linux/drivers/nvme/target/core.c

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/*
* Common code for the NVMe target.
* Copyright (c) 2015-2016 HGST, a Western Digital Company.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/random.h>
#include <linux/rculist.h>
#include "nvmet.h"
static const struct nvmet_fabrics_ops *nvmet_transports[NVMF_TRTYPE_MAX];
static DEFINE_IDA(cntlid_ida);
/*
* This read/write semaphore is used to synchronize access to configuration
* information on a target system that will result in discovery log page
* information change for at least one host.
* The full list of resources to protected by this semaphore is:
*
* - subsystems list
* - per-subsystem allowed hosts list
* - allow_any_host subsystem attribute
* - nvmet_genctr
* - the nvmet_transports array
*
* When updating any of those lists/structures write lock should be obtained,
* while when reading (popolating discovery log page or checking host-subsystem
* link) read lock is obtained to allow concurrent reads.
*/
DECLARE_RWSEM(nvmet_config_sem);
static struct nvmet_subsys *nvmet_find_get_subsys(struct nvmet_port *port,
const char *subsysnqn);
u16 nvmet_copy_to_sgl(struct nvmet_req *req, off_t off, const void *buf,
size_t len)
{
if (sg_pcopy_from_buffer(req->sg, req->sg_cnt, buf, len, off) != len)
return NVME_SC_SGL_INVALID_DATA | NVME_SC_DNR;
return 0;
}
u16 nvmet_copy_from_sgl(struct nvmet_req *req, off_t off, void *buf, size_t len)
{
if (sg_pcopy_to_buffer(req->sg, req->sg_cnt, buf, len, off) != len)
return NVME_SC_SGL_INVALID_DATA | NVME_SC_DNR;
return 0;
}
u16 nvmet_zero_sgl(struct nvmet_req *req, off_t off, size_t len)
{
if (sg_zero_buffer(req->sg, req->sg_cnt, len, off) != len)
return NVME_SC_SGL_INVALID_DATA | NVME_SC_DNR;
return 0;
}
static unsigned int nvmet_max_nsid(struct nvmet_subsys *subsys)
{
struct nvmet_ns *ns;
if (list_empty(&subsys->namespaces))
return 0;
ns = list_last_entry(&subsys->namespaces, struct nvmet_ns, dev_link);
return ns->nsid;
}
static u32 nvmet_async_event_result(struct nvmet_async_event *aen)
{
return aen->event_type | (aen->event_info << 8) | (aen->log_page << 16);
}
static void nvmet_async_events_free(struct nvmet_ctrl *ctrl)
{
struct nvmet_req *req;
while (1) {
mutex_lock(&ctrl->lock);
if (!ctrl->nr_async_event_cmds) {
mutex_unlock(&ctrl->lock);
return;
}
req = ctrl->async_event_cmds[--ctrl->nr_async_event_cmds];
mutex_unlock(&ctrl->lock);
nvmet_req_complete(req, NVME_SC_INTERNAL | NVME_SC_DNR);
}
}
static void nvmet_async_event_work(struct work_struct *work)
{
struct nvmet_ctrl *ctrl =
container_of(work, struct nvmet_ctrl, async_event_work);
struct nvmet_async_event *aen;
struct nvmet_req *req;
while (1) {
mutex_lock(&ctrl->lock);
aen = list_first_entry_or_null(&ctrl->async_events,
struct nvmet_async_event, entry);
if (!aen || !ctrl->nr_async_event_cmds) {
mutex_unlock(&ctrl->lock);
return;
}
req = ctrl->async_event_cmds[--ctrl->nr_async_event_cmds];
nvmet_set_result(req, nvmet_async_event_result(aen));
list_del(&aen->entry);
kfree(aen);
mutex_unlock(&ctrl->lock);
