Merge branch 'nvme-4.19' of git://git.infradead.org/nvme into for-4.19/block2

Pull NVMe changes from Christoph:

"This contains the support for TP4004, Asymmetric Namespace Access,
 which makes NVMe multipathing usable in practice."

* 'nvme-4.19' of git://git.infradead.org/nvme:
  nvmet: use Retain Async Event bit to clear AEN
  nvmet: support configuring ANA groups
  nvmet: add minimal ANA support
  nvmet: track and limit the number of namespaces per subsystem
  nvmet: keep a port pointer in nvmet_ctrl
  nvme: add ANA support
  nvme: remove nvme_req_needs_failover
  nvme: simplify the API for getting log pages
  nvme.h: add ANA definitions
  nvme.h: add support for the log specific field

Signed-off-by: Jens Axboe <axboe@kernel.dk>

9 files changed, 880 insertions, 74 deletions

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 9347f20190e5..603fe59756fb 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -252,7 +252,8 @@ void nvme_complete_rq(struct request *req)
         trace_nvme_complete_rq(req);
 
         if (unlikely(status != BLK_STS_OK && nvme_req_needs_retry(req))) {
-                if (nvme_req_needs_failover(req, status)) {
+                if ((req->cmd_flags & REQ_NVME_MPATH) &&
+                    blk_path_error(status)) {
                         nvme_failover_req(req);
                         return;
                 }
@@ -1067,7 +1068,7 @@ int nvme_set_queue_count(struct nvme_ctrl *ctrl, int *count)
 EXPORT_SYMBOL_GPL(nvme_set_queue_count);
 
 #define NVME_AEN_SUPPORTED \
-        (NVME_AEN_CFG_NS_ATTR | NVME_AEN_CFG_FW_ACT)
+        (NVME_AEN_CFG_NS_ATTR | NVME_AEN_CFG_FW_ACT | NVME_AEN_CFG_ANA_CHANGE)
 
 static void nvme_enable_aen(struct nvme_ctrl *ctrl)
 {
@@ -2281,21 +2282,16 @@ out_unlock:
         return ret;
 }
 
-int nvme_get_log_ext(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
-                     u8 log_page, void *log,
-                     size_t size, u64 offset)
+int nvme_get_log(struct nvme_ctrl *ctrl, u32 nsid, u8 log_page, u8 lsp,
+                void *log, size_t size, u64 offset)
 {
         struct nvme_command c = { };
         unsigned long dwlen = size / 4 - 1;
 
         c.get_log_page.opcode = nvme_admin_get_log_page;
-
-        if (ns)
-                c.get_log_page.nsid = cpu_to_le32(ns->head->ns_id);
-        else
-                c.get_log_page.nsid = cpu_to_le32(NVME_NSID_ALL);
-
+        c.get_log_page.nsid = cpu_to_le32(nsid);
         c.get_log_page.lid = log_page;
+        c.get_log_page.lsp = lsp;
         c.get_log_page.numdl = cpu_to_le16(dwlen & ((1 << 16) - 1));
         c.get_log_page.numdu = cpu_to_le16(dwlen >> 16);
         c.get_log_page.lpol = cpu_to_le32(lower_32_bits(offset));
@@ -2304,12 +2300,6 @@ int nvme_get_log_ext(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
         return nvme_submit_sync_cmd(ctrl->admin_q, &c, log, size);
 }
 
-static int nvme_get_log(struct nvme_ctrl *ctrl, u8 log_page, void *log,
-                        size_t size)
-{
-        return nvme_get_log_ext(ctrl, NULL, log_page, log, size, 0);
-}
-
 static int nvme_get_effects_log(struct nvme_ctrl *ctrl)
 {
         int ret;
@@ -2320,8 +2310,8 @@ static int nvme_get_effects_log(struct nvme_ctrl *ctrl)
         if (!ctrl->effects)
                 return 0;
 
-        ret = nvme_get_log(ctrl, NVME_LOG_CMD_EFFECTS, ctrl->effects,
-                                        sizeof(*ctrl->effects));
+        ret = nvme_get_log(ctrl, NVME_NSID_ALL, NVME_LOG_CMD_EFFECTS, 0,
+                        ctrl->effects, sizeof(*ctrl->effects), 0);
         if (ret) {
                 kfree(ctrl->effects);
                 ctrl->effects = NULL;
@@ -2412,6 +2402,7 @@ int nvme_init_identify(struct nvme_ctrl *ctrl)
         nvme_set_queue_limits(ctrl, ctrl->admin_q);
         ctrl->sgls = le32_to_cpu(id->sgls);
         ctrl->kas = le16_to_cpu(id->kas);
+        ctrl->max_namespaces = le32_to_cpu(id->mnan);
 
         if (id->rtd3e) {
                 /* us -> s */
@@ -2471,8 +2462,12 @@ int nvme_init_identify(struct nvme_ctrl *ctrl)
                 ctrl->hmmaxd = le16_to_cpu(id->hmmaxd);
         }
 
+        ret = nvme_mpath_init(ctrl, id);
         kfree(id);
 
+        if (ret < 0)
+                return ret;
+
         if (ctrl->apst_enabled && !prev_apst_enabled)
                 dev_pm_qos_expose_latency_tolerance(ctrl->device);
         else if (!ctrl->apst_enabled && prev_apst_enabled)
@@ -2691,6 +2686,10 @@ static struct attribute *nvme_ns_id_attrs[] = {
         &dev_attr_nguid.attr,
         &dev_attr_eui.attr,
         &dev_attr_nsid.attr,
+#ifdef CONFIG_NVME_MULTIPATH
+        &dev_attr_ana_grpid.attr,
+        &dev_attr_ana_state.attr,
+#endif
         NULL,
 };
 
@@ -2713,6 +2712,14 @@ static umode_t nvme_ns_id_attrs_are_visible(struct kobject *kobj,
                 if (!memchr_inv(ids->eui64, 0, sizeof(ids->eui64)))
                         return 0;
         }
+#ifdef CONFIG_NVME_MULTIPATH
+        if (a == &dev_attr_ana_grpid.attr || a == &dev_attr_ana_state.attr) {
+                if (dev_to_disk(dev)->fops != &nvme_fops) /* per-path attr */
+                        return 0;
+                if (!nvme_ctrl_use_ana(nvme_get_ns_from_dev(dev)->ctrl))
+                        return 0;
+        }
+#endif
         return a->mode;
 }
 
@@ -3086,8 +3093,6 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid)
 
         nvme_get_ctrl(ctrl);
 
-        kfree(id);
-
         device_add_disk(ctrl->device, ns->disk);
         if (sysfs_create_group(&disk_to_dev(ns->disk)->kobj,
                                         &nvme_ns_id_attr_group))
@@ -3097,8 +3102,10 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid)
                 pr_warn("%s: failed to register lightnvm sysfs group for identification\n",
                         ns->disk->disk_name);
 
-        nvme_mpath_add_disk(ns->head);
+        nvme_mpath_add_disk(ns, id);
         nvme_fault_inject_init(ns);
+        kfree(id);
+
         return;
  out_unlink_ns:
         mutex_lock(&ctrl->subsys->lock);
@@ -3240,7 +3247,8 @@ static void nvme_clear_changed_ns_log(struct nvme_ctrl *ctrl)
          * raced with us in reading the log page, which could cause us to miss
          * updates.
          */
-        error = nvme_get_log(ctrl, NVME_LOG_CHANGED_NS, log, log_size);
+        error = nvme_get_log(ctrl, NVME_NSID_ALL, NVME_LOG_CHANGED_NS, 0, log,
+                        log_size, 0);
         if (error)
                 dev_warn(ctrl->device,
                         "reading changed ns log failed: %d\n", error);
@@ -3357,9 +3365,9 @@ static void nvme_get_fw_slot_info(struct nvme_ctrl *ctrl)
         if (!log)
                 return;
 
