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1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2017-2018 Christoph Hellwig.
4  */
5 
6 #include <linux/moduleparam.h>
7 #include <trace/events/block.h>
8 #include "nvme.h"
9 
10 static bool multipath = true;
11 module_param(multipath, bool, 0444);
12 MODULE_PARM_DESC(multipath,
13 	"turn on native support for multiple controllers per subsystem");
14 
nvme_mpath_unfreeze(struct nvme_subsystem * subsys)15 void nvme_mpath_unfreeze(struct nvme_subsystem *subsys)
16 {
17 	struct nvme_ns_head *h;
18 
19 	lockdep_assert_held(&subsys->lock);
20 	list_for_each_entry(h, &subsys->nsheads, entry)
21 		if (h->disk)
22 			blk_mq_unfreeze_queue(h->disk->queue);
23 }
24 
nvme_mpath_wait_freeze(struct nvme_subsystem * subsys)25 void nvme_mpath_wait_freeze(struct nvme_subsystem *subsys)
26 {
27 	struct nvme_ns_head *h;
28 
29 	lockdep_assert_held(&subsys->lock);
30 	list_for_each_entry(h, &subsys->nsheads, entry)
31 		if (h->disk)
32 			blk_mq_freeze_queue_wait(h->disk->queue);
33 }
34 
nvme_mpath_start_freeze(struct nvme_subsystem * subsys)35 void nvme_mpath_start_freeze(struct nvme_subsystem *subsys)
36 {
37 	struct nvme_ns_head *h;
38 
39 	lockdep_assert_held(&subsys->lock);
40 	list_for_each_entry(h, &subsys->nsheads, entry)
41 		if (h->disk)
42 			blk_freeze_queue_start(h->disk->queue);
43 }
44 
45 /*
46  * If multipathing is enabled we need to always use the subsystem instance
47  * number for numbering our devices to avoid conflicts between subsystems that
48  * have multiple controllers and thus use the multipath-aware subsystem node
49  * and those that have a single controller and use the controller node
50  * directly.
51  */
nvme_set_disk_name(char * disk_name,struct nvme_ns * ns,struct nvme_ctrl * ctrl,int * flags)52 void nvme_set_disk_name(char *disk_name, struct nvme_ns *ns,
53 			struct nvme_ctrl *ctrl, int *flags)
54 {
55 	if (!multipath) {
56 		sprintf(disk_name, "nvme%dn%d", ctrl->instance, ns->head->instance);
57 	} else if (ns->head->disk) {
58 		sprintf(disk_name, "nvme%dc%dn%d", ctrl->subsys->instance,
59 				ctrl->instance, ns->head->instance);
60 		*flags = GENHD_FL_HIDDEN;
61 	} else {
62 		sprintf(disk_name, "nvme%dn%d", ctrl->subsys->instance,
63 				ns->head->instance);
64 	}
65 }
66 
nvme_failover_req(struct request * req)67 void nvme_failover_req(struct request *req)
68 {
69 	struct nvme_ns *ns = req->q->queuedata;
70 	u16 status = nvme_req(req)->status;
71 	unsigned long flags;
72 
73 	spin_lock_irqsave(&ns->head->requeue_lock, flags);
74 	blk_steal_bios(&ns->head->requeue_list, req);
75 	spin_unlock_irqrestore(&ns->head->requeue_lock, flags);
76 	blk_mq_end_request(req, 0);
77 
78 	switch (status & 0x7ff) {
79 	case NVME_SC_ANA_TRANSITION:
80 	case NVME_SC_ANA_INACCESSIBLE:
81 	case NVME_SC_ANA_PERSISTENT_LOSS:
82 		/*
83 		 * If we got back an ANA error we know the controller is alive,
84 		 * but not ready to serve this namespaces.  The spec suggests
85 		 * we should update our general state here, but due to the fact
86 		 * that the admin and I/O queues are not serialized that is
87 		 * fundamentally racy.  So instead just clear the current path,
88 		 * mark the the path as pending and kick of a re-read of the ANA
89 		 * log page ASAP.
