Re: [PATCH V2 1/3] nvmet: support reservation feature

Guixin Liu
2024-01-16T02:17:14Z

在 2024/1/15 17:26, Sagi Grimberg 写道:
>
>
> On 1/14/24 11:23, Guixin Liu wrote:
>> 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@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      |  49 +-
>>   drivers/nvme/target/nvmet.h     |  33 ++
>>   drivers/nvme/target/pr.c        | 887 ++++++++++++++++++++++++++++++++
>>   include/linux/nvme.h            |  48 ++
>>   7 files changed, 1053 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 d937fe05129e..1ac4802ec818 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 3935165048e7..a5019881d60b 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;
>> @@ -651,6 +653,7 @@ void nvmet_ns_disable(struct nvmet_ns *ns)
>>         subsys->nr_namespaces--;
>>       nvmet_ns_changed(subsys, ns->nsid);
>> +    nvmet_pr_exit_ns(ns);
>>       nvmet_ns_dev_disable(ns);
>>   out_unlock:
>>       mutex_unlock(&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 +1250,21 @@ 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;
>> +
>> +    mutex_lock(&subsys->lock);
>> +    list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) {
>> +        if (uuid_equal(hostid, &ctrl->hostid)) {
>> +            mutex_unlock(&subsys->lock);
>> +            return true;
>> +        }
>> +    }
>> +    mutex_unlock(&subsys->lock);
>> +    return false;
>> +}
>> +
>>   struct nvmet_ctrl *nvmet_ctrl_find_get(const char *subsysnqn,
>>                          const char *hostnqn, u16 cntlid,
>>                          struct nvmet_req *req)
>> @@ -1450,6 +1484,10 @@ u16 nvmet_alloc_ctrl(const char *subsysnqn,
>> const char *hostnqn,
>>       ctrl->err_counter = 0;
>>       spin_lock_init(&ctrl->error_lock);
>>   +    ctrl->resv_log_counter = 0;
>> +    mutex_init(&ctrl->resv_log_lock);
>> +    INIT_LIST_HEAD(&ctrl->resv_log_list);
>> +
>>       nvmet_start_keep_alive_timer(ctrl);
>>         mutex_lock(&subsys->lock);
>> @@ -1488,6 +1526,7 @@ 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..4ba4958768ac 100644
>> --- a/drivers/nvme/target/nvmet.h
>> +++ b/drivers/nvme/target/nvmet.h
>> @@ -56,6 +56,22 @@
>>   #define IPO_IATTR_CONNECT_SQE(x)    \
>>       (cpu_to_le32(offsetof(struct nvmf_connect_command, x)))
>>   +struct nvmet_pr_registrant {
>> +    bool            is_holder;
>> +    u64            rkey;
>> +    uuid_t            hostid;
>> +    struct list_head    entry;
>> +};
>> +
>> +struct nvmet_pr {
>> +    bool            enable;
>> +    enum nvme_pr_type    rtype;
>> +    u32            generation;
>> +    struct nvmet_pr_registrant *holder;
>> +    rwlock_t        pr_lock;
>> +    struct list_head    registrant_list;
>> +};
>> +
>>   struct nvmet_ns {
>>       struct percpu_ref    ref;
>>       struct bdev_handle    *bdev_handle;
>> @@ -85,6 +101,7 @@ 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 +207,11 @@ 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_entry {
>> +    struct nvme_pr_log log;
>> +    struct list_head entry;
>> +};
>> +
>>   struct nvmet_ctrl {
>>       struct nvmet_subsys    *subsys;
>>       struct nvmet_sq        **sqs;
>> @@ -243,6 +265,9 @@ struct nvmet_ctrl {
>>       u8            *dh_key;
>>       size_t            dh_keysize;
>>   #endif
>> +    struct mutex        resv_log_lock;
>> +    u64            resv_log_counter;
>> +    struct list_head    resv_log_list;
>>   };
>>     struct nvmet_subsys {
>> @@ -750,4 +775,12 @@ 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..900a3f7a0808
>> --- /dev/null
>> +++ b/drivers/nvme/target/pr.c
>> @@ -0,0 +1,887 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * NVMe over Fabrics Persist Reservation.
>> + * Copyright (c) 2024 Guixin Liu, Alibaba Group.
>> + * All rights reserved.
>> + */
>> +#include "nvmet.h"
>> +#include <linux/slab.h>
>> +#include <asm/unaligned.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 inline void nvmet_pr_clean_holder(struct nvmet_pr *pr)
>> +{
>> +    pr->holder = NULL;
>> +    pr->rtype = 0;
>> +}
>> +
>> +static u16 nvmet_pr_validate_and_set_rtype(struct nvmet_pr *pr, u8
>> rtype)
>> +{
>> +    if (rtype < NVME_PR_WRITE_EXCLUSIVE ||
>> +        rtype > NVME_PR_EXCLUSIVE_ACCESS_ALL_REGS)
>> +        return NVME_SC_INVALID_FIELD | NVME_SC_DNR;
>> +
>> +    pr->rtype = rtype;
>> +    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_and_set_rtype(pr, rtype);
>> +    if (!status)
>> +        pr->holder = reg;
>> +    return status;
>> +}
>> +
>> +static inline void nvmet_pr_inc_generation(struct nvmet_pr *pr)
>> +{
>> +    pr->generation++;
>> +}
>
> Useless wrapper. Shouldn't this be atomic_inc btw?

