[PATCH v6 1/1] nvmet: support reservation feature

Guixin Liu kanie at linux.alibaba.com
Tue Jan 30 03:20:46 PST 2024


This patch implements the reservation feature, includes:
1. reservation register(register, unregister and replace).
2. reservation acquire(acquire, preempt, preempt and abort).
3. reservation release(release and clear).
4. reservation report.

And also make reservation configurable, one can set ns to support
reservation before enable ns. The default of resv_enable is false.

Signed-off-by: Guixin Liu <kanie at linux.alibaba.com>
---
 drivers/nvme/target/Makefile    |   2 +-
 drivers/nvme/target/admin-cmd.c |  14 +-
 drivers/nvme/target/configfs.c  |  27 +
 drivers/nvme/target/core.c      |  51 +-
 drivers/nvme/target/nvmet.h     |  34 ++
 drivers/nvme/target/pr.c        | 978 ++++++++++++++++++++++++++++++++
 include/linux/nvme.h            |  48 ++
 7 files changed, 1147 insertions(+), 7 deletions(-)
 create mode 100644 drivers/nvme/target/pr.c

diff --git a/drivers/nvme/target/Makefile b/drivers/nvme/target/Makefile
index c66820102493..f9bfc904a5b3 100644
--- a/drivers/nvme/target/Makefile
+++ b/drivers/nvme/target/Makefile
@@ -10,7 +10,7 @@ obj-$(CONFIG_NVME_TARGET_FCLOOP)	+= nvme-fcloop.o
 obj-$(CONFIG_NVME_TARGET_TCP)		+= nvmet-tcp.o
 
 nvmet-y		+= core.o configfs.o admin-cmd.o fabrics-cmd.o \
-			discovery.o io-cmd-file.o io-cmd-bdev.o
+			discovery.o io-cmd-file.o io-cmd-bdev.o pr.o
 nvmet-$(CONFIG_NVME_TARGET_PASSTHRU)	+= passthru.o
 nvmet-$(CONFIG_BLK_DEV_ZONED)		+= zns.o
 nvmet-$(CONFIG_NVME_TARGET_AUTH)	+= fabrics-cmd-auth.o auth.o
diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
index 39cb570f833d..791bc7e740c0 100644
--- a/drivers/nvme/target/admin-cmd.c
+++ b/drivers/nvme/target/admin-cmd.c
@@ -176,6 +176,10 @@ static void nvmet_get_cmd_effects_nvm(struct nvme_effects_log *log)
 	log->iocs[nvme_cmd_read] =
 	log->iocs[nvme_cmd_flush] =
 	log->iocs[nvme_cmd_dsm]	=
+	log->iocs[nvme_cmd_resv_acquire] =
+	log->iocs[nvme_cmd_resv_register] =
+	log->iocs[nvme_cmd_resv_release] =
+	log->iocs[nvme_cmd_resv_report] =
 		cpu_to_le32(NVME_CMD_EFFECTS_CSUPP);
 	log->iocs[nvme_cmd_write] =
 	log->iocs[nvme_cmd_write_zeroes] =
@@ -340,6 +344,8 @@ static void nvmet_execute_get_log_page(struct nvmet_req *req)
 		return nvmet_execute_get_log_cmd_effects_ns(req);
 	case NVME_LOG_ANA:
 		return nvmet_execute_get_log_page_ana(req);
+	case NVME_LOG_RESERVATION:
+		return nvmet_execute_get_log_page_resv(req);
 	}
 	pr_debug("unhandled lid %d on qid %d\n",
 	       req->cmd->get_log_page.lid, req->sq->qid);
@@ -550,7 +556,13 @@ static void nvmet_execute_identify_ns(struct nvmet_req *req)
 	 */
 	id->nmic = NVME_NS_NMIC_SHARED;
 	id->anagrpid = cpu_to_le32(req->ns->anagrpid);
-
+	id->rescap = NVME_PR_SUPPORT_WRITE_EXCLUSIVE |
+		     NVME_PR_SUPPORT_EXCLUSIVE_ACCESS |
+		     NVME_PR_SUPPORT_WRITE_EXCLUSIVE_REG_ONLY |
+		     NVME_PR_SUPPORT_EXCLUSIVE_ACCESS_REG_ONLY |
+		     NVME_PR_SUPPORT_WRITE_EXCLUSIVE_ALL_REGS |
+		     NVME_PR_SUPPORT_EXCLUSIVE_ACCESS_ALL_REGS |
+		     NVME_PR_SUPPORT_IEKEY_VER_1_3_DEF;
 	memcpy(&id->nguid, &req->ns->nguid, sizeof(id->nguid));
 
 	id->lbaf[0].ds = req->ns->blksize_shift;
diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c
index 2482a0db2504..56aead89d21a 100644
--- a/drivers/nvme/target/configfs.c
+++ b/drivers/nvme/target/configfs.c
@@ -714,6 +714,32 @@ static ssize_t nvmet_ns_revalidate_size_store(struct config_item *item,
 
 CONFIGFS_ATTR_WO(nvmet_ns_, revalidate_size);
 
+static ssize_t nvmet_ns_resv_enable_show(struct config_item *item, char *page)
+{
+	return sprintf(page, "%d\n", to_nvmet_ns(item)->pr.enable);
+}
+
+static ssize_t nvmet_ns_resv_enable_store(struct config_item *item,
+					const char *page, size_t count)
+{
+	struct nvmet_ns *ns = to_nvmet_ns(item);
+	bool val;
+
+	if (kstrtobool(page, &val))
+		return -EINVAL;
+
+	mutex_lock(&ns->subsys->lock);
+	if (ns->enabled) {
+		pr_err("the ns:%d is already enabled.\n", ns->nsid);
+		mutex_unlock(&ns->subsys->lock);
+		return -EINVAL;
+	}
+	ns->pr.enable = val;
+	mutex_unlock(&ns->subsys->lock);
+	return count;
+}
+CONFIGFS_ATTR(nvmet_ns_, resv_enable);
+
 static struct configfs_attribute *nvmet_ns_attrs[] = {
 	&nvmet_ns_attr_device_path,
 	&nvmet_ns_attr_device_nguid,
@@ -722,6 +748,7 @@ static struct configfs_attribute *nvmet_ns_attrs[] = {
 	&nvmet_ns_attr_enable,
 	&nvmet_ns_attr_buffered_io,
 	&nvmet_ns_attr_revalidate_size,
+	&nvmet_ns_attr_resv_enable,
 #ifdef CONFIG_PCI_P2PDMA
 	&nvmet_ns_attr_p2pmem,
 #endif
diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
index d26aa30f8702..e98af9e09e4d 100644
--- a/drivers/nvme/target/core.c
+++ b/drivers/nvme/target/core.c
@@ -591,6 +591,8 @@ int nvmet_ns_enable(struct nvmet_ns *ns)
 	if (ns->nsid > subsys->max_nsid)
 		subsys->max_nsid = ns->nsid;
 
