Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 5551 insertions, 0 deletions

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
new file mode 100644
index 000000000..0c088db94
--- /dev/null
+++ b/drivers/nvme/host/core.c
@@ -0,0 +1,5551 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * NVM Express device driver
+ * Copyright (c) 2011-2014, Intel Corporation.
+ */
+
+#include <linux/blkdev.h>
+#include <linux/blk-mq.h>
+#include <linux/blk-integrity.h>
+#include <linux/compat.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/hdreg.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/backing-dev.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/pr.h>
+#include <linux/ptrace.h>
+#include <linux/nvme_ioctl.h>
+#include <linux/pm_qos.h>
+#include <asm/unaligned.h>
+
+#include "nvme.h"
+#include "fabrics.h"
+#include <linux/nvme-auth.h>
+
+#define CREATE_TRACE_POINTS
+#include "trace.h"
+
+#define NVME_MINORS		(1U << MINORBITS)
+
+struct nvme_ns_info {
+	struct nvme_ns_ids ids;
+	u32 nsid;
+	__le32 anagrpid;
+	bool is_shared;
+	bool is_readonly;
+	bool is_ready;
+	bool is_removed;
+};
+
+unsigned int admin_timeout = 60;
+module_param(admin_timeout, uint, 0644);
+MODULE_PARM_DESC(admin_timeout, "timeout in seconds for admin commands");
+EXPORT_SYMBOL_GPL(admin_timeout);
+
+unsigned int nvme_io_timeout = 30;
+module_param_named(io_timeout, nvme_io_timeout, uint, 0644);
+MODULE_PARM_DESC(io_timeout, "timeout in seconds for I/O");
+EXPORT_SYMBOL_GPL(nvme_io_timeout);
+
+static unsigned char shutdown_timeout = 5;
+module_param(shutdown_timeout, byte, 0644);
+MODULE_PARM_DESC(shutdown_timeout, "timeout in seconds for controller shutdown");
+
+static u8 nvme_max_retries = 5;
+module_param_named(max_retries, nvme_max_retries, byte, 0644);
+MODULE_PARM_DESC(max_retries, "max number of retries a command may have");
+
+static unsigned long default_ps_max_latency_us = 100000;
+module_param(default_ps_max_latency_us, ulong, 0644);
+MODULE_PARM_DESC(default_ps_max_latency_us,
+		 "max power saving latency for new devices; use PM QOS to change per device");
+
+static bool force_apst;
+module_param(force_apst, bool, 0644);
+MODULE_PARM_DESC(force_apst, "allow APST for newly enumerated devices even if quirked off");
+
+static unsigned long apst_primary_timeout_ms = 100;
+module_param(apst_primary_timeout_ms, ulong, 0644);
+MODULE_PARM_DESC(apst_primary_timeout_ms,
+	"primary APST timeout in ms");
+
+static unsigned long apst_secondary_timeout_ms = 2000;
+module_param(apst_secondary_timeout_ms, ulong, 0644);
+MODULE_PARM_DESC(apst_secondary_timeout_ms,
+	"secondary APST timeout in ms");
+
+static unsigned long apst_primary_latency_tol_us = 15000;
+module_param(apst_primary_latency_tol_us, ulong, 0644);
+MODULE_PARM_DESC(apst_primary_latency_tol_us,
+	"primary APST latency tolerance in us");
+
+static unsigned long apst_secondary_latency_tol_us = 100000;
+module_param(apst_secondary_latency_tol_us, ulong, 0644);
+MODULE_PARM_DESC(apst_secondary_latency_tol_us,
+	"secondary APST latency tolerance in us");
+
+/*
+ * nvme_wq - hosts nvme related works that are not reset or delete
+ * nvme_reset_wq - hosts nvme reset works
+ * nvme_delete_wq - hosts nvme delete works
+ *
+ * nvme_wq will host works such as scan, aen handling, fw activation,
+ * keep-alive, periodic reconnects etc. nvme_reset_wq
+ * runs reset works which also flush works hosted on nvme_wq for
+ * serialization purposes. nvme_delete_wq host controller deletion
+ * works which flush reset works for serialization.
+ */
+struct workqueue_struct *nvme_wq;
+EXPORT_SYMBOL_GPL(nvme_wq);
+
+struct workqueue_struct *nvme_reset_wq;
+EXPORT_SYMBOL_GPL(nvme_reset_wq);
+
+struct workqueue_struct *nvme_delete_wq;
+EXPORT_SYMBOL_GPL(nvme_delete_wq);
+
+static LIST_HEAD(nvme_subsystems);
+static DEFINE_MUTEX(nvme_subsystems_lock);
+
+static DEFINE_IDA(nvme_instance_ida);
+static dev_t nvme_ctrl_base_chr_devt;
+static struct class *nvme_class;
+static struct class *nvme_subsys_class;
+
+static DEFINE_IDA(nvme_ns_chr_minor_ida);
+static dev_t nvme_ns_chr_devt;
+static struct class *nvme_ns_chr_class;
+
+static void nvme_put_subsystem(struct nvme_subsystem *subsys);
+static void nvme_remove_invalid_namespaces(struct nvme_ctrl *ctrl,
+					   unsigned nsid);
+static void nvme_update_keep_alive(struct nvme_ctrl *ctrl,
+				   struct nvme_command *cmd);
+
+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 && ctrl->tagset)
+		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.
+ */
+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;
+}
+EXPORT_SYMBOL_GPL(nvme_try_sched_reset);
+
+static void nvme_failfast_work(struct work_struct *work)
+{
+	struct nvme_ctrl *ctrl = container_of(to_delayed_work(work),
+			struct nvme_ctrl, failfast_work);
+
+	if (ctrl->state != NVME_CTRL_CONNECTING)
+		return;
+
+	set_bit(NVME_CTRL_FAILFAST_EXPIRED, &ctrl->flags);
+	dev_info(ctrl->device, "failfast expired\n");
+	nvme_kick_requeue_lists(ctrl);
+}
+
+static inline void nvme_start_failfast_work(struct nvme_ctrl *ctrl)
+{
+	if (!ctrl->opts || ctrl->opts->fast_io_fail_tmo == -1)
+		return;
+
+	schedule_delayed_work(&ctrl->failfast_work,
+			      ctrl->opts->fast_io_fail_tmo * HZ);
+}
+
+static inline void nvme_stop_failfast_work(struct nvme_ctrl *ctrl)
+{
+	if (!ctrl->opts)
+		return;
+
+	cancel_delayed_work_sync(&ctrl->failfast_work);
+	clear_bit(NVME_CTRL_FAILFAST_EXPIRED, &ctrl->flags);
+}
+
+
+int nvme_reset_ctrl(struct nvme_ctrl *ctrl)
+{
+	if (!nvme_change_ctrl_state(ctrl, NVME_CTRL_RESETTING))
+		return -EBUSY;
+	if (!queue_work(nvme_reset_wq, &ctrl->reset_work))
+		return -EBUSY;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nvme_reset_ctrl);
+
+int nvme_reset_ctrl_sync(struct nvme_ctrl *ctrl)
+{
+	int ret;
+
+	ret = nvme_reset_ctrl(ctrl);
+	if (!ret) {
+		flush_work(&ctrl->reset_work);
+		if (ctrl->state != NVME_CTRL_LIVE)
+			ret = -ENETRESET;
+	}
+
+	return ret;
+}
+
+static void nvme_do_delete_ctrl(struct nvme_ctrl *ctrl)
+{
+	dev_info(ctrl->device,
+		 "Removing ctrl: NQN \"%s\"\n", nvmf_ctrl_subsysnqn(ctrl));
+
+	flush_work(&ctrl->reset_work);
+	nvme_stop_ctrl(ctrl);
+	nvme_remove_namespaces(ctrl);
+	ctrl->ops->delete_ctrl(ctrl);
+	nvme_uninit_ctrl(ctrl);
+}
+
+static void nvme_delete_ctrl_work(struct work_struct *work)
+{
+	struct nvme_ctrl *ctrl =
+		container_of(work, struct nvme_ctrl, delete_work);
+
+	nvme_do_delete_ctrl(ctrl);
+}
+
+int nvme_delete_ctrl(struct nvme_ctrl *ctrl)
+{
+	if (!nvme_change_ctrl_state(ctrl, NVME_CTRL_DELETING))
+		return -EBUSY;
+	if (!queue_work(nvme_delete_wq, &ctrl->delete_work))
+		return -EBUSY;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nvme_delete_ctrl);
+
+static void nvme_delete_ctrl_sync(struct nvme_ctrl *ctrl)
+{
+	/*
+	 * Keep a reference until nvme_do_delete_ctrl() complete,
+	 * since ->delete_ctrl can free the controller.
+	 */
+	nvme_get_ctrl(ctrl);
+	if (nvme_change_ctrl_state(ctrl, NVME_CTRL_DELETING))
+		nvme_do_delete_ctrl(ctrl);
+	nvme_put_ctrl(ctrl);
+}
+
+static blk_status_t nvme_error_status(u16 status)
+{
+	switch (status & 0x7ff) {
+	case NVME_SC_SUCCESS:
+		return BLK_STS_OK;
+	case NVME_SC_CAP_EXCEEDED:
+		return BLK_STS_NOSPC;
+	case NVME_SC_LBA_RANGE:
+	case NVME_SC_CMD_INTERRUPTED:
+	case NVME_SC_NS_NOT_READY:
+		return BLK_STS_TARGET;
+	case NVME_SC_BAD_ATTRIBUTES:
+	case NVME_SC_ONCS_NOT_SUPPORTED:
+	case NVME_SC_INVALID_OPCODE:
+	case NVME_SC_INVALID_FIELD:
+	case NVME_SC_INVALID_NS:
+		return BLK_STS_NOTSUPP;
+	case NVME_SC_WRITE_FAULT:
+	case NVME_SC_READ_ERROR:
+	case NVME_SC_UNWRITTEN_BLOCK:
+	case NVME_SC_ACCESS_DENIED:
+	case NVME_SC_READ_ONLY:
+	case NVME_SC_COMPARE_FAILED:
+		return BLK_STS_MEDIUM;
+	case NVME_SC_GUARD_CHECK:
+	case NVME_SC_APPTAG_CHECK:
+	case NVME_SC_REFTAG_CHECK:
+	case NVME_SC_INVALID_PI:
+		return BLK_STS_PROTECTION;
+	case NVME_SC_RESERVATION_CONFLICT:
+		return BLK_STS_NEXUS;
+	case NVME_SC_HOST_PATH_ERROR:
+		return BLK_STS_TRANSPORT;
+	case NVME_SC_ZONE_TOO_MANY_ACTIVE:
+		return BLK_STS_ZONE_ACTIVE_RESOURCE;
+	case NVME_SC_ZONE_TOO_MANY_OPEN:
+		return BLK_STS_ZONE_OPEN_RESOURCE;
+	default:
+		return BLK_STS_IOERR;
+	}
+}
+
+static void nvme_retry_req(struct request *req)
+{
+	unsigned long delay = 0;
+	u16 crd;
+
+	/* The mask and shift result must be <= 3 */
+	crd = (nvme_req(req)->status & NVME_SC_CRD) >> 11;
+	if (crd)
+		delay = nvme_req(req)->ctrl->crdt[crd - 1] * 100;
+
+	nvme_req(req)->retries++;
+	blk_mq_requeue_request(req, false);
+	blk_mq_delay_kick_requeue_list(req->q, delay);
+}
+
+static void nvme_log_error(struct request *req)
+{
+	struct nvme_ns *ns = req->q->queuedata;
+	struct nvme_request *nr = nvme_req(req);
+
+	if (ns) {
+		pr_err_ratelimited("%s: %s(0x%x) @ LBA %llu, %llu blocks, %s (sct 0x%x / sc 0x%x) %s%s\n",
+		       ns->disk ? ns->disk->disk_name : "?",
+		       nvme_get_opcode_str(nr->cmd->common.opcode),
+		       nr->cmd->common.opcode,
+		       (unsigned long long)nvme_sect_to_lba(ns, blk_rq_pos(req)),
+		       (unsigned long long)blk_rq_bytes(req) >> ns->lba_shift,
+		       nvme_get_error_status_str(nr->status),
+		       nr->status >> 8 & 7,	/* Status Code Type */
+		       nr->status & 0xff,	/* Status Code */
+		       nr->status & NVME_SC_MORE ? "MORE " : "",
+		       nr->status & NVME_SC_DNR  ? "DNR "  : "");
+		return;
+	}
+
+	pr_err_ratelimited("%s: %s(0x%x), %s (sct 0x%x / sc 0x%x) %s%s\n",
+			   dev_name(nr->ctrl->device),
+			   nvme_get_admin_opcode_str(nr->cmd->common.opcode),
+			   nr->cmd->common.opcode,
+			   nvme_get_error_status_str(nr->status),
+			   nr->status >> 8 & 7,	/* Status Code Type */
+			   nr->status & 0xff,	/* Status Code */
+			   nr->status & NVME_SC_MORE ? "MORE " : "",
+			   nr->status & NVME_SC_DNR  ? "DNR "  : "");
+}
+
+enum nvme_disposition {
+	COMPLETE,
+	RETRY,
+	FAILOVER,
+	AUTHENTICATE,
+};
+
+static inline enum nvme_disposition nvme_decide_disposition(struct request *req)
+{
+	if (likely(nvme_req(req)->status == 0))
+		return COMPLETE;
+
+	if ((nvme_req(req)->status & 0x7ff) == NVME_SC_AUTH_REQUIRED)
+		return AUTHENTICATE;
+
+	if (blk_noretry_request(req) ||
+	    (nvme_req(req)->status & NVME_SC_DNR) ||
+	    nvme_req(req)->retries >= nvme_max_retries)
+		return COMPLETE;
+
+	if (req->cmd_flags & REQ_NVME_MPATH) {
+		if (nvme_is_path_error(nvme_req(req)->status) ||
+		    blk_queue_dying(req->q))
+			return FAILOVER;
+	} else {
+		if (blk_queue_dying(req->q))
+			return COMPLETE;
+	}
+
+	return RETRY;
+}
+
+static inline void nvme_end_req_zoned(struct request *req)
+{
+	if (IS_ENABLED(CONFIG_BLK_DEV_ZONED) &&
+	    req_op(req) == REQ_OP_ZONE_APPEND)
+		req->__sector = nvme_lba_to_sect(req->q->queuedata,
+			le64_to_cpu(nvme_req(req)->result.u64));
+}
+
+static inline void nvme_end_req(struct request *req)
+{
+	blk_status_t status = nvme_error_status(nvme_req(req)->status);
+
+	if (unlikely(nvme_req(req)->status && !(req->rq_flags & RQF_QUIET)))
+		nvme_log_error(req);
+	nvme_end_req_zoned(req);
+	nvme_trace_bio_complete(req);
+	blk_mq_end_request(req, status);
+}
+
+void nvme_complete_rq(struct request *req)
+{
+	struct nvme_ctrl *ctrl = nvme_req(req)->ctrl;
+
+	trace_nvme_complete_rq(req);
+	nvme_cleanup_cmd(req);
+
+	/*
+	 * Completions of long-running commands should not be able to
+	 * defer sending of periodic keep alives, since the controller
+	 * may have completed processing such commands a long time ago
+	 * (arbitrarily close to command submission time).
+	 * req->deadline - req->timeout is the command submission time
+	 * in jiffies.
+	 */
+	if (ctrl->kas &&
+	    req->deadline - req->timeout >= ctrl->ka_last_check_time)
+		ctrl->comp_seen = true;
+
+	switch (nvme_decide_disposition(req)) {
+	case COMPLETE:
+		nvme_end_req(req);
+		return;
+	case RETRY:
+		nvme_retry_req(req);
+		return;
+	case FAILOVER:
+		nvme_failover_req(req);
+		return;
+	case AUTHENTICATE:
+#ifdef CONFIG_NVME_AUTH
+		queue_work(nvme_wq, &ctrl->dhchap_auth_work);
+		nvme_retry_req(req);
+#else
+		nvme_end_req(req);
+#endif
+		return;
+	}
+}
+EXPORT_SYMBOL_GPL(nvme_complete_rq);
+
+void nvme_complete_batch_req(struct request *req)
+{
+	trace_nvme_complete_rq(req);
+	nvme_cleanup_cmd(req);
+	nvme_end_req_zoned(req);
+}
+EXPORT_SYMBOL_GPL(nvme_complete_batch_req);
+
+/*
+ * Called to unwind from ->queue_rq on a failed command submission so that the
+ * multipathing code gets called to potentially failover to another path.
+ * The caller needs to unwind all transport specific resource allocations and
+ * must return propagate the return value.
+ */
+blk_status_t nvme_host_path_error(struct request *req)
+{
+	nvme_req(req)->status = NVME_SC_HOST_PATH_ERROR;
+	blk_mq_set_request_complete(req);
+	nvme_complete_rq(req);
+	return BLK_STS_OK;
+}
+EXPORT_SYMBOL_GPL(nvme_host_path_error);
+
+bool nvme_cancel_request(struct request *req, void *data)
+{
+	dev_dbg_ratelimited(((struct nvme_ctrl *) data)->device,
+				"Cancelling I/O %d", req->tag);
+
+	/* don't abort one completed request */
+	if (blk_mq_request_completed(req))
+		return true;
+
+	nvme_req(req)->status = NVME_SC_HOST_ABORTED_CMD;
+	nvme_req(req)->flags |= NVME_REQ_CANCELLED;
+	blk_mq_complete_request(req);
+	return true;
+}
+EXPORT_SYMBOL_GPL(nvme_cancel_request);
+
+void nvme_cancel_tagset(struct nvme_ctrl *ctrl)
+{
+	if (ctrl->tagset) {
+		blk_mq_tagset_busy_iter(ctrl->tagset,
+				nvme_cancel_request, ctrl);
+		blk_mq_tagset_wait_completed_request(ctrl->tagset);
+	}
+}
+EXPORT_SYMBOL_GPL(nvme_cancel_tagset);
+
+void nvme_cancel_admin_tagset(struct nvme_ctrl *ctrl)
+{
+	if (ctrl->admin_tagset) {
+		blk_mq_tagset_busy_iter(ctrl->admin_tagset,
+				nvme_cancel_request, ctrl);
+		blk_mq_tagset_wait_completed_request(ctrl->admin_tagset);
+	}
+}
+EXPORT_SYMBOL_GPL(nvme_cancel_admin_tagset);
+
+bool nvme_change_ctrl_state(struct nvme_ctrl *ctrl,
+		enum nvme_ctrl_state new_state)
+{
+	enum nvme_ctrl_state old_state;
+	unsigned long flags;
+	bool changed = false;
+
+	spin_lock_irqsave(&ctrl->lock, flags);
+
+	old_state = ctrl->state;
+	switch (new_state) {
+	case NVME_CTRL_LIVE:
+		switch (old_state) {
+		case NVME_CTRL_NEW:
+		case NVME_CTRL_RESETTING:
+		case NVME_CTRL_CONNECTING:
+			changed = true;
+			fallthrough;
+		default:
+			break;
+		}
+		break;
+	case NVME_CTRL_RESETTING:
+		switch (old_state) {
+		case NVME_CTRL_NEW:
+		case NVME_CTRL_LIVE:
+			changed = true;
+			fallthrough;
+		default:
+			break;
+		}
+		break;
+	case NVME_CTRL_CONNECTING:
+		switch (old_state) {
+		case NVME_CTRL_NEW:
+		case NVME_CTRL_RESETTING:
+			changed = true;
+			fallthrough;
+		default:
+			break;
+		}
+		break;
+	case NVME_CTRL_DELETING:
+		switch (old_state) {
+		case NVME_CTRL_LIVE:
+		case NVME_CTRL_RESETTING:
+		case NVME_CTRL_CONNECTING:
+			changed = true;
+			fallthrough;
+		default:
+			break;
+		}
+		break;
+	case NVME_CTRL_DELETING_NOIO:
+		switch (old_state) {
+		case NVME_CTRL_DELETING:
+		case NVME_CTRL_DEAD:
+			changed = true;
+			fallthrough;
+		default:
+			break;
+		}
+		break;
+	case NVME_CTRL_DEAD:
+		switch (old_state) {
+		case NVME_CTRL_DELETING:
+			changed = true;
+			fallthrough;
+		default:
+			break;
+		}
+		break;
+	default:
+		break;
+	}
+
+	if (changed) {
+		ctrl->state = new_state;
+		wake_up_all(&ctrl->state_wq);
+	}
+
+	spin_unlock_irqrestore(&ctrl->lock, flags);
+	if (!changed)
+		return false;
+
+	if (ctrl->state == NVME_CTRL_LIVE) {
+		if (old_state == NVME_CTRL_CONNECTING)
+			nvme_stop_failfast_work(ctrl);
+		nvme_kick_requeue_lists(ctrl);
+	} else if (ctrl->state == NVME_CTRL_CONNECTING &&
+		old_state == NVME_CTRL_RESETTING) {
+		nvme_start_failfast_work(ctrl);
+	}
+	return changed;
+}
+EXPORT_SYMBOL_GPL(nvme_change_ctrl_state);
+
+/*
+ * Returns true for sink states that can't ever transition back to live.
+ */
+static bool nvme_state_terminal(struct nvme_ctrl *ctrl)
+{
+	switch (ctrl->state) {
+	case NVME_CTRL_NEW:
+	case NVME_CTRL_LIVE:
+	case NVME_CTRL_RESETTING:
+	case NVME_CTRL_CONNECTING:
+		return false;
+	case NVME_CTRL_DELETING:
+	case NVME_CTRL_DELETING_NOIO:
+	case NVME_CTRL_DEAD:
+		return true;
+	default:
+		WARN_ONCE(1, "Unhandled ctrl state:%d", ctrl->state);
+		return true;
+	}
+}
+
+/*
+ * Waits for the controller state to be resetting, or returns false if it is
+ * not possible to ever transition to that state.
+ */
+bool nvme_wait_reset(struct nvme_ctrl *ctrl)
+{
+	wait_event(ctrl->state_wq,
+		   nvme_change_ctrl_state(ctrl, NVME_CTRL_RESETTING) ||
+		   nvme_state_terminal(ctrl));
+	return ctrl->state == NVME_CTRL_RESETTING;
+}
+EXPORT_SYMBOL_GPL(nvme_wait_reset);
+
+static void nvme_free_ns_head(struct kref *ref)
+{
+	struct nvme_ns_head *head =
+		container_of(ref, struct nvme_ns_head, ref);
+
+	nvme_mpath_remove_disk(head);
+	ida_free(&head->subsys->ns_ida, head->instance);
+	cleanup_srcu_struct(&head->srcu);
+	nvme_put_subsystem(head->subsys);
+	kfree(head);
+}
+
+bool nvme_tryget_ns_head(struct nvme_ns_head *head)
+{
+	return kref_get_unless_zero(&head->ref);
+}
+
+void nvme_put_ns_head(struct nvme_ns_head *head)
+{
+	kref_put(&head->ref, nvme_free_ns_head);
+}
+
+static void nvme_free_ns(struct kref *kref)
+{
+	struct nvme_ns *ns = container_of(kref, struct nvme_ns, kref);
+
+	put_disk(ns->disk);
+	nvme_put_ns_head(ns->head);
+	nvme_put_ctrl(ns->ctrl);
+	kfree(ns);
+}
+
+static inline bool nvme_get_ns(struct nvme_ns *ns)
+{
+	return kref_get_unless_zero(&ns->kref);
+}
+
+void nvme_put_ns(struct nvme_ns *ns)
+{
+	kref_put(&ns->kref, nvme_free_ns);
+}
+EXPORT_SYMBOL_NS_GPL(nvme_put_ns, NVME_TARGET_PASSTHRU);
+
+static inline void nvme_clear_nvme_request(struct request *req)
+{
+	nvme_req(req)->status = 0;
+	nvme_req(req)->retries = 0;
+	nvme_req(req)->flags = 0;
+	req->rq_flags |= RQF_DONTPREP;
+}
+
+/* initialize a passthrough request */
+void nvme_init_request(struct request *req, struct nvme_command *cmd)
+{
+	if (req->q->queuedata)
+		req->timeout = NVME_IO_TIMEOUT;
+	else /* no queuedata implies admin queue */
+		req->timeout = NVME_ADMIN_TIMEOUT;
+
+	/* passthru commands should let the driver set the SGL flags */
+	cmd->common.flags &= ~NVME_CMD_SGL_ALL;
+
+	req->cmd_flags |= REQ_FAILFAST_DRIVER;
+	if (req->mq_hctx->type == HCTX_TYPE_POLL)
+		req->cmd_flags |= REQ_POLLED;
+	nvme_clear_nvme_request(req);
+	req->rq_flags |= RQF_QUIET;
+	memcpy(nvme_req(req)->cmd, cmd, sizeof(*cmd));
+}
+EXPORT_SYMBOL_GPL(nvme_init_request);
+
+/*
+ * For something we're not in a state to send to the device the default action
+ * is to busy it and retry it after the controller state is recovered.  However,
+ * if the controller is deleting or if anything is marked for failfast or
+ * nvme multipath it is immediately failed.
+ *
+ * Note: commands used to initialize the controller will be marked for failfast.
+ * Note: nvme cli/ioctl commands are marked for failfast.
+ */
+blk_status_t nvme_fail_nonready_command(struct nvme_ctrl *ctrl,
+		struct request *rq)
+{
+	if (ctrl->state != NVME_CTRL_DELETING_NOIO &&
+	    ctrl->state != NVME_CTRL_DELETING &&
+	    ctrl->state != NVME_CTRL_DEAD &&
+	    !test_bit(NVME_CTRL_FAILFAST_EXPIRED, &ctrl->flags) &&
+	    !blk_noretry_request(rq) && !(rq->cmd_flags & REQ_NVME_MPATH))
+		return BLK_STS_RESOURCE;
+	return nvme_host_path_error(rq);
+}
+EXPORT_SYMBOL_GPL(nvme_fail_nonready_command);
+
+bool __nvme_check_ready(struct nvme_ctrl *ctrl, struct request *rq,
+		bool queue_live)
+{
+	struct nvme_request *req = nvme_req(rq);
+
+	/*
+	 * currently we have a problem sending passthru commands
+	 * on the admin_q if the controller is not LIVE because we can't
+	 * make sure that they are going out after the admin connect,
+	 * controller enable and/or other commands in the initialization
+	 * sequence. until the controller will be LIVE, fail with
+	 * BLK_STS_RESOURCE so that they will be rescheduled.