Sorry, I miss that generation is not protected when execut register command.

I will delete the wrapper, and put it in to pr_lock protection.

>
>> +
>> +static struct nvmet_pr_registrant *nvmet_pr_find_registrant_by_hostid(
>> +                        struct nvmet_pr *pr,
>> +                        uuid_t *hostid)
>> +{
>> +    struct nvmet_pr_registrant *reg;
>> +
>> +    list_for_each_entry(reg, &pr->registrant_list, entry) {
>> +        if (uuid_equal(&reg->hostid, hostid))
>> +            return reg;
>> +    }
>> +    return NULL;
>> +}
>> +
>> +static u16 nvmet_pr_register(struct nvmet_req *req,
>> +                 struct nvmet_pr_register_data *d)
>> +{
>> +    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;
>> +
>> +    read_lock(&pr->pr_lock);
>> +    list_for_each_entry(reg, &pr->registrant_list, entry) {
>> +        if (uuid_equal(&reg->hostid, &ctrl->hostid)) {
>> +            if (reg->rkey == le64_to_cpu(d->nrkey))
>> +                status = NVME_SC_SUCCESS;
>> +            read_unlock(&pr->pr_lock);
>> +            goto out;
>> +        }
>> +    }
>> +    read_unlock(&pr->pr_lock);
>
> Move to a wrapper?
OK.
>
>> +
>> +    reg = kmalloc(sizeof(*reg), GFP_KERNEL);
>> +    if (!reg) {
>> +        status = NVME_SC_INTERNAL;
>> +        goto out;
>> +    }
>> +
>> +    memset(reg, 0, sizeof(*reg));
>> +    INIT_LIST_HEAD(&reg->entry);
>> +    reg->rkey = le64_to_cpu(d->nrkey);
>> +    uuid_copy(&reg->hostid, &ctrl->hostid);
>> +    reg->is_holder = false;
>> +
>> +    write_lock(&pr->pr_lock);
>> +    list_add_tail(&reg->entry, &pr->registrant_list);
>> +    write_unlock(&pr->pr_lock);
>> +    status = NVME_SC_SUCCESS;
>> +out:
>> +    return status;
>> +}
>> +
>> +void nvmet_execute_get_log_page_resv(struct nvmet_req *req)
>> +{
>> +    struct nvmet_ctrl *ctrl = req->sq->ctrl;
>> +    struct nvmet_pr_log_entry *log_entry;
>> +    u16 status = NVME_SC_SUCCESS;
>> +    struct nvme_pr_log *log;
>> +
>> +    mutex_lock(&ctrl->resv_log_lock);
>> +    log_entry = list_first_entry_or_null(&ctrl->resv_log_list,
>> +                     struct nvmet_pr_log_entry, entry);
>> +    if (!log_entry)
>> +        goto out;
>> +
>> +    list_del(&log_entry->entry);
>> +    log = &log_entry->log;
>> +    log->nr_avl_pages = min(list_count_nodes(&ctrl->resv_log_list),
>> 255);
>
> nr_pages
OK.
>
>> +    status = nvmet_copy_to_sgl(req, 0, log, sizeof(*log));
>> +    kfree(log_entry);
>> +out:
>> +    mutex_unlock(&ctrl->resv_log_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_entry *log_entry;
>> +    struct nvme_pr_log *log;
>> +
>> +    mutex_lock(&ctrl->resv_log_lock);
>> +    ctrl->resv_log_counter++;
>> +    if (ctrl->resv_log_counter == U64_MAX)
>> +        ctrl->resv_log_counter = 1;
>> +    log_entry = kmalloc(sizeof(*log_entry), GFP_KERNEL);
>> +    if (!log_entry) {
>> +        pr_warn("a reservation log lost, cntlid:%d, log_type:%d,
>> nsid:%d\n",
>> +            ctrl->cntlid, log_type, nsid);
>> +        log_entry = list_last_entry(&ctrl->resv_log_list,
>> +                    struct nvmet_pr_log_entry, entry);
>> +        if (log_entry)
>> +            log_entry->log.count =
>> +            cpu_to_le64(le64_to_cpu(log_entry->log.count) + 1);
>> +        goto unlock;
>> +    }
>> +
>> +    log = &log_entry->log;
>> +    log->count = cpu_to_le64(ctrl->resv_log_counter);
>> +    log->type = log_type;
>> +    log->nsid = cpu_to_le32(nsid);
>> +
>> +    list_add_tail(&log_entry->entry, &ctrl->resv_log_list);
>
> What prevents this list from exploding?
> I think you should mimic the ctrl error log slots.