+	nvmet_pr_init_ns(ns);
+
 	ret = xa_insert(&subsys->namespaces, ns->nsid, ns, GFP_KERNEL);
 	if (ret)
 		goto out_restore_subsys_maxnsid;
@@ -646,6 +648,7 @@ void nvmet_ns_disable(struct nvmet_ns *ns)
 	synchronize_rcu();
 	wait_for_completion(&ns->disable_done);
 	percpu_ref_exit(&ns->ref);
+	nvmet_pr_exit_ns(ns);
 
 	mutex_lock(&subsys->lock);
 
@@ -904,18 +907,34 @@ static u16 nvmet_parse_io_cmd(struct nvmet_req *req)
 		return ret;
 	}
 
+	if (req->ns->pr.enable) {
+		ret = nvmet_parse_pr_cmd(req);
+		if (!ret)
+			return ret;
+	}
+
 	switch (req->ns->csi) {
 	case NVME_CSI_NVM:
 		if (req->ns->file)
-			return nvmet_file_parse_io_cmd(req);
-		return nvmet_bdev_parse_io_cmd(req);
+			ret = nvmet_file_parse_io_cmd(req);
+		else
+			ret = nvmet_bdev_parse_io_cmd(req);
+		break;
 	case NVME_CSI_ZNS:
 		if (IS_ENABLED(CONFIG_BLK_DEV_ZONED))
-			return nvmet_bdev_zns_parse_io_cmd(req);
-		return NVME_SC_INVALID_IO_CMD_SET;
+			ret = nvmet_bdev_zns_parse_io_cmd(req);
+		else
+			ret = NVME_SC_INVALID_IO_CMD_SET;
+		break;
 	default:
-		return NVME_SC_INVALID_IO_CMD_SET;
+		ret = NVME_SC_INVALID_IO_CMD_SET;
 	}
+	if (ret)
+		return ret;
+
+	if (req->ns->pr.enable)
+		ret = nvmet_pr_check_cmd_access(req);
+	return ret;
 }
 
 bool nvmet_req_init(struct nvmet_req *req, struct nvmet_cq *cq,
@@ -1231,6 +1250,22 @@ static void nvmet_init_cap(struct nvmet_ctrl *ctrl)
 		nvmet_passthrough_override_cap(ctrl);
 }
 
+bool nvmet_is_host_still_connected(uuid_t *hostid, struct nvmet_subsys *subsys)
+{
+	struct nvmet_ctrl *ctrl;
+	bool ret = false;
+
+	mutex_lock(&subsys->lock);
+	list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) {
+		if (uuid_equal(hostid, &ctrl->hostid)) {
+			ret = true;
+			break;
+		}
+	}
+	mutex_unlock(&subsys->lock);
+	return ret;
+}
+
 struct nvmet_ctrl *nvmet_ctrl_find_get(const char *subsysnqn,
 				       const char *hostnqn, u16 cntlid,
 				       struct nvmet_req *req)
@@ -1447,6 +1482,11 @@ u16 nvmet_alloc_ctrl(const char *subsysnqn, const char *hostnqn,
 	ctrl->err_counter = 0;
 	spin_lock_init(&ctrl->error_lock);
 
+	ctrl->pr_log_mgr.counter = 0;
+	ctrl->pr_log_mgr.lost_count = 0;
+	mutex_init(&ctrl->pr_log_mgr.lock);
+	INIT_KFIFO(ctrl->pr_log_mgr.log_queue);
+
 	nvmet_start_keep_alive_timer(ctrl);
 
 	mutex_lock(&subsys->lock);
@@ -1485,6 +1525,7 @@ static void nvmet_ctrl_free(struct kref *ref)
 	cancel_work_sync(&ctrl->fatal_err_work);
 
 	nvmet_destroy_auth(ctrl);
+	nvmet_ctrl_destroy_pr(ctrl);
 
 	ida_free(&cntlid_ida, ctrl->cntlid);
 
diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
index 6c8acebe1a1a..e656ee0ebd30 100644
--- a/drivers/nvme/target/nvmet.h
+++ b/drivers/nvme/target/nvmet.h
@@ -20,6 +20,7 @@
 #include <linux/blkdev.h>
 #include <linux/radix-tree.h>
 #include <linux/t10-pi.h>
+#include <linux/kfifo.h>
 
 #define NVMET_DEFAULT_VS		NVME_VS(1, 3, 0)
 
@@ -30,6 +31,7 @@
 #define NVMET_MN_MAX_SIZE		40
 #define NVMET_SN_MAX_SIZE		20
 #define NVMET_FR_MAX_SIZE		8
+#define NVMET_PR_LOG_QUEUE_SIZE		64
 
 /*
  * Supported optional AENs:
@@ -56,6 +58,21 @@
 #define IPO_IATTR_CONNECT_SQE(x)	\
 	(cpu_to_le32(offsetof(struct nvmf_connect_command, x)))
 
+struct nvmet_pr_registrant {
+	u64			rkey;
+	uuid_t			hostid;
+	enum nvme_pr_type	rtype;
+	struct list_head	entry;
+};
+
+struct nvmet_pr {
+	bool			enable;
+	atomic_t		generation;
+	struct nvmet_pr_registrant __rcu *holder;
+	struct mutex		pr_lock;
+	struct list_head	registrant_list;
+};
+
 struct nvmet_ns {
 	struct percpu_ref	ref;
 	struct bdev_handle	*bdev_handle;
@@ -85,6 +102,7 @@ struct nvmet_ns {
 	int			pi_type;
 	int			metadata_size;
 	u8			csi;
+	struct nvmet_pr		pr;
 };
 
 static inline struct nvmet_ns *to_nvmet_ns(struct config_item *item)
@@ -190,6 +208,13 @@ static inline bool nvmet_port_secure_channel_required(struct nvmet_port *port)
     return nvmet_port_disc_addr_treq_secure_channel(port) == NVMF_TREQ_REQUIRED;
 }
 
+struct nvmet_pr_log_mgr {
+	struct mutex		lock;
+	u64			lost_count;
+	u64			counter;
+	DECLARE_KFIFO(log_queue, struct nvme_pr_log, NVMET_PR_LOG_QUEUE_SIZE);
+};
+
 struct nvmet_ctrl {
 	struct nvmet_subsys	*subsys;
 	struct nvmet_sq		**sqs;
@@ -243,6 +268,7 @@ struct nvmet_ctrl {
 	u8			*dh_key;
 	size_t			dh_keysize;
 #endif
+	struct nvmet_pr_log_mgr pr_log_mgr;
 };
 
 struct nvmet_subsys {
@@ -750,4 +776,12 @@ static inline bool nvmet_has_auth(struct nvmet_ctrl *ctrl)
 static inline const char *nvmet_dhchap_dhgroup_name(u8 dhgid) { return NULL; }
 #endif
 