90 		 */
91 		nvme_mpath_clear_current_path(ns);
92 		if (ns->ctrl->ana_log_buf) {
93 			set_bit(NVME_NS_ANA_PENDING, &ns->flags);
94 			queue_work(nvme_wq, &ns->ctrl->ana_work);
95 		}
96 		break;
97 	case NVME_SC_HOST_PATH_ERROR:
98 	case NVME_SC_HOST_ABORTED_CMD:
99 		/*
100 		 * Temporary transport disruption in talking to the controller.
101 		 * Try to send on a new path.
102 		 */
103 		nvme_mpath_clear_current_path(ns);
104 		break;
105 	default:
106 		/*
107 		 * Reset the controller for any non-ANA error as we don't know
108 		 * what caused the error.
109 		 */
110 		nvme_reset_ctrl(ns->ctrl);
111 		break;
112 	}
113 
114 	kblockd_schedule_work(&ns->head->requeue_work);
115 }
116 
nvme_kick_requeue_lists(struct nvme_ctrl * ctrl)117 void nvme_kick_requeue_lists(struct nvme_ctrl *ctrl)
118 {
119 	struct nvme_ns *ns;
120 
121 	down_read(&ctrl->namespaces_rwsem);
122 	list_for_each_entry(ns, &ctrl->namespaces, list) {
123 		if (ns->head->disk)
124 			kblockd_schedule_work(&ns->head->requeue_work);
125 	}
126 	up_read(&ctrl->namespaces_rwsem);
127 }
128 
129 static const char *nvme_ana_state_names[] = {
130 	[0]				= "invalid state",
131 	[NVME_ANA_OPTIMIZED]		= "optimized",
132 	[NVME_ANA_NONOPTIMIZED]		= "non-optimized",
133 	[NVME_ANA_INACCESSIBLE]		= "inaccessible",
134 	[NVME_ANA_PERSISTENT_LOSS]	= "persistent-loss",
135 	[NVME_ANA_CHANGE]		= "change",
136 };
137 
nvme_mpath_clear_current_path(struct nvme_ns * ns)138 bool nvme_mpath_clear_current_path(struct nvme_ns *ns)
139 {
140 	struct nvme_ns_head *head = ns->head;
141 	bool changed = false;
142 	int node;
143 
144 	if (!head)
145 		goto out;
146 
147 	for_each_node(node) {
148 		if (ns == rcu_access_pointer(head->current_path[node])) {
149 			rcu_assign_pointer(head->current_path[node], NULL);
150 			changed = true;
151 		}
152 	}
153 out:
154 	return changed;
155 }
156 
nvme_mpath_clear_ctrl_paths(struct nvme_ctrl * ctrl)157 void nvme_mpath_clear_ctrl_paths(struct nvme_ctrl *ctrl)
158 {
159 	struct nvme_ns *ns;
160 
161 	mutex_lock(&ctrl->scan_lock);
162 	down_read(&ctrl->namespaces_rwsem);
163 	list_for_each_entry(ns, &ctrl->namespaces, list)
164 		if (nvme_mpath_clear_current_path(ns))
165 			kblockd_schedule_work(&ns->head->requeue_work);
166 	up_read(&ctrl->namespaces_rwsem);
167 	mutex_unlock(&ctrl->scan_lock);
168 }
169 
nvme_path_is_disabled(struct nvme_ns * ns)170 static bool nvme_path_is_disabled(struct nvme_ns *ns)
171 {
172 	return ns->ctrl->state != NVME_CTRL_LIVE ||
173 		test_bit(NVME_NS_ANA_PENDING, &ns->flags) ||
174 		test_bit(NVME_NS_REMOVING, &ns->flags);
175 }
176 
__nvme_find_path(struct nvme_ns_head * head,int node)177 static struct nvme_ns *__nvme_find_path(struct nvme_ns_head *head, int node)
178 {
179 	int found_distance = INT_MAX, fallback_distance = INT_MAX, distance;
180 	struct nvme_ns *found = NULL, *fallback = NULL, *ns;
181 
182 	list_for_each_entry_rcu(ns, &head->list, siblings) {
183 		if (nvme_path_is_disabled(ns))
184 			continue;
185 
186 		if (READ_ONCE(head->subsys->iopolicy) == NVME_IOPOLICY_NUMA)
187 			distance = node_distance(node, ns->ctrl->numa_node);
188 		else
189 			distance = LOCAL_DISTANCE;
190 
191 		switch (ns->ana_state) {
192 		case NVME_ANA_OPTIMIZED:
193 			if (distance < found_distance) {
194 				found_distance = distance;
195 				found = ns;
196 			}
197 			break;