Yeah, this is depends on the host pr_work which in another patch,

I will limit it in v3.

>
>> +unlock:
>> +    mutex_unlock(&ctrl->resv_log_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 void __nvmet_pr_unregister_one(struct nvmet_pr *pr,
>> +                      struct nvmet_pr_registrant *reg)
>> +{
>> +    u8 original_rtype = pr->rtype;
>> +
>> +    list_del(&reg->entry);
>> +
>> +    if (pr->holder != reg)
>> +        goto free_reg;
>> +
>> +    if (original_rtype == NVME_PR_WRITE_EXCLUSIVE_ALL_REGS ||
>> +        original_rtype == NVME_PR_EXCLUSIVE_ACCESS_ALL_REGS) {
>> +        pr->holder = list_first_entry_or_null(&pr->registrant_list,
>> +                    struct nvmet_pr_registrant, entry);
>> +        if (!pr->holder)
>> +            pr->rtype = 0;
>> +        goto free_reg;
>> +    }
>> +
>> +    nvmet_pr_clean_holder(pr);
>> +
>> +    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);
>> +
>> +free_reg:
>> +    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;
>> +    struct nvmet_pr_registrant *tmp;
>> +
>> +    write_lock(&pr->pr_lock);
>> +    list_for_each_entry_safe(reg, tmp, &pr->registrant_list, entry) {
>> +        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;
>> +        }
>> +    }
>> +    write_unlock(&pr->pr_lock);
>> +
>> +    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;
>> +
>> +    write_lock(&pr->pr_lock);
>> +    list_for_each_entry(reg, &pr->registrant_list, entry) {
>> +        if (uuid_equal(&reg->hostid, &ctrl->hostid)) {
>> +            if (ignore_key || reg->rkey == le64_to_cpu(d->crkey)) {
>> +                reg->rkey = le64_to_cpu(d->nrkey);
>> +                status = NVME_SC_SUCCESS;
>> +            }
>> +            break;
>> +        }
>> +    }
>> +    write_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)
>> +        nvmet_pr_inc_generation(&req->ns->pr);
>> +    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;
>> +
>> +    if (pr->holder && reg != pr->holder)
>> +        return  NVME_SC_RESERVATION_CONFLICT | NVME_SC_DNR;
>> +    if (pr->holder && reg == pr->holder) {
>> +        if (pr->rtype == rtype)
>> +            return 0;
>
> NVME_SC_SUCCESS
Sorry I miss that, it will be changed in v3.
>
>> +        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;
>> +    struct nvmet_pr_registrant *tmp;
>> +
>> +    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;
>> +    struct nvmet_pr_registrant *tmp;
>> +
>> +    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;
>> +    struct nvmet_pr_registrant *tmp;
>> +
>> +    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 rtype,
>> +                    struct nvmet_pr_registrant *reg)
>> +{
>> +    u16 status;
>> +
>> +    status = nvmet_pr_set_rtype_and_holder(pr, rtype, reg);
>> +    if (!status)
>> +        nvmet_pr_send_resv_released(pr, &reg->hostid);
>> +    return status;
>> +}
>> +
>> +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;
>> +    u16 status;
>> +
>> +    if (!pr->holder)
>> +        return nvmet_pr_unreg_by_prkey(pr, le64_to_cpu(d->prkey),
>> +                           &ctrl->hostid);
>> +
>> +    if (pr->rtype == NVME_PR_WRITE_EXCLUSIVE_ALL_REGS ||
>> +        pr->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, rtype, reg);
>> +        }
>> +        return nvmet_pr_unreg_by_prkey(pr, le64_to_cpu(d->prkey),
>> +                           &ctrl->hostid);
>> +    }
>> +
>> +    if (pr->holder == reg)
>> +        return nvmet_pr_validate_and_set_rtype(pr, rtype);
>> +
>> +    if (le64_to_cpu(d->prkey) == pr->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, 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)
>> +        nvmet_pr_inc_generation(&req->ns->pr);
>> +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;
>> +    write_lock(&pr->pr_lock);
>> +    list_for_each_entry(reg, &pr->registrant_list, entry) {
>> +        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;
>> +        }
>> +    }
>> +    write_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;