+	 */
+	if (rq->q == ctrl->admin_q && (req->flags & NVME_REQ_USERCMD))
+		return false;
+
+	if (ctrl->ops->flags & NVME_F_FABRICS) {
+		/*
+		 * Only allow commands on a live queue, except for the connect
+		 * command, which is require to set the queue live in the
+		 * appropinquate states.
+		 */
+		switch (ctrl->state) {
+		case NVME_CTRL_CONNECTING:
+			if (blk_rq_is_passthrough(rq) && nvme_is_fabrics(req->cmd) &&
+			    (req->cmd->fabrics.fctype == nvme_fabrics_type_connect ||
+			     req->cmd->fabrics.fctype == nvme_fabrics_type_auth_send ||
+			     req->cmd->fabrics.fctype == nvme_fabrics_type_auth_receive))
+				return true;
+			break;
+		default:
+			break;
+		case NVME_CTRL_DEAD:
+			return false;
+		}
+	}
+
+	return queue_live;
+}
+EXPORT_SYMBOL_GPL(__nvme_check_ready);
+
+static inline void nvme_setup_flush(struct nvme_ns *ns,
+		struct nvme_command *cmnd)
+{
+	memset(cmnd, 0, sizeof(*cmnd));
+	cmnd->common.opcode = nvme_cmd_flush;
+	cmnd->common.nsid = cpu_to_le32(ns->head->ns_id);
+}
+
+static blk_status_t nvme_setup_discard(struct nvme_ns *ns, struct request *req,
+		struct nvme_command *cmnd)
+{
+	unsigned short segments = blk_rq_nr_discard_segments(req), n = 0;
+	struct nvme_dsm_range *range;
+	struct bio *bio;
+
+	/*
+	 * Some devices do not consider the DSM 'Number of Ranges' field when
+	 * determining how much data to DMA. Always allocate memory for maximum
+	 * number of segments to prevent device reading beyond end of buffer.
+	 */
+	static const size_t alloc_size = sizeof(*range) * NVME_DSM_MAX_RANGES;
+
+	range = kzalloc(alloc_size, GFP_ATOMIC | __GFP_NOWARN);
+	if (!range) {
+		/*
+		 * If we fail allocation our range, fallback to the controller
+		 * discard page. If that's also busy, it's safe to return
+		 * busy, as we know we can make progress once that's freed.
+		 */
+		if (test_and_set_bit_lock(0, &ns->ctrl->discard_page_busy))
+			return BLK_STS_RESOURCE;
+
+		range = page_address(ns->ctrl->discard_page);
+	}
+
+	if (queue_max_discard_segments(req->q) == 1) {
+		u64 slba = nvme_sect_to_lba(ns, blk_rq_pos(req));
+		u32 nlb = blk_rq_sectors(req) >> (ns->lba_shift - 9);
+
+		range[0].cattr = cpu_to_le32(0);
+		range[0].nlb = cpu_to_le32(nlb);
+		range[0].slba = cpu_to_le64(slba);
+		n = 1;
+	} else {
+		__rq_for_each_bio(bio, req) {
+			u64 slba = nvme_sect_to_lba(ns, bio->bi_iter.bi_sector);
+			u32 nlb = bio->bi_iter.bi_size >> ns->lba_shift;
+
+			if (n < segments) {
+				range[n].cattr = cpu_to_le32(0);
+				range[n].nlb = cpu_to_le32(nlb);
+				range[n].slba = cpu_to_le64(slba);
+			}
+			n++;
+		}
+	}
+
+	if (WARN_ON_ONCE(n != segments)) {
+		if (virt_to_page(range) == ns->ctrl->discard_page)
+			clear_bit_unlock(0, &ns->ctrl->discard_page_busy);
+		else
+			kfree(range);
+		return BLK_STS_IOERR;
+	}
+
+	memset(cmnd, 0, sizeof(*cmnd));
+	cmnd->dsm.opcode = nvme_cmd_dsm;
+	cmnd->dsm.nsid = cpu_to_le32(ns->head->ns_id);
+	cmnd->dsm.nr = cpu_to_le32(segments - 1);
+	cmnd->dsm.attributes = cpu_to_le32(NVME_DSMGMT_AD);
+
+	req->special_vec.bv_page = virt_to_page(range);
+	req->special_vec.bv_offset = offset_in_page(range);
+	req->special_vec.bv_len = alloc_size;
+	req->rq_flags |= RQF_SPECIAL_PAYLOAD;
+
+	return BLK_STS_OK;
+}
+
+static void nvme_set_ref_tag(struct nvme_ns *ns, struct nvme_command *cmnd,
+			      struct request *req)
+{
+	u32 upper, lower;
+	u64 ref48;
+
+	/* both rw and write zeroes share the same reftag format */
+	switch (ns->guard_type) {
+	case NVME_NVM_NS_16B_GUARD:
+		cmnd->rw.reftag = cpu_to_le32(t10_pi_ref_tag(req));
+		break;
+	case NVME_NVM_NS_64B_GUARD:
+		ref48 = ext_pi_ref_tag(req);
+		lower = lower_32_bits(ref48);
+		upper = upper_32_bits(ref48);
+
+		cmnd->rw.reftag = cpu_to_le32(lower);
+		cmnd->rw.cdw3 = cpu_to_le32(upper);
+		break;
+	default:
+		break;
+	}
+}
+
+static inline blk_status_t nvme_setup_write_zeroes(struct nvme_ns *ns,
+		struct request *req, struct nvme_command *cmnd)
+{
+	memset(cmnd, 0, sizeof(*cmnd));
+
+	if (ns->ctrl->quirks & NVME_QUIRK_DEALLOCATE_ZEROES)
+		return nvme_setup_discard(ns, req, cmnd);
+
+	cmnd->write_zeroes.opcode = nvme_cmd_write_zeroes;
+	cmnd->write_zeroes.nsid = cpu_to_le32(ns->head->ns_id);
+	cmnd->write_zeroes.slba =
+		cpu_to_le64(nvme_sect_to_lba(ns, blk_rq_pos(req)));
+	cmnd->write_zeroes.length =
+		cpu_to_le16((blk_rq_bytes(req) >> ns->lba_shift) - 1);
+
+	if (nvme_ns_has_pi(ns)) {
+		cmnd->write_zeroes.control = cpu_to_le16(NVME_RW_PRINFO_PRACT);
+
+		switch (ns->pi_type) {
+		case NVME_NS_DPS_PI_TYPE1:
+		case NVME_NS_DPS_PI_TYPE2:
+			nvme_set_ref_tag(ns, cmnd, req);
+			break;
+		}
+	}
+
+	return BLK_STS_OK;
+}
+
+static inline blk_status_t nvme_setup_rw(struct nvme_ns *ns,
+		struct request *req, struct nvme_command *cmnd,
+		enum nvme_opcode op)
+{
+	u16 control = 0;
+	u32 dsmgmt = 0;
+
+	if (req->cmd_flags & REQ_FUA)
+		control |= NVME_RW_FUA;
+	if (req->cmd_flags & (REQ_FAILFAST_DEV | REQ_RAHEAD))
+		control |= NVME_RW_LR;
+
+	if (req->cmd_flags & REQ_RAHEAD)
+		dsmgmt |= NVME_RW_DSM_FREQ_PREFETCH;
+
+	cmnd->rw.opcode = op;
+	cmnd->rw.flags = 0;
+	cmnd->rw.nsid = cpu_to_le32(ns->head->ns_id);
+	cmnd->rw.cdw2 = 0;
+	cmnd->rw.cdw3 = 0;
+	cmnd->rw.metadata = 0;
+	cmnd->rw.slba = cpu_to_le64(nvme_sect_to_lba(ns, blk_rq_pos(req)));
+	cmnd->rw.length = cpu_to_le16((blk_rq_bytes(req) >> ns->lba_shift) - 1);
+	cmnd->rw.reftag = 0;
+	cmnd->rw.apptag = 0;
+	cmnd->rw.appmask = 0;
+
+	if (ns->ms) {
+		/*
+		 * If formated with metadata, the block layer always provides a
+		 * metadata buffer if CONFIG_BLK_DEV_INTEGRITY is enabled.  Else
+		 * we enable the PRACT bit for protection information or set the
+		 * namespace capacity to zero to prevent any I/O.
+		 */
+		if (!blk_integrity_rq(req)) {
+			if (WARN_ON_ONCE(!nvme_ns_has_pi(ns)))
+				return BLK_STS_NOTSUPP;
+			control |= NVME_RW_PRINFO_PRACT;
+		}
+
+		switch (ns->pi_type) {
+		case NVME_NS_DPS_PI_TYPE3:
+			control |= NVME_RW_PRINFO_PRCHK_GUARD;
+			break;
+		case NVME_NS_DPS_PI_TYPE1:
+		case NVME_NS_DPS_PI_TYPE2:
+			control |= NVME_RW_PRINFO_PRCHK_GUARD |
+					NVME_RW_PRINFO_PRCHK_REF;
+			if (op == nvme_cmd_zone_append)
+				control |= NVME_RW_APPEND_PIREMAP;
+			nvme_set_ref_tag(ns, cmnd, req);
+			break;
+		}
+	}
+
+	cmnd->rw.control = cpu_to_le16(control);
+	cmnd->rw.dsmgmt = cpu_to_le32(dsmgmt);
+	return 0;
+}
+
+void nvme_cleanup_cmd(struct request *req)
+{
+	if (req->rq_flags & RQF_SPECIAL_PAYLOAD) {
+		struct nvme_ctrl *ctrl = nvme_req(req)->ctrl;
+
+		if (req->special_vec.bv_page == ctrl->discard_page)
+			clear_bit_unlock(0, &ctrl->discard_page_busy);
+		else
+			kfree(bvec_virt(&req->special_vec));
+	}
+}
+EXPORT_SYMBOL_GPL(nvme_cleanup_cmd);
+
+blk_status_t nvme_setup_cmd(struct nvme_ns *ns, struct request *req)
+{
+	struct nvme_command *cmd = nvme_req(req)->cmd;
+	blk_status_t ret = BLK_STS_OK;
+
+	if (!(req->rq_flags & RQF_DONTPREP))
+		nvme_clear_nvme_request(req);
+
+	switch (req_op(req)) {
+	case REQ_OP_DRV_IN:
+	case REQ_OP_DRV_OUT:
+		/* these are setup prior to execution in nvme_init_request() */
+		break;
+	case REQ_OP_FLUSH:
+		nvme_setup_flush(ns, cmd);
+		break;
+	case REQ_OP_ZONE_RESET_ALL:
+	case REQ_OP_ZONE_RESET:
+		ret = nvme_setup_zone_mgmt_send(ns, req, cmd, NVME_ZONE_RESET);
+		break;
+	case REQ_OP_ZONE_OPEN:
+		ret = nvme_setup_zone_mgmt_send(ns, req, cmd, NVME_ZONE_OPEN);
+		break;
+	case REQ_OP_ZONE_CLOSE:
+		ret = nvme_setup_zone_mgmt_send(ns, req, cmd, NVME_ZONE_CLOSE);
+		break;
+	case REQ_OP_ZONE_FINISH:
+		ret = nvme_setup_zone_mgmt_send(ns, req, cmd, NVME_ZONE_FINISH);
+		break;
+	case REQ_OP_WRITE_ZEROES:
+		ret = nvme_setup_write_zeroes(ns, req, cmd);
+		break;
+	case REQ_OP_DISCARD:
+		ret = nvme_setup_discard(ns, req, cmd);
+		break;
+	case REQ_OP_READ:
+		ret = nvme_setup_rw(ns, req, cmd, nvme_cmd_read);
+		break;
+	case REQ_OP_WRITE:
+		ret = nvme_setup_rw(ns, req, cmd, nvme_cmd_write);
+		break;
+	case REQ_OP_ZONE_APPEND:
+		ret = nvme_setup_rw(ns, req, cmd, nvme_cmd_zone_append);
+		break;
+	default:
+		WARN_ON_ONCE(1);
+		return BLK_STS_IOERR;
+	}
+
+	cmd->common.command_id = nvme_cid(req);
+	trace_nvme_setup_cmd(req, cmd);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(nvme_setup_cmd);
+
+/*
+ * Return values:
+ * 0:  success
+ * >0: nvme controller's cqe status response
+ * <0: kernel error in lieu of controller response
+ */
+static int nvme_execute_rq(struct request *rq, bool at_head)
+{
+	blk_status_t status;
+
+	status = blk_execute_rq(rq, at_head);
+	if (nvme_req(rq)->flags & NVME_REQ_CANCELLED)
+		return -EINTR;
+	if (nvme_req(rq)->status)
+		return nvme_req(rq)->status;
+	return blk_status_to_errno(status);
+}
+
+/*
+ * Returns 0 on success.  If the result is negative, it's a Linux error code;
+ * if the result is positive, it's an NVM Express status code
+ */
+int __nvme_submit_sync_cmd(struct request_queue *q, struct nvme_command *cmd,
+		union nvme_result *result, void *buffer, unsigned bufflen,
+		int qid, int at_head, blk_mq_req_flags_t flags)
+{
+	struct request *req;
+	int ret;
+
+	if (qid == NVME_QID_ANY)
+		req = blk_mq_alloc_request(q, nvme_req_op(cmd), flags);
+	else
+		req = blk_mq_alloc_request_hctx(q, nvme_req_op(cmd), flags,
+						qid - 1);
+
+	if (IS_ERR(req))
+		return PTR_ERR(req);
+	nvme_init_request(req, cmd);
+
+	if (buffer && bufflen) {
+		ret = blk_rq_map_kern(q, req, buffer, bufflen, GFP_KERNEL);
+		if (ret)
+			goto out;
+	}
+
+	ret = nvme_execute_rq(req, at_head);
+	if (result && ret >= 0)
+		*result = nvme_req(req)->result;
+ out:
+	blk_mq_free_request(req);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(__nvme_submit_sync_cmd);
+
+int nvme_submit_sync_cmd(struct request_queue *q, struct nvme_command *cmd,
+		void *buffer, unsigned bufflen)
+{
+	return __nvme_submit_sync_cmd(q, cmd, NULL, buffer, bufflen,
+			NVME_QID_ANY, 0, 0);
+}
+EXPORT_SYMBOL_GPL(nvme_submit_sync_cmd);
+
+static u32 nvme_known_admin_effects(u8 opcode)
+{
+	switch (opcode) {
+	case nvme_admin_format_nvm:
+		return NVME_CMD_EFFECTS_LBCC | NVME_CMD_EFFECTS_NCC |
+			NVME_CMD_EFFECTS_CSE_MASK;
+	case nvme_admin_sanitize_nvm:
+		return NVME_CMD_EFFECTS_LBCC | NVME_CMD_EFFECTS_CSE_MASK;
+	default:
+		break;
+	}
+	return 0;
+}
+
+static u32 nvme_known_nvm_effects(u8 opcode)
+{
+	switch (opcode) {
+	case nvme_cmd_write:
+	case nvme_cmd_write_zeroes:
+	case nvme_cmd_write_uncor:
+		 return NVME_CMD_EFFECTS_LBCC;
+	default:
+		return 0;
+	}
+}
+
+u32 nvme_command_effects(struct nvme_ctrl *ctrl, struct nvme_ns *ns, u8 opcode)
+{
+	u32 effects = 0;
+
+	if (ns) {
+		if (ns->head->effects)
+			effects = le32_to_cpu(ns->head->effects->iocs[opcode]);
+		if (ns->head->ids.csi == NVME_CSI_NVM)
+			effects |= nvme_known_nvm_effects(opcode);
+		if (effects & ~(NVME_CMD_EFFECTS_CSUPP | NVME_CMD_EFFECTS_LBCC))
+			dev_warn_once(ctrl->device,
+				"IO command:%02x has unusual effects:%08x\n",
+				opcode, effects);
+
+		/*
+		 * NVME_CMD_EFFECTS_CSE_MASK causes a freeze all I/O queues,
+		 * which would deadlock when done on an I/O command.  Note that
+		 * We already warn about an unusual effect above.
+		 */
+		effects &= ~NVME_CMD_EFFECTS_CSE_MASK;
+	} else {
+		if (ctrl->effects)
+			effects = le32_to_cpu(ctrl->effects->acs[opcode]);
+		effects |= nvme_known_admin_effects(opcode);
+	}
+
+	return effects;
+}
+EXPORT_SYMBOL_NS_GPL(nvme_command_effects, NVME_TARGET_PASSTHRU);
+
+static u32 nvme_passthru_start(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
+			       u8 opcode)
+{
+	u32 effects = nvme_command_effects(ctrl, ns, opcode);
+
+	/*
+	 * For simplicity, IO to all namespaces is quiesced even if the command
+	 * effects say only one namespace is affected.
+	 */
+	if (effects & NVME_CMD_EFFECTS_CSE_MASK) {
+		mutex_lock(&ctrl->scan_lock);
+		mutex_lock(&ctrl->subsys->lock);
+		nvme_mpath_start_freeze(ctrl->subsys);
+		nvme_mpath_wait_freeze(ctrl->subsys);
+		nvme_start_freeze(ctrl);
+		nvme_wait_freeze(ctrl);
+	}
+	return effects;
+}
+
+void nvme_passthru_end(struct nvme_ctrl *ctrl, u32 effects,
+		       struct nvme_command *cmd, int status)
+{
+	if (effects & NVME_CMD_EFFECTS_CSE_MASK) {
+		nvme_unfreeze(ctrl);
+		nvme_mpath_unfreeze(ctrl->subsys);
+		mutex_unlock(&ctrl->subsys->lock);
+		nvme_remove_invalid_namespaces(ctrl, NVME_NSID_ALL);
+		mutex_unlock(&ctrl->scan_lock);
+	}
+	if (effects & NVME_CMD_EFFECTS_CCC)
+		nvme_init_ctrl_finish(ctrl);
+	if (effects & (NVME_CMD_EFFECTS_NIC | NVME_CMD_EFFECTS_NCC)) {
+		nvme_queue_scan(ctrl);
+		flush_work(&ctrl->scan_work);
+	}
+
+	switch (cmd->common.opcode) {
+	case nvme_admin_set_features:
+		switch (le32_to_cpu(cmd->common.cdw10) & 0xFF) {
+		case NVME_FEAT_KATO:
+			/*
+			 * Keep alive commands interval on the host should be
+			 * updated when KATO is modified by Set Features
+			 * commands.
+			 */
+			if (!status)
+				nvme_update_keep_alive(ctrl, cmd);
+			break;
+		default:
+			break;
+		}
+		break;
+	default:
+		break;
+	}
+}
+EXPORT_SYMBOL_NS_GPL(nvme_passthru_end, NVME_TARGET_PASSTHRU);
+
+int nvme_execute_passthru_rq(struct request *rq, u32 *effects)
+{
+	struct nvme_command *cmd = nvme_req(rq)->cmd;
+	struct nvme_ctrl *ctrl = nvme_req(rq)->ctrl;
+	struct nvme_ns *ns = rq->q->queuedata;
+
+	*effects = nvme_passthru_start(ctrl, ns, cmd->common.opcode);
+	return nvme_execute_rq(rq, false);
+}
+EXPORT_SYMBOL_NS_GPL(nvme_execute_passthru_rq, NVME_TARGET_PASSTHRU);
+
+/*
+ * Recommended frequency for KATO commands per NVMe 1.4 section 7.12.1:
+ * 
+ *   The host should send Keep Alive commands at half of the Keep Alive Timeout
+ *   accounting for transport roundtrip times [..].
+ */
+static unsigned long nvme_keep_alive_work_period(struct nvme_ctrl *ctrl)
+{
+	unsigned long delay = ctrl->kato * HZ / 2;
+
+	/*
+	 * When using Traffic Based Keep Alive, we need to run
+	 * nvme_keep_alive_work at twice the normal frequency, as one
+	 * command completion can postpone sending a keep alive command
+	 * by up to twice the delay between runs.
+	 */
+	if (ctrl->ctratt & NVME_CTRL_ATTR_TBKAS)
+		delay /= 2;
+	return delay;
+}
+
+static void nvme_queue_keep_alive_work(struct nvme_ctrl *ctrl)
+{
+	queue_delayed_work(nvme_wq, &ctrl->ka_work,
+			   nvme_keep_alive_work_period(ctrl));
+}
+
+static enum rq_end_io_ret nvme_keep_alive_end_io(struct request *rq,
+						 blk_status_t status)
+{
+	struct nvme_ctrl *ctrl = rq->end_io_data;
+	unsigned long flags;
+	bool startka = false;
+	unsigned long rtt = jiffies - (rq->deadline - rq->timeout);
+	unsigned long delay = nvme_keep_alive_work_period(ctrl);
+
+	/*
+	 * Subtract off the keepalive RTT so nvme_keep_alive_work runs
+	 * at the desired frequency.
+	 */
+	if (rtt <= delay) {
+		delay -= rtt;
+	} else {
+		dev_warn(ctrl->device, "long keepalive RTT (%u ms)\n",
+			 jiffies_to_msecs(rtt));
+		delay = 0;
+	}
+
+	blk_mq_free_request(rq);
+
+	if (status) {
+		dev_err(ctrl->device,
+			"failed nvme_keep_alive_end_io error=%d\n",
+				status);
+		return RQ_END_IO_NONE;
+	}
+
+	ctrl->ka_last_check_time = jiffies;
+	ctrl->comp_seen = false;
+	spin_lock_irqsave(&ctrl->lock, flags);
+	if (ctrl->state == NVME_CTRL_LIVE ||
+	    ctrl->state == NVME_CTRL_CONNECTING)
+		startka = true;
+	spin_unlock_irqrestore(&ctrl->lock, flags);
+	if (startka)
+		queue_delayed_work(nvme_wq, &ctrl->ka_work, delay);
+	return RQ_END_IO_NONE;
+}
+
+static void nvme_keep_alive_work(struct work_struct *work)
+{
+	struct nvme_ctrl *ctrl = container_of(to_delayed_work(work),
+			struct nvme_ctrl, ka_work);
+	bool comp_seen = ctrl->comp_seen;
+	struct request *rq;
+
+	ctrl->ka_last_check_time = jiffies;
+
+	if ((ctrl->ctratt & NVME_CTRL_ATTR_TBKAS) && comp_seen) {
+		dev_dbg(ctrl->device,
+			"reschedule traffic based keep-alive timer\n");
+		ctrl->comp_seen = false;
+		nvme_queue_keep_alive_work(ctrl);
+		return;
+	}
+
+	rq = blk_mq_alloc_request(ctrl->admin_q, nvme_req_op(&ctrl->ka_cmd),
+				  BLK_MQ_REQ_RESERVED | BLK_MQ_REQ_NOWAIT);
+	if (IS_ERR(rq)) {
+		/* allocation failure, reset the controller */
+		dev_err(ctrl->device, "keep-alive failed: %ld\n", PTR_ERR(rq));
+		nvme_reset_ctrl(ctrl);
+		return;
+	}
+	nvme_init_request(rq, &ctrl->ka_cmd);
+
+	rq->timeout = ctrl->kato * HZ;
+	rq->end_io = nvme_keep_alive_end_io;
+	rq->end_io_data = ctrl;
+	blk_execute_rq_nowait(rq, false);
+}
+
+static void nvme_start_keep_alive(struct nvme_ctrl *ctrl)
+{
+	if (unlikely(ctrl->kato == 0))
+		return;
+
+	nvme_queue_keep_alive_work(ctrl);
+}
+
+void nvme_stop_keep_alive(struct nvme_ctrl *ctrl)
+{
+	if (unlikely(ctrl->kato == 0))
+		return;
+
+	cancel_delayed_work_sync(&ctrl->ka_work);
+}
+EXPORT_SYMBOL_GPL(nvme_stop_keep_alive);
+
+static void nvme_update_keep_alive(struct nvme_ctrl *ctrl,
+				   struct nvme_command *cmd)
+{
+	unsigned int new_kato =
+		DIV_ROUND_UP(le32_to_cpu(cmd->common.cdw11), 1000);
+
+	dev_info(ctrl->device,
+		 "keep alive interval updated from %u ms to %u ms\n",
+		 ctrl->kato * 1000 / 2, new_kato * 1000 / 2);
+
+	nvme_stop_keep_alive(ctrl);
+	ctrl->kato = new_kato;
+	nvme_start_keep_alive(ctrl);
+}
+
+/*
+ * In NVMe 1.0 the CNS field was just a binary controller or namespace
+ * flag, thus sending any new CNS opcodes has a big chance of not working.
+ * Qemu unfortunately had that bug after reporting a 1.1 version compliance
+ * (but not for any later version).