+void nvmet_pr_init_ns(struct nvmet_ns *ns);
+u16 nvmet_parse_pr_cmd(struct nvmet_req *req);
+u16 nvmet_pr_check_cmd_access(struct nvmet_req *req);
+void nvmet_ctrl_destroy_pr(struct nvmet_ctrl *ctrl);
+void nvmet_pr_exit_ns(struct nvmet_ns *ns);
+bool nvmet_is_host_still_connected(uuid_t *hostid, struct nvmet_subsys *subsys);
+void nvmet_execute_get_log_page_resv(struct nvmet_req *req);
+
 #endif /* _NVMET_H */
diff --git a/drivers/nvme/target/pr.c b/drivers/nvme/target/pr.c
new file mode 100644
index 000000000000..b1317554a5ec
--- /dev/null
+++ b/drivers/nvme/target/pr.c
@@ -0,0 +1,978 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * NVMe over Fabrics Persist Reservation.
+ * Copyright (c) 2024 Guixin Liu, Alibaba Group.
+ * All rights reserved.
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include "nvmet.h"
+#include <linux/slab.h>
+#include <asm/unaligned.h>
+#include <linux/lockdep.h>
+
+struct nvmet_pr_register_data {
+	__le64	crkey;
+	__le64	nrkey;
+};
+
+struct nvmet_pr_acquire_data {
+	__le64	crkey;
+	__le64	prkey;
+};
+
+struct nvmet_pr_release_data {
+	__le64	crkey;
+};
+
+static inline struct nvmet_ns *nvmet_pr_to_ns(struct nvmet_pr *pr)
+{
+	return container_of(pr, struct nvmet_ns, pr);
+}
+
+static u16 nvmet_pr_validate_rtype(u8 rtype)
+{
+	if (rtype < NVME_PR_WRITE_EXCLUSIVE ||
+	    rtype > NVME_PR_EXCLUSIVE_ACCESS_ALL_REGS)
+		return NVME_SC_INVALID_FIELD | NVME_SC_DNR;
+
+	return NVME_SC_SUCCESS;
+}
+
+static u16 nvmet_pr_set_rtype_and_holder(struct nvmet_pr *pr, u8 rtype,
+					 struct nvmet_pr_registrant *reg)
+{
+	u16 status;
+
+	status = nvmet_pr_validate_rtype(rtype);
+	if (!status) {
+		reg->rtype = rtype;
+		rcu_assign_pointer(pr->holder, reg);
+	}
+	return status;
+}
+
+static struct nvmet_pr_registrant *
+nvmet_pr_find_registrant_by_hostid(struct nvmet_pr *pr, uuid_t *hostid)
+{
+	struct nvmet_pr_registrant *reg;
+
+	WARN_ON_ONCE(!rcu_read_lock_held() &&
+		     !lockdep_is_held(&pr->pr_lock));
+
+	list_for_each_entry_rcu(reg, &pr->registrant_list, entry,
+				rcu_read_lock_held() ||
+				lockdep_is_held(&pr->pr_lock)) {
+		if (uuid_equal(&reg->hostid, hostid))
+			return reg;
+	}
+	return NULL;
+}
+
+void nvmet_execute_get_log_page_resv(struct nvmet_req *req)
+{
+	struct nvmet_pr_log_mgr *log_mgr = &req->sq->ctrl->pr_log_mgr;
+	struct nvme_pr_log next_log = {0};
+	struct nvme_pr_log log = {0};
+	u16 status = NVME_SC_SUCCESS;
+	u64 lost_count;
+	u64 cur_count;
+	u64 next_count;
+
+	mutex_lock(&log_mgr->lock);
+	if (!kfifo_get(&log_mgr->log_queue, &log))
+		goto out;
+
+	/*
+	 * We can't get the last in kfifo.
+	 * Utilize the current count and the count from the next log to
+	 * calculate the number of lost logs, while also addressing cases
+	 * of overflow. If there is no subsequent log, the number of lost
+	 * logs is equal to the lost_count within the nvmet_pr_log_mgr.
+	 */
+	cur_count = le64_to_cpu(log.count);
+	if (kfifo_peek(&log_mgr->log_queue, &next_log)) {
+		next_count = le64_to_cpu(next_log.count);
+		if (next_count > cur_count)
+			lost_count = next_count - cur_count - 1;
+		else
+			lost_count = U64_MAX - cur_count + next_count - 1;
+	} else {
+		lost_count = log_mgr->lost_count;
+	}
+
+	log.count = cpu_to_le64(cur_count + lost_count);
+	log_mgr->lost_count -= lost_count;
+
+	log.nr_pages = kfifo_len(&log_mgr->log_queue);
+
+	status = nvmet_copy_to_sgl(req, 0, &log, sizeof(log));
+
+out:
+	mutex_unlock(&log_mgr->lock);
+	nvmet_req_complete(req, status);
+}
+
+static void nvmet_pr_add_resv_log(struct nvmet_ctrl *ctrl, u8 log_type, u32 nsid)
+{
+	struct nvmet_pr_log_mgr *log_mgr = &ctrl->pr_log_mgr;
+	struct nvme_pr_log log = {0};
+
+	mutex_lock(&log_mgr->lock);
+	log_mgr->counter++;
+	if (log_mgr->counter == 0)
+		log_mgr->counter = 1;
+
+	log.count = cpu_to_le64(log_mgr->counter);
+	log.type = log_type;
+	log.nsid = cpu_to_le32(nsid);
+
+	if (!kfifo_put(&log_mgr->log_queue, log)) {
+		pr_warn("a reservation log lost, cntlid:%d, log_type:%d, nsid:%d\n",
+			ctrl->cntlid, log_type, nsid);
+		log_mgr->lost_count++;
+	}
+
+	mutex_unlock(&log_mgr->lock);
+}
+
+static void nvmet_pr_send_resv_released(struct nvmet_pr *pr, uuid_t *hostid)
+{
+	struct nvmet_ns *ns = nvmet_pr_to_ns(pr);
+	struct nvmet_subsys *subsys = ns->subsys;
+	struct nvmet_ctrl *ctrl;
+
+	mutex_lock(&subsys->lock);
+	list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) {
+		if (!uuid_equal(&ctrl->hostid, hostid) &&
+		    nvmet_pr_find_registrant_by_hostid(pr, &ctrl->hostid)) {
+			nvmet_pr_add_resv_log(ctrl,
+				NVME_PR_LOG_RESERVATION_RELEASED, ns->nsid);
+			nvmet_add_async_event(ctrl, NVME_AER_CSS,
+				NVME_AEN_RESV_LOG_PAGE_AVALIABLE,
+				NVME_LOG_RESERVATION);
+		}
+	}
+	mutex_unlock(&subsys->lock);
+}
+
+static void nvmet_pr_send_event_by_hostid(struct nvmet_pr *pr, uuid_t *hostid,
+					  u8 log_type)
+{
+	struct nvmet_ns *ns = nvmet_pr_to_ns(pr);
+	struct nvmet_subsys *subsys = ns->subsys;
+	struct nvmet_ctrl *ctrl;
+
+	mutex_lock(&subsys->lock);
+	list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) {
+		if (uuid_equal(hostid, &ctrl->hostid)) {
+			nvmet_pr_add_resv_log(ctrl, log_type, ns->nsid);
+			nvmet_add_async_event(ctrl, NVME_AER_CSS,
+				NVME_AEN_RESV_LOG_PAGE_AVALIABLE,
+				NVME_LOG_RESERVATION);
+		}
+	}
+	mutex_unlock(&subsys->lock);
+}
+
+static void nvmet_pr_send_resv_preempted(struct nvmet_pr *pr, uuid_t *hostid)
+{
+	nvmet_pr_send_event_by_hostid(pr, hostid,
+		NVME_PR_LOG_RESERVATOPM_PREEMPTED);
+}
+
+static void nvmet_pr_send_registration_preempted(struct nvmet_pr *pr,