>> +    u8 original_rtype = pr->rtype;
>> +
>> +    if (reg != pr->holder || !pr->holder)
>> +        return 0;
>> +    if (pr->rtype != rtype)
>> +        return NVME_SC_RESERVATION_CONFLICT | NVME_SC_DNR;
>> +
>> +    nvmet_pr_clean_holder(pr);
>> +
>> +    if (original_rtype != NVME_PR_WRITE_EXCLUSIVE &&
>> +        original_rtype != NVME_PR_EXCLUSIVE_ACCESS)
>> +        nvmet_pr_send_resv_released(pr, &reg->hostid);
>> +
>> +    return 0;
>> +}
>> +
>> +static void nvmet_pr_clear(struct nvmet_req *req)
>> +{
>> +    struct nvmet_pr *pr = &req->ns->pr;
>> +    struct nvmet_pr_registrant *reg;
>> +    struct nvmet_pr_registrant *tmp;
>> +
>> +    list_for_each_entry_safe(reg, tmp, &pr->registrant_list, entry) {
>> +        list_del(&reg->entry);
>> +        if (!uuid_equal(&req->sq->ctrl->hostid, &reg->hostid))
>> +            nvmet_pr_send_resv_preempted(pr, &reg->hostid);
>> +        kfree(reg);
>> +    }
>> +    nvmet_pr_clean_holder(pr);
>> +
>> +    nvmet_pr_inc_generation(&req->ns->pr);
>> +}
>> +
>> +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 0;
>> +    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;
>> +    struct nvmet_pr_registrant *tmp;
>> +    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;
>> +    write_lock(&pr->pr_lock);
>> +    list_for_each_entry_safe(reg, tmp,
>> +                 &pr->registrant_list, entry) {
>> +        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;
>> +        }
>> +    }
>> +    write_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_data;
>> +    struct nvme_reservation_status_ext *data;
>> +    struct nvmet_pr *pr = &req->ns->pr;
>> +    struct nvmet_pr_registrant *reg;
>> +    struct nvmet_ctrl *ctrl;
>> +    u16 num_ctrls = 0;
>> +    u16 status;
>> +
>> +    /* 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);
>> +    read_lock(&pr->pr_lock);
>> +    list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) {
>> +        if (nvmet_pr_find_registrant_by_hostid(pr, &ctrl->hostid))
>> +            num_ctrls++;
>> +    }
>> +
>> +    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_unlock;
>> +    }
>> +    memset(data, 0, num_bytes);
>> +    data->gen = cpu_to_le32(pr->generation);
>> +    data->rtype = pr->rtype;
>> +    put_unaligned_le16(num_ctrls, data->regctl);
>> +    data->ptpls = 0;
>> +    ctrl_data = data->regctl_eds;
>> +
>> +    list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) {
>> +        if ((void *)ctrl_data >= (void *)(data + num_bytes))
>> +            break;
>> +        reg = nvmet_pr_find_registrant_by_hostid(pr, &ctrl->hostid);
>> +        if (!reg)
>> +            continue;
>> +        ctrl_data->cntlid = cpu_to_le16(ctrl->cntlid);
>> +        if (pr->rtype == NVME_PR_WRITE_EXCLUSIVE_ALL_REGS ||
>> +            pr->rtype == NVME_PR_EXCLUSIVE_ACCESS_ALL_REGS)
>> +            ctrl_data->rcsts = 1;
>> +        if (pr->holder &&
>> +            uuid_equal(&ctrl->hostid, &pr->holder->hostid))
>> +            ctrl_data->rcsts = 1;
>> +        uuid_copy((uuid_t *)&ctrl_data->hostid, &ctrl->hostid);
>> +        ctrl_data->rkey = cpu_to_le64(reg->rkey);
>> +        ctrl_data++;
>> +    }
>> +    status = nvmet_copy_to_sgl(req, 0, data, num_bytes);
>> +out_unlock:
>> +    read_unlock(&pr->pr_lock);
>> +    mutex_unlock(&subsys->lock);
>> +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 0;
>> +}
>> +
>> +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_ns *ns = req->ns;
>> +    struct nvmet_pr *pr = &ns->pr;
>> +    u16 status = NVME_SC_SUCCESS;
>> +
>> +    read_lock(&pr->pr_lock);
>> +    if (!pr->holder)
>> +        goto unlock;
>> +    if (uuid_equal(&ctrl->hostid, &pr->holder->hostid))
>> +        goto unlock;
>> +
>> +    /*
>> +     * The Reservation command group is checked in executing,
>> +     * allow it here.
>> +     */
>> +    switch ((u8)pr->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",
>> +            pr->rtype);
>> +        break;
>> +    }
>
> What about impacted admin commands? I'm assuming none of them is
> supported by nvmet?

