[PATCH v16 2/2] nvmet: support reservation feature
Guixin Liu
kanie at linux.alibaba.com
Sun Oct 20 22:58:21 PDT 2024
在 2024/10/21 07:03, Sagi Grimberg 写道:
>
>
>
> On 17/10/2024 7:48, Guixin Liu wrote:
>> This patch implements the reservation feature, including:
>> 1. reservation register(register, unregister and replace).
>> 2. reservation acquire(acquire, preempt, preempt and abort).
>> 3. reservation release(release and clear).
>> 4. reservation report.
>> 5. set feature and get feature of reservation notify mask.
>> 6. get log page of reservation event.
>>
>> Not supported:
>> 1. persistent reservation through power loss.
>>
>> Test cases:
>> Use nvme-cli and fio to test all implemented sub features:
>> 1. use nvme resv-register to register host a registrant or
>> unregister or replace a new key.
>> 2. use nvme resv-acquire to set host to the holder, and use fio
>> to send read and write io in all reservation type. And also
>> test preempt and "preempt and abort".
>> 3. use nvme resv-report to show all registrants and reservation
>> status.
>> 4. use nvme resv-release to release all registrants.
>> 5. use nvme get-log to get events generated by the preceding
>> operations.
>>
>> In addition, 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>
>> Reviewed-by: Dmitry Bogdanov <d.bogdanov at yadro.com>
>> Reviewed-by: Christoph Hellwig <hch at lst.de>
>> Tested-by: Chaitanya Kulkarni <kch at nvidia.com>
>> Reviewed-by: Chaitanya Kulkarni <kch at nvidia.com>
>> ---
>> drivers/nvme/target/Makefile | 2 +-
>> drivers/nvme/target/admin-cmd.c | 24 +-
>> drivers/nvme/target/configfs.c | 27 +
>> drivers/nvme/target/core.c | 58 +-
>> drivers/nvme/target/fabrics-cmd.c | 4 +-
>> drivers/nvme/target/nvmet.h | 55 +-
>> drivers/nvme/target/pr.c | 1172 +++++++++++++++++++++++++++++
>> 7 files changed, 1330 insertions(+), 12 deletions(-)
>> create mode 100644 drivers/nvme/target/pr.c
>>
>> diff --git a/drivers/nvme/target/Makefile b/drivers/nvme/target/Makefile
>> index c402c44350b2..f2b025bbe10c 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-$(CONFIG_NVME_TARGET_DEBUGFS) += debugfs.o
>> nvmet-$(CONFIG_NVME_TARGET_PASSTHRU) += passthru.o
>> nvmet-$(CONFIG_BLK_DEV_ZONED) += zns.o
>> diff --git a/drivers/nvme/target/admin-cmd.c
>> b/drivers/nvme/target/admin-cmd.c
>> index 081f0473cd9e..19428745c795 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);
>> @@ -433,7 +439,8 @@ static void nvmet_execute_identify_ctrl(struct
>> nvmet_req *req)
>> id->nn = cpu_to_le32(NVMET_MAX_NAMESPACES);
>> id->mnan = cpu_to_le32(NVMET_MAX_NAMESPACES);
>> id->oncs = cpu_to_le16(NVME_CTRL_ONCS_DSM |
>> - NVME_CTRL_ONCS_WRITE_ZEROES);
>> + NVME_CTRL_ONCS_WRITE_ZEROES |
>> + NVME_CTRL_ONCS_RESERVATIONS);
>> /* XXX: don't report vwc if the underlying device is write