+						 uuid_t *hostid)
+{
+	nvmet_pr_send_event_by_hostid(pr, hostid,
+		NVME_PR_LOG_REGISTRATION_PREEMPTED);
+}
+
+static u16 nvmet_pr_register(struct nvmet_req *req,
+			     struct nvmet_pr_register_data *d)
+{
+	struct nvmet_ctrl *ctrl = req->sq->ctrl;
+	struct nvmet_pr_registrant *new, *reg;
+	struct nvmet_pr *pr = &req->ns->pr;
+	u16 status = NVME_SC_SUCCESS;
+
+	new = kmalloc(sizeof(*new), GFP_KERNEL);
+	if (!new)
+		return NVME_SC_INTERNAL;
+
+	mutex_lock(&pr->pr_lock);
+	reg = nvmet_pr_find_registrant_by_hostid(pr, &ctrl->hostid);
+	if (reg) {
+		if (reg->rkey != le64_to_cpu(d->nrkey))
+			status = NVME_SC_RESERVATION_CONFLICT | NVME_SC_DNR;
+		kfree(new);
+		goto out;
+	}
+
+	memset(new, 0, sizeof(*new));
+	INIT_LIST_HEAD(&new->entry);
+	new->rkey = le64_to_cpu(d->nrkey);
+	uuid_copy(&new->hostid, &ctrl->hostid);
+	list_add_tail_rcu(&new->entry, &pr->registrant_list);
+
+out:
+	mutex_unlock(&pr->pr_lock);
+	return status;
+}
+
+static void __nvmet_pr_unregister_one(struct nvmet_pr *pr,
+				      struct nvmet_pr_registrant *reg)
+{
+	struct nvmet_pr_registrant *first_reg;
+	struct nvmet_pr_registrant *holder;
+	u8 original_rtype;
+
+	lockdep_assert_held(&pr->pr_lock);
+	list_del_rcu(&reg->entry);
+
+	holder = rcu_dereference_protected(pr->holder,
+			lockdep_is_held(&pr->pr_lock));
+	if (reg != holder)
+		goto out;
+
+	original_rtype = holder->rtype;
+	if (original_rtype == NVME_PR_WRITE_EXCLUSIVE_ALL_REGS ||
+	    original_rtype == NVME_PR_EXCLUSIVE_ACCESS_ALL_REGS) {
+		first_reg = list_first_or_null_rcu(&pr->registrant_list,
+				struct nvmet_pr_registrant, entry);
+		if (first_reg)
+			first_reg->rtype = original_rtype;
+		rcu_assign_pointer(pr->holder, first_reg);
+	} else {
+		rcu_assign_pointer(pr->holder, NULL);
+
+		if (original_rtype == NVME_PR_WRITE_EXCLUSIVE_REG_ONLY ||
+		    original_rtype == NVME_PR_WRITE_EXCLUSIVE_REG_ONLY)
+			nvmet_pr_send_resv_released(pr, &reg->hostid);
+	}
+out:
+	synchronize_rcu();
+	kfree(reg);
+}
+
+static u16 nvmet_pr_unregister(struct nvmet_req *req,
+			       struct nvmet_pr_register_data *d,
+			       bool ignore_key)
+{
+	u16 status = NVME_SC_RESERVATION_CONFLICT | NVME_SC_DNR;
+	struct nvmet_ctrl *ctrl = req->sq->ctrl;
+	struct nvmet_pr *pr = &req->ns->pr;
+	struct nvmet_pr_registrant *reg;
+
+	mutex_lock(&pr->pr_lock);
+	list_for_each_entry_rcu(reg, &pr->registrant_list, entry,
+				lockdep_is_held(&pr->pr_lock)) {
+		if (uuid_equal(&reg->hostid, &ctrl->hostid)) {
+			if (ignore_key || reg->rkey == le64_to_cpu(d->crkey)) {
+				status = NVME_SC_SUCCESS;
+				__nvmet_pr_unregister_one(pr, reg);
+			}
+			break;
+		}
+	}
+	mutex_unlock(&pr->pr_lock);
+
+	return status;
+}
+
+static u16 nvmet_pr_update_reg_rkey(struct nvmet_pr_registrant *reg,
+				    void *attr)
+{
+	reg->rkey = *(u64 *)attr;
+	return NVME_SC_SUCCESS;
+}
+
+static u16 nvmet_pr_update_reg_attr(struct nvmet_pr *pr,
+				    struct nvmet_pr_registrant *reg,
+				    u16 (*change_attr)(struct nvmet_pr_registrant *reg, void *attr),
+				    void *attr)
+{
+	struct nvmet_pr_registrant *holder;
+	struct nvmet_pr_registrant *new;
+	u16 status;
+
+	lockdep_assert_held(&pr->pr_lock);
+	holder = rcu_dereference_protected(pr->holder,
+			lockdep_is_held(&pr->pr_lock));
+	if (reg != holder)
+		return change_attr(reg, attr);
+
+	new = kmalloc(sizeof(*new), GFP_ATOMIC);
+	if (!new)
+		return NVME_SC_INTERNAL;
+
+	new->rkey = holder->rkey;
+	new->rtype = holder->rtype;
+	uuid_copy(&new->hostid, &holder->hostid);
+	INIT_LIST_HEAD(&new->entry);
+
+	status = change_attr(new, attr);
+	if (!status) {
+		list_replace_rcu(&holder->entry, &new->entry);
+		rcu_assign_pointer(pr->holder, new);
+		synchronize_rcu();
+		kfree(holder);
+	} else {
+		kfree(new);
+	}
+
+	return status;
+}
+
+static u16 nvmet_pr_replace(struct nvmet_req *req,
+			    struct nvmet_pr_register_data *d,
+			    bool ignore_key)
+{
+	u16 status = NVME_SC_RESERVATION_CONFLICT | NVME_SC_DNR;
+	struct nvmet_ctrl *ctrl = req->sq->ctrl;
+	struct nvmet_pr *pr = &req->ns->pr;
+	struct nvmet_pr_registrant *reg;
+	u64 nrkey = le64_to_cpu(d->nrkey);
+
+	mutex_lock(&pr->pr_lock);
+	list_for_each_entry_rcu(reg, &pr->registrant_list, entry,
+				lockdep_is_held(&pr->pr_lock)) {
+		if (uuid_equal(&reg->hostid, &ctrl->hostid)) {
+			if (ignore_key || reg->rkey == le64_to_cpu(d->crkey))
+				status = nvmet_pr_update_reg_attr(pr, reg,
+						nvmet_pr_update_reg_rkey,
+						&nrkey);
+			break;
+		}
+	}
+	mutex_unlock(&pr->pr_lock);
+	return status;
+}
+
+static void nvmet_execute_pr_register(struct nvmet_req *req)
+{
+	u32 cdw10 = le32_to_cpu(req->cmd->common.cdw10);
+	bool ignore_key = (bool)((cdw10 >> 3) & 1); /* Ignore existing key, bit 03 */
+	struct nvmet_pr_register_data *d;
+	u8 reg_act = cdw10 & 0x07; /* Reservation Register Action, bit 02:00 */
+	u16 status;
+
+	d = kmalloc(sizeof(*d), GFP_KERNEL);
+	if (!d) {
+		status = NVME_SC_INTERNAL;
+		goto out;
+	}
+
+	status = nvmet_copy_from_sgl(req, 0, d, sizeof(*d));
+	if (status)
+		goto free_data;
+
+	switch (reg_act) {
+	case NVME_PR_REGISTER_ACT_REG:
+		status = nvmet_pr_register(req, d);
+		break;
+	case NVME_PR_REGISTER_ACT_UNREG:
+		status = nvmet_pr_unregister(req, d, ignore_key);
+		break;
+	case NVME_PR_REGISTER_ACT_REPLACE:
+		status = nvmet_pr_replace(req, d, ignore_key);
+		break;
+	default:
+		req->error_loc = offsetof(struct nvme_common_command, cdw10);
+		status = NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
+		break;
+	}
+free_data:
+	kfree(d);
+out:
+	if (!status)