198 		case NVME_ANA_NONOPTIMIZED:
199 			if (distance < fallback_distance) {
200 				fallback_distance = distance;
201 				fallback = ns;
202 			}
203 			break;
204 		default:
205 			break;
206 		}
207 	}
208 
209 	if (!found)
210 		found = fallback;
211 	if (found)
212 		rcu_assign_pointer(head->current_path[node], found);
213 	return found;
214 }
215 
nvme_next_ns(struct nvme_ns_head * head,struct nvme_ns * ns)216 static struct nvme_ns *nvme_next_ns(struct nvme_ns_head *head,
217 		struct nvme_ns *ns)
218 {
219 	ns = list_next_or_null_rcu(&head->list, &ns->siblings, struct nvme_ns,
220 			siblings);
221 	if (ns)
222 		return ns;
223 	return list_first_or_null_rcu(&head->list, struct nvme_ns, siblings);
224 }
225 
nvme_round_robin_path(struct nvme_ns_head * head,int node,struct nvme_ns * old)226 static struct nvme_ns *nvme_round_robin_path(struct nvme_ns_head *head,
227 		int node, struct nvme_ns *old)
228 {
229 	struct nvme_ns *ns, *found, *fallback = NULL;
230 
231 	if (list_is_singular(&head->list)) {
232 		if (nvme_path_is_disabled(old))
233 			return NULL;
234 		return old;
235 	}
236 
237 	for (ns = nvme_next_ns(head, old);
238 	     ns != old;
239 	     ns = nvme_next_ns(head, ns)) {
240 		if (nvme_path_is_disabled(ns))
241 			continue;
242 
243 		if (ns->ana_state == NVME_ANA_OPTIMIZED) {
244 			found = ns;
245 			goto out;
246 		}
247 		if (ns->ana_state == NVME_ANA_NONOPTIMIZED)
248 			fallback = ns;
249 	}
250 
251 	if (!fallback)
252 		return NULL;
253 	found = fallback;
254 out:
255 	rcu_assign_pointer(head->current_path[node], found);
256 	return found;
257 }
258 
nvme_path_is_optimized(struct nvme_ns * ns)259 static inline bool nvme_path_is_optimized(struct nvme_ns *ns)
260 {
261 	return ns->ctrl->state == NVME_CTRL_LIVE &&
262 		ns->ana_state == NVME_ANA_OPTIMIZED;
263 }
264 
nvme_find_path(struct nvme_ns_head * head)265 inline struct nvme_ns *nvme_find_path(struct nvme_ns_head *head)
266 {
267 	int node = numa_node_id();
268 	struct nvme_ns *ns;
269 
270 	ns = srcu_dereference(head->current_path[node], &head->srcu);
271 	if (READ_ONCE(head->subsys->iopolicy) == NVME_IOPOLICY_RR && ns)
272 		ns = nvme_round_robin_path(head, node, ns);
273 	if (unlikely(!ns || !nvme_path_is_optimized(ns)))
274 		ns = __nvme_find_path(head, node);
275 	return ns;
276 }
277 
nvme_available_path(struct nvme_ns_head * head)278 static bool nvme_available_path(struct nvme_ns_head *head)
279 {
280 	struct nvme_ns *ns;
281 
282 	list_for_each_entry_rcu(ns, &head->list, siblings) {
283 		switch (ns->ctrl->state) {
284 		case NVME_CTRL_LIVE:
285 		case NVME_CTRL_RESETTING:
286 		case NVME_CTRL_CONNECTING:
287 			/* fallthru */
288 			return true;
289 		default:
290 			break;
291 		}
292 	}
293 	return false;
294 }
295 
nvme_ns_head_make_request(struct request_queue * q,struct bio * bio)296 static blk_qc_t nvme_ns_head_make_request(struct request_queue *q,
297 		struct bio *bio)
298 {
299 	struct nvme_ns_head *head = q->queuedata;
300 	struct device *dev = disk_to_dev(head->disk);
301 	struct nvme_ns *ns;
302 	blk_qc_t ret = BLK_QC_T_NONE;
303 	int srcu_idx;
304 
305 	/*
306 	 * The namespace might be going away and the bio might
307 	 * be moved to a different queue via blk_steal_bios(),
308 	 * so we need to use the bio_split pool from the original
309 	 * queue to allocate the bvecs from.