>> through */
>> id->vwc = NVME_CTRL_VWC_PRESENT;
>> @@ -551,6 +558,15 @@ static void nvmet_execute_identify_ns(struct
>> nvmet_req *req)
>> id->nmic = NVME_NS_NMIC_SHARED;
>> id->anagrpid = cpu_to_le32(req->ns->anagrpid);
>> + if (req->ns->pr.enable)
>> + 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;
>> @@ -861,6 +877,9 @@ void nvmet_execute_set_features(struct nvmet_req
>> *req)
>> case NVME_FEAT_WRITE_PROTECT:
>> status = nvmet_set_feat_write_protect(req);
>> break;
>> + case NVME_FEAT_RESV_MASK:
>> + status = nvmet_set_feat_resv_notif_mask(req, cdw11);
>> + break;
>> default:
>> req->error_loc = offsetof(struct nvme_common_command, cdw10);
>> status = NVME_SC_INVALID_FIELD | NVME_STATUS_DNR;
>> @@ -959,6 +978,9 @@ void nvmet_execute_get_features(struct nvmet_req
>> *req)
>> case NVME_FEAT_WRITE_PROTECT:
>> status = nvmet_get_feat_write_protect(req);
>> break;
>> + case NVME_FEAT_RESV_MASK:
>> + status = nvmet_get_feat_resv_notif_mask(req);
>> + break;
>> default:
>> req->error_loc =
>> offsetof(struct nvme_common_command, cdw10);
>> diff --git a/drivers/nvme/target/configfs.c
>> b/drivers/nvme/target/configfs.c
>> index 685e89b35d33..eeee9e9b854c 100644
>> --- a/drivers/nvme/target/configfs.c
>> +++ b/drivers/nvme/target/configfs.c
>> @@ -769,6 +769,32 @@ 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 sysfs_emit(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,
>> @@ -777,6 +803,7 @@ 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 ed2424f8a396..a2af7a9bc3b9 100644
>> --- a/drivers/nvme/target/core.c
>> +++ b/drivers/nvme/target/core.c
>> @@ -611,6 +611,12 @@ int nvmet_ns_enable(struct nvmet_ns *ns)
>> if (ret)
>> goto out_restore_subsys_maxnsid;
>> + if (ns->pr.enable) {
>> + ret = nvmet_pr_init_ns(ns);
>> + if (ret)
>> + goto out_remove_from_subsys;
>> + }
>> +
>> subsys->nr_namespaces++;
>> nvmet_ns_changed(subsys, ns->nsid);
>> @@ -620,6 +626,8 @@ int nvmet_ns_enable(struct nvmet_ns *ns)
>> mutex_unlock(&subsys->lock);
>> return ret;
>> +out_remove_from_subsys:
>> + xa_erase(&subsys->namespaces, ns->nsid);
>> out_restore_subsys_maxnsid:
>> subsys->max_nsid = nvmet_max_nsid(subsys);
>> percpu_ref_exit(&ns->ref);
>> @@ -663,6 +671,9 @@ void nvmet_ns_disable(struct nvmet_ns *ns)
>> wait_for_completion(&ns->disable_done);
>> percpu_ref_exit(&ns->ref);
>> + if (ns->pr.enable)
>> + nvmet_pr_exit_ns(ns);
>> +
>> mutex_lock(&subsys->lock);
>> subsys->nr_namespaces--;
>> @@ -766,6 +777,7 @@ static void __nvmet_req_complete(struct nvmet_req
>> *req, u16 status)
>> trace_nvmet_req_complete(req);
>> req->ops->queue_response(req);
>> + nvmet_pr_put_ns_pc_ref(req);
>> if (ns)
>> nvmet_put_namespace(ns);
>> }
>> @@ -929,18 +941,39 @@ 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);