+		atomic_inc(&req->ns->pr.generation);
+	nvmet_req_complete(req, status);
+}
+
+static u16 nvmet_pr_acquire(struct nvmet_req *req,
+			    struct nvmet_pr_registrant *reg,
+			    u8 rtype)
+{
+	struct nvmet_pr *pr = &req->ns->pr;
+	struct nvmet_pr_registrant *holder;
+
+	lockdep_assert_held(&pr->pr_lock);
+	holder = rcu_dereference_protected(pr->holder,
+			lockdep_is_held(&pr->pr_lock));
+	if (holder && reg != holder)
+		return  NVME_SC_RESERVATION_CONFLICT | NVME_SC_DNR;
+	if (holder && reg == holder) {
+		if (holder->rtype == rtype)
+			return NVME_SC_SUCCESS;
+		return NVME_SC_RESERVATION_CONFLICT | NVME_SC_DNR;
+	}
+
+	return nvmet_pr_set_rtype_and_holder(pr, rtype, reg);
+}
+
+static u16 nvmet_pr_unreg_by_prkey(struct nvmet_pr *pr, u64 prkey,
+				   uuid_t *send_hostid)
+{
+	u16 status = NVME_SC_RESERVATION_CONFLICT | NVME_SC_DNR;
+	struct nvmet_pr_registrant *reg, *tmp;
+
+	lockdep_assert_held(&pr->pr_lock);
+
+	list_for_each_entry_safe(reg, tmp, &pr->registrant_list, entry) {
+		if (reg->rkey == prkey) {
+			status = NVME_SC_SUCCESS;
+			if (!uuid_equal(&reg->hostid, send_hostid))
+				nvmet_pr_send_registration_preempted(pr,
+					&reg->hostid);
+			__nvmet_pr_unregister_one(pr, reg);
+		}
+	}
+	return status;
+}
+
+static u16 nvmet_pr_unreg_by_prkey_except_hostid(struct nvmet_pr *pr, u64 prkey,
+						 uuid_t *send_hostid)
+{
+	u16 status = NVME_SC_RESERVATION_CONFLICT | NVME_SC_DNR;
+	struct nvmet_pr_registrant *reg, *tmp;
+
+	lockdep_assert_held(&pr->pr_lock);
+
+	list_for_each_entry_safe(reg, tmp, &pr->registrant_list, entry) {
+		if (reg->rkey == prkey &&
+		    !uuid_equal(&reg->hostid, send_hostid)) {
+			status = NVME_SC_SUCCESS;
+			nvmet_pr_send_registration_preempted(pr, &reg->hostid);
+			__nvmet_pr_unregister_one(pr, reg);
+		}
+	}
+	return status;
+}
+
+static void nvmet_pr_unreg_except_hostid(struct nvmet_pr *pr,
+					 uuid_t *send_hostid)
+{
+	struct nvmet_pr_registrant *reg, *tmp;
+
+	lockdep_assert_held(&pr->pr_lock);
+
+	list_for_each_entry_safe(reg, tmp, &pr->registrant_list, entry) {
+		if (!uuid_equal(&reg->hostid, send_hostid)) {
+			nvmet_pr_send_registration_preempted(pr, &reg->hostid);
+			__nvmet_pr_unregister_one(pr, reg);
+		}
+	}
+}
+
+static u16 nvmet_pr_create_new_resv(struct nvmet_pr *pr,
+				    u8 original_rtype,
+				    u8 new_rtype,
+				    struct nvmet_pr_registrant *reg)
+{
+	u16 status;
+
+	status = nvmet_pr_set_rtype_and_holder(pr, new_rtype, reg);
+	if (!status && original_rtype != new_rtype)
+		nvmet_pr_send_resv_released(pr, &reg->hostid);
+	return status;
+}
+
+static u16 nvmet_pr_update_holder_rtype(struct nvmet_pr_registrant *reg,
+					void *attr)
+{
+	u8 new_rtype = *(u8 *)attr;
+	u16 status;
+
+	status = nvmet_pr_validate_rtype(new_rtype);
+	if (status)
+		return status;
+
+	reg->rtype = new_rtype;
+	return NVME_SC_SUCCESS;
+}
+
+static u16 nvmet_pr_preempt(struct nvmet_req *req,
+			    struct nvmet_pr_registrant *reg,
+			    u8 rtype,
+			    struct nvmet_pr_acquire_data *d)
+{
+	struct nvmet_ctrl *ctrl = req->sq->ctrl;
+	struct nvmet_pr *pr = &req->ns->pr;
+	struct nvmet_pr_registrant *holder;
+	enum nvme_pr_type original_rtype;
+	u16 status;
+
+	lockdep_assert_held(&pr->pr_lock);
+	holder = rcu_dereference_protected(pr->holder,
+			lockdep_is_held(&pr->pr_lock));
+	if (!holder)
+		return nvmet_pr_unreg_by_prkey(pr, le64_to_cpu(d->prkey),
+				&ctrl->hostid);
+
+	original_rtype = holder->rtype;
+	if (original_rtype == NVME_PR_WRITE_EXCLUSIVE_ALL_REGS ||
+	    original_rtype == NVME_PR_EXCLUSIVE_ACCESS_ALL_REGS) {
+		if (!le64_to_cpu(d->prkey)) {
+			nvmet_pr_unreg_except_hostid(pr, &ctrl->hostid);
+			return nvmet_pr_create_new_resv(pr, original_rtype,
+					rtype, reg);
+		}
+		return nvmet_pr_unreg_by_prkey(pr, le64_to_cpu(d->prkey),
+				&ctrl->hostid);
+	}
+
+	if (holder == reg) {
+		status = nvmet_pr_update_reg_attr(pr, holder,
+				nvmet_pr_update_holder_rtype, &rtype);
+		if (status)
+			return status;
+		if (original_rtype != rtype)
+			nvmet_pr_send_resv_released(pr, &reg->hostid);
+		return status;
+	}
+
+	if (le64_to_cpu(d->prkey) == holder->rkey) {
+		status = nvmet_pr_unreg_by_prkey_except_hostid(pr,
+				le64_to_cpu(d->prkey), &ctrl->hostid);
+		if (status)
+			return status;
+		return nvmet_pr_create_new_resv(pr, original_rtype, rtype, reg);
+	}
+
+	if (le64_to_cpu(d->prkey))
+		return nvmet_pr_unreg_by_prkey(pr, le64_to_cpu(d->prkey),
+				&ctrl->hostid);
+	return NVME_SC_INVALID_FIELD | NVME_SC_DNR;
+}
+
+static u16 __nvmet_execute_pr_acquire(struct nvmet_req *req,
+				      struct nvmet_pr_registrant *reg,
+				      u8 acquire_act,
+				      u8 rtype,
+				      struct nvmet_pr_acquire_data *d)
+{
+	u16 status;
+
+	switch (acquire_act) {
+	case NVME_PR_ACQUIRE_ACT_ACQUIRE:
+		status = nvmet_pr_acquire(req, reg, rtype);
+		goto out;
+	case NVME_PR_ACQUIRE_ACT_PREEMPT:
+		status = nvmet_pr_preempt(req, reg, rtype, d);
+		goto inc_gen;
+	case NVME_PR_ACQUIRE_ACT_PREEMPT_AND_ABORT:
+		status = nvmet_pr_preempt(req, reg, rtype, d);
+		goto inc_gen;
+	default:
+		req->error_loc = offsetof(struct nvme_common_command, cdw10);
+		status = NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
+		goto out;
+	}
+inc_gen:
+	if (!status)
+		atomic_inc(&req->ns->pr.generation);
+out:
+	return status;
+}
+
+static void nvmet_execute_pr_acquire(struct nvmet_req *req)
+{
+	u32 cdw10 = le32_to_cpu(req->cmd->common.cdw10);
+	bool ignore_key = (bool)((cdw10 >> 3) & 1); /* Ignore existing key, bit 03 */
+	u8 rtype = (u8)((cdw10 >> 8) & 0xff); /* Reservation type, bit 15:08 */