310 	 */
311 	blk_queue_split(q, &bio);
312 
313 	srcu_idx = srcu_read_lock(&head->srcu);
314 	ns = nvme_find_path(head);
315 	if (likely(ns)) {
316 		bio->bi_disk = ns->disk;
317 		bio->bi_opf |= REQ_NVME_MPATH;
318 		trace_block_bio_remap(bio->bi_disk->queue, bio,
319 				      disk_devt(ns->head->disk),
320 				      bio->bi_iter.bi_sector);
321 		ret = direct_make_request(bio);
322 	} else if (nvme_available_path(head)) {
323 		dev_warn_ratelimited(dev, "no usable path - requeuing I/O\n");
324 
325 		spin_lock_irq(&head->requeue_lock);
326 		bio_list_add(&head->requeue_list, bio);
327 		spin_unlock_irq(&head->requeue_lock);
328 	} else {
329 		dev_warn_ratelimited(dev, "no available path - failing I/O\n");
330 
331 		bio->bi_status = BLK_STS_IOERR;
332 		bio_endio(bio);
333 	}
334 
335 	srcu_read_unlock(&head->srcu, srcu_idx);
336 	return ret;
337 }
338 
nvme_requeue_work(struct work_struct * work)339 static void nvme_requeue_work(struct work_struct *work)
340 {
341 	struct nvme_ns_head *head =
342 		container_of(work, struct nvme_ns_head, requeue_work);
343 	struct bio *bio, *next;
344 
345 	spin_lock_irq(&head->requeue_lock);
346 	next = bio_list_get(&head->requeue_list);
347 	spin_unlock_irq(&head->requeue_lock);
348 
349 	while ((bio = next) != NULL) {
350 		next = bio->bi_next;
351 		bio->bi_next = NULL;
352 
353 		/*
354 		 * Reset disk to the mpath node and resubmit to select a new
355 		 * path.
356 		 */
357 		bio->bi_disk = head->disk;
358 		generic_make_request(bio);
359 	}
360 }
361 
nvme_mpath_alloc_disk(struct nvme_ctrl * ctrl,struct nvme_ns_head * head)362 int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl, struct nvme_ns_head *head)
363 {
364 	struct request_queue *q;
365 	bool vwc = false;
366 
367 	mutex_init(&head->lock);
368 	bio_list_init(&head->requeue_list);
369 	spin_lock_init(&head->requeue_lock);
370 	INIT_WORK(&head->requeue_work, nvme_requeue_work);
371 
372 	/*
373 	 * Add a multipath node if the subsystems supports multiple controllers.
374 	 * We also do this for private namespaces as the namespace sharing data could
375 	 * change after a rescan.