>> + if (ret)
>> + return ret;
>> +
>> + ret = nvmet_pr_get_ns_pc_ref(req);
>> }
>> + return ret;
>> }
>> bool nvmet_req_init(struct nvmet_req *req, struct nvmet_cq *cq,
>> @@ -964,6 +997,7 @@ bool nvmet_req_init(struct nvmet_req *req, struct
>> nvmet_cq *cq,
>> req->ns = NULL;
>> req->error_loc = NVMET_NO_ERROR_LOC;
>> req->error_slba = 0;
>> + req->pc_ref = NULL;
>> /* no support for fused commands yet */
>> if (unlikely(flags & (NVME_CMD_FUSE_FIRST |
>> NVME_CMD_FUSE_SECOND))) {
>> @@ -1015,6 +1049,7 @@ EXPORT_SYMBOL_GPL(nvmet_req_init);
>> void nvmet_req_uninit(struct nvmet_req *req)
>> {
>> percpu_ref_put(&req->sq->ref);
>> + nvmet_pr_put_ns_pc_ref(req);
>> if (req->ns)
>> nvmet_put_namespace(req->ns);
>> }
>> @@ -1383,7 +1418,8 @@ static void nvmet_fatal_error_handler(struct
>> work_struct *work)
>> }
>> u16 nvmet_alloc_ctrl(const char *subsysnqn, const char *hostnqn,
>> - struct nvmet_req *req, u32 kato, struct nvmet_ctrl **ctrlp)
>> + struct nvmet_req *req, u32 kato, struct nvmet_ctrl **ctrlp,
>> + uuid_t *hostid)
>> {
>> struct nvmet_subsys *subsys;
>> struct nvmet_ctrl *ctrl;
>> @@ -1462,6 +1498,8 @@ u16 nvmet_alloc_ctrl(const char *subsysnqn,
>> const char *hostnqn,
>> }
>> ctrl->cntlid = ret;
>> + uuid_copy(&ctrl->hostid, hostid);
>> +
>> /*
>> * Discovery controllers may use some arbitrary high value
>> * in order to cleanup stale discovery sessions
>> @@ -1478,6 +1516,9 @@ u16 nvmet_alloc_ctrl(const char *subsysnqn,
>> const char *hostnqn,
>> nvmet_start_keep_alive_timer(ctrl);
>> mutex_lock(&subsys->lock);
>> + ret = nvmet_ctrl_init_pr(ctrl);
>> + if (ret)
>> + goto init_pr_fail;
>> list_add_tail(&ctrl->subsys_entry, &subsys->ctrls);
>> nvmet_setup_p2p_ns_map(ctrl, req);
>> nvmet_debugfs_ctrl_setup(ctrl);
>> @@ -1486,6 +1527,10 @@ u16 nvmet_alloc_ctrl(const char *subsysnqn,
>> const char *hostnqn,
>> *ctrlp = ctrl;
>> return 0;
>> +init_pr_fail:
>> + mutex_unlock(&subsys->lock);
>> + nvmet_stop_keep_alive_timer(ctrl);
>> + ida_free(&cntlid_ida, ctrl->cntlid);
>> out_free_sqs:
>> kfree(ctrl->sqs);
>> out_free_changed_ns_list:
>> @@ -1504,6 +1549,7 @@ static void nvmet_ctrl_free(struct kref *ref)
>> struct nvmet_subsys *subsys = ctrl->subsys;
>> mutex_lock(&subsys->lock);
>> + nvmet_ctrl_destroy_pr(ctrl);
>> nvmet_release_p2p_ns_map(ctrl);
>> list_del(&ctrl->subsys_entry);
>> mutex_unlock(&subsys->lock);
>> diff --git a/drivers/nvme/target/fabrics-cmd.c
>> b/drivers/nvme/target/fabrics-cmd.c
>> index c4b2eddd5666..28a84af1b4c0 100644
>> --- a/drivers/nvme/target/fabrics-cmd.c
>> +++ b/drivers/nvme/target/fabrics-cmd.c
>> @@ -245,12 +245,10 @@ static void nvmet_execute_admin_connect(struct
>> nvmet_req *req)
>> d->subsysnqn[NVMF_NQN_FIELD_LEN - 1] = '\0';
>> d->hostnqn[NVMF_NQN_FIELD_LEN - 1] = '\0';
