| /* |
| * 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/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); |
| } |
| } |
| |
| 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); |
| blk_steal_bios(&ns->head->requeue_list, req); |
| spin_unlock_irqrestore(&ns->head->requeue_lock, flags); |
| blk_mq_end_request(req, 0); |
| |
| 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: |
| /* |
| * Reset the controller for any non-ANA error as we don't know |
| * what caused the error. |
| */ |
| nvme_reset_ctrl(ns->ctrl); |
| break; |
| } |
| |
| kblockd_schedule_work(&ns->head->requeue_work); |
| } |
| |
| 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); |
| if (sysfs_create_group(&disk_to_dev(head->disk)->kobj, |
| &nvme_ns_id_attr_group)) |
| dev_warn(&head->subsys->dev, |
| "failed to create id group.\n"); |
| } |
| |
| 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_write(&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_write(&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_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); |
| } |
| } |
| |
| void nvme_mpath_remove_disk(struct nvme_ns_head *head) |
| { |
| if (!head->disk) |
| return; |
| 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); |
| 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); |
| 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; |
| } |
| |