+	u8 acquire_act = cdw10 & 0x07; /* Reservation acquire action, bit 02:00 */
+	struct nvmet_ctrl *ctrl = req->sq->ctrl;
+	struct nvmet_pr_acquire_data *d = NULL;
+	struct nvmet_pr *pr = &req->ns->pr;
+	struct nvmet_pr_registrant *reg;
+	u16 status = NVME_SC_SUCCESS;
+
+	if (ignore_key) {
+		status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
+		goto out;
+	}
+
+	d = kmalloc(sizeof(*d), GFP_KERNEL);
+	if (!d) {
+		status = NVME_SC_INTERNAL;
+		goto out;
+	}
+
+	status = nvmet_copy_from_sgl(req, 0, d, sizeof(*d));
+	if (status)
+		goto free_data;
+
+	status = NVME_SC_RESERVATION_CONFLICT | NVME_SC_DNR;
+	mutex_lock(&pr->pr_lock);
+	list_for_each_entry_rcu(reg, &pr->registrant_list, entry,
+				lockdep_is_held(&pr->pr_lock)) {
+		if (uuid_equal(&reg->hostid, &ctrl->hostid) &&
+		    reg->rkey == le64_to_cpu(d->crkey)) {
+			status = __nvmet_execute_pr_acquire(req, reg,
+					acquire_act, rtype, d);
+			break;
+		}
+	}
+	mutex_unlock(&pr->pr_lock);
+
+free_data:
+	kfree(d);
+out:
+	nvmet_req_complete(req, status);
+}
+
+static u16 nvmet_pr_release(struct nvmet_req *req,
+			    struct nvmet_pr_registrant *reg,
+			    u8 rtype)
+{
+	struct nvmet_pr *pr = &req->ns->pr;
+	struct nvmet_pr_registrant *holder;
+	u8 original_rtype;
+
+	lockdep_assert_held(&pr->pr_lock);
+	holder = rcu_dereference_protected(pr->holder,
+			lockdep_is_held(&pr->pr_lock));
+	if (!holder || reg != holder)
+		return NVME_SC_SUCCESS;
+
+	original_rtype = holder->rtype;
+	if (original_rtype != rtype)
+		return NVME_SC_RESERVATION_CONFLICT | NVME_SC_DNR;
+
+	rcu_assign_pointer(pr->holder, NULL);
+
+	if (original_rtype != NVME_PR_WRITE_EXCLUSIVE &&
+	    original_rtype != NVME_PR_EXCLUSIVE_ACCESS)
+		nvmet_pr_send_resv_released(pr, &reg->hostid);
+
+	return NVME_SC_SUCCESS;
+}
+
+static void nvmet_pr_clear(struct nvmet_req *req)
+{
+	struct nvmet_pr_registrant *reg, *tmp;
+	struct nvmet_pr *pr = &req->ns->pr;
+
+	lockdep_assert_held(&pr->pr_lock);
+
+	rcu_assign_pointer(pr->holder, NULL);
+
+	list_for_each_entry_safe(reg, tmp, &pr->registrant_list, entry) {
+		list_del_rcu(&reg->entry);
+		if (!uuid_equal(&req->sq->ctrl->hostid, &reg->hostid))
+			nvmet_pr_send_resv_preempted(pr, &reg->hostid);
+		synchronize_rcu();
+		kfree(reg);
+	}
+
+	atomic_inc(&pr->generation);
+}
+
+static u16 __nvmet_execute_pr_release(struct nvmet_req *req,
+				      struct nvmet_pr_registrant *reg,
+				      u8 release_act, u8 rtype)
+{
+	switch (release_act) {
+	case NVME_PR_RELEASE_ACT_RELEASE:
+		return nvmet_pr_release(req, reg, rtype);
+	case NVME_PR_RELEASE_ACT_CLEAR:
+		nvmet_pr_clear(req);
+		return NVME_SC_SUCCESS;
+	default:
+		req->error_loc = offsetof(struct nvme_common_command, cdw10);
+		return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
+	}
+}
+
+static void nvmet_execute_pr_release(struct nvmet_req *req)
+{
+	u32 cdw10 = le32_to_cpu(req->cmd->common.cdw10);
+	bool ignore_key = (bool)((cdw10 >> 3) & 1); /* Ignore existing key, bit 03 */
+	u8 rtype = (u8)((cdw10 >> 8) & 0xff); /* Reservation type, bit 15:08 */
+	u8 release_act = cdw10 & 0x07; /* Reservation release action, bit 02:00 */
+	struct nvmet_ctrl *ctrl = req->sq->ctrl;
+	struct nvmet_pr *pr = &req->ns->pr;
+	struct nvmet_pr_release_data *d;
+	struct nvmet_pr_registrant *reg;
+	u16 status;
+
+	if (ignore_key) {
+		status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
+		goto out;
+	}
+
+	d = kmalloc(sizeof(*d), GFP_KERNEL);
+	if (!d) {
+		status = NVME_SC_INTERNAL;
+		goto out;
+	}
+
+	status = nvmet_copy_from_sgl(req, 0, d, sizeof(*d));
+	if (status)
+		goto free_data;
+
+	status = NVME_SC_RESERVATION_CONFLICT | NVME_SC_DNR;
+	mutex_lock(&pr->pr_lock);
+	list_for_each_entry_rcu(reg, &pr->registrant_list, entry,
+				lockdep_is_held(&pr->pr_lock)) {
+		if (uuid_equal(&reg->hostid, &ctrl->hostid) &&
+		    reg->rkey == le64_to_cpu(d->crkey)) {
+			status = __nvmet_execute_pr_release(req, reg,
+					release_act, rtype);
+			break;
+		}
+	}
+	mutex_unlock(&pr->pr_lock);
+free_data:
+	kfree(d);
+out:
+	nvmet_req_complete(req, status);
+}
+
+static void nvmet_execute_pr_report(struct nvmet_req *req)
+{
+	u32 cdw11 = le32_to_cpu(req->cmd->common.cdw11);
+	u32 cdw10 = le32_to_cpu(req->cmd->common.cdw10);
+	u32 num_bytes = 4 * (cdw10 + 1); /* cdw10 is number of dwords */
+	u8 eds = cdw11 & 1; /* Extended data structure, bit 00 */
+	struct nvmet_subsys *subsys = req->sq->ctrl->subsys;
+	struct nvme_registered_ctrl_ext *ctrl_eds;
+	struct nvme_reservation_status_ext *data;
+	struct nvmet_pr *pr = &req->ns->pr;
+	struct nvmet_pr_registrant *holder;
+	struct nvmet_pr_registrant *reg;
+	struct nvmet_ctrl *ctrl;
+	u16 num_ctrls = 0;
+	u16 status;
+	u8 rtype;
+
+	/* nvmet hostid(uuid_t) is 128 bit. */
+	if (!eds) {
+		req->error_loc = offsetof(struct nvme_common_command, cdw11);
+		status = NVME_SC_HOST_ID_INCONSIST | NVME_SC_DNR;
+		goto out;
+	}
+
+	if (num_bytes < sizeof(struct nvme_reservation_status_ext)) {
+		req->error_loc = offsetof(struct nvme_common_command, cdw10);
+		status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
+		goto out;
+	}
+
+	mutex_lock(&subsys->lock);
+	num_ctrls = list_count_nodes(&subsys->ctrls);
+	mutex_unlock(&subsys->lock);
+
+	num_bytes = min(num_bytes,
+			sizeof(struct nvme_reservation_status_ext) +
+			sizeof(struct nvme_registered_ctrl_ext) * num_ctrls);
+
+	data = kmalloc(num_bytes, GFP_KERNEL);
+	if (!data) {
+		status = NVME_SC_INTERNAL;
+		goto out;
+	}
+	memset(data, 0, num_bytes);
+	data->gen = cpu_to_le32(atomic_read(&pr->generation));
