2 * Copyright (c) 2017 Christoph Hellwig.
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms and conditions of the GNU General Public License,
6 * version 2, as published by the Free Software Foundation.
8 * This program is distributed in the hope it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
14 #include <linux/moduleparam.h>
17 static bool multipath = true;
18 module_param(multipath, bool, 0644);
19 MODULE_PARM_DESC(multipath,
20 "turn on native support for multiple controllers per subsystem");
22 void nvme_failover_req(struct request *req)
24 struct nvme_ns *ns = req->q->queuedata;
27 spin_lock_irqsave(&ns->head->requeue_lock, flags);
28 blk_steal_bios(&ns->head->requeue_list, req);
29 spin_unlock_irqrestore(&ns->head->requeue_lock, flags);
30 blk_mq_end_request(req, 0);
32 nvme_reset_ctrl(ns->ctrl);
33 kblockd_schedule_work(&ns->head->requeue_work);
36 bool nvme_req_needs_failover(struct request *req)
38 if (!(req->cmd_flags & REQ_NVME_MPATH))
41 switch (nvme_req(req)->status & 0x7ff) {
43 * Generic command status:
45 case NVME_SC_INVALID_OPCODE:
46 case NVME_SC_INVALID_FIELD:
47 case NVME_SC_INVALID_NS:
48 case NVME_SC_LBA_RANGE:
49 case NVME_SC_CAP_EXCEEDED:
50 case NVME_SC_RESERVATION_CONFLICT:
54 * I/O command set specific error. Unfortunately these values are
55 * reused for fabrics commands, but those should never get here.
57 case NVME_SC_BAD_ATTRIBUTES:
58 case NVME_SC_INVALID_PI:
59 case NVME_SC_READ_ONLY:
60 case NVME_SC_ONCS_NOT_SUPPORTED:
61 WARN_ON_ONCE(nvme_req(req)->cmd->common.opcode ==
62 nvme_fabrics_command);
66 * Media and Data Integrity Errors:
68 case NVME_SC_WRITE_FAULT:
69 case NVME_SC_READ_ERROR:
70 case NVME_SC_GUARD_CHECK:
71 case NVME_SC_APPTAG_CHECK:
72 case NVME_SC_REFTAG_CHECK:
73 case NVME_SC_COMPARE_FAILED:
74 case NVME_SC_ACCESS_DENIED:
75 case NVME_SC_UNWRITTEN_BLOCK:
79 /* Everything else could be a path failure, so should be retried */
83 void nvme_kick_requeue_lists(struct nvme_ctrl *ctrl)
87 mutex_lock(&ctrl->namespaces_mutex);
88 list_for_each_entry(ns, &ctrl->namespaces, list) {
90 kblockd_schedule_work(&ns->head->requeue_work);
92 mutex_unlock(&ctrl->namespaces_mutex);
95 static struct nvme_ns *__nvme_find_path(struct nvme_ns_head *head)
99 list_for_each_entry_rcu(ns, &head->list, siblings) {
100 if (ns->ctrl->state == NVME_CTRL_LIVE) {
101 rcu_assign_pointer(head->current_path, ns);
109 inline struct nvme_ns *nvme_find_path(struct nvme_ns_head *head)
111 struct nvme_ns *ns = srcu_dereference(head->current_path, &head->srcu);
113 if (unlikely(!ns || ns->ctrl->state != NVME_CTRL_LIVE))
114 ns = __nvme_find_path(head);
118 static blk_qc_t nvme_ns_head_make_request(struct request_queue *q,
121 struct nvme_ns_head *head = q->queuedata;
122 struct device *dev = disk_to_dev(head->disk);
124 blk_qc_t ret = BLK_QC_T_NONE;
127 srcu_idx = srcu_read_lock(&head->srcu);
128 ns = nvme_find_path(head);
130 bio->bi_disk = ns->disk;
131 bio->bi_opf |= REQ_NVME_MPATH;
132 ret = direct_make_request(bio);
133 } else if (!list_empty_careful(&head->list)) {
134 dev_warn_ratelimited(dev, "no path available - requeuing I/O\n");
136 spin_lock_irq(&head->requeue_lock);
137 bio_list_add(&head->requeue_list, bio);
138 spin_unlock_irq(&head->requeue_lock);
140 dev_warn_ratelimited(dev, "no path - failing I/O\n");
142 bio->bi_status = BLK_STS_IOERR;
146 srcu_read_unlock(&head->srcu, srcu_idx);
150 static bool nvme_ns_head_poll(struct request_queue *q, blk_qc_t qc)
152 struct nvme_ns_head *head = q->queuedata;
157 srcu_idx = srcu_read_lock(&head->srcu);
158 ns = srcu_dereference(head->current_path, &head->srcu);
159 if (likely(ns && ns->ctrl->state == NVME_CTRL_LIVE))
160 found = ns->queue->poll_fn(q, qc);
161 srcu_read_unlock(&head->srcu, srcu_idx);
165 static void nvme_requeue_work(struct work_struct *work)
167 struct nvme_ns_head *head =
168 container_of(work, struct nvme_ns_head, requeue_work);
169 struct bio *bio, *next;
171 spin_lock_irq(&head->requeue_lock);
172 next = bio_list_get(&head->requeue_list);
173 spin_unlock_irq(&head->requeue_lock);
175 while ((bio = next) != NULL) {
180 * Reset disk to the mpath node and resubmit to select a new
183 bio->bi_disk = head->disk;
184 generic_make_request(bio);
188 int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl, struct nvme_ns_head *head)
190 struct request_queue *q;
193 bio_list_init(&head->requeue_list);
194 spin_lock_init(&head->requeue_lock);
195 INIT_WORK(&head->requeue_work, nvme_requeue_work);
198 * Add a multipath node if the subsystems supports multiple controllers.