>> status = nvmet_alloc_ctrl(d->subsysnqn, d->hostnqn, req,
>> - le32_to_cpu(c->kato), &ctrl);
>> + le32_to_cpu(c->kato), &ctrl, &d->hostid);
>> if (status)
>> goto out;
>> - uuid_copy(&ctrl->hostid, &d->hostid);
>> -
>> dhchap_status = nvmet_setup_auth(ctrl);
>> if (dhchap_status) {
>> pr_err("Failed to setup authentication, dhchap status %u\n",
>> diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
>> index 190f55e6d753..51552f0430b4 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 +58,30 @@
>> #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 rcu_head rcu;
>> +};
>> +
>> +struct nvmet_pr {
>> + bool enable;
>> + unsigned long notify_mask;
>> + atomic_t generation;
>> + struct nvmet_pr_registrant __rcu *holder;
>> + struct mutex pr_lock;
>> + struct list_head registrant_list;
>> +};
>> +
>> +struct nvmet_pr_per_ctrl_ref {
>> + struct percpu_ref ref;
>> + struct completion free_done;
>> + struct completion confirm_done;
>> + uuid_t hostid;
>> +};
>> +
>> struct nvmet_ns {
>> struct percpu_ref ref;
>> struct file *bdev_file;
>> @@ -85,6 +111,8 @@ struct nvmet_ns {
>> int pi_type;
>> int metadata_size;
>> u8 csi;
>> + struct nvmet_pr pr;
>> + struct xarray pr_per_ctrl_refs;
>> };
>> static inline struct nvmet_ns *to_nvmet_ns(struct config_item *item)
>> @@ -191,6 +219,13 @@ 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;
>> @@ -246,6 +281,7 @@ struct nvmet_ctrl {
>> u8 *dh_key;
>> size_t dh_keysize;
>> #endif
>> + struct nvmet_pr_log_mgr pr_log_mgr;
>> };
>> struct nvmet_subsys {
>> @@ -412,6 +448,7 @@ struct nvmet_req {
>> struct device *p2p_client;
>> u16 error_loc;
>> u64 error_slba;
>> + struct nvmet_pr_per_ctrl_ref *pc_ref;
>> };
>> #define NVMET_MAX_MPOOL_BVEC 16
>> @@ -498,7 +535,8 @@ void nvmet_ctrl_fatal_error(struct nvmet_ctrl
>> *ctrl);
>> void nvmet_update_cc(struct nvmet_ctrl *ctrl, u32 new);
>> u16 nvmet_alloc_ctrl(const char *subsysnqn, const char *hostnqn,
>> - struct nvmet_req *req, u32 kato, struct nvmet_ctrl **ctrlp);
>> + struct nvmet_req *req, u32 kato, struct nvmet_ctrl **ctrlp,
>> + uuid_t *hostid);
>> struct nvmet_ctrl *nvmet_ctrl_find_get(const char *subsysnqn,
>> const char *hostnqn, u16 cntlid,
>> struct nvmet_req *req);
>> @@ -761,4 +799,19 @@ static inline bool nvmet_has_auth(struct
>> nvmet_ctrl *ctrl)
>> static inline const char *nvmet_dhchap_dhgroup_name(u8 dhgid) {
>> return NULL; }
>> #endif
>> +int 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);
>> +int nvmet_ctrl_init_pr(struct nvmet_ctrl *ctrl);
>> +void nvmet_ctrl_destroy_pr(struct nvmet_ctrl *ctrl);
>> +void nvmet_pr_exit_ns(struct nvmet_ns *ns);
>> +void nvmet_execute_get_log_page_resv(struct nvmet_req *req);
>> +u16 nvmet_set_feat_resv_notif_mask(struct nvmet_req *req, u32 mask);
>> +u16 nvmet_get_feat_resv_notif_mask(struct nvmet_req *req);