nvmet_req_complete(req, 0);
}
}
static void nvmet_add_async_event(struct nvmet_ctrl *ctrl, u8 event_type,
u8 event_info, u8 log_page)
{
struct nvmet_async_event *aen;
aen = kmalloc(sizeof(*aen), GFP_KERNEL);
if (!aen)
return;
aen->event_type = event_type;
aen->event_info = event_info;
aen->log_page = log_page;
mutex_lock(&ctrl->lock);
list_add_tail(&aen->entry, &ctrl->async_events);
mutex_unlock(&ctrl->lock);
schedule_work(&ctrl->async_event_work);
}
static bool nvmet_aen_disabled(struct nvmet_ctrl *ctrl, u32 aen)
{
if (!(READ_ONCE(ctrl->aen_enabled) & aen))
return true;
return test_and_set_bit(aen, &ctrl->aen_masked);
}
static void nvmet_add_to_changed_ns_log(struct nvmet_ctrl *ctrl, __le32 nsid)
{
u32 i;
mutex_lock(&ctrl->lock);
if (ctrl->nr_changed_ns > NVME_MAX_CHANGED_NAMESPACES)
goto out_unlock;
for (i = 0; i < ctrl->nr_changed_ns; i++) {
if (ctrl->changed_ns_list[i] == nsid)
goto out_unlock;
}
if (ctrl->nr_changed_ns == NVME_MAX_CHANGED_NAMESPACES) {
ctrl->changed_ns_list[0] = cpu_to_le32(0xffffffff);
ctrl->nr_changed_ns = U32_MAX;
goto out_unlock;
}
ctrl->changed_ns_list[ctrl->nr_changed_ns++] = nsid;
out_unlock:
mutex_unlock(&ctrl->lock);
}
static void nvmet_ns_changed(struct nvmet_subsys *subsys, u32 nsid)
{
struct nvmet_ctrl *ctrl;
list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) {
nvmet_add_to_changed_ns_log(ctrl, cpu_to_le32(nsid));
if (nvmet_aen_disabled(ctrl, NVME_AEN_CFG_NS_ATTR))
continue;
nvmet_add_async_event(ctrl, NVME_AER_TYPE_NOTICE,
NVME_AER_NOTICE_NS_CHANGED,
NVME_LOG_CHANGED_NS);
}
}
int nvmet_register_transport(const struct nvmet_fabrics_ops *ops)
{
int ret = 0;
down_write(&nvmet_config_sem);
if (nvmet_transports[ops->type])
ret = -EINVAL;
else
nvmet_transports[ops->type] = ops;
up_write(&nvmet_config_sem);
return ret;
}
EXPORT_SYMBOL_GPL(nvmet_register_transport);
void nvmet_unregister_transport(const struct nvmet_fabrics_ops *ops)
{
down_write(&nvmet_config_sem);
nvmet_transports[ops->type] = NULL;
up_write(&nvmet_config_sem);
}
EXPORT_SYMBOL_GPL(nvmet_unregister_transport);
int nvmet_enable_port(struct nvmet_port *port)
{
const struct nvmet_fabrics_ops *ops;
int ret;
lockdep_assert_held(&nvmet_config_sem);
ops = nvmet_transports[port->disc_addr.trtype];
if (!ops) {
up_write(&nvmet_config_sem);
request_module("nvmet-transport-%d", port->disc_addr.trtype);
down_write(&nvmet_config_sem);
ops = nvmet_transports[port->disc_addr.trtype];
if (!ops) {
pr_err("transport type %d not supported\n",
port->disc_addr.trtype);
return -EINVAL;
}
}
if (!try_module_get(ops->owner))
return -EINVAL;
ret = ops->add_port(port);
if (ret) {
module_put(ops->owner);
return ret;
}
port->enabled = true;
return 0;
}
void nvmet_disable_port(struct nvmet_port *port)
{
const struct nvmet_fabrics_ops *ops;
lockdep_assert_held(&nvmet_config_sem);
port->enabled = false;
ops = nvmet_transports[port->disc_addr.trtype];
ops->remove_port(port);
module_put(ops->owner);
}
static void nvmet_keep_alive_timer(struct work_struct *work)
{
struct nvmet_ctrl *ctrl = container_of(to_delayed_work(work),
struct nvmet_ctrl, ka_work);