376 	 */
377 	if (!(ctrl->subsys->cmic & (1 << 1)) || !multipath)
378 		return 0;
379 
380 	q = blk_alloc_queue_node(GFP_KERNEL, ctrl->numa_node);
381 	if (!q)
382 		goto out;
383 	q->queuedata = head;
384 	blk_queue_make_request(q, nvme_ns_head_make_request);
385 	blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
386 	/* set to a default value for 512 until disk is validated */
387 	blk_queue_logical_block_size(q, 512);
388 	blk_set_stacking_limits(&q->limits);
389 
390 	/* we need to propagate up the VMC settings */
391 	if (ctrl->vwc & NVME_CTRL_VWC_PRESENT)
392 		vwc = true;
393 	blk_queue_write_cache(q, vwc, vwc);
394 
395 	head->disk = alloc_disk(0);
396 	if (!head->disk)
397 		goto out_cleanup_queue;
398 	head->disk->fops = &nvme_ns_head_ops;
399 	head->disk->private_data = head;
400 	head->disk->queue = q;
401 	head->disk->flags = GENHD_FL_EXT_DEVT;
402 	sprintf(head->disk->disk_name, "nvme%dn%d",
403 			ctrl->subsys->instance, head->instance);
404 	return 0;
405 
406 out_cleanup_queue:
407 	blk_cleanup_queue(q);
408 out:
409 	return -ENOMEM;
410 }
411 
nvme_mpath_set_live(struct nvme_ns * ns)412 static void nvme_mpath_set_live(struct nvme_ns *ns)
413 {
414 	struct nvme_ns_head *head = ns->head;
415 
416 	lockdep_assert_held(&ns->head->lock);
417 
418 	if (!head->disk)
419 		return;
420 
421 	if (!(head->disk->flags & GENHD_FL_UP))
422 		device_add_disk(&head->subsys->dev, head->disk,
423 				nvme_ns_id_attr_groups);
424 
425 	if (nvme_path_is_optimized(ns)) {
426 		int node, srcu_idx;
427 
428 		srcu_idx = srcu_read_lock(&head->srcu);
429 		for_each_node(node)
430 			__nvme_find_path(head, node);
431 		srcu_read_unlock(&head->srcu, srcu_idx);
432 	}
433 
434 	synchronize_srcu(&ns->head->srcu);
435 	kblockd_schedule_work(&ns->head->requeue_work);
436 }
437 
nvme_parse_ana_log(struct nvme_ctrl * ctrl,void * data,int (* cb)(struct nvme_ctrl * ctrl,struct nvme_ana_group_desc *,void *))438 static int nvme_parse_ana_log(struct nvme_ctrl *ctrl, void *data,
439 		int (*cb)(struct nvme_ctrl *ctrl, struct nvme_ana_group_desc *,
440 			void *))
441 {
442 	void *base = ctrl->ana_log_buf;
443 	size_t offset = sizeof(struct nvme_ana_rsp_hdr);
444 	int error, i;
445 
446 	lockdep_assert_held(&ctrl->ana_lock);
447 
448 	for (i = 0; i < le16_to_cpu(ctrl->ana_log_buf->ngrps); i++) {
449 		struct nvme_ana_group_desc *desc = base + offset;
450 		u32 nr_nsids = le32_to_cpu(desc->nnsids);
451 		size_t nsid_buf_size = nr_nsids * sizeof(__le32);
452 
453 		if (WARN_ON_ONCE(desc->grpid == 0))
454 			return -EINVAL;
455 		if (WARN_ON_ONCE(le32_to_cpu(desc->grpid) > ctrl->anagrpmax))
456 			return -EINVAL;
457 		if (WARN_ON_ONCE(desc->state == 0))
458 			return -EINVAL;
459 		if (WARN_ON_ONCE(desc->state > NVME_ANA_CHANGE))
460 			return -EINVAL;
461 
462 		offset += sizeof(*desc);
463 		if (WARN_ON_ONCE(offset > ctrl->ana_log_size - nsid_buf_size))
464 			return -EINVAL;
465 
466 		error = cb(ctrl, desc, data);