>> +u16 nvmet_pr_get_ns_pc_ref(struct nvmet_req *req);
>> +static inline void nvmet_pr_put_ns_pc_ref(struct nvmet_req *req)
>> +{
>> + if (req->pc_ref)
>> + percpu_ref_put(&req->pc_ref->ref);
>> +}
>> #endif /* _NVMET_H */
>> diff --git a/drivers/nvme/target/pr.c b/drivers/nvme/target/pr.c
>> new file mode 100644
>> index 000000000000..7795a103dd3b
>> --- /dev/null
>> +++ b/drivers/nvme/target/pr.c
>> @@ -0,0 +1,1172 @@
>> +// 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 <linux/unaligned.h>
>> +#include <linux/lockdep.h>
>> +#include "nvmet.h"
>> +
>> +#define NVMET_PR_NOTIFI_MASK_ALL \
>> + (1 << NVME_PR_NOTIFY_BIT_REG_PREEMPTED | \
>> + 1 << NVME_PR_NOTIFY_BIT_RESV_RELEASED | \
>> + 1 << NVME_PR_NOTIFY_BIT_RESV_PREEMPTED)
>> +
>> +static inline bool nvmet_pr_parse_ignore_key(u32 cdw10)
>> +{
>> + /* Ignore existing key, bit 03. */
>> + return (cdw10 >> 3) & 1;
>> +}
>> +
>> +static inline struct nvmet_ns *nvmet_pr_to_ns(struct nvmet_pr *pr)
>> +{
>> + return container_of(pr, struct nvmet_ns, pr);
>> +}
>> +
>> +static struct nvmet_pr_registrant *
>> +nvmet_pr_find_registrant(struct nvmet_pr *pr, uuid_t *hostid)
>> +{
>> + struct nvmet_pr_registrant *reg;
>> +
>> + list_for_each_entry_rcu(reg, &pr->registrant_list, entry,
>> + rcu_read_lock_held() ||
>> + lockdep_is_held(&pr->pr_lock)) {
>> + if (uuid_equal(®->hostid, hostid))
>> + return reg;
>> + }
>> + return NULL;
>> +}
>> +
>> +u16 nvmet_set_feat_resv_notif_mask(struct nvmet_req *req, u32 mask)
>> +{
>> + u32 nsid = le32_to_cpu(req->cmd->common.nsid);
>> + struct nvmet_ctrl *ctrl = req->sq->ctrl;
>> + struct nvmet_ns *ns;
>> + unsigned long idx;
>> + u16 status;
>> +
>> + if (mask & ~(NVMET_PR_NOTIFI_MASK_ALL)) {
>> + req->error_loc = offsetof(struct nvme_common_command, cdw11);
>> + return NVME_SC_INVALID_FIELD | NVME_STATUS_DNR;
>> + }
>> +
>> + if (nsid != U32_MAX) {
>> + status = nvmet_req_find_ns(req);
>> + if (status)
>> + return status;
>> + if (!req->ns->pr.enable)
>> + return NVME_SC_INVALID_FIELD | NVME_STATUS_DNR;
>> +
>> + WRITE_ONCE(req->ns->pr.notify_mask, mask);
>> + goto success;
>> + }
>> +
>> + xa_for_each(&ctrl->subsys->namespaces, idx, ns) {
>> + if (ns->pr.enable)
>> + WRITE_ONCE(ns->pr.notify_mask, mask);
>> + }
>> +
>> +success:
>> + nvmet_set_result(req, mask);
>> + return NVME_SC_SUCCESS;
>> +}
>> +
>> +u16 nvmet_get_feat_resv_notif_mask(struct nvmet_req *req)
>> +{
>> + u16 status;
>> +
>> + status = nvmet_req_find_ns(req);
>> + if (status)
>> + return status;
>> +
>> + if (!req->ns->pr.enable)
>> + return NVME_SC_INVALID_FIELD | NVME_STATUS_DNR;
>> +
>> + nvmet_set_result(req, READ_ONCE(req->ns->pr.notify_mask));
>> + return status;
>> +}
>> +
>> +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) == 0 ?