+	data->ptpls = 0;
+	ctrl_eds = data->regctl_eds;
+
+	mutex_lock(&subsys->lock);
+	rcu_read_lock();
+	holder = rcu_dereference(pr->holder);
+	rtype = holder ? holder->rtype : 0;
+	data->rtype = rtype;
+	num_ctrls = 0;
+	list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) {
+		if ((void *)ctrl_eds >= (void *)(data + num_bytes))
+			break;
+		reg = nvmet_pr_find_registrant_by_hostid(pr, &ctrl->hostid);
+		if (!reg)
+			continue;
+		ctrl_eds->cntlid = cpu_to_le16(ctrl->cntlid);
+		if (rtype == NVME_PR_WRITE_EXCLUSIVE_ALL_REGS ||
+		    rtype == NVME_PR_EXCLUSIVE_ACCESS_ALL_REGS)
+			ctrl_eds->rcsts = 1;
+		if (holder && uuid_equal(&ctrl->hostid, &holder->hostid))
+			ctrl_eds->rcsts = 1;
+		uuid_copy((uuid_t *)&ctrl_eds->hostid, &ctrl->hostid);
+		ctrl_eds->rkey = cpu_to_le64(reg->rkey);
+		ctrl_eds++;
+		num_ctrls++;
+	}
+	rcu_read_unlock();
+	mutex_unlock(&subsys->lock);
+
+	put_unaligned_le16(num_ctrls, data->regctl);
+	num_bytes = sizeof(struct nvme_reservation_status_ext) +
+			sizeof(struct nvme_registered_ctrl_ext) * num_ctrls;
+	status = nvmet_copy_to_sgl(req, 0, data, num_bytes);
+	kfree(data);
+out:
+	nvmet_req_complete(req, status);
+}
+
+u16 nvmet_parse_pr_cmd(struct nvmet_req *req)
+{
+	struct nvme_command *cmd = req->cmd;
+
+	switch (cmd->common.opcode) {
+	case nvme_cmd_resv_register:
+		req->execute = nvmet_execute_pr_register;
+		break;
+	case nvme_cmd_resv_acquire:
+		req->execute = nvmet_execute_pr_acquire;
+		break;
+	case nvme_cmd_resv_release:
+		req->execute = nvmet_execute_pr_release;
+		break;
+	case nvme_cmd_resv_report:
+		req->execute = nvmet_execute_pr_report;
+		break;
+	default:
+		return 1;
+	}
+	return NVME_SC_SUCCESS;
+}
+
+static bool nvmet_is_req_write_cmd_group(struct nvmet_req *req)
+{
+	u8 opcode = req->cmd->common.opcode;
+
+	if (req->sq->qid) {
+		switch (opcode) {
+		case nvme_cmd_flush:
+		case nvme_cmd_write:
+		case nvme_cmd_write_zeroes:
+		case nvme_cmd_dsm:
+		case nvme_cmd_zone_append:
+		case nvme_cmd_zone_mgmt_send:
+			return true;
+		default:
+			return false;
+		}
+	}
+	return false;
+}
+
+static bool nvmet_is_req_read_cmd_group(struct nvmet_req *req)
+{
+	u8 opcode = req->cmd->common.opcode;
+
+	if (req->sq->qid) {
+		switch (opcode) {
+		case nvme_cmd_read:
+		case nvme_cmd_zone_mgmt_recv:
+			return true;
+		default:
+			return false;
+		}
+	}
+	return false;
+}
+
+u16 nvmet_pr_check_cmd_access(struct nvmet_req *req)
+{
+	struct nvmet_ctrl *ctrl = req->sq->ctrl;
+	struct nvmet_pr_registrant *holder;
+	struct nvmet_ns *ns = req->ns;
+	struct nvmet_pr *pr = &ns->pr;
+	u16 status = NVME_SC_SUCCESS;
+
+	rcu_read_lock();
+	holder = rcu_dereference(pr->holder);
+	if (!holder)
+		goto unlock;
+	if (uuid_equal(&ctrl->hostid, &holder->hostid))
+		goto unlock;
+
+	/*
+	 * The Reservation command group is checked in executing,
+	 * allow it here.
+	 */
+	switch (holder->rtype) {
+	case NVME_PR_WRITE_EXCLUSIVE:
+		if (nvmet_is_req_write_cmd_group(req))
+			status = NVME_SC_RESERVATION_CONFLICT | NVME_SC_DNR;
+		break;
+	case NVME_PR_EXCLUSIVE_ACCESS:
+		if (nvmet_is_req_read_cmd_group(req) ||
+		    nvmet_is_req_write_cmd_group(req))
+			status = NVME_SC_RESERVATION_CONFLICT | NVME_SC_DNR;
+		break;
+	case NVME_PR_WRITE_EXCLUSIVE_REG_ONLY:
+	case NVME_PR_WRITE_EXCLUSIVE_ALL_REGS:
+		if ((nvmet_is_req_write_cmd_group(req)) &&
+		    !nvmet_pr_find_registrant_by_hostid(pr, &ctrl->hostid))
+			status = NVME_SC_RESERVATION_CONFLICT | NVME_SC_DNR;
+		break;
+	case NVME_PR_EXCLUSIVE_ACCESS_REG_ONLY:
+	case NVME_PR_EXCLUSIVE_ACCESS_ALL_REGS:
+		if ((nvmet_is_req_read_cmd_group(req) ||
+		    nvmet_is_req_write_cmd_group(req)) &&
+		    !nvmet_pr_find_registrant_by_hostid(pr, &ctrl->hostid))
+			status = NVME_SC_RESERVATION_CONFLICT | NVME_SC_DNR;
+		break;
+	default:
+		pr_warn("the reservation type is set wrong, type:%d\n",
+			holder->rtype);
+		break;
+	}
+
+unlock:
+	rcu_read_unlock();
+	if (status)
+		req->error_loc = offsetof(struct nvme_common_command, opcode);
+	return status;
+}
+
+void nvmet_ctrl_destroy_pr(struct nvmet_ctrl *ctrl)
+{
+	struct nvmet_pr_registrant *reg;
+	struct nvmet_ns *ns;
+	unsigned long idx;
+
+	kfifo_free(&ctrl->pr_log_mgr.log_queue);
+	mutex_destroy(&ctrl->pr_log_mgr.lock);
+
+	if (nvmet_is_host_still_connected(&ctrl->hostid, ctrl->subsys))
+		return;
+
+	xa_for_each(&ctrl->subsys->namespaces, idx, ns) {
+		mutex_lock(&ns->pr.pr_lock);
+		list_for_each_entry_rcu(reg, &ns->pr.registrant_list, entry,
+					lockdep_is_held(&ns->pr.pr_lock)) {
+			if (uuid_equal(&reg->hostid, &ctrl->hostid)) {
+				__nvmet_pr_unregister_one(&ns->pr, reg);
+				break;
+			}
+		}
+		mutex_unlock(&ns->pr.pr_lock);
+	}
+}
+
+void nvmet_pr_exit_ns(struct nvmet_ns *ns)
+{
+	struct nvmet_pr_registrant *reg;
+	struct nvmet_pr_registrant *tmp;
+	struct nvmet_pr *pr = &ns->pr;
+
+	mutex_lock(&pr->pr_lock);
+	rcu_assign_pointer(pr->holder, NULL);
+	list_for_each_entry_safe(reg, tmp, &pr->registrant_list, entry) {
+		list_del_rcu(&reg->entry);
+		synchronize_rcu();
+		kfree(reg);
+	}
+	mutex_unlock(&pr->pr_lock);
+
+	mutex_destroy(&pr->pr_lock);
+}
+
+void nvmet_pr_init_ns(struct nvmet_ns *ns)
+{
+	ns->pr.holder = NULL;
+	atomic_set(&ns->pr.generation, 0);
+	mutex_init(&ns->pr.pr_lock);
+	INIT_LIST_HEAD(&ns->pr.registrant_list);
+}
diff --git a/include/linux/nvme.h b/include/linux/nvme.h
index 462c21e0e417..5140889ea04f 100644
--- a/include/linux/nvme.h
+++ b/include/linux/nvme.h
@@ -745,6 +745,26 @@ enum {
 	NVME_AEN_CFG_DISC_CHANGE	= 1 << NVME_AEN_BIT_DISC_CHANGE,
 };
 