467 		if (error)
468 			return error;
469 
470 		offset += nsid_buf_size;
471 		if (WARN_ON_ONCE(offset > ctrl->ana_log_size - sizeof(*desc)))
472 			return -EINVAL;
473 	}
474 
475 	return 0;
476 }
477 
nvme_state_is_live(enum nvme_ana_state state)478 static inline bool nvme_state_is_live(enum nvme_ana_state state)
479 {
480 	return state == NVME_ANA_OPTIMIZED || state == NVME_ANA_NONOPTIMIZED;
481 }
482 
nvme_update_ns_ana_state(struct nvme_ana_group_desc * desc,struct nvme_ns * ns)483 static void nvme_update_ns_ana_state(struct nvme_ana_group_desc *desc,
484 		struct nvme_ns *ns)
485 {
486 	mutex_lock(&ns->head->lock);
487 	ns->ana_grpid = le32_to_cpu(desc->grpid);
488 	ns->ana_state = desc->state;
489 	clear_bit(NVME_NS_ANA_PENDING, &ns->flags);
490 
491 	if (nvme_state_is_live(ns->ana_state))
492 		nvme_mpath_set_live(ns);
493 	mutex_unlock(&ns->head->lock);
494 }
495 
nvme_update_ana_state(struct nvme_ctrl * ctrl,struct nvme_ana_group_desc * desc,void * data)496 static int nvme_update_ana_state(struct nvme_ctrl *ctrl,
497 		struct nvme_ana_group_desc *desc, void *data)
498 {
499 	u32 nr_nsids = le32_to_cpu(desc->nnsids), n = 0;
500 	unsigned *nr_change_groups = data;
501 	struct nvme_ns *ns;
502 
503 	dev_dbg(ctrl->device, "ANA group %d: %s.\n",
504 			le32_to_cpu(desc->grpid),
505 			nvme_ana_state_names[desc->state]);
506 
507 	if (desc->state == NVME_ANA_CHANGE)
508 		(*nr_change_groups)++;
509 
510 	if (!nr_nsids)
511 		return 0;
512 
513 	down_write(&ctrl->namespaces_rwsem);
514 	list_for_each_entry(ns, &ctrl->namespaces, list) {
515 		unsigned nsid = le32_to_cpu(desc->nsids[n]);
516 
517 		if (ns->head->ns_id < nsid)
518 			continue;
519 		if (ns->head->ns_id == nsid)
520 			nvme_update_ns_ana_state(desc, ns);
521 		if (++n == nr_nsids)
522 			break;
523 	}
524 	up_write(&ctrl->namespaces_rwsem);
525 	return 0;
526 }
527 
nvme_read_ana_log(struct nvme_ctrl * ctrl)528 static int nvme_read_ana_log(struct nvme_ctrl *ctrl)
529 {
530 	u32 nr_change_groups = 0;
531 	int error;
532 
533 	mutex_lock(&ctrl->ana_lock);
534 	error = nvme_get_log(ctrl, NVME_NSID_ALL, NVME_LOG_ANA, 0,
535 			ctrl->ana_log_buf, ctrl->ana_log_size, 0);
536 	if (error) {
537 		dev_warn(ctrl->device, "Failed to get ANA log: %d\n", error);
538 		goto out_unlock;
539 	}
540 
541 	error = nvme_parse_ana_log(ctrl, &nr_change_groups,
542 			nvme_update_ana_state);
543 	if (error)
544 		goto out_unlock;
545 
546 	/*
547 	 * In theory we should have an ANATT timer per group as they might enter
548 	 * the change state at different times.  But that is a lot of overhead
549 	 * just to protect against a target that keeps entering new changes
550 	 * states while never finishing previous ones.  But we'll still
551 	 * eventually time out once all groups are in change state, so this
552 	 * isn't a big deal.
553 	 *
554 	 * We also double the ANATT value to provide some slack for transports
555 	 * or AEN processing overhead.