>> + 1 : (cur_count + lost_count));
>> + log_mgr->lost_count -= lost_count;
>> +
>> + log.nr_pages = kfifo_len(&log_mgr->log_queue);
>> +
>> +out:
>> + status = nvmet_copy_to_sgl(req, 0, &log, sizeof(log));
>> + 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_info("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_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;
>> +
>> + if (test_bit(NVME_PR_NOTIFY_BIT_RESV_RELEASED, &pr->notify_mask))
>> + return;
>> +
>> + mutex_lock(&subsys->lock);
>> + list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) {
>> + if (!uuid_equal(&ctrl->hostid, hostid) &&
>> + nvmet_pr_find_registrant(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_to_host(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_resv_preempted(struct nvmet_pr *pr, uuid_t
>> *hostid)
>> +{
>> + if (test_bit(NVME_PR_NOTIFY_BIT_RESV_PREEMPTED, &pr->notify_mask))
>> + return;
>> +
>> + nvmet_pr_send_event_to_host(pr, hostid,
>> + NVME_PR_LOG_RESERVATOPM_PREEMPTED);
>> +}
>> +
>> +static void nvmet_pr_registration_preempted(struct nvmet_pr *pr,
>> + uuid_t *hostid)
>> +{
>> + if (test_bit(NVME_PR_NOTIFY_BIT_REG_PREEMPTED, &pr->notify_mask))
>> + return;
>> +
>> + nvmet_pr_send_event_to_host(pr, hostid,
>> + NVME_PR_LOG_REGISTRATION_PREEMPTED);
>> +}
>> +
>> +static inline void nvmet_pr_set_new_holder(struct nvmet_pr *pr, u8
>> new_rtype,
>> + struct nvmet_pr_registrant *reg)
>> +{
>> + reg->rtype = new_rtype;
>> + rcu_assign_pointer(pr->holder, reg);
>> +}
>> +
>> +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;
>> + u64 nrkey = le64_to_cpu(d->nrkey);
>> +
>> + new = kmalloc(sizeof(*new), GFP_KERNEL);
>> + if (!new)
>> + return NVME_SC_INTERNAL;
>> +
>> + mutex_lock(&pr->pr_lock);
>> + reg = nvmet_pr_find_registrant(pr, &ctrl->hostid);
>> + if (reg) {
>> + if (reg->rkey != nrkey)
>> + status = NVME_SC_RESERVATION_CONFLICT | NVME_STATUS_DNR;
>> + kfree(new);
>> + goto out;
>> + }
>> +
>> + memset(new, 0, sizeof(*new));
>> + INIT_LIST_HEAD(&new->entry);
>> + new->rkey = 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(®->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_EXCLUSIVE_ACCESS_REG_ONLY)
>> + nvmet_pr_resv_released(pr, ®->hostid);
>> + }
>> +out:
>> + kfree_rcu(reg, rcu);
>> +}
>> +
>> +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_STATUS_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(®->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 void nvmet_pr_update_reg_rkey(struct nvmet_pr_registrant *reg,
>> + void *attr)
>> +{
>> + reg->rkey = *(u64 *)attr;
>> +}
>> +
>> +static u16 nvmet_pr_update_reg_attr(struct nvmet_pr *pr,
>> + struct nvmet_pr_registrant *reg,
>> + void (*change_attr)(struct nvmet_pr_registrant *reg,
>> + void *attr),
>> + void *attr)
>> +{
>> + struct nvmet_pr_registrant *holder;
>> + struct nvmet_pr_registrant *new;
>> +
>> + lockdep_assert_held(&pr->pr_lock);
>> + holder = rcu_dereference_protected(pr->holder,
>> + lockdep_is_held(&pr->pr_lock));
>> + if (reg != holder) {
>> + change_attr(reg, attr);
>> + return NVME_SC_SUCCESS;
>> + }
>> +
>> + 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);
>> +
>> + change_attr(new, attr);
>> + list_replace_rcu(&holder->entry, &new->entry);
>> + rcu_assign_pointer(pr->holder, new);
>> + kfree_rcu(holder, rcu);
>> +
>> + return NVME_SC_SUCCESS;
>> +}
>> +
>> +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_STATUS_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(®->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 = nvmet_pr_parse_ignore_key(cdw10);
>> + 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_STATUS_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_STATUS_DNR;
>> + if (holder && reg == holder) {
