struct *work)
 	 * If only admin queue live, keep it to do further investigation or
 	 * recovery.
 	 */
-	if (!nvme_change_ctrl_state(&dev->ctrl, new_state)) {
+	if (!nvme_change_ctrl_state(&dev->ctrl, NVME_CTRL_LIVE)) {
 		dev_warn(dev->ctrl.device,
-			"failed to mark controller state %d\n", new_state);
+			"failed to mark controller live state\n");
 		result = -ENODEV;
 		goto out;
 	}
@@ -2945,8 +2937,7 @@ static int nvme_suspend(struct device *dev)
 	nvme_wait_freeze(ctrl);
 	nvme_sync_queues(ctrl);
 
-	if (ctrl->state != NVME_CTRL_LIVE &&
-	    ctrl->state != NVME_CTRL_ADMIN_ONLY)
+	if (ctrl->state != NVME_CTRL_LIVE)
 		goto unfreeze;
 
 	ret = nvme_get_power_state(ctrl, &ndev->last_ps);