pr_err("ctrl %d keep-alive timer (%d seconds) expired!\n",
ctrl->cntlid, ctrl->kato);
nvmet_ctrl_fatal_error(ctrl);
}
static void nvmet_start_keep_alive_timer(struct nvmet_ctrl *ctrl)
{
pr_debug("ctrl %d start keep-alive timer for %d secs\n",
ctrl->cntlid, ctrl->kato);
INIT_DELAYED_WORK(&ctrl->ka_work, nvmet_keep_alive_timer);
schedule_delayed_work(&ctrl->ka_work, ctrl->kato * HZ);
}
static void nvmet_stop_keep_alive_timer(struct nvmet_ctrl *ctrl)
{
pr_debug("ctrl %d stop keep-alive\n", ctrl->cntlid);
cancel_delayed_work_sync(&ctrl->ka_work);
}
static struct nvmet_ns *__nvmet_find_namespace(struct nvmet_ctrl *ctrl,
__le32 nsid)
{
struct nvmet_ns *ns;
list_for_each_entry_rcu(ns, &ctrl->subsys->namespaces, dev_link) {
if (ns->nsid == le32_to_cpu(nsid))
return ns;
}
return NULL;
}
struct nvmet_ns *nvmet_find_namespace(struct nvmet_ctrl *ctrl, __le32 nsid)
{
struct nvmet_ns *ns;
rcu_read_lock();
ns = __nvmet_find_namespace(ctrl, nsid);
if (ns)
percpu_ref_get(&ns->ref);
rcu_read_unlock();
return ns;
}
static void nvmet_destroy_namespace(struct percpu_ref *ref)
{
struct nvmet_ns *ns = container_of(ref, struct nvmet_ns, ref);
complete(&ns->disable_done);
}
void nvmet_put_namespace(struct nvmet_ns *ns)
{
percpu_ref_put(&ns->ref);
}
static void nvmet_ns_dev_disable(struct nvmet_ns *ns)
{
nvmet_bdev_ns_disable(ns);
nvmet_file_ns_disable(ns);
}
int nvmet_ns_enable(struct nvmet_ns *ns)
{
struct nvmet_subsys *subsys = ns->subsys;
int ret = 0;
mutex_lock(&subsys->lock);
if (ns->enabled)
goto out_unlock;
ret = nvmet_bdev_ns_enable(ns);
if (ret)
ret = nvmet_file_ns_enable(ns);
if (ret)
goto out_unlock;
ret = percpu_ref_init(&ns->ref, nvmet_destroy_namespace,
0, GFP_KERNEL);
if (ret)
goto out_dev_put;
if (ns->nsid > subsys->max_nsid)
subsys->max_nsid = ns->nsid;
/*
* The namespaces list needs to be sorted to simplify the implementation
* of the Identify Namepace List subcommand.
*/
if (list_empty(&subsys->namespaces)) {
list_add_tail_rcu(&ns->dev_link, &subsys->namespaces);
} else {
struct nvmet_ns *old;
list_for_each_entry_rcu(old, &subsys->namespaces, dev_link) {
BUG_ON(ns->nsid == old->nsid);
if (ns->nsid < old->nsid)
break;
}
list_add_tail_rcu(&ns->dev_link, &old->dev_link);
}
nvmet_ns_changed(subsys, ns->nsid);
ns->enabled = true;
ret = 0;
out_unlock:
mutex_unlock(&subsys->lock);
return ret;
out_dev_put:
nvmet_ns_dev_disable(ns);
goto out_unlock;
}
void nvmet_ns_disable(struct nvmet_ns *ns)
{
struct nvmet_subsys *subsys = ns->subsys;
mutex_lock(&subsys->lock);
if (!ns->enabled)
goto out_unlock;
ns->enabled = false;
list_del_rcu(&ns->dev_link);
if (ns->nsid == subsys->max_nsid)
subsys->max_nsid = nvmet_max_nsid(subsys);
mutex_unlock(&subsys->lock);
/*
* Now that we removed the namespaces from the lookup list, we
* can kill the per_cpu ref and wait for any remaining references
* to be dropped, as well as a RCU grace period for anyone only
* using the namepace under rcu_read_lock(). Note that we can't
* use call_rcu here as we need to ensure the namespaces have
* been fully destroyed before unloading the module.