Currently there is no admin command which nvmet implemented should

check reservation.

>
> What about the passthru ctrl? Chaitanya, how does this play with
> the passthru controller?
I will take a look at passthry ctrl.
>
>> +
>> +unlock:
>> +    read_unlock(&pr->pr_lock);
>> +    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_log_entry *tmp_log_entry;
>> +    struct nvmet_pr_log_entry *log_entry;
>> +    struct nvmet_pr_registrant *reg;
>> +    struct nvmet_pr_registrant *tmp;
>> +    struct nvmet_ns *ns;
>> +    unsigned long idx;
>> +
>> +    mutex_lock(&ctrl->resv_log_lock);
>> +    list_for_each_entry_safe(log_entry, tmp_log_entry,
>> +                 &ctrl->resv_log_list, entry) {
>> +        list_del(&log_entry->entry);
>> +        kfree(log_entry);
>> +    }
>> +    mutex_unlock(&ctrl->resv_log_lock);
>> +
>> +    mutex_destroy(&ctrl->resv_log_lock);
>> +
>> +    if (nvmet_is_host_still_connected(&ctrl->hostid, ctrl->subsys))
>> +        return;
>> +
>> +    xa_for_each(&ctrl->subsys->namespaces, idx, ns) {
>> +        write_lock(&ns->pr.pr_lock);
>> +        list_for_each_entry_safe(reg, tmp,
>> +                     &ns->pr.registrant_list, entry) {
>> +            if (uuid_equal(&reg->hostid, &ctrl->hostid)) {
>> +                __nvmet_pr_unregister_one(&ns->pr, reg);
>> +                break;
>> +            }
>> +        }
>> +        write_unlock(&ns->pr.pr_lock);
>> +    }
>> +}
>> +
>> +void nvmet_pr_exit_ns(struct nvmet_ns *ns)
>> +{
>> +    struct nvmet_pr_registrant *tmp_reg;
>> +    struct nvmet_pr_registrant *tmp;
>> +    struct nvmet_pr *pr = &ns->pr;
>> +
>> +    write_lock(&pr->pr_lock);
>> +    list_for_each_entry_safe(tmp_reg, tmp, &pr->registrant_list,
>> entry) {
>> +        list_del(&tmp_reg->entry);
>> +        kfree(tmp_reg);
>> +    }
>> +    write_unlock(&pr->pr_lock);
>> +}
>> +
>> +void nvmet_pr_init_ns(struct nvmet_ns *ns)
>> +{
>> +    ns->pr.holder = NULL;
>> +    ns->pr.generation = 0;
>> +    ns->pr.rtype = 0;
>> +    rwlock_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 44325c068b6a..bb5f56ebae50 100644
>> --- a/include/linux/nvme.h
>> +++ b/include/linux/nvme.h
>> @@ -746,6 +746,26 @@ 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_avl_pages;
>> +    __u8            rsvd1[2];
>> +    __le32            nsid;
>> +    __u8            rsvd2[48];
>> +};
>> +
>>   struct nvme_lba_range_type {
>>       __u8            type;
>>       __u8            attributes;
>> @@ -766,6 +786,17 @@ 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,
>> @@ -775,6 +806,23 @@ 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,
>>   };