+ */
+static bool nvme_ctrl_limited_cns(struct nvme_ctrl *ctrl)
+{
+	if (ctrl->quirks & NVME_QUIRK_IDENTIFY_CNS)
+		return ctrl->vs < NVME_VS(1, 2, 0);
+	return ctrl->vs < NVME_VS(1, 1, 0);
+}
+
+static int nvme_identify_ctrl(struct nvme_ctrl *dev, struct nvme_id_ctrl **id)
+{
+	struct nvme_command c = { };
+	int error;
+
+	/* gcc-4.4.4 (at least) has issues with initializers and anon unions */
+	c.identify.opcode = nvme_admin_identify;
+	c.identify.cns = NVME_ID_CNS_CTRL;
+
+	*id = kmalloc(sizeof(struct nvme_id_ctrl), GFP_KERNEL);
+	if (!*id)
+		return -ENOMEM;
+
+	error = nvme_submit_sync_cmd(dev->admin_q, &c, *id,
+			sizeof(struct nvme_id_ctrl));
+	if (error)
+		kfree(*id);
+	return error;
+}
+
+static int nvme_process_ns_desc(struct nvme_ctrl *ctrl, struct nvme_ns_ids *ids,
+		struct nvme_ns_id_desc *cur, bool *csi_seen)
+{
+	const char *warn_str = "ctrl returned bogus length:";
+	void *data = cur;
+
+	switch (cur->nidt) {
+	case NVME_NIDT_EUI64:
+		if (cur->nidl != NVME_NIDT_EUI64_LEN) {
+			dev_warn(ctrl->device, "%s %d for NVME_NIDT_EUI64\n",
+				 warn_str, cur->nidl);
+			return -1;
+		}
+		if (ctrl->quirks & NVME_QUIRK_BOGUS_NID)
+			return NVME_NIDT_EUI64_LEN;
+		memcpy(ids->eui64, data + sizeof(*cur), NVME_NIDT_EUI64_LEN);
+		return NVME_NIDT_EUI64_LEN;
+	case NVME_NIDT_NGUID:
+		if (cur->nidl != NVME_NIDT_NGUID_LEN) {
+			dev_warn(ctrl->device, "%s %d for NVME_NIDT_NGUID\n",
+				 warn_str, cur->nidl);
+			return -1;
+		}
+		if (ctrl->quirks & NVME_QUIRK_BOGUS_NID)
+			return NVME_NIDT_NGUID_LEN;
+		memcpy(ids->nguid, data + sizeof(*cur), NVME_NIDT_NGUID_LEN);
+		return NVME_NIDT_NGUID_LEN;
+	case NVME_NIDT_UUID:
+		if (cur->nidl != NVME_NIDT_UUID_LEN) {
+			dev_warn(ctrl->device, "%s %d for NVME_NIDT_UUID\n",
+				 warn_str, cur->nidl);
+			return -1;
+		}
+		if (ctrl->quirks & NVME_QUIRK_BOGUS_NID)
+			return NVME_NIDT_UUID_LEN;
+		uuid_copy(&ids->uuid, data + sizeof(*cur));
+		return NVME_NIDT_UUID_LEN;
+	case NVME_NIDT_CSI:
+		if (cur->nidl != NVME_NIDT_CSI_LEN) {
+			dev_warn(ctrl->device, "%s %d for NVME_NIDT_CSI\n",
+				 warn_str, cur->nidl);
+			return -1;
+		}
+		memcpy(&ids->csi, data + sizeof(*cur), NVME_NIDT_CSI_LEN);
+		*csi_seen = true;
+		return NVME_NIDT_CSI_LEN;
+	default:
+		/* Skip unknown types */
+		return cur->nidl;
+	}
+}
+
+static int nvme_identify_ns_descs(struct nvme_ctrl *ctrl,
+		struct nvme_ns_info *info)
+{
+	struct nvme_command c = { };
+	bool csi_seen = false;
+	int status, pos, len;
+	void *data;
+
+	if (ctrl->vs < NVME_VS(1, 3, 0) && !nvme_multi_css(ctrl))
+		return 0;
+	if (ctrl->quirks & NVME_QUIRK_NO_NS_DESC_LIST)
+		return 0;
+
+	c.identify.opcode = nvme_admin_identify;
+	c.identify.nsid = cpu_to_le32(info->nsid);
+	c.identify.cns = NVME_ID_CNS_NS_DESC_LIST;
+
+	data = kzalloc(NVME_IDENTIFY_DATA_SIZE, GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	status = nvme_submit_sync_cmd(ctrl->admin_q, &c, data,
+				      NVME_IDENTIFY_DATA_SIZE);
+	if (status) {
+		dev_warn(ctrl->device,
+			"Identify Descriptors failed (nsid=%u, status=0x%x)\n",
+			info->nsid, status);
+		goto free_data;
+	}
+
+	for (pos = 0; pos < NVME_IDENTIFY_DATA_SIZE; pos += len) {
+		struct nvme_ns_id_desc *cur = data + pos;
+
+		if (cur->nidl == 0)
+			break;
+
+		len = nvme_process_ns_desc(ctrl, &info->ids, cur, &csi_seen);
+		if (len < 0)
+			break;
+
+		len += sizeof(*cur);
+	}
+
+	if (nvme_multi_css(ctrl) && !csi_seen) {
+		dev_warn(ctrl->device, "Command set not reported for nsid:%d\n",
+			 info->nsid);
+		status = -EINVAL;
+	}
+
+free_data:
+	kfree(data);
+	return status;
+}
+
+static int nvme_identify_ns(struct nvme_ctrl *ctrl, unsigned nsid,
+			struct nvme_id_ns **id)
+{
+	struct nvme_command c = { };
+	int error;
+
+	/* gcc-4.4.4 (at least) has issues with initializers and anon unions */
+	c.identify.opcode = nvme_admin_identify;
+	c.identify.nsid = cpu_to_le32(nsid);
+	c.identify.cns = NVME_ID_CNS_NS;
+
+	*id = kmalloc(sizeof(**id), GFP_KERNEL);
+	if (!*id)
+		return -ENOMEM;
+
+	error = nvme_submit_sync_cmd(ctrl->admin_q, &c, *id, sizeof(**id));
+	if (error) {
+		dev_warn(ctrl->device, "Identify namespace failed (%d)\n", error);
+		kfree(*id);
+	}
+	return error;
+}
+
+static int nvme_ns_info_from_identify(struct nvme_ctrl *ctrl,
+		struct nvme_ns_info *info)
+{
+	struct nvme_ns_ids *ids = &info->ids;
+	struct nvme_id_ns *id;
+	int ret;
+
+	ret = nvme_identify_ns(ctrl, info->nsid, &id);
+	if (ret)
+		return ret;
+
+	if (id->ncap == 0) {
+		/* namespace not allocated or attached */
+		info->is_removed = true;
+		ret = -ENODEV;
+		goto error;
+	}
+
+	info->anagrpid = id->anagrpid;
+	info->is_shared = id->nmic & NVME_NS_NMIC_SHARED;
+	info->is_readonly = id->nsattr & NVME_NS_ATTR_RO;
+	info->is_ready = true;
+	if (ctrl->quirks & NVME_QUIRK_BOGUS_NID) {
+		dev_info(ctrl->device,
+			 "Ignoring bogus Namespace Identifiers\n");
+	} else {
+		if (ctrl->vs >= NVME_VS(1, 1, 0) &&
+		    !memchr_inv(ids->eui64, 0, sizeof(ids->eui64)))
+			memcpy(ids->eui64, id->eui64, sizeof(ids->eui64));
+		if (ctrl->vs >= NVME_VS(1, 2, 0) &&
+		    !memchr_inv(ids->nguid, 0, sizeof(ids->nguid)))
+			memcpy(ids->nguid, id->nguid, sizeof(ids->nguid));
+	}
+
+error:
+	kfree(id);
+	return ret;
+}
+
+static int nvme_ns_info_from_id_cs_indep(struct nvme_ctrl *ctrl,
+		struct nvme_ns_info *info)
+{
+	struct nvme_id_ns_cs_indep *id;
+	struct nvme_command c = {
+		.identify.opcode	= nvme_admin_identify,
+		.identify.nsid		= cpu_to_le32(info->nsid),
+		.identify.cns		= NVME_ID_CNS_NS_CS_INDEP,
+	};
+	int ret;
+
+	id = kmalloc(sizeof(*id), GFP_KERNEL);
+	if (!id)
+		return -ENOMEM;
+
+	ret = nvme_submit_sync_cmd(ctrl->admin_q, &c, id, sizeof(*id));
+	if (!ret) {
+		info->anagrpid = id->anagrpid;
+		info->is_shared = id->nmic & NVME_NS_NMIC_SHARED;
+		info->is_readonly = id->nsattr & NVME_NS_ATTR_RO;
+		info->is_ready = id->nstat & NVME_NSTAT_NRDY;
+	}
+	kfree(id);
+	return ret;
+}
+
+static int nvme_features(struct nvme_ctrl *dev, u8 op, unsigned int fid,
+		unsigned int dword11, void *buffer, size_t buflen, u32 *result)
+{
+	union nvme_result res = { 0 };
+	struct nvme_command c = { };
+	int ret;
+
+	c.features.opcode = op;
+	c.features.fid = cpu_to_le32(fid);
+	c.features.dword11 = cpu_to_le32(dword11);
+
+	ret = __nvme_submit_sync_cmd(dev->admin_q, &c, &res,
+			buffer, buflen, NVME_QID_ANY, 0, 0);
+	if (ret >= 0 && result)
+		*result = le32_to_cpu(res.u32);
+	return ret;
+}
+
+int nvme_set_features(struct nvme_ctrl *dev, unsigned int fid,
+		      unsigned int dword11, void *buffer, size_t buflen,
+		      u32 *result)
+{
+	return nvme_features(dev, nvme_admin_set_features, fid, dword11, buffer,
+			     buflen, result);
+}
+EXPORT_SYMBOL_GPL(nvme_set_features);
+
+int nvme_get_features(struct nvme_ctrl *dev, unsigned int fid,
+		      unsigned int dword11, void *buffer, size_t buflen,
+		      u32 *result)
+{
+	return nvme_features(dev, nvme_admin_get_features, fid, dword11, buffer,
+			     buflen, result);
+}
+EXPORT_SYMBOL_GPL(nvme_get_features);
+
+int nvme_set_queue_count(struct nvme_ctrl *ctrl, int *count)
+{
+	u32 q_count = (*count - 1) | ((*count - 1) << 16);
+	u32 result;
+	int status, nr_io_queues;
+
+	status = nvme_set_features(ctrl, NVME_FEAT_NUM_QUEUES, q_count, NULL, 0,
+			&result);
+	if (status < 0)
+		return status;
+
+	/*
+	 * Degraded controllers might return an error when setting the queue
+	 * count.  We still want to be able to bring them online and offer
+	 * access to the admin queue, as that might be only way to fix them up.
+	 */
+	if (status > 0) {
+		dev_err(ctrl->device, "Could not set queue count (%d)\n", status);
+		*count = 0;
+	} else {
+		nr_io_queues = min(result & 0xffff, result >> 16) + 1;
+		*count = min(*count, nr_io_queues);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nvme_set_queue_count);
+
+#define NVME_AEN_SUPPORTED \
+	(NVME_AEN_CFG_NS_ATTR | NVME_AEN_CFG_FW_ACT | \
+	 NVME_AEN_CFG_ANA_CHANGE | NVME_AEN_CFG_DISC_CHANGE)
+
+static void nvme_enable_aen(struct nvme_ctrl *ctrl)
+{
+	u32 result, supported_aens = ctrl->oaes & NVME_AEN_SUPPORTED;
+	int status;
+
+	if (!supported_aens)
+		return;
+
+	status = nvme_set_features(ctrl, NVME_FEAT_ASYNC_EVENT, supported_aens,
+			NULL, 0, &result);
+	if (status)
+		dev_warn(ctrl->device, "Failed to configure AEN (cfg %x)\n",
+			 supported_aens);
+
+	queue_work(nvme_wq, &ctrl->async_event_work);
+}
+
+static int nvme_ns_open(struct nvme_ns *ns)
+{
+
+	/* should never be called due to GENHD_FL_HIDDEN */
+	if (WARN_ON_ONCE(nvme_ns_head_multipath(ns->head)))
+		goto fail;
+	if (!nvme_get_ns(ns))
+		goto fail;
+	if (!try_module_get(ns->ctrl->ops->module))
+		goto fail_put_ns;
+
+	return 0;
+
+fail_put_ns:
+	nvme_put_ns(ns);
+fail:
+	return -ENXIO;
+}
+
+static void nvme_ns_release(struct nvme_ns *ns)
+{
+
+	module_put(ns->ctrl->ops->module);
+	nvme_put_ns(ns);
+}
+
+static int nvme_open(struct block_device *bdev, fmode_t mode)
+{
+	return nvme_ns_open(bdev->bd_disk->private_data);
+}
+
+static void nvme_release(struct gendisk *disk, fmode_t mode)
+{
+	nvme_ns_release(disk->private_data);
+}
+
+int nvme_getgeo(struct block_device *bdev, struct hd_geometry *geo)
+{
+	/* some standard values */
+	geo->heads = 1 << 6;
+	geo->sectors = 1 << 5;
+	geo->cylinders = get_capacity(bdev->bd_disk) >> 11;
+	return 0;
+}
+
+#ifdef CONFIG_BLK_DEV_INTEGRITY
+static void nvme_init_integrity(struct gendisk *disk, struct nvme_ns *ns,
+				u32 max_integrity_segments)
+{
+	struct blk_integrity integrity = { };
+
+	switch (ns->pi_type) {
+	case NVME_NS_DPS_PI_TYPE3:
+		switch (ns->guard_type) {
+		case NVME_NVM_NS_16B_GUARD:
+			integrity.profile = &t10_pi_type3_crc;
+			integrity.tag_size = sizeof(u16) + sizeof(u32);
+			integrity.flags |= BLK_INTEGRITY_DEVICE_CAPABLE;
+			break;
+		case NVME_NVM_NS_64B_GUARD:
+			integrity.profile = &ext_pi_type3_crc64;
+			integrity.tag_size = sizeof(u16) + 6;
+			integrity.flags |= BLK_INTEGRITY_DEVICE_CAPABLE;
+			break;
+		default:
+			integrity.profile = NULL;
+			break;
+		}
+		break;
+	case NVME_NS_DPS_PI_TYPE1:
+	case NVME_NS_DPS_PI_TYPE2:
+		switch (ns->guard_type) {
+		case NVME_NVM_NS_16B_GUARD:
+			integrity.profile = &t10_pi_type1_crc;
+			integrity.tag_size = sizeof(u16);
+			integrity.flags |= BLK_INTEGRITY_DEVICE_CAPABLE;
+			break;
+		case NVME_NVM_NS_64B_GUARD:
+			integrity.profile = &ext_pi_type1_crc64;
+			integrity.tag_size = sizeof(u16);
+			integrity.flags |= BLK_INTEGRITY_DEVICE_CAPABLE;
+			break;
+		default:
+			integrity.profile = NULL;
+			break;
+		}
+		break;
+	default:
+		integrity.profile = NULL;
+		break;
+	}
+
+	integrity.tuple_size = ns->ms;
+	blk_integrity_register(disk, &integrity);
+	blk_queue_max_integrity_segments(disk->queue, max_integrity_segments);
+}
+#else
+static void nvme_init_integrity(struct gendisk *disk, struct nvme_ns *ns,
+				u32 max_integrity_segments)
+{
+}
+#endif /* CONFIG_BLK_DEV_INTEGRITY */
+
+static void nvme_config_discard(struct gendisk *disk, struct nvme_ns *ns)
+{
+	struct nvme_ctrl *ctrl = ns->ctrl;
+	struct request_queue *queue = disk->queue;
+	u32 size = queue_logical_block_size(queue);
+
+	if (ctrl->dmrsl && ctrl->dmrsl <= nvme_sect_to_lba(ns, UINT_MAX))
+		ctrl->max_discard_sectors = nvme_lba_to_sect(ns, ctrl->dmrsl);
+
+	if (ctrl->max_discard_sectors == 0) {
+		blk_queue_max_discard_sectors(queue, 0);
+		return;
+	}
+
+	BUILD_BUG_ON(PAGE_SIZE / sizeof(struct nvme_dsm_range) <
+			NVME_DSM_MAX_RANGES);
+
+	queue->limits.discard_granularity = size;
+
+	/* If discard is already enabled, don't reset queue limits */
+	if (queue->limits.max_discard_sectors)
+		return;
+
+	blk_queue_max_discard_sectors(queue, ctrl->max_discard_sectors);
+	blk_queue_max_discard_segments(queue, ctrl->max_discard_segments);
+
+	if (ctrl->quirks & NVME_QUIRK_DEALLOCATE_ZEROES)
+		blk_queue_max_write_zeroes_sectors(queue, UINT_MAX);
+}
+
+static bool nvme_ns_ids_equal(struct nvme_ns_ids *a, struct nvme_ns_ids *b)
+{
+	return uuid_equal(&a->uuid, &b->uuid) &&
+		memcmp(&a->nguid, &b->nguid, sizeof(a->nguid)) == 0 &&
+		memcmp(&a->eui64, &b->eui64, sizeof(a->eui64)) == 0 &&
+		a->csi == b->csi;
+}
+
+static int nvme_init_ms(struct nvme_ns *ns, struct nvme_id_ns *id)
+{
+	bool first = id->dps & NVME_NS_DPS_PI_FIRST;
+	unsigned lbaf = nvme_lbaf_index(id->flbas);
+	struct nvme_ctrl *ctrl = ns->ctrl;
+	struct nvme_command c = { };
+	struct nvme_id_ns_nvm *nvm;
+	int ret = 0;
+	u32 elbaf;
+
+	ns->pi_size = 0;
+	ns->ms = le16_to_cpu(id->lbaf[lbaf].ms);
+	if (!(ctrl->ctratt & NVME_CTRL_ATTR_ELBAS)) {
+		ns->pi_size = sizeof(struct t10_pi_tuple);
+		ns->guard_type = NVME_NVM_NS_16B_GUARD;
+		goto set_pi;
+	}
+
+	nvm = kzalloc(sizeof(*nvm), GFP_KERNEL);
+	if (!nvm)
+		return -ENOMEM;
+
+	c.identify.opcode = nvme_admin_identify;
+	c.identify.nsid = cpu_to_le32(ns->head->ns_id);
+	c.identify.cns = NVME_ID_CNS_CS_NS;
+	c.identify.csi = NVME_CSI_NVM;
+
+	ret = nvme_submit_sync_cmd(ns->ctrl->admin_q, &c, nvm, sizeof(*nvm));
+	if (ret)
+		goto free_data;
+
+	elbaf = le32_to_cpu(nvm->elbaf[lbaf]);
+
+	/* no support for storage tag formats right now */
+	if (nvme_elbaf_sts(elbaf))
+		goto free_data;
+
+	ns->guard_type = nvme_elbaf_guard_type(elbaf);
+	switch (ns->guard_type) {
+	case NVME_NVM_NS_64B_GUARD:
+		ns->pi_size = sizeof(struct crc64_pi_tuple);
+		break;
+	case NVME_NVM_NS_16B_GUARD:
+		ns->pi_size = sizeof(struct t10_pi_tuple);
+		break;
+	default:
+		break;
+	}
+
+free_data:
+	kfree(nvm);
+set_pi:
+	if (ns->pi_size && (first || ns->ms == ns->pi_size))
+		ns->pi_type = id->dps & NVME_NS_DPS_PI_MASK;
+	else
+		ns->pi_type = 0;
+
+	return ret;
+}
+
+static int nvme_configure_metadata(struct nvme_ns *ns, struct nvme_id_ns *id)
+{
+	struct nvme_ctrl *ctrl = ns->ctrl;
+	int ret;
+
+	ret = nvme_init_ms(ns, id);
+	if (ret)
+		return ret;
+
+	ns->features &= ~(NVME_NS_METADATA_SUPPORTED | NVME_NS_EXT_LBAS);
+	if (!ns->ms || !(ctrl->ops->flags & NVME_F_METADATA_SUPPORTED))
+		return 0;
+
+	if (ctrl->ops->flags & NVME_F_FABRICS) {
+		/*
+		 * The NVMe over Fabrics specification only supports metadata as
+		 * part of the extended data LBA.  We rely on HCA/HBA support to
+		 * remap the separate metadata buffer from the block layer.
+		 */
+		if (WARN_ON_ONCE(!(id->flbas & NVME_NS_FLBAS_META_EXT)))
+			return 0;
+
+		ns->features |= NVME_NS_EXT_LBAS;
+
+		/*
+		 * The current fabrics transport drivers support namespace
+		 * metadata formats only if nvme_ns_has_pi() returns true.
+		 * Suppress support for all other formats so the namespace will
+		 * have a 0 capacity and not be usable through the block stack.
+		 *
+		 * Note, this check will need to be modified if any drivers
+		 * gain the ability to use other metadata formats.
+		 */
+		if (ctrl->max_integrity_segments && nvme_ns_has_pi(ns))
+			ns->features |= NVME_NS_METADATA_SUPPORTED;
+	} else {
+		/*
+		 * For PCIe controllers, we can't easily remap the separate
+		 * metadata buffer from the block layer and thus require a
+		 * separate metadata buffer for block layer metadata/PI support.
+		 * We allow extended LBAs for the passthrough interface, though.
+		 */
+		if (id->flbas & NVME_NS_FLBAS_META_EXT)
+			ns->features |= NVME_NS_EXT_LBAS;
+		else
+			ns->features |= NVME_NS_METADATA_SUPPORTED;
+	}
+	return 0;
+}
+
+static void nvme_set_queue_limits(struct nvme_ctrl *ctrl,
+		struct request_queue *q)
+{
+	bool vwc = ctrl->vwc & NVME_CTRL_VWC_PRESENT;
+
+	if (ctrl->max_hw_sectors) {
+		u32 max_segments =
+			(ctrl->max_hw_sectors / (NVME_CTRL_PAGE_SIZE >> 9)) + 1;
+
+		max_segments = min_not_zero(max_segments, ctrl->max_segments);
+		blk_queue_max_hw_sectors(q, ctrl->max_hw_sectors);
+		blk_queue_max_segments(q, min_t(u32, max_segments, USHRT_MAX));
+	}
+	blk_queue_virt_boundary(q, NVME_CTRL_PAGE_SIZE - 1);
+	blk_queue_dma_alignment(q, 3);
+	blk_queue_write_cache(q, vwc, vwc);
+}
+
+static void nvme_update_disk_info(struct gendisk *disk,
+		struct nvme_ns *ns, struct nvme_id_ns *id)
+{
+	sector_t capacity = nvme_lba_to_sect(ns, le64_to_cpu(id->nsze));
+	unsigned short bs = 1 << ns->lba_shift;
+	u32 atomic_bs, phys_bs, io_opt = 0;
+
+	/*
+	 * The block layer can't support LBA sizes larger than the page size
+	 * or smaller than a sector size yet, so catch this early and don't
+	 * allow block I/O.
+	 */
+	if (ns->lba_shift > PAGE_SHIFT || ns->lba_shift < SECTOR_SHIFT) {
+		capacity = 0;
+		bs = (1 << 9);
+	}
+
+	blk_integrity_unregister(disk);
+
+	atomic_bs = phys_bs = bs;
+	if (id->nabo == 0) {
+		/*
+		 * Bit 1 indicates whether NAWUPF is defined for this namespace
+		 * and whether it should be used instead of AWUPF. If NAWUPF ==
+		 * 0 then AWUPF must be used instead.
+		 */
+		if (id->nsfeat & NVME_NS_FEAT_ATOMICS && id->nawupf)
+			atomic_bs = (1 + le16_to_cpu(id->nawupf)) * bs;
+		else
+			atomic_bs = (1 + ns->ctrl->subsys->awupf) * bs;
+	}
+
+	if (id->nsfeat & NVME_NS_FEAT_IO_OPT) {
+		/* NPWG = Namespace Preferred Write Granularity */
+		phys_bs = bs * (1 + le16_to_cpu(id->npwg));
+		/* NOWS = Namespace Optimal Write Size */
+		io_opt = bs * (1 + le16_to_cpu(id->nows));
+	}
+
+	blk_queue_logical_block_size(disk->queue, bs);
+	/*
+	 * Linux filesystems assume writing a single physical block is
+	 * an atomic operation. Hence limit the physical block size to the
+	 * value of the Atomic Write Unit Power Fail parameter.
+	 */
+	blk_queue_physical_block_size(disk->queue, min(phys_bs, atomic_bs));
+	blk_queue_io_min(disk->queue, phys_bs);
+	blk_queue_io_opt(disk->queue, io_opt);
+
+	/*
+	 * Register a metadata profile for PI, or the plain non-integrity NVMe
+	 * metadata masquerading as Type 0 if supported, otherwise reject block
+	 * I/O to namespaces with metadata except when the namespace supports
+	 * PI, as it can strip/insert in that case.
+	 */
+	if (ns->ms) {
+		if (IS_ENABLED(CONFIG_BLK_DEV_INTEGRITY) &&
+		    (ns->features & NVME_NS_METADATA_SUPPORTED))
+			nvme_init_integrity(disk, ns,
+					    ns->ctrl->max_integrity_segments);
+		else if (!nvme_ns_has_pi(ns))
+			capacity = 0;
+	}
+
+	set_capacity_and_notify(disk, capacity);
+
+	nvme_config_discard(disk, ns);
+	blk_queue_max_write_zeroes_sectors(disk->queue,
+					   ns->ctrl->max_zeroes_sectors);
+}
+
+static bool nvme_ns_is_readonly(struct nvme_ns *ns, struct nvme_ns_info *info)
+{
+	return info->is_readonly || test_bit(NVME_NS_FORCE_RO, &ns->flags);
+}
+
+static inline bool nvme_first_scan(struct gendisk *disk)
+{
+	/* nvme_alloc_ns() scans the disk prior to adding it */
+	return !disk_live(disk);
+}
+
+static void nvme_set_chunk_sectors(struct nvme_ns *ns, struct nvme_id_ns *id)
+{
+	struct nvme_ctrl *ctrl = ns->ctrl;
+	u32 iob;
+
+	if ((ctrl->quirks & NVME_QUIRK_STRIPE_SIZE) &&
+	    is_power_of_2(ctrl->max_hw_sectors))
+		iob = ctrl->max_hw_sectors;
+	else
+		iob = nvme_lba_to_sect(ns, le16_to_cpu(id->noiob));
+
+	if (!iob)
+		return;
+
+	if (!is_power_of_2(iob)) {
+		if (nvme_first_scan(ns->disk))
+			pr_warn("%s: ignoring unaligned IO boundary:%u\n",
+				ns->disk->disk_name, iob);
+		return;
+	}
+
+	if (blk_queue_is_zoned(ns->disk->queue)) {
+		if (nvme_first_scan(ns->disk))
+			pr_warn("%s: ignoring zoned namespace IO boundary\n",
+				ns->disk->disk_name);
+		return;
+	}
+
+	blk_queue_chunk_sectors(ns->queue, iob);
+}
+
+static int nvme_update_ns_info_generic(struct nvme_ns *ns,
+		struct nvme_ns_info *info)
+{
+	blk_mq_freeze_queue(ns->disk->queue);
+	nvme_set_queue_limits(ns->ctrl, ns->queue);
+	set_disk_ro(ns->disk, nvme_ns_is_readonly(ns, info));
+	blk_mq_unfreeze_queue(ns->disk->queue);
+
+	if (nvme_ns_head_multipath(ns->head)) {
+		blk_mq_freeze_queue(ns->head->disk->queue);
+		set_disk_ro(ns->head->disk, nvme_ns_is_readonly(ns, info));
+		nvme_mpath_revalidate_paths(ns);
+		blk_stack_limits(&ns->head->disk->queue->limits,
+				 &ns->queue->limits, 0);
+		ns->head->disk->flags |= GENHD_FL_HIDDEN;
+		blk_mq_unfreeze_queue(ns->head->disk->queue);
+	}
+
+	/* Hide the block-interface for these devices */
+	ns->disk->flags |= GENHD_FL_HIDDEN;
+	set_bit(NVME_NS_READY, &ns->flags);
+
+	return 0;
+}
+
+static int nvme_update_ns_info_block(struct nvme_ns *ns,
+		struct nvme_ns_info *info)
+{
+	struct nvme_id_ns *id;
+	unsigned lbaf;
+	int ret;
+
+	ret = nvme_identify_ns(ns->ctrl, info->nsid, &id);
+	if (ret)
+		return ret;
+
+	if (id->ncap == 0) {
+		/* namespace not allocated or attached */
+		info->is_removed = true;
+		ret = -ENODEV;
+		goto error;
+	}
+
+	blk_mq_freeze_queue(ns->disk->queue);
+	lbaf = nvme_lbaf_index(id->flbas);
+	ns->lba_shift = id->lbaf[lbaf].ds;
+	nvme_set_queue_limits(ns->ctrl, ns->queue);
+
+	ret = nvme_configure_metadata(ns, id);
+	if (ret < 0) {
+		blk_mq_unfreeze_queue(ns->disk->queue);
+		goto out;
+	}
+	nvme_set_chunk_sectors(ns, id);
+	nvme_update_disk_info(ns->disk, ns, id);
+
+	if (ns->head->ids.csi == NVME_CSI_ZNS) {
+		ret = nvme_update_zone_info(ns, lbaf);
+		if (ret) {
+			blk_mq_unfreeze_queue(ns->disk->queue);
+			goto out;
+		}
+	}
+
+	set_disk_ro(ns->disk, nvme_ns_is_readonly(ns, info));
+	set_bit(NVME_NS_READY, &ns->flags);
+	blk_mq_unfreeze_queue(ns->disk->queue);
+
+	if (blk_queue_is_zoned(ns->queue)) {
+		ret = nvme_revalidate_zones(ns);
+		if (ret && !nvme_first_scan(ns->disk))
+			goto out;
+	}
+
+	if (nvme_ns_head_multipath(ns->head)) {
+		blk_mq_freeze_queue(ns->head->disk->queue);
+		nvme_update_disk_info(ns->head->disk, ns, id);
+		set_disk_ro(ns->head->disk, nvme_ns_is_readonly(ns, info));
+		nvme_mpath_revalidate_paths(ns);
+		blk_stack_limits(&ns->head->disk->queue->limits,
+				 &ns->queue->limits, 0);
+		disk_update_readahead(ns->head->disk);
+		blk_mq_unfreeze_queue(ns->head->disk->queue);
+	}
+
+	ret = 0;
+out:
+	/*
+	 * If probing fails due an unsupported feature, hide the block device,
+	 * but still allow other access.