*/
percpu_ref_kill(&ns->ref);
synchronize_rcu();
wait_for_completion(&ns->disable_done);
percpu_ref_exit(&ns->ref);
mutex_lock(&subsys->lock);
nvmet_ns_changed(subsys, ns->nsid);
nvmet_ns_dev_disable(ns);
out_unlock:
mutex_unlock(&subsys->lock);
}
void nvmet_ns_free(struct nvmet_ns *ns)
{
nvmet_ns_disable(ns);
kfree(ns->device_path);
kfree(ns);
}
struct nvmet_ns *nvmet_ns_alloc(struct nvmet_subsys *subsys, u32 nsid)
{
struct nvmet_ns *ns;
ns = kzalloc(sizeof(*ns), GFP_KERNEL);
if (!ns)
return NULL;
INIT_LIST_HEAD(&ns->dev_link);
init_completion(&ns->disable_done);
ns->nsid = nsid;
ns->subsys = subsys;
uuid_gen(&ns->uuid);
return ns;
}
static void __nvmet_req_complete(struct nvmet_req *req, u16 status)
{
u32 old_sqhd, new_sqhd;
u16 sqhd;
if (status)
nvmet_set_status(req, status);
if (req->sq->size) {
do {
old_sqhd = req->sq->sqhd;
new_sqhd = (old_sqhd + 1) % req->sq->size;
} while (cmpxchg(&req->sq->sqhd, old_sqhd, new_sqhd) !=
old_sqhd);
}
sqhd = req->sq->sqhd & 0x0000FFFF;
req->rsp->sq_head = cpu_to_le16(sqhd);
req->rsp->sq_id = cpu_to_le16(req->sq->qid);
req->rsp->command_id = req->cmd->common.command_id;
if (req->ns)
nvmet_put_namespace(req->ns);
req->ops->queue_response(req);
}
void nvmet_req_complete(struct nvmet_req *req, u16 status)
{
__nvmet_req_complete(req, status);
percpu_ref_put(&req->sq->ref);
}
EXPORT_SYMBOL_GPL(nvmet_req_complete);
void nvmet_cq_setup(struct nvmet_ctrl *ctrl, struct nvmet_cq *cq,
u16 qid, u16 size)
{
cq->qid = qid;
cq->size = size;
ctrl->cqs[qid] = cq;
}
void nvmet_sq_setup(struct nvmet_ctrl *ctrl, struct nvmet_sq *sq,
u16 qid, u16 size)
{
sq->sqhd = 0;
sq->qid = qid;
sq->size = size;
ctrl->sqs[qid] = sq;
}
static void nvmet_confirm_sq(struct percpu_ref *ref)
{
struct nvmet_sq *sq = container_of(ref, struct nvmet_sq, ref);
complete(&sq->confirm_done);
}
void nvmet_sq_destroy(struct nvmet_sq *sq)
{
/*
* If this is the admin queue, complete all AERs so that our
* queue doesn't have outstanding requests on it.
*/
if (sq->ctrl && sq->ctrl->sqs && sq->ctrl->sqs[0] == sq)
nvmet_async_events_free(sq->ctrl);
percpu_ref_kill_and_confirm(&sq->ref, nvmet_confirm_sq);
wait_for_completion(&sq->confirm_done);
wait_for_completion(&sq->free_done);
percpu_ref_exit(&sq->ref);
if (sq->ctrl) {
nvmet_ctrl_put(sq->ctrl);
sq->ctrl = NULL; /* allows reusing the queue later */
}
}
EXPORT_SYMBOL_GPL(nvmet_sq_destroy);
static void nvmet_sq_free(struct percpu_ref *ref)
{
struct nvmet_sq *sq = container_of(ref, struct nvmet_sq, ref);
complete(&sq->free_done);
}
int nvmet_sq_init(struct nvmet_sq *sq)
{
int ret;
ret = percpu_ref_init(&sq->ref, nvmet_sq_free, 0, GFP_KERNEL);
if (ret) {
pr_err("percpu_ref init failed!\n");
return ret;
}
init_completion(&sq->free_done);
init_completion(&sq->confirm_done);
return 0;
}
EXPORT_SYMBOL_GPL(nvmet_sq_init);
static u16 nvmet_parse_io_cmd(struct nvmet_req *req)
{
struct nvme_command *cmd = req->cmd;
u16 ret;
ret = nvmet_check_ctrl_status(req, cmd);
if (unlikely(ret))
return ret;
req->ns = nvmet_find_namespace(req->sq->ctrl, cmd->rw.nsid);
if (unlikely(!req->ns))
return NVME_SC_INVALID_NS | NVME_SC_DNR;
if (req->ns->file)
return nvmet_file_parse_io_cmd(req);
else
return nvmet_bdev_parse_io_cmd(req);
}
bool nvmet_req_init(struct nvmet_req *req, struct nvmet_cq *cq,
struct nvmet_sq *sq, const struct nvmet_fabrics_ops *ops)
{
u8 flags = req->cmd->common.flags;
u16 status;
req->cq = cq;
req->sq = sq;
req->ops = ops;
req->sg = NULL;
req->sg_cnt = 0;
req->transfer_len = 0;
req->rsp->status = 0;
req->ns = NULL;
/* no support for fused commands yet */
if (unlikely(flags & (NVME_CMD_FUSE_FIRST | NVME_CMD_FUSE_SECOND))) {
status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
goto fail;
}
/*
* For fabrics, PSDT field shall describe metadata pointer (MPTR) that
* contains an address of a single contiguous physical buffer that is
* byte aligned.