199 * We also do this for private namespaces as the namespace sharing data could
200 * change after a rescan.
202 if (!(ctrl->subsys->cmic & (1 << 1)) || !multipath)
205 q = blk_alloc_queue_node(GFP_KERNEL, NUMA_NO_NODE);
209 blk_queue_make_request(q, nvme_ns_head_make_request);
210 q->poll_fn = nvme_ns_head_poll;
211 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
212 /* set to a default value for 512 until disk is validated */
213 blk_queue_logical_block_size(q, 512);
215 /* we need to propagate up the VMC settings */
216 if (ctrl->vwc & NVME_CTRL_VWC_PRESENT)
218 blk_queue_write_cache(q, vwc, vwc);
220 head->disk = alloc_disk(0);
222 goto out_cleanup_queue;
223 head->disk->fops = &nvme_ns_head_ops;
224 head->disk->private_data = head;
225 head->disk->queue = q;
226 head->disk->flags = GENHD_FL_EXT_DEVT;
227 sprintf(head->disk->disk_name, "nvme%dn%d",
228 ctrl->subsys->instance, head->instance);
232 blk_cleanup_queue(q);
237 void nvme_mpath_add_disk(struct nvme_ns_head *head)
241 device_add_disk(&head->subsys->dev, head->disk);
242 if (sysfs_create_group(&disk_to_dev(head->disk)->kobj,
243 &nvme_ns_id_attr_group))
244 pr_warn("%s: failed to create sysfs group for identification\n",
245 head->disk->disk_name);
248 void nvme_mpath_add_disk_links(struct nvme_ns *ns)
250 struct kobject *slave_disk_kobj, *holder_disk_kobj;
255 slave_disk_kobj = &disk_to_dev(ns->disk)->kobj;
256 if (sysfs_create_link(ns->head->disk->slave_dir, slave_disk_kobj,
257 kobject_name(slave_disk_kobj)))
260 holder_disk_kobj = &disk_to_dev(ns->head->disk)->kobj;
261 if (sysfs_create_link(ns->disk->part0.holder_dir, holder_disk_kobj,
262 kobject_name(holder_disk_kobj)))
263 sysfs_remove_link(ns->head->disk->slave_dir,
264 kobject_name(slave_disk_kobj));
267 void nvme_mpath_remove_disk(struct nvme_ns_head *head)
271 sysfs_remove_group(&disk_to_dev(head->disk)->kobj,
272 &nvme_ns_id_attr_group);
273 del_gendisk(head->disk);
274 blk_set_queue_dying(head->disk->queue);
275 /* make sure all pending bios are cleaned up */
276 kblockd_schedule_work(&head->requeue_work);
277 flush_work(&head->requeue_work);
278 blk_cleanup_queue(head->disk->queue);
279 put_disk(head->disk);
282 void nvme_mpath_remove_disk_links(struct nvme_ns *ns)
287 sysfs_remove_link(ns->disk->part0.holder_dir,
288 kobject_name(&disk_to_dev(ns->head->disk)->kobj));
289 sysfs_remove_link(ns->head->disk->slave_dir,
290 kobject_name(&disk_to_dev(ns->disk)->kobj));