+	 */
+	if (ret == -ENODEV) {
+		ns->disk->flags |= GENHD_FL_HIDDEN;
+		set_bit(NVME_NS_READY, &ns->flags);
+		ret = 0;
+	}
+
+error:
+	kfree(id);
+	return ret;
+}
+
+static int nvme_update_ns_info(struct nvme_ns *ns, struct nvme_ns_info *info)
+{
+	switch (info->ids.csi) {
+	case NVME_CSI_ZNS:
+		if (!IS_ENABLED(CONFIG_BLK_DEV_ZONED)) {
+			dev_info(ns->ctrl->device,
+	"block device for nsid %u not supported without CONFIG_BLK_DEV_ZONED\n",
+				info->nsid);
+			return nvme_update_ns_info_generic(ns, info);
+		}
+		return nvme_update_ns_info_block(ns, info);
+	case NVME_CSI_NVM:
+		return nvme_update_ns_info_block(ns, info);
+	default:
+		dev_info(ns->ctrl->device,
+			"block device for nsid %u not supported (csi %u)\n",
+			info->nsid, info->ids.csi);
+		return nvme_update_ns_info_generic(ns, info);
+	}
+}
+
+static char nvme_pr_type(enum pr_type type)
+{
+	switch (type) {
+	case PR_WRITE_EXCLUSIVE:
+		return 1;
+	case PR_EXCLUSIVE_ACCESS:
+		return 2;
+	case PR_WRITE_EXCLUSIVE_REG_ONLY:
+		return 3;
+	case PR_EXCLUSIVE_ACCESS_REG_ONLY:
+		return 4;
+	case PR_WRITE_EXCLUSIVE_ALL_REGS:
+		return 5;
+	case PR_EXCLUSIVE_ACCESS_ALL_REGS:
+		return 6;
+	default:
+		return 0;
+	}
+}
+
+static int nvme_send_ns_head_pr_command(struct block_device *bdev,
+		struct nvme_command *c, u8 data[16])
+{
+	struct nvme_ns_head *head = bdev->bd_disk->private_data;
+	int srcu_idx = srcu_read_lock(&head->srcu);
+	struct nvme_ns *ns = nvme_find_path(head);
+	int ret = -EWOULDBLOCK;
+
+	if (ns) {
+		c->common.nsid = cpu_to_le32(ns->head->ns_id);
+		ret = nvme_submit_sync_cmd(ns->queue, c, data, 16);
+	}
+	srcu_read_unlock(&head->srcu, srcu_idx);
+	return ret;
+}
+	
+static int nvme_send_ns_pr_command(struct nvme_ns *ns, struct nvme_command *c,
+		u8 data[16])
+{
+	c->common.nsid = cpu_to_le32(ns->head->ns_id);
+	return nvme_submit_sync_cmd(ns->queue, c, data, 16);
+}
+
+static int nvme_pr_command(struct block_device *bdev, u32 cdw10,
+				u64 key, u64 sa_key, u8 op)
+{
+	struct nvme_command c = { };
+	u8 data[16] = { 0, };
+
+	put_unaligned_le64(key, &data[0]);
+	put_unaligned_le64(sa_key, &data[8]);
+
+	c.common.opcode = op;
+	c.common.cdw10 = cpu_to_le32(cdw10);
+
+	if (IS_ENABLED(CONFIG_NVME_MULTIPATH) &&
+	    bdev->bd_disk->fops == &nvme_ns_head_ops)
+		return nvme_send_ns_head_pr_command(bdev, &c, data);
+	return nvme_send_ns_pr_command(bdev->bd_disk->private_data, &c, data);
+}
+
+static int nvme_pr_register(struct block_device *bdev, u64 old,
+		u64 new, unsigned flags)
+{
+	u32 cdw10;
+
+	if (flags & ~PR_FL_IGNORE_KEY)
+		return -EOPNOTSUPP;
+
+	cdw10 = old ? 2 : 0;
+	cdw10 |= (flags & PR_FL_IGNORE_KEY) ? 1 << 3 : 0;
+	cdw10 |= (1 << 30) | (1 << 31); /* PTPL=1 */
+	return nvme_pr_command(bdev, cdw10, old, new, nvme_cmd_resv_register);
+}
+
+static int nvme_pr_reserve(struct block_device *bdev, u64 key,
+		enum pr_type type, unsigned flags)
+{
+	u32 cdw10;
+
+	if (flags & ~PR_FL_IGNORE_KEY)
+		return -EOPNOTSUPP;
+
+	cdw10 = nvme_pr_type(type) << 8;
+	cdw10 |= ((flags & PR_FL_IGNORE_KEY) ? 1 << 3 : 0);
+	return nvme_pr_command(bdev, cdw10, key, 0, nvme_cmd_resv_acquire);
+}
+
+static int nvme_pr_preempt(struct block_device *bdev, u64 old, u64 new,
+		enum pr_type type, bool abort)
+{
+	u32 cdw10 = nvme_pr_type(type) << 8 | (abort ? 2 : 1);
+
+	return nvme_pr_command(bdev, cdw10, old, new, nvme_cmd_resv_acquire);
+}
+
+static int nvme_pr_clear(struct block_device *bdev, u64 key)
+{
+	u32 cdw10 = 1 | (key ? 0 : 1 << 3);
+
+	return nvme_pr_command(bdev, cdw10, key, 0, nvme_cmd_resv_release);
+}
+
+static int nvme_pr_release(struct block_device *bdev, u64 key, enum pr_type type)
+{
+	u32 cdw10 = nvme_pr_type(type) << 8 | (key ? 0 : 1 << 3);
+
+	return nvme_pr_command(bdev, cdw10, key, 0, nvme_cmd_resv_release);
+}
+
+const struct pr_ops nvme_pr_ops = {
+	.pr_register	= nvme_pr_register,
+	.pr_reserve	= nvme_pr_reserve,
+	.pr_release	= nvme_pr_release,
+	.pr_preempt	= nvme_pr_preempt,
+	.pr_clear	= nvme_pr_clear,
+};
+
+#ifdef CONFIG_BLK_SED_OPAL
+int nvme_sec_submit(void *data, u16 spsp, u8 secp, void *buffer, size_t len,
+		bool send)
+{
+	struct nvme_ctrl *ctrl = data;
+	struct nvme_command cmd = { };
+
+	if (send)
+		cmd.common.opcode = nvme_admin_security_send;
+	else
+		cmd.common.opcode = nvme_admin_security_recv;
+	cmd.common.nsid = 0;
+	cmd.common.cdw10 = cpu_to_le32(((u32)secp) << 24 | ((u32)spsp) << 8);
+	cmd.common.cdw11 = cpu_to_le32(len);
+
+	return __nvme_submit_sync_cmd(ctrl->admin_q, &cmd, NULL, buffer, len,
+			NVME_QID_ANY, 1, 0);
+}
+EXPORT_SYMBOL_GPL(nvme_sec_submit);
+#endif /* CONFIG_BLK_SED_OPAL */
+
+#ifdef CONFIG_BLK_DEV_ZONED
+static int nvme_report_zones(struct gendisk *disk, sector_t sector,
+		unsigned int nr_zones, report_zones_cb cb, void *data)
+{
+	return nvme_ns_report_zones(disk->private_data, sector, nr_zones, cb,
+			data);
+}
+#else
+#define nvme_report_zones	NULL
+#endif /* CONFIG_BLK_DEV_ZONED */
+
+static const struct block_device_operations nvme_bdev_ops = {
+	.owner		= THIS_MODULE,
+	.ioctl		= nvme_ioctl,
+	.compat_ioctl	= blkdev_compat_ptr_ioctl,
+	.open		= nvme_open,
+	.release	= nvme_release,
+	.getgeo		= nvme_getgeo,
+	.report_zones	= nvme_report_zones,
+	.pr_ops		= &nvme_pr_ops,
+};
+
+static int nvme_wait_ready(struct nvme_ctrl *ctrl, u32 timeout, bool enabled)
+{
+	unsigned long timeout_jiffies = ((timeout + 1) * HZ / 2) + jiffies;
+	u32 csts, bit = enabled ? NVME_CSTS_RDY : 0;
+	int ret;
+
+	while ((ret = ctrl->ops->reg_read32(ctrl, NVME_REG_CSTS, &csts)) == 0) {
+		if (csts == ~0)
+			return -ENODEV;
+		if ((csts & NVME_CSTS_RDY) == bit)
+			break;
+
+		usleep_range(1000, 2000);
+		if (fatal_signal_pending(current))
+			return -EINTR;
+		if (time_after(jiffies, timeout_jiffies)) {
+			dev_err(ctrl->device,
+				"Device not ready; aborting %s, CSTS=0x%x\n",
+				enabled ? "initialisation" : "reset", csts);
+			return -ENODEV;
+		}
+	}
+
+	return ret;
+}
+
+/*
+ * If the device has been passed off to us in an enabled state, just clear
+ * the enabled bit.  The spec says we should set the 'shutdown notification
+ * bits', but doing so may cause the device to complete commands to the
+ * admin queue ... and we don't know what memory that might be pointing at!
+ */
+int nvme_disable_ctrl(struct nvme_ctrl *ctrl)
+{
+	int ret;
+
+	ctrl->ctrl_config &= ~NVME_CC_SHN_MASK;
+	ctrl->ctrl_config &= ~NVME_CC_ENABLE;
+
+	ret = ctrl->ops->reg_write32(ctrl, NVME_REG_CC, ctrl->ctrl_config);
+	if (ret)
+		return ret;
+
+	if (ctrl->quirks & NVME_QUIRK_DELAY_BEFORE_CHK_RDY)
+		msleep(NVME_QUIRK_DELAY_AMOUNT);
+
+	return nvme_wait_ready(ctrl, NVME_CAP_TIMEOUT(ctrl->cap), false);
+}
+EXPORT_SYMBOL_GPL(nvme_disable_ctrl);
+
+int nvme_enable_ctrl(struct nvme_ctrl *ctrl)
+{
+	unsigned dev_page_min;
+	u32 timeout;
+	int ret;
+
+	ret = ctrl->ops->reg_read64(ctrl, NVME_REG_CAP, &ctrl->cap);
+	if (ret) {
+		dev_err(ctrl->device, "Reading CAP failed (%d)\n", ret);
+		return ret;
+	}
+	dev_page_min = NVME_CAP_MPSMIN(ctrl->cap) + 12;
+
+	if (NVME_CTRL_PAGE_SHIFT < dev_page_min) {
+		dev_err(ctrl->device,
+			"Minimum device page size %u too large for host (%u)\n",
+			1 << dev_page_min, 1 << NVME_CTRL_PAGE_SHIFT);
+		return -ENODEV;
+	}
+
+	if (NVME_CAP_CSS(ctrl->cap) & NVME_CAP_CSS_CSI)
+		ctrl->ctrl_config = NVME_CC_CSS_CSI;
+	else
+		ctrl->ctrl_config = NVME_CC_CSS_NVM;
+
+	if (ctrl->cap & NVME_CAP_CRMS_CRWMS && ctrl->cap & NVME_CAP_CRMS_CRIMS)
+		ctrl->ctrl_config |= NVME_CC_CRIME;
+
+	ctrl->ctrl_config |= (NVME_CTRL_PAGE_SHIFT - 12) << NVME_CC_MPS_SHIFT;
+	ctrl->ctrl_config |= NVME_CC_AMS_RR | NVME_CC_SHN_NONE;
+	ctrl->ctrl_config |= NVME_CC_IOSQES | NVME_CC_IOCQES;
+	ret = ctrl->ops->reg_write32(ctrl, NVME_REG_CC, ctrl->ctrl_config);
+	if (ret)
+		return ret;
+
+	/* Flush write to device (required if transport is PCI) */
+	ret = ctrl->ops->reg_read32(ctrl, NVME_REG_CC, &ctrl->ctrl_config);
+	if (ret)
+		return ret;
+
+	/* CAP value may change after initial CC write */
+	ret = ctrl->ops->reg_read64(ctrl, NVME_REG_CAP, &ctrl->cap);
+	if (ret)
+		return ret;
+
+	timeout = NVME_CAP_TIMEOUT(ctrl->cap);
+	if (ctrl->cap & NVME_CAP_CRMS_CRWMS) {
+		u32 crto, ready_timeout;
+
+		ret = ctrl->ops->reg_read32(ctrl, NVME_REG_CRTO, &crto);
+		if (ret) {
+			dev_err(ctrl->device, "Reading CRTO failed (%d)\n",
+				ret);
+			return ret;
+		}
+
+		/*
+		 * CRTO should always be greater or equal to CAP.TO, but some
+		 * devices are known to get this wrong. Use the larger of the
+		 * two values.
+		 */
+		if (ctrl->ctrl_config & NVME_CC_CRIME)
+			ready_timeout = NVME_CRTO_CRIMT(crto);
+		else
+			ready_timeout = NVME_CRTO_CRWMT(crto);
+
+		if (ready_timeout < timeout)
+			dev_warn_once(ctrl->device, "bad crto:%x cap:%llx\n",
+				      crto, ctrl->cap);
+		else
+			timeout = ready_timeout;
+	}
+
+	ctrl->ctrl_config |= NVME_CC_ENABLE;
+	ret = ctrl->ops->reg_write32(ctrl, NVME_REG_CC, ctrl->ctrl_config);
+	if (ret)
+		return ret;
+	return nvme_wait_ready(ctrl, timeout, true);
+}
+EXPORT_SYMBOL_GPL(nvme_enable_ctrl);
+
+int nvme_shutdown_ctrl(struct nvme_ctrl *ctrl)
+{
+	unsigned long timeout = jiffies + (ctrl->shutdown_timeout * HZ);
+	u32 csts;
+	int ret;
+
+	ctrl->ctrl_config &= ~NVME_CC_SHN_MASK;
+	ctrl->ctrl_config |= NVME_CC_SHN_NORMAL;
+
+	ret = ctrl->ops->reg_write32(ctrl, NVME_REG_CC, ctrl->ctrl_config);
+	if (ret)
+		return ret;
+
+	while ((ret = ctrl->ops->reg_read32(ctrl, NVME_REG_CSTS, &csts)) == 0) {
+		if ((csts & NVME_CSTS_SHST_MASK) == NVME_CSTS_SHST_CMPLT)
+			break;
+
+		msleep(100);
+		if (fatal_signal_pending(current))
+			return -EINTR;
+		if (time_after(jiffies, timeout)) {
+			dev_err(ctrl->device,
+				"Device shutdown incomplete; abort shutdown\n");
+			return -ENODEV;
+		}
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(nvme_shutdown_ctrl);
+
+static int nvme_configure_timestamp(struct nvme_ctrl *ctrl)
+{
+	__le64 ts;
+	int ret;
+
+	if (!(ctrl->oncs & NVME_CTRL_ONCS_TIMESTAMP))
+		return 0;
+
+	ts = cpu_to_le64(ktime_to_ms(ktime_get_real()));
+	ret = nvme_set_features(ctrl, NVME_FEAT_TIMESTAMP, 0, &ts, sizeof(ts),
+			NULL);
+	if (ret)
+		dev_warn_once(ctrl->device,
+			"could not set timestamp (%d)\n", ret);
+	return ret;
+}
+
+static int nvme_configure_host_options(struct nvme_ctrl *ctrl)
+{
+	struct nvme_feat_host_behavior *host;
+	u8 acre = 0, lbafee = 0;
+	int ret;
+
+	/* Don't bother enabling the feature if retry delay is not reported */
+	if (ctrl->crdt[0])
+		acre = NVME_ENABLE_ACRE;
+	if (ctrl->ctratt & NVME_CTRL_ATTR_ELBAS)
+		lbafee = NVME_ENABLE_LBAFEE;
+
+	if (!acre && !lbafee)
+		return 0;
+
+	host = kzalloc(sizeof(*host), GFP_KERNEL);
+	if (!host)
+		return 0;
+
+	host->acre = acre;
+	host->lbafee = lbafee;
+	ret = nvme_set_features(ctrl, NVME_FEAT_HOST_BEHAVIOR, 0,
+				host, sizeof(*host), NULL);
+	kfree(host);
+	return ret;
+}
+
+/*
+ * The function checks whether the given total (exlat + enlat) latency of
+ * a power state allows the latter to be used as an APST transition target.
+ * It does so by comparing the latency to the primary and secondary latency
+ * tolerances defined by module params. If there's a match, the corresponding
+ * timeout value is returned and the matching tolerance index (1 or 2) is
+ * reported.
+ */
+static bool nvme_apst_get_transition_time(u64 total_latency,
+		u64 *transition_time, unsigned *last_index)
+{
+	if (total_latency <= apst_primary_latency_tol_us) {
+		if (*last_index == 1)
+			return false;
+		*last_index = 1;
+		*transition_time = apst_primary_timeout_ms;
+		return true;
+	}
+	if (apst_secondary_timeout_ms &&
+		total_latency <= apst_secondary_latency_tol_us) {
+		if (*last_index <= 2)
+			return false;
+		*last_index = 2;
+		*transition_time = apst_secondary_timeout_ms;
+		return true;
+	}
+	return false;
+}
+
+/*
+ * APST (Autonomous Power State Transition) lets us program a table of power
+ * state transitions that the controller will perform automatically.
+ *
+ * Depending on module params, one of the two supported techniques will be used:
+ *
+ * - If the parameters provide explicit timeouts and tolerances, they will be
+ *   used to build a table with up to 2 non-operational states to transition to.
+ *   The default parameter values were selected based on the values used by
+ *   Microsoft's and Intel's NVMe drivers. Yet, since we don't implement dynamic
+ *   regeneration of the APST table in the event of switching between external
+ *   and battery power, the timeouts and tolerances reflect a compromise
+ *   between values used by Microsoft for AC and battery scenarios.
+ * - If not, we'll configure the table with a simple heuristic: we are willing
+ *   to spend at most 2% of the time transitioning between power states.
+ *   Therefore, when running in any given state, we will enter the next
+ *   lower-power non-operational state after waiting 50 * (enlat + exlat)
+ *   microseconds, as long as that state's exit latency is under the requested
+ *   maximum latency.
+ *
+ * We will not autonomously enter any non-operational state for which the total
+ * latency exceeds ps_max_latency_us.
+ *
+ * Users can set ps_max_latency_us to zero to turn off APST.
+ */
+static int nvme_configure_apst(struct nvme_ctrl *ctrl)
+{
+	struct nvme_feat_auto_pst *table;
+	unsigned apste = 0;
+	u64 max_lat_us = 0;
+	__le64 target = 0;
+	int max_ps = -1;
+	int state;
+	int ret;
+	unsigned last_lt_index = UINT_MAX;
+
+	/*
+	 * If APST isn't supported or if we haven't been initialized yet,
+	 * then don't do anything.
+	 */
+	if (!ctrl->apsta)
+		return 0;
+
+	if (ctrl->npss > 31) {
+		dev_warn(ctrl->device, "NPSS is invalid; not using APST\n");
+		return 0;
+	}
+
+	table = kzalloc(sizeof(*table), GFP_KERNEL);
+	if (!table)
+		return 0;
+
+	if (!ctrl->apst_enabled || ctrl->ps_max_latency_us == 0) {
+		/* Turn off APST. */
+		dev_dbg(ctrl->device, "APST disabled\n");
+		goto done;
+	}
+
+	/*
+	 * Walk through all states from lowest- to highest-power.
+	 * According to the spec, lower-numbered states use more power.  NPSS,
+	 * despite the name, is the index of the lowest-power state, not the
+	 * number of states.
+	 */
+	for (state = (int)ctrl->npss; state >= 0; state--) {
+		u64 total_latency_us, exit_latency_us, transition_ms;
+
+		if (target)
+			table->entries[state] = target;
+
+		/*
+		 * Don't allow transitions to the deepest state if it's quirked
+		 * off.
+		 */
+		if (state == ctrl->npss &&
+		    (ctrl->quirks & NVME_QUIRK_NO_DEEPEST_PS))
+			continue;
+
+		/*
+		 * Is this state a useful non-operational state for higher-power
+		 * states to autonomously transition to?
+		 */
+		if (!(ctrl->psd[state].flags & NVME_PS_FLAGS_NON_OP_STATE))
+			continue;
+
+		exit_latency_us = (u64)le32_to_cpu(ctrl->psd[state].exit_lat);
+		if (exit_latency_us > ctrl->ps_max_latency_us)
+			continue;
+
+		total_latency_us = exit_latency_us +
+			le32_to_cpu(ctrl->psd[state].entry_lat);
+
+		/*
+		 * This state is good. It can be used as the APST idle target
+		 * for higher power states.
+		 */
+		if (apst_primary_timeout_ms && apst_primary_latency_tol_us) {
+			if (!nvme_apst_get_transition_time(total_latency_us,
+					&transition_ms, &last_lt_index))
+				continue;
+		} else {
+			transition_ms = total_latency_us + 19;
+			do_div(transition_ms, 20);
+			if (transition_ms > (1 << 24) - 1)
+				transition_ms = (1 << 24) - 1;
+		}
+
+		target = cpu_to_le64((state << 3) | (transition_ms << 8));
+		if (max_ps == -1)
+			max_ps = state;
+		if (total_latency_us > max_lat_us)
+			max_lat_us = total_latency_us;
+	}
+
+	if (max_ps == -1)
+		dev_dbg(ctrl->device, "APST enabled but no non-operational states are available\n");
+	else
+		dev_dbg(ctrl->device, "APST enabled: max PS = %d, max round-trip latency = %lluus, table = %*phN\n",
+			max_ps, max_lat_us, (int)sizeof(*table), table);
+	apste = 1;
+
+done:
+	ret = nvme_set_features(ctrl, NVME_FEAT_AUTO_PST, apste,
+				table, sizeof(*table), NULL);
+	if (ret)
+		dev_err(ctrl->device, "failed to set APST feature (%d)\n", ret);
+	kfree(table);
+	return ret;
+}
+
+static void nvme_set_latency_tolerance(struct device *dev, s32 val)
+{
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+	u64 latency;
+
+	switch (val) {
+	case PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT:
+	case PM_QOS_LATENCY_ANY:
+		latency = U64_MAX;
+		break;
+
+	default:
+		latency = val;
+	}
+
+	if (ctrl->ps_max_latency_us != latency) {
+		ctrl->ps_max_latency_us = latency;
+		if (ctrl->state == NVME_CTRL_LIVE)
+			nvme_configure_apst(ctrl);
+	}
+}
+
+struct nvme_core_quirk_entry {
+	/*
+	 * NVMe model and firmware strings are padded with spaces.  For
+	 * simplicity, strings in the quirk table are padded with NULLs
+	 * instead.
+	 */
+	u16 vid;
+	const char *mn;
+	const char *fr;
+	unsigned long quirks;
+};
+
+static const struct nvme_core_quirk_entry core_quirks[] = {
+	{
+		/*
+		 * This Toshiba device seems to die using any APST states.  See:
+		 * https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1678184/comments/11
+		 */
+		.vid = 0x1179,
+		.mn = "THNSF5256GPUK TOSHIBA",
+		.quirks = NVME_QUIRK_NO_APST,
+	},
+	{
+		/*
+		 * This LiteON CL1-3D*-Q11 firmware version has a race
+		 * condition associated with actions related to suspend to idle
+		 * LiteON has resolved the problem in future firmware
+		 */
+		.vid = 0x14a4,
+		.fr = "22301111",
+		.quirks = NVME_QUIRK_SIMPLE_SUSPEND,
+	},
+	{
+		/*
+		 * This Kioxia CD6-V Series / HPE PE8030 device times out and
+		 * aborts I/O during any load, but more easily reproducible
+		 * with discards (fstrim).
+		 *
+		 * The device is left in a state where it is also not possible
+		 * to use "nvme set-feature" to disable APST, but booting with
+		 * nvme_core.default_ps_max_latency=0 works.
+		 */
+		.vid = 0x1e0f,
+		.mn = "KCD6XVUL6T40",
+		.quirks = NVME_QUIRK_NO_APST,
+	},
+	{
+		/*
+		 * The external Samsung X5 SSD fails initialization without a
+		 * delay before checking if it is ready and has a whole set of
+		 * other problems.  To make this even more interesting, it
+		 * shares the PCI ID with internal Samsung 970 Evo Plus that
+		 * does not need or want these quirks.