*/
if (unlikely((flags & NVME_CMD_SGL_ALL) != NVME_CMD_SGL_METABUF)) {
status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
goto fail;
}
if (unlikely(!req->sq->ctrl))
/* will return an error for any Non-connect command: */
status = nvmet_parse_connect_cmd(req);
else if (likely(req->sq->qid != 0))
status = nvmet_parse_io_cmd(req);
else if (req->cmd->common.opcode == nvme_fabrics_command)
status = nvmet_parse_fabrics_cmd(req);
else if (req->sq->ctrl->subsys->type == NVME_NQN_DISC)
status = nvmet_parse_discovery_cmd(req);
else
status = nvmet_parse_admin_cmd(req);
if (status)
goto fail;
if (unlikely(!percpu_ref_tryget_live(&sq->ref))) {
status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
goto fail;
}
return true;
fail:
__nvmet_req_complete(req, status);
return false;
}
EXPORT_SYMBOL_GPL(nvmet_req_init);
void nvmet_req_uninit(struct nvmet_req *req)
{
percpu_ref_put(&req->sq->ref);
if (req->ns)
nvmet_put_namespace(req->ns);
}
EXPORT_SYMBOL_GPL(nvmet_req_uninit);
void nvmet_req_execute(struct nvmet_req *req)
{
if (unlikely(req->data_len != req->transfer_len))
nvmet_req_complete(req, NVME_SC_SGL_INVALID_DATA | NVME_SC_DNR);
else
req->execute(req);
}
EXPORT_SYMBOL_GPL(nvmet_req_execute);
static inline bool nvmet_cc_en(u32 cc)
{
return (cc >> NVME_CC_EN_SHIFT) & 0x1;
}
static inline u8 nvmet_cc_css(u32 cc)
{
return (cc >> NVME_CC_CSS_SHIFT) & 0x7;
}
static inline u8 nvmet_cc_mps(u32 cc)
{
return (cc >> NVME_CC_MPS_SHIFT) & 0xf;
}
static inline u8 nvmet_cc_ams(u32 cc)
{
return (cc >> NVME_CC_AMS_SHIFT) & 0x7;
}
static inline u8 nvmet_cc_shn(u32 cc)
{
return (cc >> NVME_CC_SHN_SHIFT) & 0x3;
}
static inline u8 nvmet_cc_iosqes(u32 cc)
{
return (cc >> NVME_CC_IOSQES_SHIFT) & 0xf;
}
static inline u8 nvmet_cc_iocqes(u32 cc)
{
return (cc >> NVME_CC_IOCQES_SHIFT) & 0xf;
}
static void nvmet_start_ctrl(struct nvmet_ctrl *ctrl)
{
lockdep_assert_held(&ctrl->lock);
if (nvmet_cc_iosqes(ctrl->cc) != NVME_NVM_IOSQES ||
nvmet_cc_iocqes(ctrl->cc) != NVME_NVM_IOCQES ||
nvmet_cc_mps(ctrl->cc) != 0 ||
nvmet_cc_ams(ctrl->cc) != 0 ||
nvmet_cc_css(ctrl->cc) != 0) {
ctrl->csts = NVME_CSTS_CFS;
return;
}
ctrl->csts = NVME_CSTS_RDY;
}
static void nvmet_clear_ctrl(struct nvmet_ctrl *ctrl)
{
lockdep_assert_held(&ctrl->lock);
/* XXX: tear down queues? */
ctrl->csts &= ~NVME_CSTS_RDY;
ctrl->cc = 0;
}
void nvmet_update_cc(struct nvmet_ctrl *ctrl, u32 new)
{
u32 old;
mutex_lock(&ctrl->lock);
old = ctrl->cc;
ctrl->cc = new;
if (nvmet_cc_en(new) && !nvmet_cc_en(old))
nvmet_start_ctrl(ctrl);
if (!nvmet_cc_en(new) && nvmet_cc_en(old))
nvmet_clear_ctrl(ctrl);
if (nvmet_cc_shn(new) && !nvmet_cc_shn(old)) {
nvmet_clear_ctrl(ctrl);
ctrl->csts |= NVME_CSTS_SHST_CMPLT;
}
if (!nvmet_cc_shn(new) && nvmet_cc_shn(old))
ctrl->csts &= ~NVME_CSTS_SHST_CMPLT;
mutex_unlock(&ctrl->lock);
}
static void nvmet_init_cap(struct nvmet_ctrl *ctrl)
{
/* command sets supported: NVMe command set: */
ctrl->cap = (1ULL << 37);
/* CC.EN timeout in 500msec units: */
ctrl->cap |= (15ULL << 24);
/* maximum queue entries supported: */
ctrl->cap |= NVMET_QUEUE_SIZE - 1;
}
