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- /*
- * 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,
- * 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.
- */
- #include <linux/backing-dev.h>
- #include <linux/moduleparam.h>
- #include <trace/events/block.h>
- #include "nvme.h"
- static bool multipath = true;
- module_param(multipath, bool, 0444);
- MODULE_PARM_DESC(multipath,
- "turn on native support for multiple controllers per subsystem");
- void nvme_mpath_unfreeze(struct nvme_subsystem *subsys)
- {
- struct nvme_ns_head *h;
- lockdep_assert_held(&subsys->lock);
- list_for_each_entry(h, &subsys->nsheads, entry)
- if (h->disk)
- blk_mq_unfreeze_queue(h->disk->queue);
- }
- void nvme_mpath_wait_freeze(struct nvme_subsystem *subsys)
- {
- struct nvme_ns_head *h;
- lockdep_assert_held(&subsys->lock);
- list_for_each_entry(h, &subsys->nsheads, entry)
- if (h->disk)
- blk_mq_freeze_queue_wait(h->disk->queue);
- }
- void nvme_mpath_start_freeze(struct nvme_subsystem *subsys)
- {
- struct nvme_ns_head *h;
- lockdep_assert_held(&subsys->lock);
- list_for_each_entry(h, &subsys->nsheads, entry)
- if (h->disk)
- blk_freeze_queue_start(h->disk->queue);
- }
- /*
- * If multipathing is enabled we need to always use the subsystem instance
- * number for numbering our devices to avoid conflicts between subsystems that
- * have multiple controllers and thus use the multipath-aware subsystem node
- * and those that have a single controller and use the controller node
- * directly.
- */
- void nvme_set_disk_name(char *disk_name, struct nvme_ns *ns,
- struct nvme_ctrl *ctrl, int *flags)
- {
- if (!multipath) {
- sprintf(disk_name, "nvme%dn%d", ctrl->instance, ns->head->instance);
- } else if (ns->head->disk) {
- sprintf(disk_name, "nvme%dc%dn%d", ctrl->subsys->instance,
- ctrl->cntlid, ns->head->instance);
- *flags = GENHD_FL_HIDDEN;
- } else {
- sprintf(disk_name, "nvme%dn%d", ctrl->subsys->instance,
- ns->head->instance);
- }
- }
- bool nvme_failover_req(struct request *req)
- {
- struct nvme_ns *ns = req->q->queuedata;
- u16 status = nvme_req(req)->status;
- unsigned long flags;
- 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;
- case NVME_SC_HOST_PATH_ERROR:
- /*
- * Temporary transport disruption in talking to the controller.
- * Try to send on a new path.
- */
- nvme_mpath_clear_current_path(ns);
- break;
- default:
- /* This was a non-ANA error so follow the normal error path. */
- return false;
- }
- spin_lock_irqsave(&ns->head->requeue_lock, flags);
- blk_steal_bios(&ns->head->requeue_list, req);
- spin_unlock_irqrestore(&ns->head->requeue_lock, flags);
- blk_mq_end_request(req, 0);
- kblockd_schedule_work(&ns->head->requeue_work);
- return true;
- }
- void nvme_kick_requeue_lists(struct nvme_ctrl *ctrl)
- {
- struct nvme_ns *ns;
- down_read(&ctrl->namespaces_rwsem);
- list_for_each_entry(ns, &ctrl->namespaces, list) {
- if (ns->head->disk)
- kblockd_schedule_work(&ns->head->requeue_work);
- }
- 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, *fallback = NULL;
- list_for_each_entry_rcu(ns, &head->list, siblings) {
- 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;
- }
- }
- 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 || !nvme_path_is_optimized(ns)))
- ns = __nvme_find_path(head);
- return ns;
- }
- static blk_qc_t nvme_ns_head_make_request(struct request_queue *q,
- struct bio *bio)
- {
- struct nvme_ns_head *head = q->queuedata;
- struct device *dev = disk_to_dev(head->disk);
- struct nvme_ns *ns;
- blk_qc_t ret = BLK_QC_T_NONE;
- int srcu_idx;
- srcu_idx = srcu_read_lock(&head->srcu);
- ns = nvme_find_path(head);
- if (likely(ns)) {
- bio->bi_disk = ns->disk;
- bio->bi_opf |= REQ_NVME_MPATH;
- trace_block_bio_remap(bio->bi_disk->queue, bio,
- disk_devt(ns->head->disk),
- bio->bi_iter.bi_sector);
- ret = direct_make_request(bio);
- } else if (!list_empty_careful(&head->list)) {
- dev_warn_ratelimited(dev, "no path available - requeuing I/O\n");
- spin_lock_irq(&head->requeue_lock);
- bio_list_add(&head->requeue_list, bio);
- spin_unlock_irq(&head->requeue_lock);
- } else {
- dev_warn_ratelimited(dev, "no path - failing I/O\n");
- bio->bi_status = BLK_STS_IOERR;
- bio_endio(bio);
- }
- srcu_read_unlock(&head->srcu, srcu_idx);
- return ret;
- }
- static bool nvme_ns_head_poll(struct request_queue *q, blk_qc_t qc)
- {
- struct nvme_ns_head *head = q->queuedata;
- struct nvme_ns *ns;
- bool found = false;
- int srcu_idx;
- srcu_idx = srcu_read_lock(&head->srcu);
- ns = srcu_dereference(head->current_path, &head->srcu);
- if (likely(ns && nvme_path_is_optimized(ns)))
- found = ns->queue->poll_fn(q, qc);
- srcu_read_unlock(&head->srcu, srcu_idx);
- return found;
- }
- static void nvme_requeue_work(struct work_struct *work)
- {
- struct nvme_ns_head *head =
- container_of(work, struct nvme_ns_head, requeue_work);
- struct bio *bio, *next;
- spin_lock_irq(&head->requeue_lock);
- next = bio_list_get(&head->requeue_list);
- spin_unlock_irq(&head->requeue_lock);
- while ((bio = next) != NULL) {
- next = bio->bi_next;
- bio->bi_next = NULL;
- /*
- * Reset disk to the mpath node and resubmit to select a new
- * path.