-        if (nvme_get_log(ctrl, NVME_LOG_FW_SLOT, log, sizeof(*log)))
-                dev_warn(ctrl->device,
-                                "Get FW SLOT INFO log error\n");
+        if (nvme_get_log(ctrl, NVME_NSID_ALL, 0, NVME_LOG_FW_SLOT, log,
+                        sizeof(*log), 0))
+                dev_warn(ctrl->device, "Get FW SLOT INFO log error\n");
         kfree(log);
 }
 
@@ -3405,6 +3413,13 @@ static void nvme_handle_aen_notice(struct nvme_ctrl *ctrl, u32 result)
         case NVME_AER_NOTICE_FW_ACT_STARTING:
                 queue_work(nvme_wq, &ctrl->fw_act_work);
                 break;
+#ifdef CONFIG_NVME_MULTIPATH
+        case NVME_AER_NOTICE_ANA:
+                if (!ctrl->ana_log_buf)
+                        break;
+                queue_work(nvme_wq, &ctrl->ana_work);
+                break;
+#endif
         default:
                 dev_warn(ctrl->device, "async event result %08x\n", result);
         }
@@ -3437,6 +3452,7 @@ EXPORT_SYMBOL_GPL(nvme_complete_async_event);
 
 void nvme_stop_ctrl(struct nvme_ctrl *ctrl)
 {
+        nvme_mpath_stop(ctrl);
         nvme_stop_keep_alive(ctrl);
         flush_work(&ctrl->async_event_work);
         flush_work(&ctrl->scan_work);
@@ -3474,6 +3490,7 @@ static void nvme_free_ctrl(struct device *dev)
 
         ida_simple_remove(&nvme_instance_ida, ctrl->instance);
         kfree(ctrl->effects);
+        nvme_mpath_uninit(ctrl);
 
         if (subsys) {
                 mutex_lock(&subsys->lock);
diff --git a/drivers/nvme/host/lightnvm.c b/drivers/nvme/host/lightnvm.c
index d9e4cccd5b66..7e4cf4eb9d66 100644
--- a/drivers/nvme/host/lightnvm.c
+++ b/drivers/nvme/host/lightnvm.c
@@ -604,8 +604,9 @@ static int nvme_nvm_get_chk_meta(struct nvm_dev *ndev,
         while (left) {
                 len = min_t(unsigned int, left, max_len);
 
-                ret = nvme_get_log_ext(ctrl, ns, NVME_NVM_LOG_REPORT_CHUNK,
-                                dev_meta, len, offset);
+                ret = nvme_get_log(ctrl, ns->head->ns_id,
+                                NVME_NVM_LOG_REPORT_CHUNK, 0, dev_meta, len,
+                                offset);
                 if (ret) {
                         dev_err(ctrl->device, "Get REPORT CHUNK log error\n");
                         break;
diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
index 1ffd3e8b13a1..c643872f8dac 100644
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017 Christoph Hellwig.
+ * Copyright (c) 2017-2018 Christoph Hellwig.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
@@ -20,6 +20,11 @@ module_param(multipath, bool, 0444);
 MODULE_PARM_DESC(multipath,
         "turn on native support for multiple controllers per subsystem");
 
+inline bool nvme_ctrl_use_ana(struct nvme_ctrl *ctrl)
+{
+        return multipath && (ctrl->subsys->cmic & (1 << 3));
+}
+
 /*
  * If multipathing is enabled we need to always use the subsystem instance
  * number for numbering our devices to avoid conflicts between subsystems that
@@ -45,6 +50,7 @@ void nvme_set_disk_name(char *disk_name, struct nvme_ns *ns,
 void nvme_failover_req(struct request *req)
 {
         struct nvme_ns *ns = req->q->queuedata;
+        u16 status = nvme_req(req)->status;
         unsigned long flags;
 
         spin_lock_irqsave(&ns->head->requeue_lock, flags);
@@ -52,15 +58,35 @@ void nvme_failover_req(struct request *req)
         spin_unlock_irqrestore(&ns->head->requeue_lock, flags);
         blk_mq_end_request(req, 0);
 
-        nvme_reset_ctrl(ns->ctrl);
-        kblockd_schedule_work(&ns->head->requeue_work);
-}
+        switch (status & 0x7ff) {
+        case NVME_SC_ANA_TRANSITION:
+        case NVME_SC_ANA_INACCESSIBLE:
+        case NVME_SC_ANA_PERSISTENT_LOSS:
+                /*
+                 * If we got back an ANA error we know the controller is alive,
+                 * but not ready to serve this namespaces.  The spec suggests
+                 * we should update our general state here, but due to the fact
+                 * that the admin and I/O queues are not serialized that is
+                 * fundamentally racy.  So instead just clear the current path,
+                 * mark the the path as pending and kick of a re-read of the ANA
+                 * log page ASAP.
+                 */
+                nvme_mpath_clear_current_path(ns);
+                if (ns->ctrl->ana_log_buf) {
+                        set_bit(NVME_NS_ANA_PENDING, &ns->flags);
+                        queue_work(nvme_wq, &ns->ctrl->ana_work);
+                }
+                break;
+        default:
+                /*
+                 * Reset the controller for any non-ANA error as we don't know
+                 * what caused the error.
+                 */
+                nvme_reset_ctrl(ns->ctrl);
+                break;
+        }
 
-bool nvme_req_needs_failover(struct request *req, blk_status_t error)
-{
-        if (!(req->cmd_flags & REQ_NVME_MPATH))
-                return false;
-        return blk_path_error(error);
+        kblockd_schedule_work(&ns->head->requeue_work);
 }
 
 void nvme_kick_requeue_lists(struct nvme_ctrl *ctrl)
@@ -75,25 +101,51 @@ void nvme_kick_requeue_lists(struct nvme_ctrl *ctrl)
         up_read(&ctrl->namespaces_rwsem);
 }
 
+static const char *nvme_ana_state_names[] = {
+        [0]                             = "invalid state",
+        [NVME_ANA_OPTIMIZED]            = "optimized",
+        [NVME_ANA_NONOPTIMIZED]         = "non-optimized",
+        [NVME_ANA_INACCESSIBLE]         = "inaccessible",
+        [NVME_ANA_PERSISTENT_LOSS]      = "persistent-loss",
+        [NVME_ANA_CHANGE]               = "change",
+};
+
 static struct nvme_ns *__nvme_find_path(struct nvme_ns_head *head)
 {
-        struct nvme_ns *ns;
+        struct nvme_ns *ns, *fallback = NULL;
 
         list_for_each_entry_rcu(ns, &head->list, siblings) {
-                if (ns->ctrl->state == NVME_CTRL_LIVE) {
+                if (ns->ctrl->state != NVME_CTRL_LIVE ||
+                    test_bit(NVME_NS_ANA_PENDING, &ns->flags))
+                        continue;
+                switch (ns->ana_state) {
+                case NVME_ANA_OPTIMIZED:
                         rcu_assign_pointer(head->current_path, ns);
                         return ns;
+                case NVME_ANA_NONOPTIMIZED:
+                        fallback = ns;
+                        break;
+                default:
+                        break;
                 }
         }
 
-        return NULL;
+        if (fallback)
+                rcu_assign_pointer(head->current_path, fallback);
+        return fallback;
+}
+
+static inline bool nvme_path_is_optimized(struct nvme_ns *ns)
+{
+        return ns->ctrl->state == NVME_CTRL_LIVE &&
+                ns->ana_state == NVME_ANA_OPTIMIZED;
 }
 
 inline struct nvme_ns *nvme_find_path(struct nvme_ns_head *head)
 {
         struct nvme_ns *ns = srcu_dereference(head->current_path, &head->srcu);
 