>> + if (holder->rtype == rtype)
>> + return NVME_SC_SUCCESS;
>> + return NVME_SC_RESERVATION_CONFLICT | NVME_STATUS_DNR;
>> + }
>> +
>> + nvmet_pr_set_new_holder(pr, rtype, reg);
>> + return NVME_SC_SUCCESS;
>> +}
>> +
>> +static void nvmet_pr_confirm_ns_pc_ref(struct percpu_ref *ref)
>> +{
>> + struct nvmet_pr_per_ctrl_ref *pc_ref =
>> + container_of(ref, struct nvmet_pr_per_ctrl_ref, ref);
>> +
>> + complete(&pc_ref->confirm_done);
>> +}
>> +
>> +static void nvmet_pr_set_ctrl_to_abort(struct nvmet_req *req, uuid_t
>> *hostid)
>> +{
>> + struct nvmet_pr_per_ctrl_ref *pc_ref;
>> + struct nvmet_ns *ns = req->ns;
>> + unsigned long idx;
>> +
>> + xa_for_each(&ns->pr_per_ctrl_refs, idx, pc_ref) {
>> + if (uuid_equal(&pc_ref->hostid, hostid)) {
>> + percpu_ref_kill_and_confirm(&pc_ref->ref,
>> + nvmet_pr_confirm_ns_pc_ref);
>> + wait_for_completion(&pc_ref->confirm_done);
>> + }
>> + }
>> +}
>> +
>> +static u16 nvmet_pr_unreg_all_host_by_prkey(struct nvmet_req *req,
>> u64 prkey,
>> + uuid_t *send_hostid,
>> + bool abort)
>> +{
>> + u16 status = NVME_SC_RESERVATION_CONFLICT | NVME_STATUS_DNR;
>> + struct nvmet_pr_registrant *reg, *tmp;
>> + struct nvmet_pr *pr = &req->ns->pr;
>> + uuid_t hostid;
>> +
>> + 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;
>> + uuid_copy(&hostid, ®->hostid);
>> + if (abort)
>> + nvmet_pr_set_ctrl_to_abort(req, &hostid);
>> + nvmet_pr_unregister_one(pr, reg);
>> + if (!uuid_equal(&hostid, send_hostid))
>> + nvmet_pr_registration_preempted(pr, &hostid);
>> + }
>> + }
>> + return status;
>> +}
>> +
>> +static void nvmet_pr_unreg_all_others_by_prkey(struct nvmet_req *req,
>> + u64 prkey,
>> + uuid_t *send_hostid,
>> + bool abort)
>> +{
>> + struct nvmet_pr_registrant *reg, *tmp;
>> + struct nvmet_pr *pr = &req->ns->pr;
>> + uuid_t hostid;
>> +
>> + lockdep_assert_held(&pr->pr_lock);
>> +
>> + list_for_each_entry_safe(reg, tmp, &pr->registrant_list, entry) {
>> + if (reg->rkey == prkey &&
>> + !uuid_equal(®->hostid, send_hostid)) {
>> + uuid_copy(&hostid, ®->hostid);
>> + if (abort)
>> + nvmet_pr_set_ctrl_to_abort(req, &hostid);
>> + nvmet_pr_unregister_one(pr, reg);
>> + nvmet_pr_registration_preempted(pr, &hostid);
>> + }
>> + }
>> +}
>> +
>> +static void nvmet_pr_unreg_all_others(struct nvmet_req *req,
>> + uuid_t *send_hostid,
>> + bool abort)
>> +{
>> + struct nvmet_pr_registrant *reg, *tmp;
>> + struct nvmet_pr *pr = &req->ns->pr;
>> + uuid_t hostid;
>> +
>> + lockdep_assert_held(&pr->pr_lock);
>> +
>> + list_for_each_entry_safe(reg, tmp, &pr->registrant_list, entry) {
>> + if (!uuid_equal(®->hostid, send_hostid)) {
>> + uuid_copy(&hostid, ®->hostid);
>> + if (abort)
>> + nvmet_pr_set_ctrl_to_abort(req, &hostid);
>> + nvmet_pr_unregister_one(pr, reg);
>> + nvmet_pr_registration_preempted(pr, &hostid);
>> + }
>> + }
>> +}
>> +
>> +static void nvmet_pr_update_holder_rtype(struct nvmet_pr_registrant
>> *reg,
>> + void *attr)
>> +{
>> + u8 new_rtype = *(u8 *)attr;
>> +
>> + reg->rtype = new_rtype;
>> +}
>> +
>> +static u16 nvmet_pr_preempt(struct nvmet_req *req,
>> + struct nvmet_pr_registrant *reg,
>> + u8 rtype,
>> + struct nvmet_pr_acquire_data *d,
>> + bool abort)
>> +{
>> + 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;
>> + u64 prkey = le64_to_cpu(d->prkey);
>> + 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_all_host_by_prkey(req, prkey,
>> + &ctrl->hostid, abort);
>> +
>> + original_rtype = holder->rtype;
>> + if (original_rtype == NVME_PR_WRITE_EXCLUSIVE_ALL_REGS ||
>> + original_rtype == NVME_PR_EXCLUSIVE_ACCESS_ALL_REGS) {
>> + if (!prkey) {
>> + /*
>> + * To prevent possible access from other hosts, and
>> + * avoid terminate the holder, set the new holder
>> + * first before unregistering.