556 	 */
557 	if (nr_change_groups)
558 		mod_timer(&ctrl->anatt_timer, ctrl->anatt * HZ * 2 + jiffies);
559 	else
560 		del_timer_sync(&ctrl->anatt_timer);
561 out_unlock:
562 	mutex_unlock(&ctrl->ana_lock);
563 	return error;
564 }
565 
nvme_ana_work(struct work_struct * work)566 static void nvme_ana_work(struct work_struct *work)
567 {
568 	struct nvme_ctrl *ctrl = container_of(work, struct nvme_ctrl, ana_work);
569 
570 	nvme_read_ana_log(ctrl);
571 }
572 
nvme_anatt_timeout(struct timer_list * t)573 static void nvme_anatt_timeout(struct timer_list *t)
574 {
575 	struct nvme_ctrl *ctrl = from_timer(ctrl, t, anatt_timer);
576 
577 	dev_info(ctrl->device, "ANATT timeout, resetting controller.\n");
578 	nvme_reset_ctrl(ctrl);
579 }
580 
nvme_mpath_stop(struct nvme_ctrl * ctrl)581 void nvme_mpath_stop(struct nvme_ctrl *ctrl)
582 {
583 	if (!nvme_ctrl_use_ana(ctrl))
584 		return;
585 	del_timer_sync(&ctrl->anatt_timer);
586 	cancel_work_sync(&ctrl->ana_work);
587 }
588 
589 #define SUBSYS_ATTR_RW(_name, _mode, _show, _store)  \
590 	struct device_attribute subsys_attr_##_name =	\
591 		__ATTR(_name, _mode, _show, _store)
592 
593 static const char *nvme_iopolicy_names[] = {
594 	[NVME_IOPOLICY_NUMA]	= "numa",
595 	[NVME_IOPOLICY_RR]	= "round-robin",
596 };
597 
nvme_subsys_iopolicy_show(struct device * dev,struct device_attribute * attr,char * buf)598 static ssize_t nvme_subsys_iopolicy_show(struct device *dev,
599 		struct device_attribute *attr, char *buf)
600 {
601 	struct nvme_subsystem *subsys =
602 		container_of(dev, struct nvme_subsystem, dev);
603 
604 	return sprintf(buf, "%s\n",
605 			nvme_iopolicy_names[READ_ONCE(subsys->iopolicy)]);
606 }
607 
nvme_subsys_iopolicy_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)608 static ssize_t nvme_subsys_iopolicy_store(struct device *dev,
609 		struct device_attribute *attr, const char *buf, size_t count)
610 {
611 	struct nvme_subsystem *subsys =
612 		container_of(dev, struct nvme_subsystem, dev);
613 	int i;
614 
615 	for (i = 0; i < ARRAY_SIZE(nvme_iopolicy_names); i++) {
616 		if (sysfs_streq(buf, nvme_iopolicy_names[i])) {
617 			WRITE_ONCE(subsys->iopolicy, i);
618 			return count;
619 		}
620 	}
621 
622 	return -EINVAL;
623 }
624 SUBSYS_ATTR_RW(iopolicy, S_IRUGO | S_IWUSR,
625 		      nvme_subsys_iopolicy_show, nvme_subsys_iopolicy_store);
626 
ana_grpid_show(struct device * dev,struct device_attribute * attr,char * buf)627 static ssize_t ana_grpid_show(struct device *dev, struct device_attribute *attr,
628 		char *buf)
629 {
630 	return sprintf(buf, "%d\n", nvme_get_ns_from_dev(dev)->ana_grpid);
631 }
632 DEVICE_ATTR_RO(ana_grpid);
633 
ana_state_show(struct device * dev,struct device_attribute * attr,char * buf)634 static ssize_t ana_state_show(struct device *dev, struct device_attribute *attr,
635 		char *buf)
636 {
637 	struct nvme_ns *ns = nvme_get_ns_from_dev(dev);
638 
639 	return sprintf(buf, "%s\n", nvme_ana_state_names[ns->ana_state]);
640 }
641 DEVICE_ATTR_RO(ana_state);
642 
nvme_set_ns_ana_state(struct nvme_ctrl * ctrl,struct nvme_ana_group_desc * desc,void * data)643 static int nvme_set_ns_ana_state(struct nvme_ctrl *ctrl,