-        if (unlikely(!ns || ns->ctrl->state != NVME_CTRL_LIVE))
+        if (unlikely(!ns || !nvme_path_is_optimized(ns)))
                 ns = __nvme_find_path(head);
         return ns;
 }
@@ -142,7 +194,7 @@ static bool nvme_ns_head_poll(struct request_queue *q, blk_qc_t qc)
 
         srcu_idx = srcu_read_lock(&head->srcu);
         ns = srcu_dereference(head->current_path, &head->srcu);
-        if (likely(ns && ns->ctrl->state == NVME_CTRL_LIVE))
+        if (likely(ns && nvme_path_is_optimized(ns)))
                 found = ns->queue->poll_fn(q, qc);
         srcu_read_unlock(&head->srcu, srcu_idx);
         return found;
@@ -176,6 +228,7 @@ int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl, struct nvme_ns_head *head)
         struct request_queue *q;
         bool vwc = false;
 
+        mutex_init(&head->lock);
         bio_list_init(&head->requeue_list);
         spin_lock_init(&head->requeue_lock);
         INIT_WORK(&head->requeue_work, nvme_requeue_work);
@@ -220,29 +273,232 @@ out:
         return -ENOMEM;
 }
 
-void nvme_mpath_add_disk(struct nvme_ns_head *head)
+static void nvme_mpath_set_live(struct nvme_ns *ns)
 {
+        struct nvme_ns_head *head = ns->head;
+
+        lockdep_assert_held(&ns->head->lock);
+
         if (!head->disk)
                 return;
 
-        mutex_lock(&head->subsys->lock);
         if (!(head->disk->flags & GENHD_FL_UP)) {
                 device_add_disk(&head->subsys->dev, head->disk);
                 if (sysfs_create_group(&disk_to_dev(head->disk)->kobj,
                                 &nvme_ns_id_attr_group))
-                        pr_warn("%s: failed to create sysfs group for identification\n",
-                                head->disk->disk_name);
+                        dev_warn(&head->subsys->dev,
+                                 "failed to create id group.\n");
+        }
+
+        kblockd_schedule_work(&ns->head->requeue_work);
+}
+
+static int nvme_parse_ana_log(struct nvme_ctrl *ctrl, void *data,
+                int (*cb)(struct nvme_ctrl *ctrl, struct nvme_ana_group_desc *,
+                        void *))
+{
+        void *base = ctrl->ana_log_buf;
+        size_t offset = sizeof(struct nvme_ana_rsp_hdr);
+        int error, i;
+
+        lockdep_assert_held(&ctrl->ana_lock);
+
+        for (i = 0; i < le16_to_cpu(ctrl->ana_log_buf->ngrps); i++) {
+                struct nvme_ana_group_desc *desc = base + offset;
+                u32 nr_nsids = le32_to_cpu(desc->nnsids);
+                size_t nsid_buf_size = nr_nsids * sizeof(__le32);
+
+                if (WARN_ON_ONCE(desc->grpid == 0))
+                        return -EINVAL;
+                if (WARN_ON_ONCE(le32_to_cpu(desc->grpid) > ctrl->anagrpmax))
+                        return -EINVAL;
+                if (WARN_ON_ONCE(desc->state == 0))
+                        return -EINVAL;
+                if (WARN_ON_ONCE(desc->state > NVME_ANA_CHANGE))
+                        return -EINVAL;
+
+                offset += sizeof(*desc);
+                if (WARN_ON_ONCE(offset > ctrl->ana_log_size - nsid_buf_size))
+                        return -EINVAL;
+
+                error = cb(ctrl, desc, data);
+                if (error)
+                        return error;
+
+                offset += nsid_buf_size;
+                if (WARN_ON_ONCE(offset > ctrl->ana_log_size - sizeof(*desc)))
+                        return -EINVAL;
+        }
+
+        return 0;
+}
+
+static inline bool nvme_state_is_live(enum nvme_ana_state state)
+{
+        return state == NVME_ANA_OPTIMIZED || state == NVME_ANA_NONOPTIMIZED;
+}
+
+static void nvme_update_ns_ana_state(struct nvme_ana_group_desc *desc,
+                struct nvme_ns *ns)
+{
+        enum nvme_ana_state old;
+
+        mutex_lock(&ns->head->lock);
+        old = ns->ana_state;
+        ns->ana_grpid = le32_to_cpu(desc->grpid);
+        ns->ana_state = desc->state;
+        clear_bit(NVME_NS_ANA_PENDING, &ns->flags);
+
+        if (nvme_state_is_live(ns->ana_state) && !nvme_state_is_live(old))
+                nvme_mpath_set_live(ns);
+        mutex_unlock(&ns->head->lock);
+}
+
+static int nvme_update_ana_state(struct nvme_ctrl *ctrl,
+                struct nvme_ana_group_desc *desc, void *data)
+{
+        u32 nr_nsids = le32_to_cpu(desc->nnsids), n = 0;
+        unsigned *nr_change_groups = data;
+        struct nvme_ns *ns;
+
+        dev_info(ctrl->device, "ANA group %d: %s.\n",
+                        le32_to_cpu(desc->grpid),
+                        nvme_ana_state_names[desc->state]);
+
+        if (desc->state == NVME_ANA_CHANGE)
+                (*nr_change_groups)++;
+
+        if (!nr_nsids)
+                return 0;
+
+        down_write(&ctrl->namespaces_rwsem);
+        list_for_each_entry(ns, &ctrl->namespaces, list) {
+                if (ns->head->ns_id != le32_to_cpu(desc->nsids[n]))
+                        continue;
+                nvme_update_ns_ana_state(desc, ns);
+                if (++n == nr_nsids)
+                        break;
+        }
+        up_write(&ctrl->namespaces_rwsem);
+        WARN_ON_ONCE(n < nr_nsids);
+        return 0;
+}
+
+static int nvme_read_ana_log(struct nvme_ctrl *ctrl, bool groups_only)
+{
+        u32 nr_change_groups = 0;
+        int error;
+
+        mutex_lock(&ctrl->ana_lock);
+        error = nvme_get_log(ctrl, NVME_NSID_ALL, NVME_LOG_ANA,
+                        groups_only ? NVME_ANA_LOG_RGO : 0,
+                        ctrl->ana_log_buf, ctrl->ana_log_size, 0);
+        if (error) {
+                dev_warn(ctrl->device, "Failed to get ANA log: %d\n", error);
+                goto out_unlock;
+        }
+
+        error = nvme_parse_ana_log(ctrl, &nr_change_groups,
+                        nvme_update_ana_state);
+        if (error)
+                goto out_unlock;
+
+        /*
+         * In theory we should have an ANATT timer per group as they might enter
+         * the change state at different times.  But that is a lot of overhead
+         * just to protect against a target that keeps entering new changes
+         * states while never finishing previous ones.  But we'll still
+         * eventually time out once all groups are in change state, so this
+         * isn't a big deal.
+         *
+         * We also double the ANATT value to provide some slack for transports
+         * or AEN processing overhead.
+         */
+        if (nr_change_groups)
+                mod_timer(&ctrl->anatt_timer, ctrl->anatt * HZ * 2 + jiffies);
+        else
+                del_timer_sync(&ctrl->anatt_timer);
+out_unlock:
+        mutex_unlock(&ctrl->ana_lock);
+        return error;
+}
+
+static void nvme_ana_work(struct work_struct *work)
+{
+        struct nvme_ctrl *ctrl = container_of(work, struct nvme_ctrl, ana_work);
+
+        nvme_read_ana_log(ctrl, false);
+}
+
+static void nvme_anatt_timeout(struct timer_list *t)
+{
+        struct nvme_ctrl *ctrl = from_timer(ctrl, t, anatt_timer);
+
+        dev_info(ctrl->device, "ANATT timeout, resetting controller.\n");
+        nvme_reset_ctrl(ctrl);
+}
+
+void nvme_mpath_stop(struct nvme_ctrl *ctrl)
+{
+        if (!nvme_ctrl_use_ana(ctrl))
+                return;
+        del_timer_sync(&ctrl->anatt_timer);
+        cancel_work_sync(&ctrl->ana_work);
+}
+
+static ssize_t ana_grpid_show(struct device *dev, struct device_attribute *attr,
+                char *buf)
+{
+        return sprintf(buf, "%d\n", nvme_get_ns_from_dev(dev)->ana_grpid);
+}
+DEVICE_ATTR_RO(ana_grpid);
+
+static ssize_t ana_state_show(struct device *dev, struct device_attribute *attr,
+                char *buf)
+{
+        struct nvme_ns *ns = nvme_get_ns_from_dev(dev);
+
+        return sprintf(buf, "%s\n", nvme_ana_state_names[ns->ana_state]);
+}
+DEVICE_ATTR_RO(ana_state);
+
+static int nvme_set_ns_ana_state(struct nvme_ctrl *ctrl,
+                struct nvme_ana_group_desc *desc, void *data)
+{
+        struct nvme_ns *ns = data;
+
+        if (ns->ana_grpid == le32_to_cpu(desc->grpid)) {
+                nvme_update_ns_ana_state(desc, ns);
+                return -ENXIO; /* just break out of the loop */
+        }
+
+        return 0;
+}
+
+void nvme_mpath_add_disk(struct nvme_ns *ns, struct nvme_id_ns *id)
+{
+        if (nvme_ctrl_use_ana(ns->ctrl)) {
+                mutex_lock(&ns->ctrl->ana_lock);
+                ns->ana_grpid = le32_to_cpu(id->anagrpid);
+                nvme_parse_ana_log(ns->ctrl, ns, nvme_set_ns_ana_state);
+                mutex_unlock(&ns->ctrl->ana_lock);
+        } else {
+                mutex_lock(&ns->head->lock);
+                ns->ana_state = NVME_ANA_OPTIMIZED; 
+                nvme_mpath_set_live(ns);
+                mutex_unlock(&ns->head->lock);
         }
-        mutex_unlock(&head->subsys->lock);
 }
 