u16 nvmet_ctrl_find_get(const char *subsysnqn, const char *hostnqn, u16 cntlid,
struct nvmet_req *req, struct nvmet_ctrl **ret)
{
struct nvmet_subsys *subsys;
struct nvmet_ctrl *ctrl;
u16 status = 0;
subsys = nvmet_find_get_subsys(req->port, subsysnqn);
if (!subsys) {
pr_warn("connect request for invalid subsystem %s!\n",
subsysnqn);
req->rsp->result.u32 = IPO_IATTR_CONNECT_DATA(subsysnqn);
return NVME_SC_CONNECT_INVALID_PARAM | NVME_SC_DNR;
}
mutex_lock(&subsys->lock);
list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) {
if (ctrl->cntlid == cntlid) {
if (strncmp(hostnqn, ctrl->hostnqn, NVMF_NQN_SIZE)) {
pr_warn("hostnqn mismatch.\n");
continue;
}
if (!kref_get_unless_zero(&ctrl->ref))
continue;
*ret = ctrl;
goto out;
}
}
pr_warn("could not find controller %d for subsys %s / host %s\n",
cntlid, subsysnqn, hostnqn);
req->rsp->result.u32 = IPO_IATTR_CONNECT_DATA(cntlid);
status = NVME_SC_CONNECT_INVALID_PARAM | NVME_SC_DNR;
out:
mutex_unlock(&subsys->lock);
nvmet_subsys_put(subsys);
return status;
}
u16 nvmet_check_ctrl_status(struct nvmet_req *req, struct nvme_command *cmd)
{
if (unlikely(!(req->sq->ctrl->cc & NVME_CC_ENABLE))) {
pr_err("got cmd %d while CC.EN == 0 on qid = %d\n",
cmd->common.opcode, req->sq->qid);
return NVME_SC_CMD_SEQ_ERROR | NVME_SC_DNR;
}
if (unlikely(!(req->sq->ctrl->csts & NVME_CSTS_RDY))) {
pr_err("got cmd %d while CSTS.RDY == 0 on qid = %d\n",
cmd->common.opcode, req->sq->qid);
return NVME_SC_CMD_SEQ_ERROR | NVME_SC_DNR;
}
return 0;
}
static bool __nvmet_host_allowed(struct nvmet_subsys *subsys,
const char *hostnqn)
{
struct nvmet_host_link *p;
if (subsys->allow_any_host)
return true;
list_for_each_entry(p, &subsys->hosts, entry) {
if (!strcmp(nvmet_host_name(p->host), hostnqn))
return true;
}
return false;
}
static bool nvmet_host_discovery_allowed(struct nvmet_req *req,
const char *hostnqn)
{
struct nvmet_subsys_link *s;
list_for_each_entry(s, &req->port->subsystems, entry) {
if (__nvmet_host_allowed(s->subsys, hostnqn))
return true;
}
return false;
}
bool nvmet_host_allowed(struct nvmet_req *req, struct nvmet_subsys *subsys,
const char *hostnqn)
{
lockdep_assert_held(&nvmet_config_sem);
if (subsys->type == NVME_NQN_DISC)
return nvmet_host_discovery_allowed(req, hostnqn);
else
return __nvmet_host_allowed(subsys, hostnqn);
}
u16 nvmet_alloc_ctrl(const char *subsysnqn, const char *hostnqn,
struct nvmet_req *req, u32 kato, struct nvmet_ctrl **ctrlp)
{
struct nvmet_subsys *subsys;
struct nvmet_ctrl *ctrl;
int ret;
u16 status;
status = NVME_SC_CONNECT_INVALID_PARAM | NVME_SC_DNR;
subsys = nvmet_find_get_subsys(req->port, subsysnqn);
if (!subsys) {
pr_warn("connect request for invalid subsystem %s!\n",
subsysnqn);
req->rsp->result.u32 = IPO_IATTR_CONNECT_DATA(subsysnqn);
goto out;
}
status = NVME_SC_CONNECT_INVALID_PARAM | NVME_SC_DNR;
down_read(&nvmet_config_sem);
if (!nvmet_host_allowed(req, subsys, hostnqn)) {
pr_info("connect by host %s for subsystem %s not allowed\n",
hostnqn, subsysnqn);
req->rsp->result.u32 = IPO_IATTR_CONNECT_DATA(hostnqn);
up_read(&nvmet_config_sem);