+enum {
+	NVME_AEN_RESV_LOG_PAGE_AVALIABLE	= 0x00,
+};
+
+enum {
+	NVME_PR_LOG_EMPTY_LOG_PAGE			= 0x00,
+	NVME_PR_LOG_REGISTRATION_PREEMPTED		= 0x01,
+	NVME_PR_LOG_RESERVATION_RELEASED		= 0x02,
+	NVME_PR_LOG_RESERVATOPM_PREEMPTED		= 0x03,
+};
+
+struct nvme_pr_log {
+	__le64			count;
+	__u8			type;
+	__u8			nr_pages;
+	__u8			rsvd1[2];
+	__le32			nsid;
+	__u8			rsvd2[48];
+};
+
 struct nvme_lba_range_type {
 	__u8			type;
 	__u8			attributes;
@@ -765,6 +785,17 @@ enum {
 	NVME_LBART_ATTRIB_HIDE	= 1 << 1,
 };
 
+enum nvme_pr_capabilities {
+	NVME_PR_SUPPORT_PTPL				= 1,
+	NVME_PR_SUPPORT_WRITE_EXCLUSIVE			= 1 << 1,
+	NVME_PR_SUPPORT_EXCLUSIVE_ACCESS		= 1 << 2,
+	NVME_PR_SUPPORT_WRITE_EXCLUSIVE_REG_ONLY	= 1 << 3,
+	NVME_PR_SUPPORT_EXCLUSIVE_ACCESS_REG_ONLY	= 1 << 4,
+	NVME_PR_SUPPORT_WRITE_EXCLUSIVE_ALL_REGS	= 1 << 5,
+	NVME_PR_SUPPORT_EXCLUSIVE_ACCESS_ALL_REGS	= 1 << 6,
+	NVME_PR_SUPPORT_IEKEY_VER_1_3_DEF		= 1 << 7,
+};
+
 enum nvme_pr_type {
 	NVME_PR_WRITE_EXCLUSIVE			= 1,
 	NVME_PR_EXCLUSIVE_ACCESS		= 2,
@@ -774,6 +805,23 @@ enum nvme_pr_type {
 	NVME_PR_EXCLUSIVE_ACCESS_ALL_REGS	= 6,
 };
 
+enum nvme_pr_register_action {
+	NVME_PR_REGISTER_ACT_REG		= 0,
+	NVME_PR_REGISTER_ACT_UNREG		= 1,
+	NVME_PR_REGISTER_ACT_REPLACE		= 1 << 1,
+};
+
+enum nvme_pr_acquire_action {
+	NVME_PR_ACQUIRE_ACT_ACQUIRE		= 0,
+	NVME_PR_ACQUIRE_ACT_PREEMPT		= 1,
+	NVME_PR_ACQUIRE_ACT_PREEMPT_AND_ABORT	= 1 << 1,
+};
+
+enum nvme_pr_release_action {
+	NVME_PR_RELEASE_ACT_RELEASE		= 0,
+	NVME_PR_RELEASE_ACT_CLEAR		= 1,
+};
+
 enum nvme_eds {
 	NVME_EXTENDED_DATA_STRUCT	= 0x1,
 };
-- 
2.43.0




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