 void nvme_mpath_remove_disk(struct nvme_ns_head *head)
 {
         if (!head->disk)
                 return;
-        sysfs_remove_group(&disk_to_dev(head->disk)->kobj,
-                           &nvme_ns_id_attr_group);
-        del_gendisk(head->disk);
+        if (head->disk->flags & GENHD_FL_UP) {
+                sysfs_remove_group(&disk_to_dev(head->disk)->kobj,
+                                   &nvme_ns_id_attr_group);
+                del_gendisk(head->disk);
+        }
         blk_set_queue_dying(head->disk->queue);
         /* make sure all pending bios are cleaned up */
         kblockd_schedule_work(&head->requeue_work);
@@ -250,3 +506,52 @@ void nvme_mpath_remove_disk(struct nvme_ns_head *head)
         blk_cleanup_queue(head->disk->queue);
         put_disk(head->disk);
 }
+
+int nvme_mpath_init(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id)
+{
+        int error;
+
+        if (!nvme_ctrl_use_ana(ctrl))
+                return 0;
+
+        ctrl->anacap = id->anacap;
+        ctrl->anatt = id->anatt;
+        ctrl->nanagrpid = le32_to_cpu(id->nanagrpid);
+        ctrl->anagrpmax = le32_to_cpu(id->anagrpmax);
+
+        mutex_init(&ctrl->ana_lock);
+        timer_setup(&ctrl->anatt_timer, nvme_anatt_timeout, 0);
+        ctrl->ana_log_size = sizeof(struct nvme_ana_rsp_hdr) +
+                ctrl->nanagrpid * sizeof(struct nvme_ana_group_desc);
+        if (!(ctrl->anacap & (1 << 6)))
+                ctrl->ana_log_size += ctrl->max_namespaces * sizeof(__le32);
+
+        if (ctrl->ana_log_size > ctrl->max_hw_sectors << SECTOR_SHIFT) {
+                dev_err(ctrl->device,
+                        "ANA log page size (%zd) larger than MDTS (%d).\n",
+                        ctrl->ana_log_size,
+                        ctrl->max_hw_sectors << SECTOR_SHIFT);
+                dev_err(ctrl->device, "disabling ANA support.\n");
+                return 0;
+        }
+
+        INIT_WORK(&ctrl->ana_work, nvme_ana_work);
+        ctrl->ana_log_buf = kmalloc(ctrl->ana_log_size, GFP_KERNEL);
+        if (!ctrl->ana_log_buf)
+                goto out;
+
+        error = nvme_read_ana_log(ctrl, true);
+        if (error)
+                goto out_free_ana_log_buf;
+        return 0;
+out_free_ana_log_buf:
+        kfree(ctrl->ana_log_buf);
+out:
+        return -ENOMEM;
+}
+
+void nvme_mpath_uninit(struct nvme_ctrl *ctrl)
+{
+        kfree(ctrl->ana_log_buf);
+}
+
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index cf970f9543a6..bb4a2003c097 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -183,6 +183,7 @@ struct nvme_ctrl {
         u16 oacs;
         u16 nssa;
         u16 nr_streams;
+        u32 max_namespaces;
         atomic_t abort_limit;
         u8 vwc;
         u32 vs;
@@ -205,6 +206,19 @@ struct nvme_ctrl {
         struct work_struct fw_act_work;
         unsigned long events;
 
+#ifdef CONFIG_NVME_MULTIPATH
+        /* asymmetric namespace access: */
+        u8 anacap;
+        u8 anatt;
+        u32 anagrpmax;
+        u32 nanagrpid;
+        struct mutex ana_lock;
+        struct nvme_ana_rsp_hdr *ana_log_buf;
+        size_t ana_log_size;
+        struct timer_list anatt_timer;
+        struct work_struct ana_work;
+#endif
+
         /* Power saving configuration */
         u64 ps_max_latency_us;
         bool apst_enabled;
@@ -269,6 +283,7 @@ struct nvme_ns_head {
         struct bio_list         requeue_list;
         spinlock_t              requeue_lock;
         struct work_struct      requeue_work;
+        struct mutex            lock;
 #endif
         struct list_head        list;
         struct srcu_struct      srcu;
@@ -295,6 +310,10 @@ struct nvme_ns {
         struct nvme_ctrl *ctrl;
         struct request_queue *queue;
         struct gendisk *disk;
+#ifdef CONFIG_NVME_MULTIPATH
+        enum nvme_ana_state ana_state;
+        u32 ana_grpid;
+#endif
         struct list_head siblings;
         struct nvm_dev *ndev;
         struct kref kref;
@@ -307,8 +326,9 @@ struct nvme_ns {
         bool ext;
         u8 pi_type;
         unsigned long flags;
-#define NVME_NS_REMOVING 0
-#define NVME_NS_DEAD     1
+#define NVME_NS_REMOVING        0
+#define NVME_NS_DEAD            1
+#define NVME_NS_ANA_PENDING     2
         u16 noiob;
 
 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
@@ -436,21 +456,24 @@ int nvme_reset_ctrl_sync(struct nvme_ctrl *ctrl);
 int nvme_delete_ctrl(struct nvme_ctrl *ctrl);
 int nvme_delete_ctrl_sync(struct nvme_ctrl *ctrl);
 
-int nvme_get_log_ext(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
-                u8 log_page, void *log, size_t size, u64 offset);
+int nvme_get_log(struct nvme_ctrl *ctrl, u32 nsid, u8 log_page, u8 lsp,
+                void *log, size_t size, u64 offset);
 
 extern const struct attribute_group nvme_ns_id_attr_group;
 extern const struct block_device_operations nvme_ns_head_ops;
 