+		 */
+		.vid = 0x144d,
+		.mn = "Samsung Portable SSD X5",
+		.quirks = NVME_QUIRK_DELAY_BEFORE_CHK_RDY |
+			  NVME_QUIRK_NO_DEEPEST_PS |
+			  NVME_QUIRK_IGNORE_DEV_SUBNQN,
+	}
+};
+
+/* match is null-terminated but idstr is space-padded. */
+static bool string_matches(const char *idstr, const char *match, size_t len)
+{
+	size_t matchlen;
+
+	if (!match)
+		return true;
+
+	matchlen = strlen(match);
+	WARN_ON_ONCE(matchlen > len);
+
+	if (memcmp(idstr, match, matchlen))
+		return false;
+
+	for (; matchlen < len; matchlen++)
+		if (idstr[matchlen] != ' ')
+			return false;
+
+	return true;
+}
+
+static bool quirk_matches(const struct nvme_id_ctrl *id,
+			  const struct nvme_core_quirk_entry *q)
+{
+	return q->vid == le16_to_cpu(id->vid) &&
+		string_matches(id->mn, q->mn, sizeof(id->mn)) &&
+		string_matches(id->fr, q->fr, sizeof(id->fr));
+}
+
+static void nvme_init_subnqn(struct nvme_subsystem *subsys, struct nvme_ctrl *ctrl,
+		struct nvme_id_ctrl *id)
+{
+	size_t nqnlen;
+	int off;
+
+	if(!(ctrl->quirks & NVME_QUIRK_IGNORE_DEV_SUBNQN)) {
+		nqnlen = strnlen(id->subnqn, NVMF_NQN_SIZE);
+		if (nqnlen > 0 && nqnlen < NVMF_NQN_SIZE) {
+			strscpy(subsys->subnqn, id->subnqn, NVMF_NQN_SIZE);
+			return;
+		}
+
+		if (ctrl->vs >= NVME_VS(1, 2, 1))
+			dev_warn(ctrl->device, "missing or invalid SUBNQN field.\n");
+	}
+
+	/*
+	 * Generate a "fake" NQN similar to the one in Section 4.5 of the NVMe
+	 * Base Specification 2.0.  It is slightly different from the format
+	 * specified there due to historic reasons, and we can't change it now.
+	 */
+	off = snprintf(subsys->subnqn, NVMF_NQN_SIZE,
+			"nqn.2014.08.org.nvmexpress:%04x%04x",
+			le16_to_cpu(id->vid), le16_to_cpu(id->ssvid));
+	memcpy(subsys->subnqn + off, id->sn, sizeof(id->sn));
+	off += sizeof(id->sn);
+	memcpy(subsys->subnqn + off, id->mn, sizeof(id->mn));
+	off += sizeof(id->mn);
+	memset(subsys->subnqn + off, 0, sizeof(subsys->subnqn) - off);
+}
+
+static void nvme_release_subsystem(struct device *dev)
+{
+	struct nvme_subsystem *subsys =
+		container_of(dev, struct nvme_subsystem, dev);
+
+	if (subsys->instance >= 0)
+		ida_free(&nvme_instance_ida, subsys->instance);
+	kfree(subsys);
+}
+
+static void nvme_destroy_subsystem(struct kref *ref)
+{
+	struct nvme_subsystem *subsys =
+			container_of(ref, struct nvme_subsystem, ref);
+
+	mutex_lock(&nvme_subsystems_lock);
+	list_del(&subsys->entry);
+	mutex_unlock(&nvme_subsystems_lock);
+
+	ida_destroy(&subsys->ns_ida);
+	device_del(&subsys->dev);
+	put_device(&subsys->dev);
+}
+
+static void nvme_put_subsystem(struct nvme_subsystem *subsys)
+{
+	kref_put(&subsys->ref, nvme_destroy_subsystem);
+}
+
+static struct nvme_subsystem *__nvme_find_get_subsystem(const char *subsysnqn)
+{
+	struct nvme_subsystem *subsys;
+
+	lockdep_assert_held(&nvme_subsystems_lock);
+
+	/*
+	 * Fail matches for discovery subsystems. This results
+	 * in each discovery controller bound to a unique subsystem.
+	 * This avoids issues with validating controller values
+	 * that can only be true when there is a single unique subsystem.
+	 * There may be multiple and completely independent entities
+	 * that provide discovery controllers.
+	 */
+	if (!strcmp(subsysnqn, NVME_DISC_SUBSYS_NAME))
+		return NULL;
+
+	list_for_each_entry(subsys, &nvme_subsystems, entry) {
+		if (strcmp(subsys->subnqn, subsysnqn))
+			continue;
+		if (!kref_get_unless_zero(&subsys->ref))
+			continue;
+		return subsys;
+	}
+
+	return NULL;
+}
+
+#define SUBSYS_ATTR_RO(_name, _mode, _show)			\
+	struct device_attribute subsys_attr_##_name = \
+		__ATTR(_name, _mode, _show, NULL)
+
+static ssize_t nvme_subsys_show_nqn(struct device *dev,
+				    struct device_attribute *attr,
+				    char *buf)
+{
+	struct nvme_subsystem *subsys =
+		container_of(dev, struct nvme_subsystem, dev);
+
+	return sysfs_emit(buf, "%s\n", subsys->subnqn);
+}
+static SUBSYS_ATTR_RO(subsysnqn, S_IRUGO, nvme_subsys_show_nqn);
+
+static ssize_t nvme_subsys_show_type(struct device *dev,
+				    struct device_attribute *attr,
+				    char *buf)
+{
+	struct nvme_subsystem *subsys =
+		container_of(dev, struct nvme_subsystem, dev);
+
+	switch (subsys->subtype) {
+	case NVME_NQN_DISC:
+		return sysfs_emit(buf, "discovery\n");
+	case NVME_NQN_NVME:
+		return sysfs_emit(buf, "nvm\n");
+	default:
+		return sysfs_emit(buf, "reserved\n");
+	}
+}
+static SUBSYS_ATTR_RO(subsystype, S_IRUGO, nvme_subsys_show_type);
+
+#define nvme_subsys_show_str_function(field)				\
+static ssize_t subsys_##field##_show(struct device *dev,		\
+			    struct device_attribute *attr, char *buf)	\
+{									\
+	struct nvme_subsystem *subsys =					\
+		container_of(dev, struct nvme_subsystem, dev);		\
+	return sysfs_emit(buf, "%.*s\n",				\
+			   (int)sizeof(subsys->field), subsys->field);	\
+}									\
+static SUBSYS_ATTR_RO(field, S_IRUGO, subsys_##field##_show);
+
+nvme_subsys_show_str_function(model);
+nvme_subsys_show_str_function(serial);
+nvme_subsys_show_str_function(firmware_rev);
+
+static struct attribute *nvme_subsys_attrs[] = {
+	&subsys_attr_model.attr,
+	&subsys_attr_serial.attr,
+	&subsys_attr_firmware_rev.attr,
+	&subsys_attr_subsysnqn.attr,
+	&subsys_attr_subsystype.attr,
+#ifdef CONFIG_NVME_MULTIPATH
+	&subsys_attr_iopolicy.attr,
+#endif
+	NULL,
+};
+
+static const struct attribute_group nvme_subsys_attrs_group = {
+	.attrs = nvme_subsys_attrs,
+};
+
+static const struct attribute_group *nvme_subsys_attrs_groups[] = {
+	&nvme_subsys_attrs_group,
+	NULL,
+};
+
+static inline bool nvme_discovery_ctrl(struct nvme_ctrl *ctrl)
+{
+	return ctrl->opts && ctrl->opts->discovery_nqn;
+}
+
+static bool nvme_validate_cntlid(struct nvme_subsystem *subsys,
+		struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id)
+{
+	struct nvme_ctrl *tmp;
+
+	lockdep_assert_held(&nvme_subsystems_lock);
+
+	list_for_each_entry(tmp, &subsys->ctrls, subsys_entry) {
+		if (nvme_state_terminal(tmp))
+			continue;
+
+		if (tmp->cntlid == ctrl->cntlid) {
+			dev_err(ctrl->device,
+				"Duplicate cntlid %u with %s, subsys %s, rejecting\n",
+				ctrl->cntlid, dev_name(tmp->device),
+				subsys->subnqn);
+			return false;
+		}
+
+		if ((id->cmic & NVME_CTRL_CMIC_MULTI_CTRL) ||
+		    nvme_discovery_ctrl(ctrl))
+			continue;
+
+		dev_err(ctrl->device,
+			"Subsystem does not support multiple controllers\n");
+		return false;
+	}
+
+	return true;
+}
+
+static int nvme_init_subsystem(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id)
+{
+	struct nvme_subsystem *subsys, *found;
+	int ret;
+
+	subsys = kzalloc(sizeof(*subsys), GFP_KERNEL);
+	if (!subsys)
+		return -ENOMEM;
+
+	subsys->instance = -1;
+	mutex_init(&subsys->lock);
+	kref_init(&subsys->ref);
+	INIT_LIST_HEAD(&subsys->ctrls);
+	INIT_LIST_HEAD(&subsys->nsheads);
+	nvme_init_subnqn(subsys, ctrl, id);
+	memcpy(subsys->serial, id->sn, sizeof(subsys->serial));
+	memcpy(subsys->model, id->mn, sizeof(subsys->model));
+	subsys->vendor_id = le16_to_cpu(id->vid);
+	subsys->cmic = id->cmic;
+
+	/* Versions prior to 1.4 don't necessarily report a valid type */
+	if (id->cntrltype == NVME_CTRL_DISC ||
+	    !strcmp(subsys->subnqn, NVME_DISC_SUBSYS_NAME))
+		subsys->subtype = NVME_NQN_DISC;
+	else
+		subsys->subtype = NVME_NQN_NVME;
+
+	if (nvme_discovery_ctrl(ctrl) && subsys->subtype != NVME_NQN_DISC) {
+		dev_err(ctrl->device,
+			"Subsystem %s is not a discovery controller",
+			subsys->subnqn);
+		kfree(subsys);
+		return -EINVAL;
+	}
+	subsys->awupf = le16_to_cpu(id->awupf);
+	nvme_mpath_default_iopolicy(subsys);
+
+	subsys->dev.class = nvme_subsys_class;
+	subsys->dev.release = nvme_release_subsystem;
+	subsys->dev.groups = nvme_subsys_attrs_groups;
+	dev_set_name(&subsys->dev, "nvme-subsys%d", ctrl->instance);
+	device_initialize(&subsys->dev);
+
+	mutex_lock(&nvme_subsystems_lock);
+	found = __nvme_find_get_subsystem(subsys->subnqn);
+	if (found) {
+		put_device(&subsys->dev);
+		subsys = found;
+
+		if (!nvme_validate_cntlid(subsys, ctrl, id)) {
+			ret = -EINVAL;
+			goto out_put_subsystem;
+		}
+	} else {
+		ret = device_add(&subsys->dev);
+		if (ret) {
+			dev_err(ctrl->device,
+				"failed to register subsystem device.\n");
+			put_device(&subsys->dev);
+			goto out_unlock;
+		}
+		ida_init(&subsys->ns_ida);
+		list_add_tail(&subsys->entry, &nvme_subsystems);
+	}
+
+	ret = sysfs_create_link(&subsys->dev.kobj, &ctrl->device->kobj,
+				dev_name(ctrl->device));
+	if (ret) {
+		dev_err(ctrl->device,
+			"failed to create sysfs link from subsystem.\n");
+		goto out_put_subsystem;
+	}
+
+	if (!found)
+		subsys->instance = ctrl->instance;
+	ctrl->subsys = subsys;
+	list_add_tail(&ctrl->subsys_entry, &subsys->ctrls);
+	mutex_unlock(&nvme_subsystems_lock);
+	return 0;
+
+out_put_subsystem:
+	nvme_put_subsystem(subsys);
+out_unlock:
+	mutex_unlock(&nvme_subsystems_lock);
+	return ret;
+}
+
+int nvme_get_log(struct nvme_ctrl *ctrl, u32 nsid, u8 log_page, u8 lsp, u8 csi,
+		void *log, size_t size, u64 offset)
+{
+	struct nvme_command c = { };
+	u32 dwlen = nvme_bytes_to_numd(size);
+
+	c.get_log_page.opcode = nvme_admin_get_log_page;
+	c.get_log_page.nsid = cpu_to_le32(nsid);
+	c.get_log_page.lid = log_page;
+	c.get_log_page.lsp = lsp;
+	c.get_log_page.numdl = cpu_to_le16(dwlen & ((1 << 16) - 1));
+	c.get_log_page.numdu = cpu_to_le16(dwlen >> 16);
+	c.get_log_page.lpol = cpu_to_le32(lower_32_bits(offset));
+	c.get_log_page.lpou = cpu_to_le32(upper_32_bits(offset));
+	c.get_log_page.csi = csi;
+
+	return nvme_submit_sync_cmd(ctrl->admin_q, &c, log, size);
+}
+
+static int nvme_get_effects_log(struct nvme_ctrl *ctrl, u8 csi,
+				struct nvme_effects_log **log)
+{
+	struct nvme_effects_log	*cel = xa_load(&ctrl->cels, csi);
+	int ret;
+
+	if (cel)
+		goto out;
+
+	cel = kzalloc(sizeof(*cel), GFP_KERNEL);
+	if (!cel)
+		return -ENOMEM;
+
+	ret = nvme_get_log(ctrl, 0x00, NVME_LOG_CMD_EFFECTS, 0, csi,
+			cel, sizeof(*cel), 0);
+	if (ret) {
+		kfree(cel);
+		return ret;
+	}
+
+	xa_store(&ctrl->cels, csi, cel, GFP_KERNEL);
+out:
+	*log = cel;
+	return 0;
+}
+
+static inline u32 nvme_mps_to_sectors(struct nvme_ctrl *ctrl, u32 units)
+{
+	u32 page_shift = NVME_CAP_MPSMIN(ctrl->cap) + 12, val;
+
+	if (check_shl_overflow(1U, units + page_shift - 9, &val))
+		return UINT_MAX;
+	return val;
+}
+
+static int nvme_init_non_mdts_limits(struct nvme_ctrl *ctrl)
+{
+	struct nvme_command c = { };
+	struct nvme_id_ctrl_nvm *id;
+	int ret;
+
+	if (ctrl->oncs & NVME_CTRL_ONCS_DSM) {
+		ctrl->max_discard_sectors = UINT_MAX;
+		ctrl->max_discard_segments = NVME_DSM_MAX_RANGES;
+	} else {
+		ctrl->max_discard_sectors = 0;
+		ctrl->max_discard_segments = 0;
+	}
+
+	/*
+	 * Even though NVMe spec explicitly states that MDTS is not applicable
+	 * to the write-zeroes, we are cautious and limit the size to the
+	 * controllers max_hw_sectors value, which is based on the MDTS field
+	 * and possibly other limiting factors.
+	 */
+	if ((ctrl->oncs & NVME_CTRL_ONCS_WRITE_ZEROES) &&
+	    !(ctrl->quirks & NVME_QUIRK_DISABLE_WRITE_ZEROES))
+		ctrl->max_zeroes_sectors = ctrl->max_hw_sectors;
+	else
+		ctrl->max_zeroes_sectors = 0;
+
+	if (ctrl->subsys->subtype != NVME_NQN_NVME ||
+	    nvme_ctrl_limited_cns(ctrl))
+		return 0;
+
+	id = kzalloc(sizeof(*id), GFP_KERNEL);
+	if (!id)
+		return -ENOMEM;
+
+	c.identify.opcode = nvme_admin_identify;
+	c.identify.cns = NVME_ID_CNS_CS_CTRL;
+	c.identify.csi = NVME_CSI_NVM;
+
+	ret = nvme_submit_sync_cmd(ctrl->admin_q, &c, id, sizeof(*id));
+	if (ret)
+		goto free_data;
+
+	if (id->dmrl)
+		ctrl->max_discard_segments = id->dmrl;
+	ctrl->dmrsl = le32_to_cpu(id->dmrsl);
+	if (id->wzsl)
+		ctrl->max_zeroes_sectors = nvme_mps_to_sectors(ctrl, id->wzsl);
+
+free_data:
+	kfree(id);
+	return ret;
+}
+
+static int nvme_init_identify(struct nvme_ctrl *ctrl)
+{
+	struct nvme_id_ctrl *id;
+	u32 max_hw_sectors;
+	bool prev_apst_enabled;
+	int ret;
+
+	ret = nvme_identify_ctrl(ctrl, &id);
+	if (ret) {
+		dev_err(ctrl->device, "Identify Controller failed (%d)\n", ret);
+		return -EIO;
+	}
+
+	if (id->lpa & NVME_CTRL_LPA_CMD_EFFECTS_LOG) {
+		ret = nvme_get_effects_log(ctrl, NVME_CSI_NVM, &ctrl->effects);
+		if (ret < 0)
+			goto out_free;
+	}
+
+	if (!(ctrl->ops->flags & NVME_F_FABRICS))
+		ctrl->cntlid = le16_to_cpu(id->cntlid);
+
+	if (!ctrl->identified) {
+		unsigned int i;
+
+		/*
+		 * Check for quirks.  Quirk can depend on firmware version,
+		 * so, in principle, the set of quirks present can change
+		 * across a reset.  As a possible future enhancement, we
+		 * could re-scan for quirks every time we reinitialize
+		 * the device, but we'd have to make sure that the driver
+		 * behaves intelligently if the quirks change.
+		 */
+		for (i = 0; i < ARRAY_SIZE(core_quirks); i++) {
+			if (quirk_matches(id, &core_quirks[i]))
+				ctrl->quirks |= core_quirks[i].quirks;
+		}
+
+		ret = nvme_init_subsystem(ctrl, id);
+		if (ret)
+			goto out_free;
+	}
+	memcpy(ctrl->subsys->firmware_rev, id->fr,
+	       sizeof(ctrl->subsys->firmware_rev));
+
+	if (force_apst && (ctrl->quirks & NVME_QUIRK_NO_DEEPEST_PS)) {
+		dev_warn(ctrl->device, "forcibly allowing all power states due to nvme_core.force_apst -- use at your own risk\n");
+		ctrl->quirks &= ~NVME_QUIRK_NO_DEEPEST_PS;
+	}
+
+	ctrl->crdt[0] = le16_to_cpu(id->crdt1);
+	ctrl->crdt[1] = le16_to_cpu(id->crdt2);
+	ctrl->crdt[2] = le16_to_cpu(id->crdt3);
+
+	ctrl->oacs = le16_to_cpu(id->oacs);
+	ctrl->oncs = le16_to_cpu(id->oncs);
+	ctrl->mtfa = le16_to_cpu(id->mtfa);
+	ctrl->oaes = le32_to_cpu(id->oaes);
+	ctrl->wctemp = le16_to_cpu(id->wctemp);
+	ctrl->cctemp = le16_to_cpu(id->cctemp);
+
+	atomic_set(&ctrl->abort_limit, id->acl + 1);
+	ctrl->vwc = id->vwc;
+	if (id->mdts)
+		max_hw_sectors = nvme_mps_to_sectors(ctrl, id->mdts);
+	else
+		max_hw_sectors = UINT_MAX;
+	ctrl->max_hw_sectors =
+		min_not_zero(ctrl->max_hw_sectors, max_hw_sectors);
+
+	nvme_set_queue_limits(ctrl, ctrl->admin_q);
+	ctrl->sgls = le32_to_cpu(id->sgls);
+	ctrl->kas = le16_to_cpu(id->kas);
+	ctrl->max_namespaces = le32_to_cpu(id->mnan);
+	ctrl->ctratt = le32_to_cpu(id->ctratt);
+
+	ctrl->cntrltype = id->cntrltype;
+	ctrl->dctype = id->dctype;
+
+	if (id->rtd3e) {
+		/* us -> s */
+		u32 transition_time = le32_to_cpu(id->rtd3e) / USEC_PER_SEC;
+
+		ctrl->shutdown_timeout = clamp_t(unsigned int, transition_time,
+						 shutdown_timeout, 60);
+
+		if (ctrl->shutdown_timeout != shutdown_timeout)
+			dev_info(ctrl->device,
+				 "Shutdown timeout set to %u seconds\n",
+				 ctrl->shutdown_timeout);
+	} else
+		ctrl->shutdown_timeout = shutdown_timeout;
+
+	ctrl->npss = id->npss;
+	ctrl->apsta = id->apsta;
+	prev_apst_enabled = ctrl->apst_enabled;
+	if (ctrl->quirks & NVME_QUIRK_NO_APST) {
+		if (force_apst && id->apsta) {
+			dev_warn(ctrl->device, "forcibly allowing APST due to nvme_core.force_apst -- use at your own risk\n");
+			ctrl->apst_enabled = true;
+		} else {
+			ctrl->apst_enabled = false;
+		}
+	} else {
+		ctrl->apst_enabled = id->apsta;
+	}
+	memcpy(ctrl->psd, id->psd, sizeof(ctrl->psd));
+
+	if (ctrl->ops->flags & NVME_F_FABRICS) {
+		ctrl->icdoff = le16_to_cpu(id->icdoff);
+		ctrl->ioccsz = le32_to_cpu(id->ioccsz);
+		ctrl->iorcsz = le32_to_cpu(id->iorcsz);
+		ctrl->maxcmd = le16_to_cpu(id->maxcmd);
+
+		/*
+		 * In fabrics we need to verify the cntlid matches the
+		 * admin connect
+		 */
+		if (ctrl->cntlid != le16_to_cpu(id->cntlid)) {
+			dev_err(ctrl->device,
+				"Mismatching cntlid: Connect %u vs Identify "
+				"%u, rejecting\n",
+				ctrl->cntlid, le16_to_cpu(id->cntlid));
+			ret = -EINVAL;
+			goto out_free;
+		}
+
+		if (!nvme_discovery_ctrl(ctrl) && !ctrl->kas) {
+			dev_err(ctrl->device,
+				"keep-alive support is mandatory for fabrics\n");
+			ret = -EINVAL;
+			goto out_free;
+		}
+	} else {
+		ctrl->hmpre = le32_to_cpu(id->hmpre);
+		ctrl->hmmin = le32_to_cpu(id->hmmin);
+		ctrl->hmminds = le32_to_cpu(id->hmminds);
+		ctrl->hmmaxd = le16_to_cpu(id->hmmaxd);
+	}
+
+	ret = nvme_mpath_init_identify(ctrl, id);
+	if (ret < 0)
+		goto out_free;
+
+	if (ctrl->apst_enabled && !prev_apst_enabled)
+		dev_pm_qos_expose_latency_tolerance(ctrl->device);
+	else if (!ctrl->apst_enabled && prev_apst_enabled)
+		dev_pm_qos_hide_latency_tolerance(ctrl->device);
+
+out_free:
+	kfree(id);
+	return ret;
+}
+
+/*
+ * Initialize the cached copies of the Identify data and various controller
+ * register in our nvme_ctrl structure.  This should be called as soon as
+ * the admin queue is fully up and running.
+ */
+int nvme_init_ctrl_finish(struct nvme_ctrl *ctrl)
+{
+	int ret;
+
+	ret = ctrl->ops->reg_read32(ctrl, NVME_REG_VS, &ctrl->vs);
+	if (ret) {
+		dev_err(ctrl->device, "Reading VS failed (%d)\n", ret);
+		return ret;
+	}
+
+	ctrl->sqsize = min_t(u16, NVME_CAP_MQES(ctrl->cap), ctrl->sqsize);
+
+	if (ctrl->vs >= NVME_VS(1, 1, 0))
+		ctrl->subsystem = NVME_CAP_NSSRC(ctrl->cap);
+
+	ret = nvme_init_identify(ctrl);
+	if (ret)
+		return ret;
+
+	ret = nvme_configure_apst(ctrl);
+	if (ret < 0)
+		return ret;
+
+	ret = nvme_configure_timestamp(ctrl);
+	if (ret < 0)
+		return ret;
+
+	ret = nvme_configure_host_options(ctrl);
+	if (ret < 0)
+		return ret;
+
+	if (!ctrl->identified && !nvme_discovery_ctrl(ctrl)) {
+		/*
+		 * Do not return errors unless we are in a controller reset,
+		 * the controller works perfectly fine without hwmon.
