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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /drivers/nvme/target/core.c
parentInitial commit. (diff)
downloadlinux-upstream.tar.xz
linux-upstream.zip
Adding upstream version 4.19.249.upstream/4.19.249upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/nvme/target/core.c')
-rw-r--r--drivers/nvme/target/core.c1260
1 files changed, 1260 insertions, 0 deletions
diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
new file mode 100644
index 000000000..1a35d73c3
--- /dev/null
+++ b/drivers/nvme/target/core.c
@@ -0,0 +1,1260 @@
+/*
+ * 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"
+
+struct workqueue_struct *buffered_io_wq;
+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);
+
+u32 nvmet_ana_group_enabled[NVMET_MAX_ANAGRPS + 1];
+u64 nvmet_ana_chgcnt;
+DECLARE_RWSEM(nvmet_ana_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);
+}
+
+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);
+ }
+}
+
+void nvmet_send_ana_event(struct nvmet_subsys *subsys,
+ struct nvmet_port *port)
+{
+ struct nvmet_ctrl *ctrl;
+
+ mutex_lock(&subsys->lock);
+ list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) {
+ if (port && ctrl->port != port)
+ continue;
+ if (nvmet_aen_disabled(ctrl, NVME_AEN_CFG_ANA_CHANGE))
+ continue;
+ nvmet_add_async_event(ctrl, NVME_AER_TYPE_NOTICE,
+ NVME_AER_NOTICE_ANA, NVME_LOG_ANA);
+ }
+ mutex_unlock(&subsys->lock);
+}
+
+void nvmet_port_send_ana_event(struct nvmet_port *port)
+{
+ struct nvmet_subsys_link *p;
+
+ down_read(&nvmet_config_sem);
+ list_for_each_entry(p, &port->subsystems, entry)
+ nvmet_send_ana_event(p->subsys, port);
+ up_read(&nvmet_config_sem);
+}
+
+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;
+ }
+
+ /* If the transport didn't set inline_data_size, then disable it. */
+ if (port->inline_data_size < 0)
+ port->inline_data_size = 0;
+
+ 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)
+{
+ if (unlikely(ctrl->kato == 0))
+ return;
+
+ 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)
+{
+ if (unlikely(ctrl->kato == 0))
+ return;
+
+ 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;
+
+ mutex_lock(&subsys->lock);
+ ret = -EMFILE;
+ if (subsys->nr_namespaces == NVMET_MAX_NAMESPACES)
+ goto out_unlock;
+ ret = 0;
+ if (ns->enabled)
+ goto out_unlock;
+
+ ret = nvmet_bdev_ns_enable(ns);
+ if (ret == -ENOTBLK)
+ 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);
+ }
+ subsys->nr_namespaces++;
+
+ 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);
+ subsys->nr_namespaces--;
+ 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);
+
+ down_write(&nvmet_ana_sem);
+ nvmet_ana_group_enabled[ns->anagrpid]--;
+ up_write(&nvmet_ana_sem);
+
+ 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;
+
+ down_write(&nvmet_ana_sem);
+ ns->anagrpid = NVMET_DEFAULT_ANA_GRPID;
+ nvmet_ana_group_enabled[ns->anagrpid]++;
+ up_write(&nvmet_ana_sem);
+
+ uuid_gen(&ns->uuid);
+ ns->buffered_io = false;
+
+ 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 inline u16 nvmet_check_ana_state(struct nvmet_port *port,
+ struct nvmet_ns *ns)
+{
+ enum nvme_ana_state state = port->ana_state[ns->anagrpid];
+
+ if (unlikely(state == NVME_ANA_INACCESSIBLE))
+ return NVME_SC_ANA_INACCESSIBLE;
+ if (unlikely(state == NVME_ANA_PERSISTENT_LOSS))
+ return NVME_SC_ANA_PERSISTENT_LOSS;
+ if (unlikely(state == NVME_ANA_CHANGE))
+ return NVME_SC_ANA_TRANSITION;
+ return 0;
+}
+
+static inline u16 nvmet_io_cmd_check_access(struct nvmet_req *req)
+{
+ if (unlikely(req->ns->readonly)) {
+ switch (req->cmd->common.opcode) {
+ case nvme_cmd_read:
+ case nvme_cmd_flush:
+ break;
+ default:
+ return NVME_SC_NS_WRITE_PROTECTED;
+ }
+ }
+
+ return 0;
+}
+
+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;
+ ret = nvmet_check_ana_state(req->port, req->ns);
+ if (unlikely(ret))
+ return ret;
+ ret = nvmet_io_cmd_check_access(req);
+ if (unlikely(ret))
+ return ret;
+
+ 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);
+
+ /*
+ * Only I/O controllers should verify iosqes,iocqes.
+ * Strictly speaking, the spec says a discovery controller
+ * should verify iosqes,iocqes are zeroed, however that
+ * would break backwards compatibility, so don't enforce it.
+ */
+ if (ctrl->subsys->type != NVME_NQN_DISC &&
+ (nvmet_cc_iosqes(ctrl->cc) != NVME_NVM_IOSQES ||
+ nvmet_cc_iocqes(ctrl->cc) != NVME_NVM_IOCQES)) {
+ ctrl->csts = NVME_CSTS_CFS;
+ return;
+ }
+
+ if (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;
+
+ /*
+ * Controllers that are not yet enabled should not really enforce the
+ * keep alive timeout, but we still want to track a timeout and cleanup
+ * in case a host died before it enabled the controller. Hence, simply
+ * reset the keep alive timer when the controller is enabled.
+ */
+ if (ctrl->kato)
+ mod_delayed_work(system_wq, &ctrl->ka_work, ctrl->kato * HZ);
+}
+
+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);
+}
+
+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);
+}
+
+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);
+
+ ctrl->port = req->port;
+
+ INIT_WORK(&ctrl->async_event_work, nvmet_async_event_work);
+ INIT_LIST_HEAD(&ctrl->async_events);
+ INIT_WORK(&ctrl->fatal_err_work, nvmet_fatal_error_handler);
+
+ 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);
+}
+
+void nvmet_ctrl_fatal_error(struct nvmet_ctrl *ctrl)
+{
+ mutex_lock(&ctrl->lock);
+ if (!(ctrl->csts & NVME_CSTS_CFS)) {
+ ctrl->csts |= NVME_CSTS_CFS;
+ 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;
+
+ nvmet_ana_group_enabled[NVMET_DEFAULT_ANA_GRPID] = 1;
+
+ buffered_io_wq = alloc_workqueue("nvmet-buffered-io-wq",
+ WQ_MEM_RECLAIM, 0);
+ if (!buffered_io_wq) {
+ error = -ENOMEM;
+ goto out;
+ }
+
+ error = nvmet_init_discovery();
+ if (error)
+ goto out_free_work_queue;
+
+ error = nvmet_init_configfs();
+ if (error)
+ goto out_exit_discovery;
+ return 0;
+
+out_exit_discovery:
+ nvmet_exit_discovery();
+out_free_work_queue:
+ destroy_workqueue(buffered_io_wq);
+out:
+ return error;
+}
+
+static void __exit nvmet_exit(void)
+{
+ nvmet_exit_configfs();
+ nvmet_exit_discovery();
+ ida_destroy(&cntlid_ida);
+ destroy_workqueue(buffered_io_wq);
+
+ 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");