 #ifdef CONFIG_NVME_MULTIPATH
+bool nvme_ctrl_use_ana(struct nvme_ctrl *ctrl);
 void nvme_set_disk_name(char *disk_name, struct nvme_ns *ns,
                         struct nvme_ctrl *ctrl, int *flags);
 void nvme_failover_req(struct request *req);
-bool nvme_req_needs_failover(struct request *req, blk_status_t error);
 void nvme_kick_requeue_lists(struct nvme_ctrl *ctrl);
 int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl,struct nvme_ns_head *head);
-void nvme_mpath_add_disk(struct nvme_ns_head *head);
+void nvme_mpath_add_disk(struct nvme_ns *ns, struct nvme_id_ns *id);
 void nvme_mpath_remove_disk(struct nvme_ns_head *head);
+int nvme_mpath_init(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id);
+void nvme_mpath_uninit(struct nvme_ctrl *ctrl);
+void nvme_mpath_stop(struct nvme_ctrl *ctrl);
 
 static inline void nvme_mpath_clear_current_path(struct nvme_ns *ns)
 {
@@ -469,7 +492,14 @@ static inline void nvme_mpath_check_last_path(struct nvme_ns *ns)
                 kblockd_schedule_work(&head->requeue_work);
 }
 
+extern struct device_attribute dev_attr_ana_grpid;
+extern struct device_attribute dev_attr_ana_state;
+
 #else
+static inline bool nvme_ctrl_use_ana(struct nvme_ctrl *ctrl)
+{
+        return false;
+}
 /*
  * Without the multipath code enabled, multiple controller per subsystems are
  * visible as devices and thus we cannot use the subsystem instance.
@@ -483,11 +513,6 @@ static inline void nvme_set_disk_name(char *disk_name, struct nvme_ns *ns,
 static inline void nvme_failover_req(struct request *req)
 {
 }
-static inline bool nvme_req_needs_failover(struct request *req,
-                                           blk_status_t error)
-{
-        return false;
-}
 static inline void nvme_kick_requeue_lists(struct nvme_ctrl *ctrl)
 {
 }
@@ -496,7 +521,8 @@ static inline int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl,
 {
         return 0;
 }
-static inline void nvme_mpath_add_disk(struct nvme_ns_head *head)
+static inline void nvme_mpath_add_disk(struct nvme_ns *ns,
+                struct nvme_id_ns *id)
 {
 }
 static inline void nvme_mpath_remove_disk(struct nvme_ns_head *head)
@@ -508,6 +534,17 @@ static inline void nvme_mpath_clear_current_path(struct nvme_ns *ns)
 static inline void nvme_mpath_check_last_path(struct nvme_ns *ns)
 {
 }
+static inline int nvme_mpath_init(struct nvme_ctrl *ctrl,
+                struct nvme_id_ctrl *id)
+{
+        return 0;
+}
+static inline void nvme_mpath_uninit(struct nvme_ctrl *ctrl)
+{
+}
+static inline void nvme_mpath_stop(struct nvme_ctrl *ctrl)
+{
+}
 #endif /* CONFIG_NVME_MULTIPATH */
 
 #ifdef CONFIG_NVM
diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
index 16a9b24270f9..f517bc562d26 100644
--- a/drivers/nvme/target/admin-cmd.c
+++ b/drivers/nvme/target/admin-cmd.c
@@ -19,6 +19,19 @@
 #include <asm/unaligned.h>
 #include "nvmet.h"
 
+/*
+ * This helper allows us to clear the AEN based on the RAE bit,
+ * Please use this helper when processing the log pages which are
+ * associated with the AEN.
+ */
+static inline void nvmet_clear_aen(struct nvmet_req *req, u32 aen_bit)
+{
+        int rae = le32_to_cpu(req->cmd->common.cdw10[0]) & 1 << 15;
+
+        if (!rae)
+                clear_bit(aen_bit, &req->sq->ctrl->aen_masked);
+}
+
 u32 nvmet_get_log_page_len(struct nvme_command *cmd)
 {
         u32 len = le16_to_cpu(cmd->get_log_page.numdu);
@@ -176,12 +189,76 @@ static void nvmet_execute_get_log_changed_ns(struct nvmet_req *req)
         if (!status)
                 status = nvmet_zero_sgl(req, len, req->data_len - len);
         ctrl->nr_changed_ns = 0;
-        clear_bit(NVME_AEN_CFG_NS_ATTR, &ctrl->aen_masked);
+        nvmet_clear_aen(req, NVME_AEN_CFG_NS_ATTR);
         mutex_unlock(&ctrl->lock);
 out:
         nvmet_req_complete(req, status);
 }
 
+static u32 nvmet_format_ana_group(struct nvmet_req *req, u32 grpid,
+                struct nvme_ana_group_desc *desc)
+{
+        struct nvmet_ctrl *ctrl = req->sq->ctrl;
+        struct nvmet_ns *ns;
+        u32 count = 0;
+
+        if (!(req->cmd->get_log_page.lsp & NVME_ANA_LOG_RGO)) {
+                rcu_read_lock();
+                list_for_each_entry_rcu(ns, &ctrl->subsys->namespaces, dev_link)
+                        if (ns->anagrpid == grpid)
+                                desc->nsids[count++] = cpu_to_le32(ns->nsid);
+                rcu_read_unlock();
+        }
+
+        desc->grpid = cpu_to_le32(grpid);
+        desc->nnsids = cpu_to_le32(count);
+        desc->chgcnt = cpu_to_le64(nvmet_ana_chgcnt);
+        desc->state = req->port->ana_state[grpid];
+        memset(desc->rsvd17, 0, sizeof(desc->rsvd17));
+        return sizeof(struct nvme_ana_group_desc) + count * sizeof(__le32);
+}
+
+static void nvmet_execute_get_log_page_ana(struct nvmet_req *req)
+{
+        struct nvme_ana_rsp_hdr hdr = { 0, };
+        struct nvme_ana_group_desc *desc;
+        size_t offset = sizeof(struct nvme_ana_rsp_hdr); /* start beyond hdr */
+        size_t len;
+        u32 grpid;
+        u16 ngrps = 0;
+        u16 status;
+
+        status = NVME_SC_INTERNAL;
+        desc = kmalloc(sizeof(struct nvme_ana_group_desc) +
+                        NVMET_MAX_NAMESPACES * sizeof(__le32), GFP_KERNEL);
+        if (!desc)
+                goto out;
+
+        down_read(&nvmet_ana_sem);
+        for (grpid = 1; grpid <= NVMET_MAX_ANAGRPS; grpid++) {
+                if (!nvmet_ana_group_enabled[grpid])
+                        continue;
+                len = nvmet_format_ana_group(req, grpid, desc);
+                status = nvmet_copy_to_sgl(req, offset, desc, len);
+                if (status)
+                        break;
+                offset += len;
+                ngrps++;
+        }
+
+        hdr.chgcnt = cpu_to_le64(nvmet_ana_chgcnt);
+        hdr.ngrps = cpu_to_le16(ngrps);
+        nvmet_clear_aen(req, NVME_AEN_CFG_ANA_CHANGE);
+        up_read(&nvmet_ana_sem);
+
+        kfree(desc);
+
+        /* copy the header last once we know the number of groups */
+        status = nvmet_copy_to_sgl(req, 0, &hdr, sizeof(hdr));
+out:
+        nvmet_req_complete(req, status);
+}
+
 static void nvmet_execute_identify_ctrl(struct nvmet_req *req)
 {
         struct nvmet_ctrl *ctrl = req->sq->ctrl;
@@ -213,8 +290,8 @@ static void nvmet_execute_identify_ctrl(struct nvmet_req *req)
          * the safest is to leave it as zeroes.
          */
 
-        /* we support multiple ports and multiples hosts: */
-        id->cmic = (1 << 0) | (1 << 1);
+        /* we support multiple ports, multiples hosts and ANA: */
+        id->cmic = (1 << 0) | (1 << 1) | (1 << 3);
 
         /* no limit on data transfer sizes for now */
         id->mdts = 0;
@@ -252,6 +329,7 @@ static void nvmet_execute_identify_ctrl(struct nvmet_req *req)
         id->maxcmd = cpu_to_le16(NVMET_MAX_CMD);
 
         id->nn = cpu_to_le32(ctrl->subsys->max_nsid);
+        id->mnan = cpu_to_le32(NVMET_MAX_NAMESPACES);
         id->oncs = cpu_to_le16(NVME_CTRL_ONCS_DSM |
                         NVME_CTRL_ONCS_WRITE_ZEROES);
 