+		 */
+		ret = nvme_hwmon_init(ctrl);
+		if (ret == -EINTR)
+			return ret;
+	}
+
+	ctrl->identified = true;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nvme_init_ctrl_finish);
+
+static int nvme_dev_open(struct inode *inode, struct file *file)
+{
+	struct nvme_ctrl *ctrl =
+		container_of(inode->i_cdev, struct nvme_ctrl, cdev);
+
+	switch (ctrl->state) {
+	case NVME_CTRL_LIVE:
+		break;
+	default:
+		return -EWOULDBLOCK;
+	}
+
+	nvme_get_ctrl(ctrl);
+	if (!try_module_get(ctrl->ops->module)) {
+		nvme_put_ctrl(ctrl);
+		return -EINVAL;
+	}
+
+	file->private_data = ctrl;
+	return 0;
+}
+
+static int nvme_dev_release(struct inode *inode, struct file *file)
+{
+	struct nvme_ctrl *ctrl =
+		container_of(inode->i_cdev, struct nvme_ctrl, cdev);
+
+	module_put(ctrl->ops->module);
+	nvme_put_ctrl(ctrl);
+	return 0;
+}
+
+static const struct file_operations nvme_dev_fops = {
+	.owner		= THIS_MODULE,
+	.open		= nvme_dev_open,
+	.release	= nvme_dev_release,
+	.unlocked_ioctl	= nvme_dev_ioctl,
+	.compat_ioctl	= compat_ptr_ioctl,
+	.uring_cmd	= nvme_dev_uring_cmd,
+};
+
+static ssize_t nvme_sysfs_reset(struct device *dev,
+				struct device_attribute *attr, const char *buf,
+				size_t count)
+{
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+	int ret;
+
+	ret = nvme_reset_ctrl_sync(ctrl);
+	if (ret < 0)
+		return ret;
+	return count;
+}
+static DEVICE_ATTR(reset_controller, S_IWUSR, NULL, nvme_sysfs_reset);
+
+static ssize_t nvme_sysfs_rescan(struct device *dev,
+				struct device_attribute *attr, const char *buf,
+				size_t count)
+{
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+
+	nvme_queue_scan(ctrl);
+	return count;
+}
+static DEVICE_ATTR(rescan_controller, S_IWUSR, NULL, nvme_sysfs_rescan);
+
+static inline struct nvme_ns_head *dev_to_ns_head(struct device *dev)
+{
+	struct gendisk *disk = dev_to_disk(dev);
+
+	if (disk->fops == &nvme_bdev_ops)
+		return nvme_get_ns_from_dev(dev)->head;
+	else
+		return disk->private_data;
+}
+
+static ssize_t wwid_show(struct device *dev, struct device_attribute *attr,
+		char *buf)
+{
+	struct nvme_ns_head *head = dev_to_ns_head(dev);
+	struct nvme_ns_ids *ids = &head->ids;
+	struct nvme_subsystem *subsys = head->subsys;
+	int serial_len = sizeof(subsys->serial);
+	int model_len = sizeof(subsys->model);
+
+	if (!uuid_is_null(&ids->uuid))
+		return sysfs_emit(buf, "uuid.%pU\n", &ids->uuid);
+
+	if (memchr_inv(ids->nguid, 0, sizeof(ids->nguid)))
+		return sysfs_emit(buf, "eui.%16phN\n", ids->nguid);
+
+	if (memchr_inv(ids->eui64, 0, sizeof(ids->eui64)))
+		return sysfs_emit(buf, "eui.%8phN\n", ids->eui64);
+
+	while (serial_len > 0 && (subsys->serial[serial_len - 1] == ' ' ||
+				  subsys->serial[serial_len - 1] == '\0'))
+		serial_len--;
+	while (model_len > 0 && (subsys->model[model_len - 1] == ' ' ||
+				 subsys->model[model_len - 1] == '\0'))
+		model_len--;
+
+	return sysfs_emit(buf, "nvme.%04x-%*phN-%*phN-%08x\n", subsys->vendor_id,
+		serial_len, subsys->serial, model_len, subsys->model,
+		head->ns_id);
+}
+static DEVICE_ATTR_RO(wwid);
+
+static ssize_t nguid_show(struct device *dev, struct device_attribute *attr,
+		char *buf)
+{
+	return sysfs_emit(buf, "%pU\n", dev_to_ns_head(dev)->ids.nguid);
+}
+static DEVICE_ATTR_RO(nguid);
+
+static ssize_t uuid_show(struct device *dev, struct device_attribute *attr,
+		char *buf)
+{
+	struct nvme_ns_ids *ids = &dev_to_ns_head(dev)->ids;
+
+	/* For backward compatibility expose the NGUID to userspace if
+	 * we have no UUID set
+	 */
+	if (uuid_is_null(&ids->uuid)) {
+		dev_warn_ratelimited(dev,
+			"No UUID available providing old NGUID\n");
+		return sysfs_emit(buf, "%pU\n", ids->nguid);
+	}
+	return sysfs_emit(buf, "%pU\n", &ids->uuid);
+}
+static DEVICE_ATTR_RO(uuid);
+
+static ssize_t eui_show(struct device *dev, struct device_attribute *attr,
+		char *buf)
+{
+	return sysfs_emit(buf, "%8ph\n", dev_to_ns_head(dev)->ids.eui64);
+}
+static DEVICE_ATTR_RO(eui);
+
+static ssize_t nsid_show(struct device *dev, struct device_attribute *attr,
+		char *buf)
+{
+	return sysfs_emit(buf, "%d\n", dev_to_ns_head(dev)->ns_id);
+}
+static DEVICE_ATTR_RO(nsid);
+
+static struct attribute *nvme_ns_id_attrs[] = {
+	&dev_attr_wwid.attr,
+	&dev_attr_uuid.attr,
+	&dev_attr_nguid.attr,
+	&dev_attr_eui.attr,
+	&dev_attr_nsid.attr,
+#ifdef CONFIG_NVME_MULTIPATH
+	&dev_attr_ana_grpid.attr,
+	&dev_attr_ana_state.attr,
+#endif
+	NULL,
+};
+
+static umode_t nvme_ns_id_attrs_are_visible(struct kobject *kobj,
+		struct attribute *a, int n)
+{
+	struct device *dev = container_of(kobj, struct device, kobj);
+	struct nvme_ns_ids *ids = &dev_to_ns_head(dev)->ids;
+
+	if (a == &dev_attr_uuid.attr) {
+		if (uuid_is_null(&ids->uuid) &&
+		    !memchr_inv(ids->nguid, 0, sizeof(ids->nguid)))
+			return 0;
+	}
+	if (a == &dev_attr_nguid.attr) {
+		if (!memchr_inv(ids->nguid, 0, sizeof(ids->nguid)))
+			return 0;
+	}
+	if (a == &dev_attr_eui.attr) {
+		if (!memchr_inv(ids->eui64, 0, sizeof(ids->eui64)))
+			return 0;
+	}
+#ifdef CONFIG_NVME_MULTIPATH
+	if (a == &dev_attr_ana_grpid.attr || a == &dev_attr_ana_state.attr) {
+		if (dev_to_disk(dev)->fops != &nvme_bdev_ops) /* per-path attr */
+			return 0;
+		if (!nvme_ctrl_use_ana(nvme_get_ns_from_dev(dev)->ctrl))
+			return 0;
+	}
+#endif
+	return a->mode;
+}
+
+static const struct attribute_group nvme_ns_id_attr_group = {
+	.attrs		= nvme_ns_id_attrs,
+	.is_visible	= nvme_ns_id_attrs_are_visible,
+};
+
+const struct attribute_group *nvme_ns_id_attr_groups[] = {
+	&nvme_ns_id_attr_group,
+	NULL,
+};
+
+#define nvme_show_str_function(field)						\
+static ssize_t  field##_show(struct device *dev,				\
+			    struct device_attribute *attr, char *buf)		\
+{										\
+        struct nvme_ctrl *ctrl = dev_get_drvdata(dev);				\
+        return sysfs_emit(buf, "%.*s\n",					\
+		(int)sizeof(ctrl->subsys->field), ctrl->subsys->field);		\
+}										\
+static DEVICE_ATTR(field, S_IRUGO, field##_show, NULL);
+
+nvme_show_str_function(model);
+nvme_show_str_function(serial);
+nvme_show_str_function(firmware_rev);
+
+#define nvme_show_int_function(field)						\
+static ssize_t  field##_show(struct device *dev,				\
+			    struct device_attribute *attr, char *buf)		\
+{										\
+        struct nvme_ctrl *ctrl = dev_get_drvdata(dev);				\
+        return sysfs_emit(buf, "%d\n", ctrl->field);				\
+}										\
+static DEVICE_ATTR(field, S_IRUGO, field##_show, NULL);
+
+nvme_show_int_function(cntlid);
+nvme_show_int_function(numa_node);
+nvme_show_int_function(queue_count);
+nvme_show_int_function(sqsize);
+nvme_show_int_function(kato);
+
+static ssize_t nvme_sysfs_delete(struct device *dev,
+				struct device_attribute *attr, const char *buf,
+				size_t count)
+{
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+
+	if (!test_bit(NVME_CTRL_STARTED_ONCE, &ctrl->flags))
+		return -EBUSY;
+
+	if (device_remove_file_self(dev, attr))
+		nvme_delete_ctrl_sync(ctrl);
+	return count;
+}
+static DEVICE_ATTR(delete_controller, S_IWUSR, NULL, nvme_sysfs_delete);
+
+static ssize_t nvme_sysfs_show_transport(struct device *dev,
+					 struct device_attribute *attr,
+					 char *buf)
+{
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%s\n", ctrl->ops->name);
+}
+static DEVICE_ATTR(transport, S_IRUGO, nvme_sysfs_show_transport, NULL);
+
+static ssize_t nvme_sysfs_show_state(struct device *dev,
+				     struct device_attribute *attr,
+				     char *buf)
+{
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+	static const char *const state_name[] = {
+		[NVME_CTRL_NEW]		= "new",
+		[NVME_CTRL_LIVE]	= "live",
+		[NVME_CTRL_RESETTING]	= "resetting",
+		[NVME_CTRL_CONNECTING]	= "connecting",
+		[NVME_CTRL_DELETING]	= "deleting",
+		[NVME_CTRL_DELETING_NOIO]= "deleting (no IO)",
+		[NVME_CTRL_DEAD]	= "dead",
+	};
+
+	if ((unsigned)ctrl->state < ARRAY_SIZE(state_name) &&
+	    state_name[ctrl->state])
+		return sysfs_emit(buf, "%s\n", state_name[ctrl->state]);
+
+	return sysfs_emit(buf, "unknown state\n");
+}
+
+static DEVICE_ATTR(state, S_IRUGO, nvme_sysfs_show_state, NULL);
+
+static ssize_t nvme_sysfs_show_subsysnqn(struct device *dev,
+					 struct device_attribute *attr,
+					 char *buf)
+{
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%s\n", ctrl->subsys->subnqn);
+}
+static DEVICE_ATTR(subsysnqn, S_IRUGO, nvme_sysfs_show_subsysnqn, NULL);
+
+static ssize_t nvme_sysfs_show_hostnqn(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%s\n", ctrl->opts->host->nqn);
+}
+static DEVICE_ATTR(hostnqn, S_IRUGO, nvme_sysfs_show_hostnqn, NULL);
+
+static ssize_t nvme_sysfs_show_hostid(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%pU\n", &ctrl->opts->host->id);
+}
+static DEVICE_ATTR(hostid, S_IRUGO, nvme_sysfs_show_hostid, NULL);
+
+static ssize_t nvme_sysfs_show_address(struct device *dev,
+					 struct device_attribute *attr,
+					 char *buf)
+{
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+
+	return ctrl->ops->get_address(ctrl, buf, PAGE_SIZE);
+}
+static DEVICE_ATTR(address, S_IRUGO, nvme_sysfs_show_address, NULL);
+
+static ssize_t nvme_ctrl_loss_tmo_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+	struct nvmf_ctrl_options *opts = ctrl->opts;
+
+	if (ctrl->opts->max_reconnects == -1)
+		return sysfs_emit(buf, "off\n");
+	return sysfs_emit(buf, "%d\n",
+			  opts->max_reconnects * opts->reconnect_delay);
+}
+
+static ssize_t nvme_ctrl_loss_tmo_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+	struct nvmf_ctrl_options *opts = ctrl->opts;
+	int ctrl_loss_tmo, err;
+
+	err = kstrtoint(buf, 10, &ctrl_loss_tmo);
+	if (err)
+		return -EINVAL;
+
+	if (ctrl_loss_tmo < 0)
+		opts->max_reconnects = -1;
+	else
+		opts->max_reconnects = DIV_ROUND_UP(ctrl_loss_tmo,
+						opts->reconnect_delay);
+	return count;
+}
+static DEVICE_ATTR(ctrl_loss_tmo, S_IRUGO | S_IWUSR,
+	nvme_ctrl_loss_tmo_show, nvme_ctrl_loss_tmo_store);
+
+static ssize_t nvme_ctrl_reconnect_delay_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+
+	if (ctrl->opts->reconnect_delay == -1)
+		return sysfs_emit(buf, "off\n");
+	return sysfs_emit(buf, "%d\n", ctrl->opts->reconnect_delay);
+}
+
+static ssize_t nvme_ctrl_reconnect_delay_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+	unsigned int v;
+	int err;
+
+	err = kstrtou32(buf, 10, &v);
+	if (err)
+		return err;
+
+	ctrl->opts->reconnect_delay = v;
+	return count;
+}
+static DEVICE_ATTR(reconnect_delay, S_IRUGO | S_IWUSR,
+	nvme_ctrl_reconnect_delay_show, nvme_ctrl_reconnect_delay_store);
+
+static ssize_t nvme_ctrl_fast_io_fail_tmo_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+
+	if (ctrl->opts->fast_io_fail_tmo == -1)
+		return sysfs_emit(buf, "off\n");
+	return sysfs_emit(buf, "%d\n", ctrl->opts->fast_io_fail_tmo);
+}
+
+static ssize_t nvme_ctrl_fast_io_fail_tmo_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+	struct nvmf_ctrl_options *opts = ctrl->opts;
+	int fast_io_fail_tmo, err;
+
+	err = kstrtoint(buf, 10, &fast_io_fail_tmo);
+	if (err)
+		return -EINVAL;
+
+	if (fast_io_fail_tmo < 0)
+		opts->fast_io_fail_tmo = -1;
+	else
+		opts->fast_io_fail_tmo = fast_io_fail_tmo;
+	return count;
+}
+static DEVICE_ATTR(fast_io_fail_tmo, S_IRUGO | S_IWUSR,
+	nvme_ctrl_fast_io_fail_tmo_show, nvme_ctrl_fast_io_fail_tmo_store);
+
+static ssize_t cntrltype_show(struct device *dev,
+			      struct device_attribute *attr, char *buf)
+{
+	static const char * const type[] = {
+		[NVME_CTRL_IO] = "io\n",
+		[NVME_CTRL_DISC] = "discovery\n",
+		[NVME_CTRL_ADMIN] = "admin\n",
+	};
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+
+	if (ctrl->cntrltype > NVME_CTRL_ADMIN || !type[ctrl->cntrltype])
+		return sysfs_emit(buf, "reserved\n");
+
+	return sysfs_emit(buf, type[ctrl->cntrltype]);
+}
+static DEVICE_ATTR_RO(cntrltype);
+
+static ssize_t dctype_show(struct device *dev,
+			   struct device_attribute *attr, char *buf)
+{
+	static const char * const type[] = {
+		[NVME_DCTYPE_NOT_REPORTED] = "none\n",
+		[NVME_DCTYPE_DDC] = "ddc\n",
+		[NVME_DCTYPE_CDC] = "cdc\n",
+	};
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+
+	if (ctrl->dctype > NVME_DCTYPE_CDC || !type[ctrl->dctype])
+		return sysfs_emit(buf, "reserved\n");
+
+	return sysfs_emit(buf, type[ctrl->dctype]);
+}
+static DEVICE_ATTR_RO(dctype);
+
+#ifdef CONFIG_NVME_AUTH
+static ssize_t nvme_ctrl_dhchap_secret_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+	struct nvmf_ctrl_options *opts = ctrl->opts;
+
+	if (!opts->dhchap_secret)
+		return sysfs_emit(buf, "none\n");
+	return sysfs_emit(buf, "%s\n", opts->dhchap_secret);
+}
+
+static ssize_t nvme_ctrl_dhchap_secret_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+	struct nvmf_ctrl_options *opts = ctrl->opts;
+	char *dhchap_secret;
+
+	if (!ctrl->opts->dhchap_secret)
+		return -EINVAL;
+	if (count < 7)
+		return -EINVAL;
+	if (memcmp(buf, "DHHC-1:", 7))
+		return -EINVAL;
+
+	dhchap_secret = kzalloc(count + 1, GFP_KERNEL);
+	if (!dhchap_secret)
+		return -ENOMEM;
+	memcpy(dhchap_secret, buf, count);
+	nvme_auth_stop(ctrl);
+	if (strcmp(dhchap_secret, opts->dhchap_secret)) {
+		struct nvme_dhchap_key *key, *host_key;
+		int ret;
+
+		ret = nvme_auth_generate_key(dhchap_secret, &key);
+		if (ret) {
+			kfree(dhchap_secret);
+			return ret;
+		}
+		kfree(opts->dhchap_secret);
+		opts->dhchap_secret = dhchap_secret;
+		host_key = ctrl->host_key;
+		ctrl->host_key = key;
+		nvme_auth_free_key(host_key);
+	} else
+		kfree(dhchap_secret);
+	/* Start re-authentication */
+	dev_info(ctrl->device, "re-authenticating controller\n");
+	queue_work(nvme_wq, &ctrl->dhchap_auth_work);
+
+	return count;
+}
+static DEVICE_ATTR(dhchap_secret, S_IRUGO | S_IWUSR,
+	nvme_ctrl_dhchap_secret_show, nvme_ctrl_dhchap_secret_store);
+
+static ssize_t nvme_ctrl_dhchap_ctrl_secret_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+	struct nvmf_ctrl_options *opts = ctrl->opts;
+
+	if (!opts->dhchap_ctrl_secret)
+		return sysfs_emit(buf, "none\n");
+	return sysfs_emit(buf, "%s\n", opts->dhchap_ctrl_secret);
+}
+
+static ssize_t nvme_ctrl_dhchap_ctrl_secret_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+	struct nvmf_ctrl_options *opts = ctrl->opts;
+	char *dhchap_secret;
+
+	if (!ctrl->opts->dhchap_ctrl_secret)
+		return -EINVAL;
+	if (count < 7)
+		return -EINVAL;
+	if (memcmp(buf, "DHHC-1:", 7))
+		return -EINVAL;
+
+	dhchap_secret = kzalloc(count + 1, GFP_KERNEL);
+	if (!dhchap_secret)
+		return -ENOMEM;
+	memcpy(dhchap_secret, buf, count);
+	nvme_auth_stop(ctrl);
+	if (strcmp(dhchap_secret, opts->dhchap_ctrl_secret)) {
+		struct nvme_dhchap_key *key, *ctrl_key;
+		int ret;
+
+		ret = nvme_auth_generate_key(dhchap_secret, &key);
+		if (ret) {
+			kfree(dhchap_secret);
+			return ret;
+		}
+		kfree(opts->dhchap_ctrl_secret);
+		opts->dhchap_ctrl_secret = dhchap_secret;
+		ctrl_key = ctrl->ctrl_key;
+		ctrl->ctrl_key = key;
+		nvme_auth_free_key(ctrl_key);
+	} else
+		kfree(dhchap_secret);
+	/* Start re-authentication */
+	dev_info(ctrl->device, "re-authenticating controller\n");
+	queue_work(nvme_wq, &ctrl->dhchap_auth_work);
+
+	return count;
+}
+static DEVICE_ATTR(dhchap_ctrl_secret, S_IRUGO | S_IWUSR,
+	nvme_ctrl_dhchap_ctrl_secret_show, nvme_ctrl_dhchap_ctrl_secret_store);
+#endif
+
+static struct attribute *nvme_dev_attrs[] = {
+	&dev_attr_reset_controller.attr,
+	&dev_attr_rescan_controller.attr,
+	&dev_attr_model.attr,
+	&dev_attr_serial.attr,
+	&dev_attr_firmware_rev.attr,
+	&dev_attr_cntlid.attr,
+	&dev_attr_delete_controller.attr,
+	&dev_attr_transport.attr,
+	&dev_attr_subsysnqn.attr,
+	&dev_attr_address.attr,
+	&dev_attr_state.attr,
+	&dev_attr_numa_node.attr,
+	&dev_attr_queue_count.attr,
+	&dev_attr_sqsize.attr,
+	&dev_attr_hostnqn.attr,
+	&dev_attr_hostid.attr,
+	&dev_attr_ctrl_loss_tmo.attr,
+	&dev_attr_reconnect_delay.attr,
+	&dev_attr_fast_io_fail_tmo.attr,
+	&dev_attr_kato.attr,
+	&dev_attr_cntrltype.attr,
+	&dev_attr_dctype.attr,
+#ifdef CONFIG_NVME_AUTH
+	&dev_attr_dhchap_secret.attr,
+	&dev_attr_dhchap_ctrl_secret.attr,
+#endif
+	NULL
+};
+
+static umode_t nvme_dev_attrs_are_visible(struct kobject *kobj,
+		struct attribute *a, int n)
+{
+	struct device *dev = container_of(kobj, struct device, kobj);
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+
+	if (a == &dev_attr_delete_controller.attr && !ctrl->ops->delete_ctrl)
+		return 0;
+	if (a == &dev_attr_address.attr && !ctrl->ops->get_address)
+		return 0;
+	if (a == &dev_attr_hostnqn.attr && !ctrl->opts)
+		return 0;
+	if (a == &dev_attr_hostid.attr && !ctrl->opts)
+		return 0;
+	if (a == &dev_attr_ctrl_loss_tmo.attr && !ctrl->opts)
+		return 0;
+	if (a == &dev_attr_reconnect_delay.attr && !ctrl->opts)
+		return 0;
+	if (a == &dev_attr_fast_io_fail_tmo.attr && !ctrl->opts)
+		return 0;
+#ifdef CONFIG_NVME_AUTH
+	if (a == &dev_attr_dhchap_secret.attr && !ctrl->opts)
+		return 0;
+	if (a == &dev_attr_dhchap_ctrl_secret.attr && !ctrl->opts)
+		return 0;
+#endif
+
+	return a->mode;
+}
+
+const struct attribute_group nvme_dev_attrs_group = {
+	.attrs		= nvme_dev_attrs,
+	.is_visible	= nvme_dev_attrs_are_visible,
+};
+EXPORT_SYMBOL_GPL(nvme_dev_attrs_group);
+
+static const struct attribute_group *nvme_dev_attr_groups[] = {
+	&nvme_dev_attrs_group,
+	NULL,
+};
+
+static struct nvme_ns_head *nvme_find_ns_head(struct nvme_ctrl *ctrl,
+		unsigned nsid)
+{
+	struct nvme_ns_head *h;
+
+	lockdep_assert_held(&ctrl->subsys->lock);
+
+	list_for_each_entry(h, &ctrl->subsys->nsheads, entry) {
+		/*
+		 * Private namespaces can share NSIDs under some conditions.
+		 * In that case we can't use the same ns_head for namespaces
+		 * with the same NSID.
+		 */
+		if (h->ns_id != nsid || !nvme_is_unique_nsid(ctrl, h))
+			continue;
+		if (!list_empty(&h->list) && nvme_tryget_ns_head(h))
+			return h;
+	}
+
+	return NULL;
+}
+
+static int nvme_subsys_check_duplicate_ids(struct nvme_subsystem *subsys,
+		struct nvme_ns_ids *ids)
+{
+	bool has_uuid = !uuid_is_null(&ids->uuid);
+	bool has_nguid = memchr_inv(ids->nguid, 0, sizeof(ids->nguid));
+	bool has_eui64 = memchr_inv(ids->eui64, 0, sizeof(ids->eui64));
+	struct nvme_ns_head *h;
+
+	lockdep_assert_held(&subsys->lock);
+
+	list_for_each_entry(h, &subsys->nsheads, entry) {
+		if (has_uuid && uuid_equal(&ids->uuid, &h->ids.uuid))
+			return -EINVAL;
+		if (has_nguid &&
+		    memcmp(&ids->nguid, &h->ids.nguid, sizeof(ids->nguid)) == 0)
+			return -EINVAL;
+		if (has_eui64 &&
+		    memcmp(&ids->eui64, &h->ids.eui64, sizeof(ids->eui64)) == 0)
+			return -EINVAL;
+	}
+
+	return 0;
+}
+
+static void nvme_cdev_rel(struct device *dev)
+{
+	ida_free(&nvme_ns_chr_minor_ida, MINOR(dev->devt));
+}
+
+void nvme_cdev_del(struct cdev *cdev, struct device *cdev_device)
+{
+	cdev_device_del(cdev, cdev_device);
+	put_device(cdev_device);
+}
+
+int nvme_cdev_add(struct cdev *cdev, struct device *cdev_device,
+		const struct file_operations *fops, struct module *owner)
+{
+	int minor, ret;
+
+	minor = ida_alloc(&nvme_ns_chr_minor_ida, GFP_KERNEL);
+	if (minor < 0)
+		return minor;
+	cdev_device->devt = MKDEV(MAJOR(nvme_ns_chr_devt), minor);
+	cdev_device->class = nvme_ns_chr_class;
+	cdev_device->release = nvme_cdev_rel;
+	device_initialize(cdev_device);
+	cdev_init(cdev, fops);
+	cdev->owner = owner;
+	ret = cdev_device_add(cdev, cdev_device);
+	if (ret)
+		put_device(cdev_device);
+
+	return ret;
+}
+
+static int nvme_ns_chr_open(struct inode *inode, struct file *file)
+{
+	return nvme_ns_open(container_of(inode->i_cdev, struct nvme_ns, cdev));
+}
+
+static int nvme_ns_chr_release(struct inode *inode, struct file *file)
+{
+	nvme_ns_release(container_of(inode->i_cdev, struct nvme_ns, cdev));
+	return 0;
+}
+
+static const struct file_operations nvme_ns_chr_fops = {
+	.owner		= THIS_MODULE,
+	.open		= nvme_ns_chr_open,
+	.release	= nvme_ns_chr_release,
+	.unlocked_ioctl	= nvme_ns_chr_ioctl,
+	.compat_ioctl	= compat_ptr_ioctl,
+	.uring_cmd	= nvme_ns_chr_uring_cmd,
+	.uring_cmd_iopoll = nvme_ns_chr_uring_cmd_iopoll,
+};
+
+static int nvme_add_ns_cdev(struct nvme_ns *ns)
+{
+	int ret;
+
+	ns->cdev_device.parent = ns->ctrl->device;
+	ret = dev_set_name(&ns->cdev_device, "ng%dn%d",
+			   ns->ctrl->instance, ns->head->instance);
+	if (ret)
+		return ret;
+
+	return nvme_cdev_add(&ns->cdev, &ns->cdev_device, &nvme_ns_chr_fops,
+			     ns->ctrl->ops->module);
+}
+
+static struct nvme_ns_head *nvme_alloc_ns_head(struct nvme_ctrl *ctrl,
+		struct nvme_ns_info *info)
+{
+	struct nvme_ns_head *head;
+	size_t size = sizeof(*head);
+	int ret = -ENOMEM;
+
+#ifdef CONFIG_NVME_MULTIPATH
+	size += num_possible_nodes() * sizeof(struct nvme_ns *);
+#endif
+
+	head = kzalloc(size, GFP_KERNEL);
+	if (!head)
+		goto out;
+	ret = ida_alloc_min(&ctrl->subsys->ns_ida, 1, GFP_KERNEL);
+	if (ret < 0)
+		goto out_free_head;
+	head->instance = ret;
+	INIT_LIST_HEAD(&head->list);
+	ret = init_srcu_struct(&head->srcu);
+	if (ret)
+		goto out_ida_remove;
+	head->subsys = ctrl->subsys;
+	head->ns_id = info->nsid;
+	head->ids = info->ids;
+	head->shared = info->is_shared;
+	kref_init(&head->ref);
+
+	if (head->ids.csi) {
+		ret = nvme_get_effects_log(ctrl, head->ids.csi, &head->effects);
+		if (ret)
+			goto out_cleanup_srcu;
+	} else
+		head->effects = ctrl->effects;
+
+	ret = nvme_mpath_alloc_disk(ctrl, head);
+	if (ret)
+		goto out_cleanup_srcu;
+
+	list_add_tail(&head->entry, &ctrl->subsys->nsheads);
+
+	kref_get(&ctrl->subsys->ref);
+
+	return head;
+out_cleanup_srcu:
+	cleanup_srcu_struct(&head->srcu);
+out_ida_remove:
+	ida_free(&ctrl->subsys->ns_ida, head->instance);
+out_free_head:
+	kfree(head);
+out:
+	if (ret > 0)
+		ret = blk_status_to_errno(nvme_error_status(ret));
+	return ERR_PTR(ret);
+}
+
+static int nvme_global_check_duplicate_ids(struct nvme_subsystem *this,
+		struct nvme_ns_ids *ids)
+{
+	struct nvme_subsystem *s;
+	int ret = 0;
+
+	/*
+	 * Note that this check is racy as we try to avoid holding the global
+	 * lock over the whole ns_head creation.  But it is only intended as
+	 * a sanity check anyway.