- */
- bio->bi_disk = head->disk;
- generic_make_request(bio);
- }
- }
- 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);
- /*
- * Add a multipath node if the subsystems supports multiple controllers.
- * We also do this for private namespaces as the namespace sharing data could
- * change after a rescan.
- */
- if (!(ctrl->subsys->cmic & (1 << 1)) || !multipath)
- return 0;
- q = blk_alloc_queue_node(GFP_KERNEL, NUMA_NO_NODE, NULL);
- if (!q)
- goto out;
- q->queuedata = head;
- blk_queue_make_request(q, nvme_ns_head_make_request);
- q->poll_fn = nvme_ns_head_poll;
- blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
- /* set to a default value for 512 until disk is validated */
- blk_queue_logical_block_size(q, 512);
- blk_set_stacking_limits(&q->limits);
- /* we need to propagate up the VMC settings */
- if (ctrl->vwc & NVME_CTRL_VWC_PRESENT)
- vwc = true;
- blk_queue_write_cache(q, vwc, vwc);
- head->disk = alloc_disk(0);
- if (!head->disk)
- goto out_cleanup_queue;
- head->disk->fops = &nvme_ns_head_ops;
- head->disk->private_data = head;
- head->disk->queue = q;
- head->disk->flags = GENHD_FL_EXT_DEVT;
- sprintf(head->disk->disk_name, "nvme%dn%d",
- ctrl->subsys->instance, head->instance);
- return 0;
- out_cleanup_queue:
- blk_cleanup_queue(q);
- out:
- return -ENOMEM;
- }
- 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;
- if (!(head->disk->flags & GENHD_FL_UP))
- device_add_disk(&head->subsys->dev, head->disk,
- nvme_ns_id_attr_groups);
- synchronize_srcu(&ns->head->srcu);
- 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)
- {
- mutex_lock(&ns->head->lock);
- 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_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_read(&ctrl->namespaces_rwsem);
- list_for_each_entry(ns, &ctrl->namespaces, list) {
- unsigned nsid = le32_to_cpu(desc->nsids[n]);
- if (ns->head->ns_id < nsid)
- continue;
- if (ns->head->ns_id == nsid)
- nvme_update_ns_ana_state(desc, ns);
- if (++n == nr_nsids)
- break;
- }
- up_read(&ctrl->namespaces_rwsem);
- 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_lookup_ana_group_desc(struct nvme_ctrl *ctrl,
- struct nvme_ana_group_desc *desc, void *data)
- {
- struct nvme_ana_group_desc *dst = data;
- if (desc->grpid != dst->grpid)
- return 0;
- *dst = *desc;
- return -ENXIO; /* just break out of the loop */
- }
- void nvme_mpath_add_disk(struct nvme_ns *ns, struct nvme_id_ns *id)
- {
- if (nvme_ctrl_use_ana(ns->ctrl)) {
- struct nvme_ana_group_desc desc = {
- .grpid = id->anagrpid,
- .state = 0,
- };
- mutex_lock(&ns->ctrl->ana_lock);
- ns->ana_grpid = le32_to_cpu(id->anagrpid);
- nvme_parse_ana_log(ns->ctrl, &desc, nvme_lookup_ana_group_desc);
- mutex_unlock(&ns->ctrl->ana_lock);
- if (desc.state) {
- /* found the group desc: update */
- nvme_update_ns_ana_state(&desc, ns);
- } else {
- /* group desc not found: trigger a re-read */
- set_bit(NVME_NS_ANA_PENDING, &ns->flags);
- queue_work(nvme_wq, &ns->ctrl->ana_work);
- }
- } else {
- mutex_lock(&ns->head->lock);
- ns->ana_state = NVME_ANA_OPTIMIZED;
- nvme_mpath_set_live(ns);
- mutex_unlock(&ns->head->lock);
- }
- if (bdi_cap_stable_pages_required(ns->queue->backing_dev_info)) {
- struct gendisk *disk = ns->head->disk;
- if (disk)
- disk->queue->backing_dev_info->capabilities |=
- BDI_CAP_STABLE_WRITES;
- }
- }
- void nvme_mpath_remove_disk(struct nvme_ns_head *head)
- {
- if (!head->disk)
- return;
- if (head->disk->flags & GENHD_FL_UP)
- 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);
- flush_work(&head->requeue_work);
- 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;
- /* check if multipath is enabled and we have the capability */
- if (!multipath || !ctrl->subsys || !(ctrl->subsys->cmic & (1 << 3)))
- 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);
- 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);
- kfree(ctrl->ana_log_buf);
- ctrl->ana_log_buf = kmalloc(ctrl->ana_log_size, GFP_KERNEL);
- if (!ctrl->ana_log_buf) {
- error = -ENOMEM;
- goto out;
- }
- error = nvme_read_ana_log(ctrl, false);
- if (error)
- goto out_free_ana_log_buf;
- return 0;
- out_free_ana_log_buf:
- kfree(ctrl->ana_log_buf);
- ctrl->ana_log_buf = NULL;
- out:
- return error;
- }
- void nvme_mpath_uninit(struct nvme_ctrl *ctrl)
- {
- kfree(ctrl->ana_log_buf);
- ctrl->ana_log_buf = NULL;
- }
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