@@ -281,6 +359,11 @@ static void nvmet_execute_identify_ctrl(struct nvmet_req *req)
 
         id->msdbd = ctrl->ops->msdbd;
 
+        id->anacap = (1 << 0) | (1 << 1) | (1 << 2) | (1 << 3) | (1 << 4);
+        id->anatt = 10; /* random value */
+        id->anagrpmax = cpu_to_le32(NVMET_MAX_ANAGRPS);
+        id->nanagrpid = cpu_to_le32(NVMET_MAX_ANAGRPS);
+
         /*
          * Meh, we don't really support any power state.  Fake up the same
          * values that qemu does.
@@ -322,8 +405,15 @@ static void nvmet_execute_identify_ns(struct nvmet_req *req)
          * nuse = ncap = nsze isn't always true, but we have no way to find
          * that out from the underlying device.
          */
-        id->ncap = id->nuse = id->nsze =
-                cpu_to_le64(ns->size >> ns->blksize_shift);
+        id->ncap = id->nsze = cpu_to_le64(ns->size >> ns->blksize_shift);
+        switch (req->port->ana_state[ns->anagrpid]) {
+        case NVME_ANA_INACCESSIBLE:
+        case NVME_ANA_PERSISTENT_LOSS:
+                break;
+        default:
+                id->nuse = id->nsze;
+                break;
+        }
 
         /*
          * We just provide a single LBA format that matches what the
@@ -337,6 +427,7 @@ static void nvmet_execute_identify_ns(struct nvmet_req *req)
          * controllers, but also with any other user of the block device.
          */
         id->nmic = (1 << 0);
+        id->anagrpid = cpu_to_le32(ns->anagrpid);
 
         memcpy(&id->nguid, &ns->nguid, sizeof(id->nguid));
 
@@ -619,6 +710,9 @@ u16 nvmet_parse_admin_cmd(struct nvmet_req *req)
                 case NVME_LOG_CMD_EFFECTS:
                         req->execute = nvmet_execute_get_log_cmd_effects_ns;
                         return 0;
+                case NVME_LOG_ANA:
+                        req->execute = nvmet_execute_get_log_page_ana;
+                        return 0;
                 }
                 break;
         case nvme_admin_identify:
diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c
index 3ba5ea5c4376..51f5a8c092b4 100644
--- a/drivers/nvme/target/configfs.c
+++ b/drivers/nvme/target/configfs.c
@@ -411,6 +411,39 @@ out_unlock:
 
 CONFIGFS_ATTR(nvmet_ns_, device_nguid);
 
+static ssize_t nvmet_ns_ana_grpid_show(struct config_item *item, char *page)
+{
+        return sprintf(page, "%u\n", to_nvmet_ns(item)->anagrpid);
+}
+
+static ssize_t nvmet_ns_ana_grpid_store(struct config_item *item,
+                const char *page, size_t count)
+{
+        struct nvmet_ns *ns = to_nvmet_ns(item);
+        u32 oldgrpid, newgrpid;
+        int ret;
+
+        ret = kstrtou32(page, 0, &newgrpid);
+        if (ret)
+                return ret;
+
+        if (newgrpid < 1 || newgrpid > NVMET_MAX_ANAGRPS)
+                return -EINVAL;
+
+        down_write(&nvmet_ana_sem);
+        oldgrpid = ns->anagrpid;
+        nvmet_ana_group_enabled[newgrpid]++;
+        ns->anagrpid = newgrpid;
+        nvmet_ana_group_enabled[oldgrpid]--;
+        nvmet_ana_chgcnt++;
+        up_write(&nvmet_ana_sem);
+
+        nvmet_send_ana_event(ns->subsys, NULL);
+        return count;
+}
+
+CONFIGFS_ATTR(nvmet_ns_, ana_grpid);
+
 static ssize_t nvmet_ns_enable_show(struct config_item *item, char *page)
 {
         return sprintf(page, "%d\n", to_nvmet_ns(item)->enabled);
@@ -468,6 +501,7 @@ static struct configfs_attribute *nvmet_ns_attrs[] = {
         &nvmet_ns_attr_device_path,
         &nvmet_ns_attr_device_nguid,
         &nvmet_ns_attr_device_uuid,
+        &nvmet_ns_attr_ana_grpid,
         &nvmet_ns_attr_enable,
         &nvmet_ns_attr_buffered_io,
         NULL,
@@ -916,6 +950,134 @@ static const struct config_item_type nvmet_referrals_type = {
         .ct_group_ops   = &nvmet_referral_group_ops,
 };
 
+static struct {
+        enum nvme_ana_state     state;
+        const char              *name;
+} nvmet_ana_state_names[] = {
+        { NVME_ANA_OPTIMIZED,           "optimized" },
+        { NVME_ANA_NONOPTIMIZED,        "non-optimized" },
+        { NVME_ANA_INACCESSIBLE,        "inaccessible" },
+        { NVME_ANA_PERSISTENT_LOSS,     "persistent-loss" },
+        { NVME_ANA_CHANGE,              "change" },
+};
+
+static ssize_t nvmet_ana_group_ana_state_show(struct config_item *item,
+                char *page)
+{
+        struct nvmet_ana_group *grp = to_ana_group(item);
+        enum nvme_ana_state state = grp->port->ana_state[grp->grpid];
+        int i;
+
+        for (i = 0; i < ARRAY_SIZE(nvmet_ana_state_names); i++) {
+                if (state != nvmet_ana_state_names[i].state)
+                        continue;
+                return sprintf(page, "%s\n", nvmet_ana_state_names[i].name);
+        }
+
+        return sprintf(page, "\n");
+}
+
+static ssize_t nvmet_ana_group_ana_state_store(struct config_item *item,
+                const char *page, size_t count)
+{
+        struct nvmet_ana_group *grp = to_ana_group(item);
+        int i;
+
+        for (i = 0; i < ARRAY_SIZE(nvmet_ana_state_names); i++) {
+                if (sysfs_streq(page, nvmet_ana_state_names[i].name))
+                        goto found;
+        }
+
+        pr_err("Invalid value '%s' for ana_state\n", page);
+        return -EINVAL;
+
+found:
+        down_write(&nvmet_ana_sem);
+        grp->port->ana_state[grp->grpid] = nvmet_ana_state_names[i].state;
+        nvmet_ana_chgcnt++;
+        up_write(&nvmet_ana_sem);
+
+        nvmet_port_send_ana_event(grp->port);
+        return count;
+}
+
+CONFIGFS_ATTR(nvmet_ana_group_, ana_state);
+
+static struct configfs_attribute *nvmet_ana_group_attrs[] = {
+        &nvmet_ana_group_attr_ana_state,
+        NULL,
+};
+
+static void nvmet_ana_group_release(struct config_item *item)
+{
+        struct nvmet_ana_group *grp = to_ana_group(item);
+
+        if (grp == &grp->port->ana_default_group)
+                return;
+
+        down_write(&nvmet_ana_sem);
+        grp->port->ana_state[grp->grpid] = NVME_ANA_INACCESSIBLE;
+        nvmet_ana_group_enabled[grp->grpid]--;
+        up_write(&nvmet_ana_sem);
+
+        nvmet_port_send_ana_event(grp->port);
+        kfree(grp);
+}
+
+static struct configfs_item_operations nvmet_ana_group_item_ops = {
+        .release                = nvmet_ana_group_release,
+};
+
+static const struct config_item_type nvmet_ana_group_type = {
+        .ct_item_ops            = &nvmet_ana_group_item_ops,
+        .ct_attrs               = nvmet_ana_group_attrs,
+        .ct_owner               = THIS_MODULE,
+};
+
+static struct config_group *nvmet_ana_groups_make_group(
+                struct config_group *group, const char *name)
+{
+        struct nvmet_port *port = ana_groups_to_port(&group->cg_item);
+        struct nvmet_ana_group *grp;
+        u32 grpid;
+        int ret;
+
+        ret = kstrtou32(name, 0, &grpid);
+        if (ret)
+                goto out;
+
+        ret = -EINVAL;
+        if (grpid <= 1 || grpid > NVMET_MAX_ANAGRPS)
+                goto out;
+
+        ret = -ENOMEM;
+        grp = kzalloc(sizeof(*grp), GFP_KERNEL);
+        if (!grp)
+                goto out;
+        grp->port = port;
+        grp->grpid = grpid;
+
+        down_write(&nvmet_ana_sem);
+        nvmet_ana_group_enabled[grpid]++;
+        up_write(&nvmet_ana_sem);
+
+        nvmet_port_send_ana_event(grp->port);
+
+        config_group_init_type_name(&grp->group, name, &nvmet_ana_group_type);
+        return &grp->group;
+out:
+        return ERR_PTR(ret);
+}
+
+static struct configfs_group_operations nvmet_ana_groups_group_ops = {
+        .make_group             = nvmet_ana_groups_make_group,
+};
+
+static const struct config_item_type nvmet_ana_groups_type = {
+        .ct_group_ops           = &nvmet_ana_groups_group_ops,
+        .ct_owner               = THIS_MODULE,
+};
+
 /*
  * Ports definitions.
  */
@@ -923,6 +1085,7 @@ static void nvmet_port_release(struct config_item *item)
 {
         struct nvmet_port *port = to_nvmet_port(item);
 