644 		struct nvme_ana_group_desc *desc, void *data)
645 {
646 	struct nvme_ns *ns = data;
647 
648 	if (ns->ana_grpid == le32_to_cpu(desc->grpid)) {
649 		nvme_update_ns_ana_state(desc, ns);
650 		return -ENXIO; /* just break out of the loop */
651 	}
652 
653 	return 0;
654 }
655 
nvme_mpath_add_disk(struct nvme_ns * ns,struct nvme_id_ns * id)656 void nvme_mpath_add_disk(struct nvme_ns *ns, struct nvme_id_ns *id)
657 {
658 	if (nvme_ctrl_use_ana(ns->ctrl)) {
659 		mutex_lock(&ns->ctrl->ana_lock);
660 		ns->ana_grpid = le32_to_cpu(id->anagrpid);
661 		nvme_parse_ana_log(ns->ctrl, ns, nvme_set_ns_ana_state);
662 		mutex_unlock(&ns->ctrl->ana_lock);
663 	} else {
664 		mutex_lock(&ns->head->lock);
665 		ns->ana_state = NVME_ANA_OPTIMIZED;
666 		nvme_mpath_set_live(ns);
667 		mutex_unlock(&ns->head->lock);
668 	}
669 }
670 
nvme_mpath_remove_disk(struct nvme_ns_head * head)671 void nvme_mpath_remove_disk(struct nvme_ns_head *head)
672 {
673 	if (!head->disk)
674 		return;
675 	if (head->disk->flags & GENHD_FL_UP)
676 		del_gendisk(head->disk);
677 	blk_set_queue_dying(head->disk->queue);
678 	/* make sure all pending bios are cleaned up */
679 	kblockd_schedule_work(&head->requeue_work);
680 	flush_work(&head->requeue_work);
681 	blk_cleanup_queue(head->disk->queue);
682 	put_disk(head->disk);
683 }
684 
nvme_mpath_init(struct nvme_ctrl * ctrl,struct nvme_id_ctrl * id)685 int nvme_mpath_init(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id)
686 {
687 	int error;
688 
689 	/* check if multipath is enabled and we have the capability */
690 	if (!multipath || !ctrl->subsys || !(ctrl->subsys->cmic & (1 << 3)))
691 		return 0;
692 
693 	ctrl->anacap = id->anacap;
694 	ctrl->anatt = id->anatt;
695 	ctrl->nanagrpid = le32_to_cpu(id->nanagrpid);
696 	ctrl->anagrpmax = le32_to_cpu(id->anagrpmax);
697 
698 	mutex_init(&ctrl->ana_lock);
699 	timer_setup(&ctrl->anatt_timer, nvme_anatt_timeout, 0);
700 	ctrl->ana_log_size = sizeof(struct nvme_ana_rsp_hdr) +
701 		ctrl->nanagrpid * sizeof(struct nvme_ana_group_desc);
702 	ctrl->ana_log_size += ctrl->max_namespaces * sizeof(__le32);
703 
704 	if (ctrl->ana_log_size > ctrl->max_hw_sectors << SECTOR_SHIFT) {
705 		dev_err(ctrl->device,
706 			"ANA log page size (%zd) larger than MDTS (%d).\n",
707 			ctrl->ana_log_size,
708 			ctrl->max_hw_sectors << SECTOR_SHIFT);
709 		dev_err(ctrl->device, "disabling ANA support.\n");
710 		return 0;
711 	}
712 
713 	INIT_WORK(&ctrl->ana_work, nvme_ana_work);
714 	ctrl->ana_log_buf = kmalloc(ctrl->ana_log_size, GFP_KERNEL);
715 	if (!ctrl->ana_log_buf) {
716 		error = -ENOMEM;
717 		goto out;
718 	}
719 
720 	error = nvme_read_ana_log(ctrl);
721 	if (error)
722 		goto out_free_ana_log_buf;
723 	return 0;
724 out_free_ana_log_buf:
725 	kfree(ctrl->ana_log_buf);
726 	ctrl->ana_log_buf = NULL;
727 out:
728 	return error;
729 }
730 
nvme_mpath_uninit(struct nvme_ctrl * ctrl)731 void nvme_mpath_uninit(struct nvme_ctrl *ctrl)
732 {
733 	kfree(ctrl->ana_log_buf);
734 	ctrl->ana_log_buf = NULL;
735 }
736 
737