+	 */
+	mutex_lock(&nvme_subsystems_lock);
+	list_for_each_entry(s, &nvme_subsystems, entry) {
+		if (s == this)
+			continue;
+		mutex_lock(&s->lock);
+		ret = nvme_subsys_check_duplicate_ids(s, ids);
+		mutex_unlock(&s->lock);
+		if (ret)
+			break;
+	}
+	mutex_unlock(&nvme_subsystems_lock);
+
+	return ret;
+}
+
+static int nvme_init_ns_head(struct nvme_ns *ns, struct nvme_ns_info *info)
+{
+	struct nvme_ctrl *ctrl = ns->ctrl;
+	struct nvme_ns_head *head = NULL;
+	int ret;
+
+	ret = nvme_global_check_duplicate_ids(ctrl->subsys, &info->ids);
+	if (ret) {
+		/*
+		 * We've found two different namespaces on two different
+		 * subsystems that report the same ID.  This is pretty nasty
+		 * for anything that actually requires unique device
+		 * identification.  In the kernel we need this for multipathing,
+		 * and in user space the /dev/disk/by-id/ links rely on it.
+		 *
+		 * If the device also claims to be multi-path capable back off
+		 * here now and refuse the probe the second device as this is a
+		 * recipe for data corruption.  If not this is probably a
+		 * cheap consumer device if on the PCIe bus, so let the user
+		 * proceed and use the shiny toy, but warn that with changing
+		 * probing order (which due to our async probing could just be
+		 * device taking longer to startup) the other device could show
+		 * up at any time.
+		 */
+		nvme_print_device_info(ctrl);
+		if ((ns->ctrl->ops->flags & NVME_F_FABRICS) || /* !PCIe */
+		    ((ns->ctrl->subsys->cmic & NVME_CTRL_CMIC_MULTI_CTRL) &&
+		     info->is_shared)) {
+			dev_err(ctrl->device,
+				"ignoring nsid %d because of duplicate IDs\n",
+				info->nsid);
+			return ret;
+		}
+
+		dev_err(ctrl->device,
+			"clearing duplicate IDs for nsid %d\n", info->nsid);
+		dev_err(ctrl->device,
+			"use of /dev/disk/by-id/ may cause data corruption\n");
+		memset(&info->ids.nguid, 0, sizeof(info->ids.nguid));
+		memset(&info->ids.uuid, 0, sizeof(info->ids.uuid));
+		memset(&info->ids.eui64, 0, sizeof(info->ids.eui64));
+		ctrl->quirks |= NVME_QUIRK_BOGUS_NID;
+	}
+
+	mutex_lock(&ctrl->subsys->lock);
+	head = nvme_find_ns_head(ctrl, info->nsid);
+	if (!head) {
+		ret = nvme_subsys_check_duplicate_ids(ctrl->subsys, &info->ids);
+		if (ret) {
+			dev_err(ctrl->device,
+				"duplicate IDs in subsystem for nsid %d\n",
+				info->nsid);
+			goto out_unlock;
+		}
+		head = nvme_alloc_ns_head(ctrl, info);
+		if (IS_ERR(head)) {
+			ret = PTR_ERR(head);
+			goto out_unlock;
+		}
+	} else {
+		ret = -EINVAL;
+		if (!info->is_shared || !head->shared) {
+			dev_err(ctrl->device,
+				"Duplicate unshared namespace %d\n",
+				info->nsid);
+			goto out_put_ns_head;
+		}
+		if (!nvme_ns_ids_equal(&head->ids, &info->ids)) {
+			dev_err(ctrl->device,
+				"IDs don't match for shared namespace %d\n",
+					info->nsid);
+			goto out_put_ns_head;
+		}
+
+		if (!multipath && !list_empty(&head->list)) {
+			dev_warn(ctrl->device,
+				"Found shared namespace %d, but multipathing not supported.\n",
+				info->nsid);
+			dev_warn_once(ctrl->device,
+				"Support for shared namespaces without CONFIG_NVME_MULTIPATH is deprecated and will be removed in Linux 6.0\n.");
+		}
+	}
+
+	list_add_tail_rcu(&ns->siblings, &head->list);
+	ns->head = head;
+	mutex_unlock(&ctrl->subsys->lock);
+	return 0;
+
+out_put_ns_head:
+	nvme_put_ns_head(head);
+out_unlock:
+	mutex_unlock(&ctrl->subsys->lock);
+	return ret;
+}
+
+struct nvme_ns *nvme_find_get_ns(struct nvme_ctrl *ctrl, unsigned nsid)
+{
+	struct nvme_ns *ns, *ret = NULL;
+
+	down_read(&ctrl->namespaces_rwsem);
+	list_for_each_entry(ns, &ctrl->namespaces, list) {
+		if (ns->head->ns_id == nsid) {
+			if (!nvme_get_ns(ns))
+				continue;
+			ret = ns;
+			break;
+		}
+		if (ns->head->ns_id > nsid)
+			break;
+	}
+	up_read(&ctrl->namespaces_rwsem);
+	return ret;
+}
+EXPORT_SYMBOL_NS_GPL(nvme_find_get_ns, NVME_TARGET_PASSTHRU);
+
+/*
+ * Add the namespace to the controller list while keeping the list ordered.
+ */
+static void nvme_ns_add_to_ctrl_list(struct nvme_ns *ns)
+{
+	struct nvme_ns *tmp;
+
+	list_for_each_entry_reverse(tmp, &ns->ctrl->namespaces, list) {
+		if (tmp->head->ns_id < ns->head->ns_id) {
+			list_add(&ns->list, &tmp->list);
+			return;
+		}
+	}
+	list_add(&ns->list, &ns->ctrl->namespaces);
+}
+
+static void nvme_alloc_ns(struct nvme_ctrl *ctrl, struct nvme_ns_info *info)
+{
+	struct nvme_ns *ns;
+	struct gendisk *disk;
+	int node = ctrl->numa_node;
+
+	ns = kzalloc_node(sizeof(*ns), GFP_KERNEL, node);
+	if (!ns)
+		return;
+
+	disk = blk_mq_alloc_disk(ctrl->tagset, ns);
+	if (IS_ERR(disk))
+		goto out_free_ns;
+	disk->fops = &nvme_bdev_ops;
+	disk->private_data = ns;
+
+	ns->disk = disk;
+	ns->queue = disk->queue;
+
+	if (ctrl->opts && ctrl->opts->data_digest)
+		blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, ns->queue);
+
+	blk_queue_flag_set(QUEUE_FLAG_NONROT, ns->queue);
+	if (ctrl->ops->supports_pci_p2pdma &&
+	    ctrl->ops->supports_pci_p2pdma(ctrl))
+		blk_queue_flag_set(QUEUE_FLAG_PCI_P2PDMA, ns->queue);
+
+	ns->ctrl = ctrl;
+	kref_init(&ns->kref);
+
+	if (nvme_init_ns_head(ns, info))
+		goto out_cleanup_disk;
+
+	/*
+	 * If multipathing is enabled, the device name for all disks and not
+	 * just those that represent shared namespaces needs to be based on the
+	 * subsystem instance.  Using the controller instance for private
+	 * namespaces could lead to naming collisions between shared and private
+	 * namespaces if they don't use a common numbering scheme.
+	 *
+	 * If multipathing is not enabled, disk names must use the controller
+	 * instance as shared namespaces will show up as multiple block
+	 * devices.
+	 */
+	if (ns->head->disk) {
+		sprintf(disk->disk_name, "nvme%dc%dn%d", ctrl->subsys->instance,
+			ctrl->instance, ns->head->instance);
+		disk->flags |= GENHD_FL_HIDDEN;
+	} else if (multipath) {
+		sprintf(disk->disk_name, "nvme%dn%d", ctrl->subsys->instance,
+			ns->head->instance);
+	} else {
+		sprintf(disk->disk_name, "nvme%dn%d", ctrl->instance,
+			ns->head->instance);
+	}
+
+	if (nvme_update_ns_info(ns, info))
+		goto out_unlink_ns;
+
+	down_write(&ctrl->namespaces_rwsem);
+	nvme_ns_add_to_ctrl_list(ns);
+	up_write(&ctrl->namespaces_rwsem);
+	nvme_get_ctrl(ctrl);
+
+	if (device_add_disk(ctrl->device, ns->disk, nvme_ns_id_attr_groups))
+		goto out_cleanup_ns_from_list;
+
+	if (!nvme_ns_head_multipath(ns->head))
+		nvme_add_ns_cdev(ns);
+
+	nvme_mpath_add_disk(ns, info->anagrpid);
+	nvme_fault_inject_init(&ns->fault_inject, ns->disk->disk_name);
+
+	return;
+
+ out_cleanup_ns_from_list:
+	nvme_put_ctrl(ctrl);
+	down_write(&ctrl->namespaces_rwsem);
+	list_del_init(&ns->list);
+	up_write(&ctrl->namespaces_rwsem);
+ out_unlink_ns:
+	mutex_lock(&ctrl->subsys->lock);
+	list_del_rcu(&ns->siblings);
+	if (list_empty(&ns->head->list))
+		list_del_init(&ns->head->entry);
+	mutex_unlock(&ctrl->subsys->lock);
+	nvme_put_ns_head(ns->head);
+ out_cleanup_disk:
+	put_disk(disk);
+ out_free_ns:
+	kfree(ns);
+}
+
+static void nvme_ns_remove(struct nvme_ns *ns)
+{
+	bool last_path = false;
+
+	if (test_and_set_bit(NVME_NS_REMOVING, &ns->flags))
+		return;
+
+	clear_bit(NVME_NS_READY, &ns->flags);
+	set_capacity(ns->disk, 0);
+	nvme_fault_inject_fini(&ns->fault_inject);
+
+	/*
+	 * Ensure that !NVME_NS_READY is seen by other threads to prevent
+	 * this ns going back into current_path.
+	 */
+	synchronize_srcu(&ns->head->srcu);
+
+	/* wait for concurrent submissions */
+	if (nvme_mpath_clear_current_path(ns))
+		synchronize_srcu(&ns->head->srcu);
+
+	mutex_lock(&ns->ctrl->subsys->lock);
+	list_del_rcu(&ns->siblings);
+	if (list_empty(&ns->head->list)) {
+		list_del_init(&ns->head->entry);
+		last_path = true;
+	}
+	mutex_unlock(&ns->ctrl->subsys->lock);
+
+	/* guarantee not available in head->list */
+	synchronize_srcu(&ns->head->srcu);
+
+	if (!nvme_ns_head_multipath(ns->head))
+		nvme_cdev_del(&ns->cdev, &ns->cdev_device);
+	del_gendisk(ns->disk);
+
+	down_write(&ns->ctrl->namespaces_rwsem);
+	list_del_init(&ns->list);
+	up_write(&ns->ctrl->namespaces_rwsem);
+
+	if (last_path)
+		nvme_mpath_shutdown_disk(ns->head);
+	nvme_put_ns(ns);
+}
+
+static void nvme_ns_remove_by_nsid(struct nvme_ctrl *ctrl, u32 nsid)
+{
+	struct nvme_ns *ns = nvme_find_get_ns(ctrl, nsid);
+
+	if (ns) {
+		nvme_ns_remove(ns);
+		nvme_put_ns(ns);
+	}
+}
+
+static void nvme_validate_ns(struct nvme_ns *ns, struct nvme_ns_info *info)
+{
+	int ret = NVME_SC_INVALID_NS | NVME_SC_DNR;
+
+	if (test_bit(NVME_NS_DEAD, &ns->flags))
+		goto out;
+
+	ret = NVME_SC_INVALID_NS | NVME_SC_DNR;
+	if (!nvme_ns_ids_equal(&ns->head->ids, &info->ids)) {
+		dev_err(ns->ctrl->device,
+			"identifiers changed for nsid %d\n", ns->head->ns_id);
+		goto out;
+	}
+
+	ret = nvme_update_ns_info(ns, info);
+out:
+	/*
+	 * Only remove the namespace if we got a fatal error back from the
+	 * device, otherwise ignore the error and just move on.
+	 *
+	 * TODO: we should probably schedule a delayed retry here.
+	 */
+	if (ret > 0 && (ret & NVME_SC_DNR))
+		nvme_ns_remove(ns);
+}
+
+static void nvme_scan_ns(struct nvme_ctrl *ctrl, unsigned nsid)
+{
+	struct nvme_ns_info info = { .nsid = nsid };
+	struct nvme_ns *ns;
+	int ret;
+
+	if (nvme_identify_ns_descs(ctrl, &info))
+		return;
+
+	if (info.ids.csi != NVME_CSI_NVM && !nvme_multi_css(ctrl)) {
+		dev_warn(ctrl->device,
+			"command set not reported for nsid: %d\n", nsid);
+		return;
+	}
+
+	/*
+	 * If available try to use the Command Set Idependent Identify Namespace
+	 * data structure to find all the generic information that is needed to
+	 * set up a namespace.  If not fall back to the legacy version.
+	 */
+	if ((ctrl->cap & NVME_CAP_CRMS_CRIMS) ||
+	    (info.ids.csi != NVME_CSI_NVM && info.ids.csi != NVME_CSI_ZNS))
+		ret = nvme_ns_info_from_id_cs_indep(ctrl, &info);
+	else
+		ret = nvme_ns_info_from_identify(ctrl, &info);
+
+	if (info.is_removed)
+		nvme_ns_remove_by_nsid(ctrl, nsid);
+
+	/*
+	 * Ignore the namespace if it is not ready. We will get an AEN once it
+	 * becomes ready and restart the scan.
+	 */
+	if (ret || !info.is_ready)
+		return;
+
+	ns = nvme_find_get_ns(ctrl, nsid);
+	if (ns) {
+		nvme_validate_ns(ns, &info);
+		nvme_put_ns(ns);
+	} else {
+		nvme_alloc_ns(ctrl, &info);
+	}
+}
+
+static void nvme_remove_invalid_namespaces(struct nvme_ctrl *ctrl,
+					unsigned nsid)
+{
+	struct nvme_ns *ns, *next;
+	LIST_HEAD(rm_list);
+
+	down_write(&ctrl->namespaces_rwsem);
+	list_for_each_entry_safe(ns, next, &ctrl->namespaces, list) {
+		if (ns->head->ns_id > nsid || test_bit(NVME_NS_DEAD, &ns->flags))
+			list_move_tail(&ns->list, &rm_list);
+	}
+	up_write(&ctrl->namespaces_rwsem);
+
+	list_for_each_entry_safe(ns, next, &rm_list, list)
+		nvme_ns_remove(ns);
+
+}
+
+static int nvme_scan_ns_list(struct nvme_ctrl *ctrl)
+{
+	const int nr_entries = NVME_IDENTIFY_DATA_SIZE / sizeof(__le32);
+	__le32 *ns_list;
+	u32 prev = 0;
+	int ret = 0, i;
+
+	if (nvme_ctrl_limited_cns(ctrl))
+		return -EOPNOTSUPP;
+
+	ns_list = kzalloc(NVME_IDENTIFY_DATA_SIZE, GFP_KERNEL);
+	if (!ns_list)
+		return -ENOMEM;
+
+	for (;;) {
+		struct nvme_command cmd = {
+			.identify.opcode	= nvme_admin_identify,
+			.identify.cns		= NVME_ID_CNS_NS_ACTIVE_LIST,
+			.identify.nsid		= cpu_to_le32(prev),
+		};
+
+		ret = nvme_submit_sync_cmd(ctrl->admin_q, &cmd, ns_list,
+					    NVME_IDENTIFY_DATA_SIZE);
+		if (ret) {
+			dev_warn(ctrl->device,
+				"Identify NS List failed (status=0x%x)\n", ret);
+			goto free;
+		}
+
+		for (i = 0; i < nr_entries; i++) {
+			u32 nsid = le32_to_cpu(ns_list[i]);
+
+			if (!nsid)	/* end of the list? */
+				goto out;
+			nvme_scan_ns(ctrl, nsid);
+			while (++prev < nsid)
+				nvme_ns_remove_by_nsid(ctrl, prev);
+		}
+	}
+ out:
+	nvme_remove_invalid_namespaces(ctrl, prev);
+ free:
+	kfree(ns_list);
+	return ret;
+}
+
+static void nvme_scan_ns_sequential(struct nvme_ctrl *ctrl)
+{
+	struct nvme_id_ctrl *id;
+	u32 nn, i;
+
+	if (nvme_identify_ctrl(ctrl, &id))
+		return;
+	nn = le32_to_cpu(id->nn);
+	kfree(id);
+
+	for (i = 1; i <= nn; i++)
+		nvme_scan_ns(ctrl, i);
+
+	nvme_remove_invalid_namespaces(ctrl, nn);
+}
+
+static void nvme_clear_changed_ns_log(struct nvme_ctrl *ctrl)
+{
+	size_t log_size = NVME_MAX_CHANGED_NAMESPACES * sizeof(__le32);
+	__le32 *log;
+	int error;
+
+	log = kzalloc(log_size, GFP_KERNEL);
+	if (!log)
+		return;
+
+	/*
+	 * We need to read the log to clear the AEN, but we don't want to rely
+	 * on it for the changed namespace information as userspace could have
+	 * raced with us in reading the log page, which could cause us to miss
+	 * updates.
+	 */
+	error = nvme_get_log(ctrl, NVME_NSID_ALL, NVME_LOG_CHANGED_NS, 0,
+			NVME_CSI_NVM, log, log_size, 0);
+	if (error)
+		dev_warn(ctrl->device,
+			"reading changed ns log failed: %d\n", error);
+
+	kfree(log);
+}
+
+static void nvme_scan_work(struct work_struct *work)
+{
+	struct nvme_ctrl *ctrl =
+		container_of(work, struct nvme_ctrl, scan_work);
+	int ret;
+
+	/* No tagset on a live ctrl means IO queues could not created */
+	if (ctrl->state != NVME_CTRL_LIVE || !ctrl->tagset)
+		return;
+
+	/*
+	 * Identify controller limits can change at controller reset due to
+	 * new firmware download, even though it is not common we cannot ignore
+	 * such scenario. Controller's non-mdts limits are reported in the unit
+	 * of logical blocks that is dependent on the format of attached
+	 * namespace. Hence re-read the limits at the time of ns allocation.
+	 */
+	ret = nvme_init_non_mdts_limits(ctrl);
+	if (ret < 0) {
+		dev_warn(ctrl->device,
+			"reading non-mdts-limits failed: %d\n", ret);
+		return;
+	}
+
+	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);
+	}
+
+	mutex_lock(&ctrl->scan_lock);
+	if (nvme_scan_ns_list(ctrl) != 0)
+		nvme_scan_ns_sequential(ctrl);
+	mutex_unlock(&ctrl->scan_lock);
+}
+
+/*
+ * This function iterates the namespace list unlocked to allow recovery from
+ * controller failure. It is up to the caller to ensure the namespace list is
+ * not modified by scan work while this function is executing.
+ */
+void nvme_remove_namespaces(struct nvme_ctrl *ctrl)
+{
+	struct nvme_ns *ns, *next;
+	LIST_HEAD(ns_list);
+
+	/*
+	 * make sure to requeue I/O to all namespaces as these
+	 * might result from the scan itself and must complete
+	 * for the scan_work to make progress
+	 */
+	nvme_mpath_clear_ctrl_paths(ctrl);
+
+	/* prevent racing with ns scanning */
+	flush_work(&ctrl->scan_work);
+
+	/*
+	 * The dead states indicates the controller was not gracefully
+	 * disconnected. In that case, we won't be able to flush any data while
+	 * removing the namespaces' disks; fail all the queues now to avoid
+	 * potentially having to clean up the failed sync later.
+	 */
+	if (ctrl->state == NVME_CTRL_DEAD)
+		nvme_kill_queues(ctrl);
+
+	/* this is a no-op when called from the controller reset handler */
+	nvme_change_ctrl_state(ctrl, NVME_CTRL_DELETING_NOIO);
+
+	down_write(&ctrl->namespaces_rwsem);
+	list_splice_init(&ctrl->namespaces, &ns_list);
+	up_write(&ctrl->namespaces_rwsem);
+
+	list_for_each_entry_safe(ns, next, &ns_list, list)
+		nvme_ns_remove(ns);
+}
+EXPORT_SYMBOL_GPL(nvme_remove_namespaces);
+
+static int nvme_class_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+	struct nvme_ctrl *ctrl =
+		container_of(dev, struct nvme_ctrl, ctrl_device);
+	struct nvmf_ctrl_options *opts = ctrl->opts;
+	int ret;
+
+	ret = add_uevent_var(env, "NVME_TRTYPE=%s", ctrl->ops->name);
+	if (ret)
+		return ret;
+
+	if (opts) {
+		ret = add_uevent_var(env, "NVME_TRADDR=%s", opts->traddr);
+		if (ret)
+			return ret;
+
+		ret = add_uevent_var(env, "NVME_TRSVCID=%s",
+				opts->trsvcid ?: "none");
+		if (ret)
+			return ret;
+
+		ret = add_uevent_var(env, "NVME_HOST_TRADDR=%s",
+				opts->host_traddr ?: "none");
+		if (ret)
+			return ret;
+
+		ret = add_uevent_var(env, "NVME_HOST_IFACE=%s",
+				opts->host_iface ?: "none");
+	}
+	return ret;
+}
+
+static void nvme_change_uevent(struct nvme_ctrl *ctrl, char *envdata)
+{
+	char *envp[2] = { envdata, NULL };
+
+	kobject_uevent_env(&ctrl->device->kobj, KOBJ_CHANGE, envp);
+}
+
+static void nvme_aen_uevent(struct nvme_ctrl *ctrl)
+{
+	char *envp[2] = { NULL, NULL };
+	u32 aen_result = ctrl->aen_result;
+
+	ctrl->aen_result = 0;
+	if (!aen_result)
+		return;
+
+	envp[0] = kasprintf(GFP_KERNEL, "NVME_AEN=%#08x", aen_result);
+	if (!envp[0])
+		return;
+	kobject_uevent_env(&ctrl->device->kobj, KOBJ_CHANGE, envp);
+	kfree(envp[0]);
+}
+
+static void nvme_async_event_work(struct work_struct *work)
+{
+	struct nvme_ctrl *ctrl =
+		container_of(work, struct nvme_ctrl, async_event_work);
+
+	nvme_aen_uevent(ctrl);
+
+	/*
+	 * The transport drivers must guarantee AER submission here is safe by
+	 * flushing ctrl async_event_work after changing the controller state
+	 * from LIVE and before freeing the admin queue.
+	*/
+	if (ctrl->state == NVME_CTRL_LIVE)
+		ctrl->ops->submit_async_event(ctrl);
+}
+
+static bool nvme_ctrl_pp_status(struct nvme_ctrl *ctrl)
+{
+
+	u32 csts;
+
+	if (ctrl->ops->reg_read32(ctrl, NVME_REG_CSTS, &csts))
+		return false;
+
+	if (csts == ~0)
+		return false;
+
+	return ((ctrl->ctrl_config & NVME_CC_ENABLE) && (csts & NVME_CSTS_PP));
+}
+
+static void nvme_get_fw_slot_info(struct nvme_ctrl *ctrl)
+{
+	struct nvme_fw_slot_info_log *log;
+
+	log = kmalloc(sizeof(*log), GFP_KERNEL);
+	if (!log)
+		return;
+
+	if (nvme_get_log(ctrl, NVME_NSID_ALL, NVME_LOG_FW_SLOT, 0, NVME_CSI_NVM,
+			log, sizeof(*log), 0))
+		dev_warn(ctrl->device, "Get FW SLOT INFO log error\n");
+	kfree(log);
+}
+
+static void nvme_fw_act_work(struct work_struct *work)
+{
+	struct nvme_ctrl *ctrl = container_of(work,
+				struct nvme_ctrl, fw_act_work);
+	unsigned long fw_act_timeout;
+
+	nvme_auth_stop(ctrl);
+
+	if (ctrl->mtfa)
+		fw_act_timeout = jiffies +
+				msecs_to_jiffies(ctrl->mtfa * 100);
+	else
+		fw_act_timeout = jiffies +
+				msecs_to_jiffies(admin_timeout * 1000);
+
+	nvme_stop_queues(ctrl);
+	while (nvme_ctrl_pp_status(ctrl)) {
+		if (time_after(jiffies, fw_act_timeout)) {
+			dev_warn(ctrl->device,
+				"Fw activation timeout, reset controller\n");
+			nvme_try_sched_reset(ctrl);
+			return;
+		}
+		msleep(100);
+	}
+
+	if (!nvme_change_ctrl_state(ctrl, NVME_CTRL_LIVE))
+		return;
+
+	nvme_start_queues(ctrl);
+	/* read FW slot information to clear the AER */
+	nvme_get_fw_slot_info(ctrl);
+
+	queue_work(nvme_wq, &ctrl->async_event_work);
+}
+
+static u32 nvme_aer_type(u32 result)
+{
+	return result & 0x7;
+}
+
+static u32 nvme_aer_subtype(u32 result)
+{
+	return (result & 0xff00) >> 8;
+}
+
+static bool nvme_handle_aen_notice(struct nvme_ctrl *ctrl, u32 result)
+{
+	u32 aer_notice_type = nvme_aer_subtype(result);
+	bool requeue = true;
+
+	switch (aer_notice_type) {
+	case NVME_AER_NOTICE_NS_CHANGED:
+		set_bit(NVME_AER_NOTICE_NS_CHANGED, &ctrl->events);
+		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)) {
+			requeue = false;
+			queue_work(nvme_wq, &ctrl->fw_act_work);
+		}
+		break;
+#ifdef CONFIG_NVME_MULTIPATH
+	case NVME_AER_NOTICE_ANA:
+		if (!ctrl->ana_log_buf)
+			break;
+		queue_work(nvme_wq, &ctrl->ana_work);
+		break;
+#endif
+	case NVME_AER_NOTICE_DISC_CHANGED:
+		ctrl->aen_result = result;
+		break;
+	default:
+		dev_warn(ctrl->device, "async event result %08x\n", result);
+	}
+	return requeue;
+}
+
+static void nvme_handle_aer_persistent_error(struct nvme_ctrl *ctrl)
+{
+	dev_warn(ctrl->device, "resetting controller due to AER\n");
+	nvme_reset_ctrl(ctrl);
+}
+
+void nvme_complete_async_event(struct nvme_ctrl *ctrl, __le16 status,
+		volatile union nvme_result *res)
+{
+	u32 result = le32_to_cpu(res->u32);
+	u32 aer_type = nvme_aer_type(result);
+	u32 aer_subtype = nvme_aer_subtype(result);
+	bool requeue = true;
+
+	if (le16_to_cpu(status) >> 1 != NVME_SC_SUCCESS)
+		return;
+
+	trace_nvme_async_event(ctrl, result);
+	switch (aer_type) {
+	case NVME_AER_NOTICE:
+		requeue = nvme_handle_aen_notice(ctrl, result);
+		break;
+	case NVME_AER_ERROR:
+		/*
+		 * For a persistent internal error, don't run async_event_work
+		 * to submit a new AER. The controller reset will do it.