+        kfree(port->ana_state);
         kfree(port);
 }
 
@@ -951,6 +1114,7 @@ static struct config_group *nvmet_ports_make(struct config_group *group,
 {
         struct nvmet_port *port;
         u16 portid;
+        u32 i;
 
         if (kstrtou16(name, 0, &portid))
                 return ERR_PTR(-EINVAL);
@@ -959,6 +1123,20 @@ static struct config_group *nvmet_ports_make(struct config_group *group,
         if (!port)
                 return ERR_PTR(-ENOMEM);
 
+        port->ana_state = kcalloc(NVMET_MAX_ANAGRPS + 1,
+                        sizeof(*port->ana_state), GFP_KERNEL);
+        if (!port->ana_state) {
+                kfree(port);
+                return ERR_PTR(-ENOMEM);
+        }
+
+        for (i = 1; i <= NVMET_MAX_ANAGRPS; i++) {
+                if (i == NVMET_DEFAULT_ANA_GRPID)
+                        port->ana_state[1] = NVME_ANA_OPTIMIZED;
+                else
+                        port->ana_state[i] = NVME_ANA_INACCESSIBLE;
+        }
+
         INIT_LIST_HEAD(&port->entry);
         INIT_LIST_HEAD(&port->subsystems);
         INIT_LIST_HEAD(&port->referrals);
@@ -975,6 +1153,18 @@ static struct config_group *nvmet_ports_make(struct config_group *group,
                         "referrals", &nvmet_referrals_type);
         configfs_add_default_group(&port->referrals_group, &port->group);
 
+        config_group_init_type_name(&port->ana_groups_group,
+                        "ana_groups", &nvmet_ana_groups_type);
+        configfs_add_default_group(&port->ana_groups_group, &port->group);
+
+        port->ana_default_group.port = port;
+        port->ana_default_group.grpid = NVMET_DEFAULT_ANA_GRPID;
+        config_group_init_type_name(&port->ana_default_group.group,
+                        __stringify(NVMET_DEFAULT_ANA_GRPID),
+                        &nvmet_ana_group_type);
+        configfs_add_default_group(&port->ana_default_group.group,
+                        &port->ana_groups_group);
+
         return &port->group;
 }
 
diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
index ddd85715a00a..3ceb7a03bb2a 100644
--- a/drivers/nvme/target/core.c
+++ b/drivers/nvme/target/core.c
@@ -40,6 +40,10 @@ static DEFINE_IDA(cntlid_ida);
  */
 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);
 
@@ -190,6 +194,33 @@ static void nvmet_ns_changed(struct nvmet_subsys *subsys, u32 nsid)
         }
 }
 
+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;
@@ -337,9 +368,13 @@ static void nvmet_ns_dev_disable(struct nvmet_ns *ns)
 int nvmet_ns_enable(struct nvmet_ns *ns)
 {
         struct nvmet_subsys *subsys = ns->subsys;
-        int ret = 0;
+        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;
 
@@ -374,6 +409,7 @@ int nvmet_ns_enable(struct nvmet_ns *ns)
 
                 list_add_tail_rcu(&ns->dev_link, &old->dev_link);
         }
+        subsys->nr_namespaces++;
 
         nvmet_ns_changed(subsys, ns->nsid);
         ns->enabled = true;
@@ -414,6 +450,7 @@ void nvmet_ns_disable(struct nvmet_ns *ns)
         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:
@@ -424,6 +461,10 @@ 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);
 }
@@ -441,6 +482,12 @@ struct nvmet_ns *nvmet_ns_alloc(struct nvmet_subsys *subsys, u32 nsid)
 
         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;
 
@@ -548,6 +595,20 @@ int nvmet_sq_init(struct nvmet_sq *sq)
 }
 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 u16 nvmet_parse_io_cmd(struct nvmet_req *req)
 {
         struct nvme_command *cmd = req->cmd;
@@ -560,6 +621,9 @@ static u16 nvmet_parse_io_cmd(struct nvmet_req *req)
         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;
 
         if (req->ns->file)
                 return nvmet_file_parse_io_cmd(req);
@@ -876,6 +940,8 @@ u16 nvmet_alloc_ctrl(const char *subsysnqn, const char *hostnqn,
 
         nvmet_init_cap(ctrl);
 
+        ctrl->port = req->port;
+
         INIT_WORK(&ctrl->async_event_work, nvmet_async_event_work);
         INIT_LIST_HEAD(&ctrl->async_events);
 
@@ -1115,12 +1181,15 @@ 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;
diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
index 688993855402..22941045f46e 100644
--- a/drivers/nvme/target/nvmet.h
+++ b/drivers/nvme/target/nvmet.h
@@ -30,12 +30,11 @@
 #define NVMET_ASYNC_EVENTS              4
 #define NVMET_ERROR_LOG_SLOTS           128
 
-
 /*
  * Supported optional AENs:
  */
 #define NVMET_AEN_CFG_OPTIONAL \
-        NVME_AEN_CFG_NS_ATTR
+        (NVME_AEN_CFG_NS_ATTR | NVME_AEN_CFG_ANA_CHANGE)
 
 /*
  * Plus mandatory SMART AENs (we'll never send them, but allow enabling them):
@@ -64,6 +63,7 @@ struct nvmet_ns {
         loff_t                  size;
         u8                      nguid[16];
         uuid_t                  uuid;
+        u32                     anagrpid;
 
         bool                    buffered_io;
         bool                    enabled;
@@ -98,6 +98,18 @@ struct nvmet_sq {
         struct completion       confirm_done;
 };
 
+struct nvmet_ana_group {
+        struct config_group     group;
+        struct nvmet_port       *port;
+        u32                     grpid;
+};
+
+static inline struct nvmet_ana_group *to_ana_group(struct config_item *item)
+{
+        return container_of(to_config_group(item), struct nvmet_ana_group,
+                        group);
+}
+
 /**
  * struct nvmet_port -  Common structure to keep port
  *                              information for the target.
@@ -115,6 +127,9 @@ struct nvmet_port {
         struct list_head                subsystems;
         struct config_group             referrals_group;
         struct list_head                referrals;
+        struct config_group             ana_groups_group;
+        struct nvmet_ana_group          ana_default_group;
+        enum nvme_ana_state             *ana_state;
         void                            *priv;
         bool                            enabled;
         int                             inline_data_size;
@@ -126,6 +141,13 @@ static inline struct nvmet_port *to_nvmet_port(struct config_item *item)
                         group);
 }
 