status = NVME_SC_CONNECT_INVALID_HOST | NVME_SC_DNR;
goto out_put_subsystem;
}
up_read(&nvmet_config_sem);
status = NVME_SC_INTERNAL;
ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
if (!ctrl)
goto out_put_subsystem;
mutex_init(&ctrl->lock);
nvmet_init_cap(ctrl);
INIT_WORK(&ctrl->async_event_work, nvmet_async_event_work);
INIT_LIST_HEAD(&ctrl->async_events);
memcpy(ctrl->subsysnqn, subsysnqn, NVMF_NQN_SIZE);
memcpy(ctrl->hostnqn, hostnqn, NVMF_NQN_SIZE);
kref_init(&ctrl->ref);
ctrl->subsys = subsys;
WRITE_ONCE(ctrl->aen_enabled, NVMET_AEN_CFG_OPTIONAL);
ctrl->changed_ns_list = kmalloc_array(NVME_MAX_CHANGED_NAMESPACES,
sizeof(__le32), GFP_KERNEL);
if (!ctrl->changed_ns_list)
goto out_free_ctrl;
ctrl->cqs = kcalloc(subsys->max_qid + 1,
sizeof(struct nvmet_cq *),
GFP_KERNEL);
if (!ctrl->cqs)
goto out_free_changed_ns_list;
ctrl->sqs = kcalloc(subsys->max_qid + 1,
sizeof(struct nvmet_sq *),
GFP_KERNEL);
if (!ctrl->sqs)
goto out_free_cqs;
ret = ida_simple_get(&cntlid_ida,
NVME_CNTLID_MIN, NVME_CNTLID_MAX,
GFP_KERNEL);
if (ret < 0) {
status = NVME_SC_CONNECT_CTRL_BUSY | NVME_SC_DNR;
goto out_free_sqs;
}
ctrl->cntlid = ret;
ctrl->ops = req->ops;
if (ctrl->subsys->type == NVME_NQN_DISC) {
/* Don't accept keep-alive timeout for discovery controllers */
if (kato) {
status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
goto out_remove_ida;
}
/*
* Discovery controllers use some arbitrary high value in order
* to cleanup stale discovery sessions
*
* From the latest base diff RC:
* "The Keep Alive command is not supported by
* Discovery controllers. A transport may specify a
* fixed Discovery controller activity timeout value
* (e.g., 2 minutes). If no commands are received
* by a Discovery controller within that time
* period, the controller may perform the
* actions for Keep Alive Timer expiration".
*/
ctrl->kato = NVMET_DISC_KATO;
} else {
/* keep-alive timeout in seconds */
ctrl->kato = DIV_ROUND_UP(kato, 1000);
}
nvmet_start_keep_alive_timer(ctrl);
mutex_lock(&subsys->lock);
list_add_tail(&ctrl->subsys_entry, &subsys->ctrls);
mutex_unlock(&subsys->lock);
*ctrlp = ctrl;
return 0;
out_remove_ida:
ida_simple_remove(&cntlid_ida, ctrl->cntlid);
out_free_sqs:
kfree(ctrl->sqs);
out_free_cqs:
kfree(ctrl->cqs);
out_free_changed_ns_list:
kfree(ctrl->changed_ns_list);
out_free_ctrl:
kfree(ctrl);
out_put_subsystem:
nvmet_subsys_put(subsys);
out:
return status;
}
static void nvmet_ctrl_free(struct kref *ref)
{
struct nvmet_ctrl *ctrl = container_of(ref, struct nvmet_ctrl, ref);
struct nvmet_subsys *subsys = ctrl->subsys;
mutex_lock(&subsys->lock);
list_del(&ctrl->subsys_entry);
mutex_unlock(&subsys->lock);
nvmet_stop_keep_alive_timer(ctrl);
flush_work(&ctrl->async_event_work);
cancel_work_sync(&ctrl->fatal_err_work);
ida_simple_remove(&cntlid_ida, ctrl->cntlid);
kfree(ctrl->sqs);
kfree(ctrl->cqs);
kfree(ctrl->changed_ns_list);
kfree(ctrl);
nvmet_subsys_put(subsys);
}
void nvmet_ctrl_put(struct nvmet_ctrl *ctrl)
{
kref_put(&ctrl->ref, nvmet_ctrl_free);
}
static void nvmet_fatal_error_handler(struct work_struct *work)
{
struct nvmet_ctrl *ctrl =