+		 */
+		if (aer_subtype == NVME_AER_ERROR_PERSIST_INT_ERR) {
+			nvme_handle_aer_persistent_error(ctrl);
+			return;
+		}
+		fallthrough;
+	case NVME_AER_SMART:
+	case NVME_AER_CSS:
+	case NVME_AER_VS:
+		ctrl->aen_result = result;
+		break;
+	default:
+		break;
+	}
+
+	if (requeue)
+		queue_work(nvme_wq, &ctrl->async_event_work);
+}
+EXPORT_SYMBOL_GPL(nvme_complete_async_event);
+
+int nvme_alloc_admin_tag_set(struct nvme_ctrl *ctrl, struct blk_mq_tag_set *set,
+		const struct blk_mq_ops *ops, unsigned int cmd_size)
+{
+	int ret;
+
+	memset(set, 0, sizeof(*set));
+	set->ops = ops;
+	set->queue_depth = NVME_AQ_MQ_TAG_DEPTH;
+	if (ctrl->ops->flags & NVME_F_FABRICS)
+		set->reserved_tags = NVMF_RESERVED_TAGS;
+	set->numa_node = ctrl->numa_node;
+	set->flags = BLK_MQ_F_NO_SCHED;
+	if (ctrl->ops->flags & NVME_F_BLOCKING)
+		set->flags |= BLK_MQ_F_BLOCKING;
+	set->cmd_size = cmd_size;
+	set->driver_data = ctrl;
+	set->nr_hw_queues = 1;
+	set->timeout = NVME_ADMIN_TIMEOUT;
+	ret = blk_mq_alloc_tag_set(set);
+	if (ret)
+		return ret;
+
+	ctrl->admin_q = blk_mq_init_queue(set);
+	if (IS_ERR(ctrl->admin_q)) {
+		ret = PTR_ERR(ctrl->admin_q);
+		goto out_free_tagset;
+	}
+
+	if (ctrl->ops->flags & NVME_F_FABRICS) {
+		ctrl->fabrics_q = blk_mq_init_queue(set);
+		if (IS_ERR(ctrl->fabrics_q)) {
+			ret = PTR_ERR(ctrl->fabrics_q);
+			goto out_cleanup_admin_q;
+		}
+	}
+
+	ctrl->admin_tagset = set;
+	return 0;
+
+out_cleanup_admin_q:
+	blk_mq_destroy_queue(ctrl->admin_q);
+out_free_tagset:
+	blk_mq_free_tag_set(set);
+	ctrl->admin_q = NULL;
+	ctrl->fabrics_q = NULL;
+	return ret;
+}
+EXPORT_SYMBOL_GPL(nvme_alloc_admin_tag_set);
+
+void nvme_remove_admin_tag_set(struct nvme_ctrl *ctrl)
+{
+	blk_mq_destroy_queue(ctrl->admin_q);
+	if (ctrl->ops->flags & NVME_F_FABRICS)
+		blk_mq_destroy_queue(ctrl->fabrics_q);
+	blk_mq_free_tag_set(ctrl->admin_tagset);
+}
+EXPORT_SYMBOL_GPL(nvme_remove_admin_tag_set);
+
+int nvme_alloc_io_tag_set(struct nvme_ctrl *ctrl, struct blk_mq_tag_set *set,
+		const struct blk_mq_ops *ops, unsigned int nr_maps,
+		unsigned int cmd_size)
+{
+	int ret;
+
+	memset(set, 0, sizeof(*set));
+	set->ops = ops;
+	set->queue_depth = ctrl->sqsize + 1;
+	set->reserved_tags = NVMF_RESERVED_TAGS;
+	set->numa_node = ctrl->numa_node;
+	set->flags = BLK_MQ_F_SHOULD_MERGE;
+	if (ctrl->ops->flags & NVME_F_BLOCKING)
+		set->flags |= BLK_MQ_F_BLOCKING;
+	set->cmd_size = cmd_size,
+	set->driver_data = ctrl;
+	set->nr_hw_queues = ctrl->queue_count - 1;
+	set->timeout = NVME_IO_TIMEOUT;
+	set->nr_maps = nr_maps;
+	ret = blk_mq_alloc_tag_set(set);
+	if (ret)
+		return ret;
+
+	if (ctrl->ops->flags & NVME_F_FABRICS) {
+		ctrl->connect_q = blk_mq_init_queue(set);
+        	if (IS_ERR(ctrl->connect_q)) {
+			ret = PTR_ERR(ctrl->connect_q);
+			goto out_free_tag_set;
+		}
+	}
+
+	ctrl->tagset = set;
+	return 0;
+
+out_free_tag_set:
+	blk_mq_free_tag_set(set);
+	ctrl->connect_q = NULL;
+	return ret;
+}
+EXPORT_SYMBOL_GPL(nvme_alloc_io_tag_set);
+
+void nvme_remove_io_tag_set(struct nvme_ctrl *ctrl)
+{
+	if (ctrl->ops->flags & NVME_F_FABRICS)
+		blk_mq_destroy_queue(ctrl->connect_q);
+	blk_mq_free_tag_set(ctrl->tagset);
+}
+EXPORT_SYMBOL_GPL(nvme_remove_io_tag_set);
+
+void nvme_stop_ctrl(struct nvme_ctrl *ctrl)
+{
+	nvme_mpath_stop(ctrl);
+	nvme_auth_stop(ctrl);
+	nvme_stop_keep_alive(ctrl);
+	nvme_stop_failfast_work(ctrl);
+	flush_work(&ctrl->async_event_work);
+	cancel_work_sync(&ctrl->fw_act_work);
+	if (ctrl->ops->stop_ctrl)
+		ctrl->ops->stop_ctrl(ctrl);
+}
+EXPORT_SYMBOL_GPL(nvme_stop_ctrl);
+
+void nvme_start_ctrl(struct nvme_ctrl *ctrl)
+{
+	nvme_start_keep_alive(ctrl);
+
+	nvme_enable_aen(ctrl);
+
+	/*
+	 * persistent discovery controllers need to send indication to userspace
+	 * to re-read the discovery log page to learn about possible changes
+	 * that were missed. We identify persistent discovery controllers by
+	 * checking that they started once before, hence are reconnecting back.
+	 */
+	if (test_bit(NVME_CTRL_STARTED_ONCE, &ctrl->flags) &&
+	    nvme_discovery_ctrl(ctrl))
+		nvme_change_uevent(ctrl, "NVME_EVENT=rediscover");
+
+	if (ctrl->queue_count > 1) {
+		nvme_queue_scan(ctrl);
+		nvme_start_queues(ctrl);
+		nvme_mpath_update(ctrl);
+	}
+
+	nvme_change_uevent(ctrl, "NVME_EVENT=connected");
+	set_bit(NVME_CTRL_STARTED_ONCE, &ctrl->flags);
+}
+EXPORT_SYMBOL_GPL(nvme_start_ctrl);
+
+void nvme_uninit_ctrl(struct nvme_ctrl *ctrl)
+{
+	nvme_hwmon_exit(ctrl);
+	nvme_fault_inject_fini(&ctrl->fault_inject);
+	dev_pm_qos_hide_latency_tolerance(ctrl->device);
+	cdev_device_del(&ctrl->cdev, ctrl->device);
+	nvme_put_ctrl(ctrl);
+}
+EXPORT_SYMBOL_GPL(nvme_uninit_ctrl);
+
+static void nvme_free_cels(struct nvme_ctrl *ctrl)
+{
+	struct nvme_effects_log	*cel;
+	unsigned long i;
+
+	xa_for_each(&ctrl->cels, i, cel) {
+		xa_erase(&ctrl->cels, i);
+		kfree(cel);
+	}
+
+	xa_destroy(&ctrl->cels);
+}
+
+static void nvme_free_ctrl(struct device *dev)
+{
+	struct nvme_ctrl *ctrl =
+		container_of(dev, struct nvme_ctrl, ctrl_device);
+	struct nvme_subsystem *subsys = ctrl->subsys;
+
+	if (!subsys || ctrl->instance != subsys->instance)
+		ida_free(&nvme_instance_ida, ctrl->instance);
+
+	nvme_free_cels(ctrl);
+	nvme_mpath_uninit(ctrl);
+	nvme_auth_stop(ctrl);
+	nvme_auth_free(ctrl);
+	__free_page(ctrl->discard_page);
+
+	if (subsys) {
+		mutex_lock(&nvme_subsystems_lock);
+		list_del(&ctrl->subsys_entry);
+		sysfs_remove_link(&subsys->dev.kobj, dev_name(ctrl->device));
+		mutex_unlock(&nvme_subsystems_lock);
+	}
+
+	ctrl->ops->free_ctrl(ctrl);
+
+	if (subsys)
+		nvme_put_subsystem(subsys);
+}
+
+/*
+ * Initialize a NVMe controller structures.  This needs to be called during
+ * earliest initialization so that we have the initialized structured around
+ * during probing.
+ */
+int nvme_init_ctrl(struct nvme_ctrl *ctrl, struct device *dev,
+		const struct nvme_ctrl_ops *ops, unsigned long quirks)
+{
+	int ret;
+
+	ctrl->state = NVME_CTRL_NEW;
+	clear_bit(NVME_CTRL_FAILFAST_EXPIRED, &ctrl->flags);
+	spin_lock_init(&ctrl->lock);
+	mutex_init(&ctrl->scan_lock);
+	INIT_LIST_HEAD(&ctrl->namespaces);
+	xa_init(&ctrl->cels);
+	init_rwsem(&ctrl->namespaces_rwsem);
+	ctrl->dev = dev;
+	ctrl->ops = ops;
+	ctrl->quirks = quirks;
+	ctrl->numa_node = NUMA_NO_NODE;
+	INIT_WORK(&ctrl->scan_work, nvme_scan_work);
+	INIT_WORK(&ctrl->async_event_work, nvme_async_event_work);
+	INIT_WORK(&ctrl->fw_act_work, nvme_fw_act_work);
+	INIT_WORK(&ctrl->delete_work, nvme_delete_ctrl_work);
+	init_waitqueue_head(&ctrl->state_wq);
+
+	INIT_DELAYED_WORK(&ctrl->ka_work, nvme_keep_alive_work);
+	INIT_DELAYED_WORK(&ctrl->failfast_work, nvme_failfast_work);
+	memset(&ctrl->ka_cmd, 0, sizeof(ctrl->ka_cmd));
+	ctrl->ka_cmd.common.opcode = nvme_admin_keep_alive;
+
+	BUILD_BUG_ON(NVME_DSM_MAX_RANGES * sizeof(struct nvme_dsm_range) >
+			PAGE_SIZE);
+	ctrl->discard_page = alloc_page(GFP_KERNEL);
+	if (!ctrl->discard_page) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	ret = ida_alloc(&nvme_instance_ida, GFP_KERNEL);
+	if (ret < 0)
+		goto out;
+	ctrl->instance = ret;
+
+	device_initialize(&ctrl->ctrl_device);
+	ctrl->device = &ctrl->ctrl_device;
+	ctrl->device->devt = MKDEV(MAJOR(nvme_ctrl_base_chr_devt),
+			ctrl->instance);
+	ctrl->device->class = nvme_class;
+	ctrl->device->parent = ctrl->dev;
+	if (ops->dev_attr_groups)
+		ctrl->device->groups = ops->dev_attr_groups;
+	else
+		ctrl->device->groups = nvme_dev_attr_groups;
+	ctrl->device->release = nvme_free_ctrl;
+	dev_set_drvdata(ctrl->device, ctrl);
+	ret = dev_set_name(ctrl->device, "nvme%d", ctrl->instance);
+	if (ret)
+		goto out_release_instance;
+
+	nvme_get_ctrl(ctrl);
+	cdev_init(&ctrl->cdev, &nvme_dev_fops);
+	ctrl->cdev.owner = ops->module;
+	ret = cdev_device_add(&ctrl->cdev, ctrl->device);
+	if (ret)
+		goto out_free_name;
+
+	/*
+	 * Initialize latency tolerance controls.  The sysfs files won't
+	 * be visible to userspace unless the device actually supports APST.
+	 */
+	ctrl->device->power.set_latency_tolerance = nvme_set_latency_tolerance;
+	dev_pm_qos_update_user_latency_tolerance(ctrl->device,
+		min(default_ps_max_latency_us, (unsigned long)S32_MAX));
+
+	nvme_fault_inject_init(&ctrl->fault_inject, dev_name(ctrl->device));
+	nvme_mpath_init_ctrl(ctrl);
+	ret = nvme_auth_init_ctrl(ctrl);
+	if (ret)
+		goto out_free_cdev;
+
+	return 0;
+out_free_cdev:
+	nvme_fault_inject_fini(&ctrl->fault_inject);
+	dev_pm_qos_hide_latency_tolerance(ctrl->device);
+	cdev_device_del(&ctrl->cdev, ctrl->device);
+out_free_name:
+	nvme_put_ctrl(ctrl);
+	kfree_const(ctrl->device->kobj.name);
+out_release_instance:
+	ida_free(&nvme_instance_ida, ctrl->instance);
+out:
+	if (ctrl->discard_page)
+		__free_page(ctrl->discard_page);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(nvme_init_ctrl);
+
+static void nvme_start_ns_queue(struct nvme_ns *ns)
+{
+	if (test_and_clear_bit(NVME_NS_STOPPED, &ns->flags))
+		blk_mq_unquiesce_queue(ns->queue);
+}
+
+static void nvme_stop_ns_queue(struct nvme_ns *ns)
+{
+	if (!test_and_set_bit(NVME_NS_STOPPED, &ns->flags))
+		blk_mq_quiesce_queue(ns->queue);
+	else
+		blk_mq_wait_quiesce_done(ns->queue);
+}
+
+/*
+ * Prepare a queue for teardown.
+ *
+ * This must forcibly unquiesce queues to avoid blocking dispatch, and only set
+ * the capacity to 0 after that to avoid blocking dispatchers that may be
+ * holding bd_butex.  This will end buffered writers dirtying pages that can't
+ * be synced.
+ */
+static void nvme_set_queue_dying(struct nvme_ns *ns)
+{
+	if (test_and_set_bit(NVME_NS_DEAD, &ns->flags))
+		return;
+
+	blk_mark_disk_dead(ns->disk);
+	nvme_start_ns_queue(ns);
+
+	set_capacity_and_notify(ns->disk, 0);
+}
+
+/**
+ * nvme_kill_queues(): Ends all namespace queues
+ * @ctrl: the dead controller that needs to end
+ *
+ * Call this function when the driver determines it is unable to get the
+ * controller in a state capable of servicing IO.
+ */
+void nvme_kill_queues(struct nvme_ctrl *ctrl)
+{
+	struct nvme_ns *ns;
+
+	down_read(&ctrl->namespaces_rwsem);
+
+	/* Forcibly unquiesce queues to avoid blocking dispatch */
+	if (ctrl->admin_q && !blk_queue_dying(ctrl->admin_q))
+		nvme_start_admin_queue(ctrl);
+
+	list_for_each_entry(ns, &ctrl->namespaces, list)
+		nvme_set_queue_dying(ns);
+
+	up_read(&ctrl->namespaces_rwsem);
+}
+EXPORT_SYMBOL_GPL(nvme_kill_queues);
+
+void nvme_unfreeze(struct nvme_ctrl *ctrl)
+{
+	struct nvme_ns *ns;
+
+	down_read(&ctrl->namespaces_rwsem);
+	list_for_each_entry(ns, &ctrl->namespaces, list)
+		blk_mq_unfreeze_queue(ns->queue);
+	up_read(&ctrl->namespaces_rwsem);
+}
+EXPORT_SYMBOL_GPL(nvme_unfreeze);
+
+int nvme_wait_freeze_timeout(struct nvme_ctrl *ctrl, long timeout)
+{
+	struct nvme_ns *ns;
+
+	down_read(&ctrl->namespaces_rwsem);
+	list_for_each_entry(ns, &ctrl->namespaces, list) {
+		timeout = blk_mq_freeze_queue_wait_timeout(ns->queue, timeout);
+		if (timeout <= 0)
+			break;
+	}
+	up_read(&ctrl->namespaces_rwsem);
+	return timeout;
+}
+EXPORT_SYMBOL_GPL(nvme_wait_freeze_timeout);
+
+void nvme_wait_freeze(struct nvme_ctrl *ctrl)
+{
+	struct nvme_ns *ns;
+
+	down_read(&ctrl->namespaces_rwsem);
+	list_for_each_entry(ns, &ctrl->namespaces, list)
+		blk_mq_freeze_queue_wait(ns->queue);
+	up_read(&ctrl->namespaces_rwsem);
+}
+EXPORT_SYMBOL_GPL(nvme_wait_freeze);
+
+void nvme_start_freeze(struct nvme_ctrl *ctrl)
+{
+	struct nvme_ns *ns;
+
+	down_read(&ctrl->namespaces_rwsem);
+	list_for_each_entry(ns, &ctrl->namespaces, list)
+		blk_freeze_queue_start(ns->queue);
+	up_read(&ctrl->namespaces_rwsem);
+}
+EXPORT_SYMBOL_GPL(nvme_start_freeze);
+
+void nvme_stop_queues(struct nvme_ctrl *ctrl)
+{
+	struct nvme_ns *ns;
+
+	down_read(&ctrl->namespaces_rwsem);
+	list_for_each_entry(ns, &ctrl->namespaces, list)
+		nvme_stop_ns_queue(ns);
+	up_read(&ctrl->namespaces_rwsem);
+}
+EXPORT_SYMBOL_GPL(nvme_stop_queues);
+
+void nvme_start_queues(struct nvme_ctrl *ctrl)
+{
+	struct nvme_ns *ns;
+
+	down_read(&ctrl->namespaces_rwsem);
+	list_for_each_entry(ns, &ctrl->namespaces, list)
+		nvme_start_ns_queue(ns);
+	up_read(&ctrl->namespaces_rwsem);
+}
+EXPORT_SYMBOL_GPL(nvme_start_queues);
+
+void nvme_stop_admin_queue(struct nvme_ctrl *ctrl)
+{
+	if (!test_and_set_bit(NVME_CTRL_ADMIN_Q_STOPPED, &ctrl->flags))
+		blk_mq_quiesce_queue(ctrl->admin_q);
+	else
+		blk_mq_wait_quiesce_done(ctrl->admin_q);
+}
+EXPORT_SYMBOL_GPL(nvme_stop_admin_queue);
+
+void nvme_start_admin_queue(struct nvme_ctrl *ctrl)
+{
+	if (test_and_clear_bit(NVME_CTRL_ADMIN_Q_STOPPED, &ctrl->flags))
+		blk_mq_unquiesce_queue(ctrl->admin_q);
+}
+EXPORT_SYMBOL_GPL(nvme_start_admin_queue);
+
+void nvme_sync_io_queues(struct nvme_ctrl *ctrl)
+{
+	struct nvme_ns *ns;
+
+	down_read(&ctrl->namespaces_rwsem);
+	list_for_each_entry(ns, &ctrl->namespaces, list)
+		blk_sync_queue(ns->queue);
+	up_read(&ctrl->namespaces_rwsem);
+}
+EXPORT_SYMBOL_GPL(nvme_sync_io_queues);
+
+void nvme_sync_queues(struct nvme_ctrl *ctrl)
+{
+	nvme_sync_io_queues(ctrl);
+	if (ctrl->admin_q)
+		blk_sync_queue(ctrl->admin_q);
+}
+EXPORT_SYMBOL_GPL(nvme_sync_queues);
+
+struct nvme_ctrl *nvme_ctrl_from_file(struct file *file)
+{
+	if (file->f_op != &nvme_dev_fops)
+		return NULL;
+	return file->private_data;
+}
+EXPORT_SYMBOL_NS_GPL(nvme_ctrl_from_file, NVME_TARGET_PASSTHRU);
+
+/*
+ * Check we didn't inadvertently grow the command structure sizes:
+ */
+static inline void _nvme_check_size(void)
+{
+	BUILD_BUG_ON(sizeof(struct nvme_common_command) != 64);
+	BUILD_BUG_ON(sizeof(struct nvme_rw_command) != 64);
+	BUILD_BUG_ON(sizeof(struct nvme_identify) != 64);
+	BUILD_BUG_ON(sizeof(struct nvme_features) != 64);
+	BUILD_BUG_ON(sizeof(struct nvme_download_firmware) != 64);
+	BUILD_BUG_ON(sizeof(struct nvme_format_cmd) != 64);
+	BUILD_BUG_ON(sizeof(struct nvme_dsm_cmd) != 64);
+	BUILD_BUG_ON(sizeof(struct nvme_write_zeroes_cmd) != 64);
+	BUILD_BUG_ON(sizeof(struct nvme_abort_cmd) != 64);
+	BUILD_BUG_ON(sizeof(struct nvme_get_log_page_command) != 64);
+	BUILD_BUG_ON(sizeof(struct nvme_command) != 64);
+	BUILD_BUG_ON(sizeof(struct nvme_id_ctrl) != NVME_IDENTIFY_DATA_SIZE);
+	BUILD_BUG_ON(sizeof(struct nvme_id_ns) != NVME_IDENTIFY_DATA_SIZE);
+	BUILD_BUG_ON(sizeof(struct nvme_id_ns_cs_indep) !=
+			NVME_IDENTIFY_DATA_SIZE);
+	BUILD_BUG_ON(sizeof(struct nvme_id_ns_zns) != NVME_IDENTIFY_DATA_SIZE);
+	BUILD_BUG_ON(sizeof(struct nvme_id_ns_nvm) != NVME_IDENTIFY_DATA_SIZE);
+	BUILD_BUG_ON(sizeof(struct nvme_id_ctrl_zns) != NVME_IDENTIFY_DATA_SIZE);
+	BUILD_BUG_ON(sizeof(struct nvme_id_ctrl_nvm) != NVME_IDENTIFY_DATA_SIZE);
+	BUILD_BUG_ON(sizeof(struct nvme_lba_range_type) != 64);
+	BUILD_BUG_ON(sizeof(struct nvme_smart_log) != 512);
+	BUILD_BUG_ON(sizeof(struct nvme_dbbuf) != 64);
+	BUILD_BUG_ON(sizeof(struct nvme_directive_cmd) != 64);
+	BUILD_BUG_ON(sizeof(struct nvme_feat_host_behavior) != 512);
+}
+
+
+static int __init nvme_core_init(void)
+{
+	int result = -ENOMEM;
+
+	_nvme_check_size();
+
+	nvme_wq = alloc_workqueue("nvme-wq",
+			WQ_UNBOUND | WQ_MEM_RECLAIM | WQ_SYSFS, 0);
+	if (!nvme_wq)
+		goto out;
+
+	nvme_reset_wq = alloc_workqueue("nvme-reset-wq",
+			WQ_UNBOUND | WQ_MEM_RECLAIM | WQ_SYSFS, 0);
+	if (!nvme_reset_wq)
+		goto destroy_wq;
+
+	nvme_delete_wq = alloc_workqueue("nvme-delete-wq",
+			WQ_UNBOUND | WQ_MEM_RECLAIM | WQ_SYSFS, 0);
+	if (!nvme_delete_wq)
+		goto destroy_reset_wq;
+
+	result = alloc_chrdev_region(&nvme_ctrl_base_chr_devt, 0,
+			NVME_MINORS, "nvme");
+	if (result < 0)
+		goto destroy_delete_wq;
+
+	nvme_class = class_create(THIS_MODULE, "nvme");
+	if (IS_ERR(nvme_class)) {
+		result = PTR_ERR(nvme_class);
+		goto unregister_chrdev;
+	}
+	nvme_class->dev_uevent = nvme_class_uevent;
+
+	nvme_subsys_class = class_create(THIS_MODULE, "nvme-subsystem");
+	if (IS_ERR(nvme_subsys_class)) {
+		result = PTR_ERR(nvme_subsys_class);
+		goto destroy_class;
+	}
+
+	result = alloc_chrdev_region(&nvme_ns_chr_devt, 0, NVME_MINORS,
+				     "nvme-generic");
+	if (result < 0)
+		goto destroy_subsys_class;
+
+	nvme_ns_chr_class = class_create(THIS_MODULE, "nvme-generic");
+	if (IS_ERR(nvme_ns_chr_class)) {
+		result = PTR_ERR(nvme_ns_chr_class);
+		goto unregister_generic_ns;
+	}
+
+	return 0;
+
+unregister_generic_ns:
+	unregister_chrdev_region(nvme_ns_chr_devt, NVME_MINORS);
+destroy_subsys_class:
+	class_destroy(nvme_subsys_class);
+destroy_class:
+	class_destroy(nvme_class);
+unregister_chrdev:
+	unregister_chrdev_region(nvme_ctrl_base_chr_devt, NVME_MINORS);
+destroy_delete_wq:
+	destroy_workqueue(nvme_delete_wq);
+destroy_reset_wq:
+	destroy_workqueue(nvme_reset_wq);
+destroy_wq:
+	destroy_workqueue(nvme_wq);
+out:
+	return result;
+}
+
+static void __exit nvme_core_exit(void)
+{
+	class_destroy(nvme_ns_chr_class);
+	class_destroy(nvme_subsys_class);
+	class_destroy(nvme_class);
+	unregister_chrdev_region(nvme_ns_chr_devt, NVME_MINORS);
+	unregister_chrdev_region(nvme_ctrl_base_chr_devt, NVME_MINORS);
+	destroy_workqueue(nvme_delete_wq);
+	destroy_workqueue(nvme_reset_wq);
+	destroy_workqueue(nvme_wq);
+	ida_destroy(&nvme_ns_chr_minor_ida);
+	ida_destroy(&nvme_instance_ida);
+}
+
+MODULE_LICENSE("GPL");
+MODULE_VERSION("1.0");
+module_init(nvme_core_init);
+module_exit(nvme_core_exit);