+static inline struct nvmet_port *ana_groups_to_port(
+                struct config_item *item)
+{
+        return container_of(to_config_group(item), struct nvmet_port,
+                        ana_groups_group);
+}
+
 struct nvmet_ctrl {
         struct nvmet_subsys     *subsys;
         struct nvmet_cq         **cqs;
@@ -140,6 +162,8 @@ struct nvmet_ctrl {
         u16                     cntlid;
         u32                     kato;
 
+        struct nvmet_port       *port;
+
         u32                     aen_enabled;
         unsigned long           aen_masked;
         struct nvmet_req        *async_event_cmds[NVMET_ASYNC_EVENTS];
@@ -168,6 +192,7 @@ struct nvmet_subsys {
         struct kref             ref;
 
         struct list_head        namespaces;
+        unsigned int            nr_namespaces;
         unsigned int            max_nsid;
 
         struct list_head        ctrls;
@@ -340,6 +365,10 @@ void nvmet_ns_disable(struct nvmet_ns *ns);
 struct nvmet_ns *nvmet_ns_alloc(struct nvmet_subsys *subsys, u32 nsid);
 void nvmet_ns_free(struct nvmet_ns *ns);
 
+void nvmet_send_ana_event(struct nvmet_subsys *subsys,
+                struct nvmet_port *port);
+void nvmet_port_send_ana_event(struct nvmet_port *port);
+
 int nvmet_register_transport(const struct nvmet_fabrics_ops *ops);
 void nvmet_unregister_transport(const struct nvmet_fabrics_ops *ops);
 
@@ -360,6 +389,22 @@ u32 nvmet_get_log_page_len(struct nvme_command *cmd);
 #define NVMET_QUEUE_SIZE        1024
 #define NVMET_NR_QUEUES         128
 #define NVMET_MAX_CMD           NVMET_QUEUE_SIZE
+
+/*
+ * Nice round number that makes a list of nsids fit into a page.
+ * Should become tunable at some point in the future.
+ */
+#define NVMET_MAX_NAMESPACES    1024
+
+/*
+ * 0 is not a valid ANA group ID, so we start numbering at 1.
+ *
+ * ANA Group 1 exists without manual intervention, has namespaces assigned to it
+ * by default, and is available in an optimized state through all ports.
+ */
+#define NVMET_MAX_ANAGRPS       128
+#define NVMET_DEFAULT_ANA_GRPID 1
+
 #define NVMET_KAS               10
 #define NVMET_DISC_KATO         120
 
@@ -373,6 +418,10 @@ extern struct nvmet_subsys *nvmet_disc_subsys;
 extern u64 nvmet_genctr;
 extern struct rw_semaphore nvmet_config_sem;
 
+extern u32 nvmet_ana_group_enabled[NVMET_MAX_ANAGRPS + 1];
+extern u64 nvmet_ana_chgcnt;
+extern struct rw_semaphore nvmet_ana_sem;
+
 bool nvmet_host_allowed(struct nvmet_req *req, struct nvmet_subsys *subsys,
                 const char *hostnqn);
 
diff --git a/include/linux/nvme.h b/include/linux/nvme.h
index 80dfedcf0bf7..64c9175723de 100644
--- a/include/linux/nvme.h
+++ b/include/linux/nvme.h
@@ -242,7 +242,12 @@ struct nvme_id_ctrl {
         __le32                  sanicap;
         __le32                  hmminds;
         __le16                  hmmaxd;
-        __u8                    rsvd338[174];
+        __u8                    rsvd338[4];
+        __u8                    anatt;
+        __u8                    anacap;
+        __le32                  anagrpmax;
+        __le32                  nanagrpid;
+        __u8                    rsvd352[160];
         __u8                    sqes;
         __u8                    cqes;
         __le16                  maxcmd;
@@ -258,7 +263,8 @@ struct nvme_id_ctrl {
         __le16                  acwu;
         __u8                    rsvd534[2];
         __le32                  sgls;
-        __u8                    rsvd540[228];
+        __le32                  mnan;
+        __u8                    rsvd544[224];
         char                    subnqn[256];
         __u8                    rsvd1024[768];
         __le32                  ioccsz;
@@ -312,7 +318,9 @@ struct nvme_id_ns {
         __le16                  nabspf;
         __le16                  noiob;
         __u8                    nvmcap[16];
-        __u8                    rsvd64[40];
+        __u8                    rsvd64[28];
+        __le32                  anagrpid;
+        __u8                    rsvd96[8];
         __u8                    nguid[16];
         __u8                    eui64[8];
         struct nvme_lbaf        lbaf[16];
@@ -425,6 +433,32 @@ struct nvme_effects_log {
         __u8   resv[2048];
 };
 
+enum nvme_ana_state {
+        NVME_ANA_OPTIMIZED              = 0x01,
+        NVME_ANA_NONOPTIMIZED           = 0x02,
+        NVME_ANA_INACCESSIBLE           = 0x03,
+        NVME_ANA_PERSISTENT_LOSS        = 0x04,
+        NVME_ANA_CHANGE                 = 0x0f,
+};
+
+struct nvme_ana_group_desc {
+        __le32  grpid;
+        __le32  nnsids;
+        __le64  chgcnt;
+        __u8    state;
+        __u8    rsvd17[7];
+        __le32  nsids[];
+};
+
+/* flag for the log specific field of the ANA log */
+#define NVME_ANA_LOG_RGO        (1 << 0)
+
+struct nvme_ana_rsp_hdr {
+        __le64  chgcnt;
+        __le16  ngrps;
+        __le16  rsvd10[3];
+};
+
 enum {
         NVME_SMART_CRIT_SPARE           = 1 << 0,
         NVME_SMART_CRIT_TEMPERATURE     = 1 << 1,
@@ -444,11 +478,13 @@ enum {
 enum {
         NVME_AER_NOTICE_NS_CHANGED      = 0x00,
         NVME_AER_NOTICE_FW_ACT_STARTING = 0x01,
+        NVME_AER_NOTICE_ANA             = 0x03,
 };
 
 enum {
         NVME_AEN_CFG_NS_ATTR            = 1 << 8,
         NVME_AEN_CFG_FW_ACT             = 1 << 9,
+        NVME_AEN_CFG_ANA_CHANGE         = 1 << 11,
 };
 
 struct nvme_lba_range_type {
@@ -763,6 +799,7 @@ enum {
         NVME_LOG_FW_SLOT        = 0x03,
         NVME_LOG_CHANGED_NS     = 0x04,
         NVME_LOG_CMD_EFFECTS    = 0x05,
+        NVME_LOG_ANA            = 0x0c,
         NVME_LOG_DISC           = 0x70,
         NVME_LOG_RESERVATION    = 0x80,
         NVME_FWACT_REPL         = (0 << 3),
@@ -885,7 +922,7 @@ struct nvme_get_log_page_command {
         __u64                   rsvd2[2];
         union nvme_data_ptr     dptr;
         __u8                    lid;
-        __u8                    rsvd10;
+        __u8                    lsp; /* upper 4 bits reserved */
         __le16                  numdl;
         __le16                  numdu;
         __u16                   rsvd11;
@@ -1185,6 +1222,13 @@ enum {
         NVME_SC_ACCESS_DENIED           = 0x286,
         NVME_SC_UNWRITTEN_BLOCK         = 0x287,
 
+        /*
+         * Path-related Errors:
+         */
+        NVME_SC_ANA_PERSISTENT_LOSS     = 0x301,
+        NVME_SC_ANA_INACCESSIBLE        = 0x302,
+        NVME_SC_ANA_TRANSITION          = 0x303,
+
         NVME_SC_DNR                     = 0x4000,
 };