>> + */
>> + nvmet_pr_set_new_holder(pr, rtype, reg);
>> + nvmet_pr_unreg_all_others(req, &ctrl->hostid, abort);
>> + return NVME_SC_SUCCESS;
>> + }
>> + return nvmet_pr_unreg_all_host_by_prkey(req, prkey,
>> + &ctrl->hostid, abort);
>> + }
>> +
>> + if (holder == reg) {
>> + status = nvmet_pr_update_reg_attr(pr, holder,
>> + nvmet_pr_update_holder_rtype, &rtype);
>> + if (!status && original_rtype != rtype)
>> + nvmet_pr_resv_released(pr, ®->hostid);
>> + return status;
>> + }
>> +
>> + if (prkey == holder->rkey) {
>> + /*
>> + * Same as before, set the new holder first.
>> + */
>> + nvmet_pr_set_new_holder(pr, rtype, reg);
>> + nvmet_pr_unreg_all_others_by_prkey(req, prkey, &ctrl->hostid,
>> + abort);
>> + if (original_rtype != rtype)
>> + nvmet_pr_resv_released(pr, ®->hostid);
>> + return NVME_SC_SUCCESS;
>> + }
>> +
>> + if (prkey)
>> + return nvmet_pr_unreg_all_host_by_prkey(req, prkey,
>> + &ctrl->hostid, abort);
>> + return NVME_SC_INVALID_FIELD | NVME_STATUS_DNR;
>> +}
>> +
>> +static void nvmet_pr_do_abort(struct nvmet_req *req)
>> +{
>> + struct nvmet_pr_per_ctrl_ref *pc_ref;
>> + struct nvmet_ns *ns = req->ns;
>> + unsigned long idx;
>> +
>> + /*
>> + * The target does not support abort, just wait per-controller
>> ref to 0.
>> + */
>> + xa_for_each(&ns->pr_per_ctrl_refs, idx, pc_ref) {
>> + if (percpu_ref_is_dying(&pc_ref->ref)) {
>
> Is this possible that we get here without the ref dying? Maybe a warn
> is appropriate here? just feels incorrect to blindly do nothing and just
> skip...
>
The pc_ref will only be in a dying state when the command is preempt and
abort,
and when the controller's reservation is preempted or released.
I killed it in the nvmet_pr_set_ctrl_to_abort() function. As for
the pc_ref of other controllers that are not affected, they are
not in a dying state. In this case, we don't need to wait;
skipping is the correct approach.
>> + wait_for_completion(&pc_ref->free_done);
>> + reinit_completion(&pc_ref->confirm_done);
>> + reinit_completion(&pc_ref->free_done);
>> + percpu_ref_resurrect(&pc_ref->ref);
>> + }
>> + }
>
> I'm wandering if the do_abort should be deferred to a wq? this will
> block the transport thread for a long time, preventing progress
> for other namespaces that can accept IO perhaps?
>
Here we are already in wq, ib_cq_poll_work and nvmet_tcp_io_work,
still we still need another wq? If need, I will send the v17 patch to
change.
Best Regards,
Guixin Liu
> The rest looks fine, although I am having a hard time reviewing a single
> patch of this size...
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