container_of(work, struct nvmet_ctrl, fatal_err_work);
pr_err("ctrl %d fatal error occurred!\n", ctrl->cntlid);
ctrl->ops->delete_ctrl(ctrl);
}
void nvmet_ctrl_fatal_error(struct nvmet_ctrl *ctrl)
{
mutex_lock(&ctrl->lock);
if (!(ctrl->csts & NVME_CSTS_CFS)) {
ctrl->csts |= NVME_CSTS_CFS;
INIT_WORK(&ctrl->fatal_err_work, nvmet_fatal_error_handler);
schedule_work(&ctrl->fatal_err_work);
}
mutex_unlock(&ctrl->lock);
}
EXPORT_SYMBOL_GPL(nvmet_ctrl_fatal_error);
static struct nvmet_subsys *nvmet_find_get_subsys(struct nvmet_port *port,
const char *subsysnqn)
{
struct nvmet_subsys_link *p;
if (!port)
return NULL;
if (!strncmp(NVME_DISC_SUBSYS_NAME, subsysnqn,
NVMF_NQN_SIZE)) {
if (!kref_get_unless_zero(&nvmet_disc_subsys->ref))
return NULL;
return nvmet_disc_subsys;
}
down_read(&nvmet_config_sem);
list_for_each_entry(p, &port->subsystems, entry) {
if (!strncmp(p->subsys->subsysnqn, subsysnqn,
NVMF_NQN_SIZE)) {
if (!kref_get_unless_zero(&p->subsys->ref))
break;
up_read(&nvmet_config_sem);
return p->subsys;
}
}
up_read(&nvmet_config_sem);
return NULL;
}
struct nvmet_subsys *nvmet_subsys_alloc(const char *subsysnqn,
enum nvme_subsys_type type)
{
struct nvmet_subsys *subsys;
subsys = kzalloc(sizeof(*subsys), GFP_KERNEL);
if (!subsys)
return NULL;
subsys->ver = NVME_VS(1, 3, 0); /* NVMe 1.3.0 */
/* generate a random serial number as our controllers are ephemeral: */
get_random_bytes(&subsys->serial, sizeof(subsys->serial));
switch (type) {
case NVME_NQN_NVME:
subsys->max_qid = NVMET_NR_QUEUES;
break;
case NVME_NQN_DISC:
subsys->max_qid = 0;
break;
default:
pr_err("%s: Unknown Subsystem type - %d\n", __func__, type);
kfree(subsys);
return NULL;
}
subsys->type = type;
subsys->subsysnqn = kstrndup(subsysnqn, NVMF_NQN_SIZE,
GFP_KERNEL);
if (!subsys->subsysnqn) {
kfree(subsys);
return NULL;
}
kref_init(&subsys->ref);
mutex_init(&subsys->lock);
INIT_LIST_HEAD(&subsys->namespaces);
INIT_LIST_HEAD(&subsys->ctrls);
INIT_LIST_HEAD(&subsys->hosts);
return subsys;
}
static void nvmet_subsys_free(struct kref *ref)
{
struct nvmet_subsys *subsys =
container_of(ref, struct nvmet_subsys, ref);
WARN_ON_ONCE(!list_empty(&subsys->namespaces));
kfree(subsys->subsysnqn);
kfree(subsys);
}
void nvmet_subsys_del_ctrls(struct nvmet_subsys *subsys)
{
struct nvmet_ctrl *ctrl;
mutex_lock(&subsys->lock);
list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry)
ctrl->ops->delete_ctrl(ctrl);
mutex_unlock(&subsys->lock);
}
void nvmet_subsys_put(struct nvmet_subsys *subsys)
{
kref_put(&subsys->ref, nvmet_subsys_free);
}
static int __init nvmet_init(void)
{
int error;
error = nvmet_init_discovery();
if (error)
goto out;
error = nvmet_init_configfs();
if (error)
goto out_exit_discovery;
return 0;
out_exit_discovery:
nvmet_exit_discovery();
out:
return error;
}
static void __exit nvmet_exit(void)
{
nvmet_exit_configfs();
nvmet_exit_discovery();
ida_destroy(&cntlid_ida);
BUILD_BUG_ON(sizeof(struct nvmf_disc_rsp_page_entry) != 1024);
BUILD_BUG_ON(sizeof(struct nvmf_disc_rsp_page_hdr) != 1024);
}
module_init(nvmet_init);
module_exit(nvmet_exit);
MODULE_LICENSE("GPL v2");