1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2017 Western Digital Corporation or its affiliates.
4 *
5 * This file is released under the GPL.
6 */
7
8#include "dm-zoned.h"
9
10#include <linux/module.h>
11
12#define	DM_MSG_PREFIX		"zoned"
13
14#define DMZ_MIN_BIOS		8192
15
16/*
17 * Zone BIO context.
18 */
19struct dmz_bioctx {
20	struct dmz_dev		*dev;
21	struct dm_zone		*zone;
22	struct bio		*bio;
23	refcount_t		ref;
24};
25
26/*
27 * Chunk work descriptor.
28 */
29struct dm_chunk_work {
30	struct work_struct	work;
31	refcount_t		refcount;
32	struct dmz_target	*target;
33	unsigned int		chunk;
34	struct bio_list		bio_list;
35};
36
37/*
38 * Target descriptor.
39 */
40struct dmz_target {
41	struct dm_dev		**ddev;
42	unsigned int		nr_ddevs;
43
44	unsigned int		flags;
45
46	/* Zoned block device information */
47	struct dmz_dev		*dev;
48
49	/* For metadata handling */
50	struct dmz_metadata     *metadata;
51
52	/* For chunk work */
53	struct radix_tree_root	chunk_rxtree;
54	struct workqueue_struct *chunk_wq;
55	struct mutex		chunk_lock;
56
57	/* For cloned BIOs to zones */
58	struct bio_set		bio_set;
59
60	/* For flush */
61	spinlock_t		flush_lock;
62	struct bio_list		flush_list;
63	struct delayed_work	flush_work;
64	struct workqueue_struct *flush_wq;
65};
66
67/*
68 * Flush intervals (seconds).
69 */
70#define DMZ_FLUSH_PERIOD	(10 * HZ)
71
72/*
73 * Target BIO completion.
74 */
75static inline void dmz_bio_endio(struct bio *bio, blk_status_t status)
76{
77	struct dmz_bioctx *bioctx =
78		dm_per_bio_data(bio, sizeof(struct dmz_bioctx));
79
80	if (status != BLK_STS_OK && bio->bi_status == BLK_STS_OK)
81		bio->bi_status = status;
82	if (bioctx->dev && bio->bi_status != BLK_STS_OK)
83		bioctx->dev->flags |= DMZ_CHECK_BDEV;
84
85	if (refcount_dec_and_test(&bioctx->ref)) {
86		struct dm_zone *zone = bioctx->zone;
87
88		if (zone) {
89			if (bio->bi_status != BLK_STS_OK &&
90			    bio_op(bio) == REQ_OP_WRITE &&
91			    dmz_is_seq(zone))
92				set_bit(DMZ_SEQ_WRITE_ERR, &zone->flags);
93			dmz_deactivate_zone(zone);
94		}
95		bio_endio(bio);
96	}
97}
98
99/*
100 * Completion callback for an internally cloned target BIO. This terminates the
101 * target BIO when there are no more references to its context.
102 */
103static void dmz_clone_endio(struct bio *clone)
104{
105	struct dmz_bioctx *bioctx = clone->bi_private;
106	blk_status_t status = clone->bi_status;
107
108	bio_put(clone);
109	dmz_bio_endio(bioctx->bio, status);
110}
111
112/*
113 * Issue a clone of a target BIO. The clone may only partially process the
114 * original target BIO.
115 */
116static int dmz_submit_bio(struct dmz_target *dmz, struct dm_zone *zone,
117			  struct bio *bio, sector_t chunk_block,
118			  unsigned int nr_blocks)
119{
120	struct dmz_bioctx *bioctx =
121		dm_per_bio_data(bio, sizeof(struct dmz_bioctx));
122	struct dmz_dev *dev = zone->dev;
123	struct bio *clone;
124
125	if (dev->flags & DMZ_BDEV_DYING)
126		return -EIO;
127
128	clone = bio_clone_fast(bio, GFP_NOIO, &dmz->bio_set);
129	if (!clone)
130		return -ENOMEM;
131
132	bio_set_dev(clone, dev->bdev);
133	bioctx->dev = dev;
134	clone->bi_iter.bi_sector =
135		dmz_start_sect(dmz->metadata, zone) + dmz_blk2sect(chunk_block);
136	clone->bi_iter.bi_size = dmz_blk2sect(nr_blocks) << SECTOR_SHIFT;
137	clone->bi_end_io = dmz_clone_endio;
138	clone->bi_private = bioctx;
139
140	bio_advance(bio, clone->bi_iter.bi_size);
141
142	refcount_inc(&bioctx->ref);
143	submit_bio_noacct(clone);
144
145	if (bio_op(bio) == REQ_OP_WRITE && dmz_is_seq(zone))
146		zone->wp_block += nr_blocks;
147
148	return 0;
149}
150
151/*
152 * Zero out pages of discarded blocks accessed by a read BIO.
153 */
154static void dmz_handle_read_zero(struct dmz_target *dmz, struct bio *bio,
155				 sector_t chunk_block, unsigned int nr_blocks)
156{
157	unsigned int size = nr_blocks << DMZ_BLOCK_SHIFT;
158
159	/* Clear nr_blocks */
160	swap(bio->bi_iter.bi_size, size);
161	zero_fill_bio(bio);
162	swap(bio->bi_iter.bi_size, size);
163
164	bio_advance(bio, size);
165}
166
167/*
168 * Process a read BIO.
169 */
170static int dmz_handle_read(struct dmz_target *dmz, struct dm_zone *zone,
171			   struct bio *bio)
172{
173	struct dmz_metadata *zmd = dmz->metadata;
174	sector_t chunk_block = dmz_chunk_block(zmd, dmz_bio_block(bio));
175	unsigned int nr_blocks = dmz_bio_blocks(bio);
176	sector_t end_block = chunk_block + nr_blocks;
177	struct dm_zone *rzone, *bzone;
178	int ret;
179
180	/* Read into unmapped chunks need only zeroing the BIO buffer */
181	if (!zone) {
182		zero_fill_bio(bio);
183		return 0;
184	}
185
186	DMDEBUG("(%s): READ chunk %llu -> %s zone %u, block %llu, %u blocks",
187		dmz_metadata_label(zmd),
188		(unsigned long long)dmz_bio_chunk(zmd, bio),
189		(dmz_is_rnd(zone) ? "RND" :
190		 (dmz_is_cache(zone) ? "CACHE" : "SEQ")),
191		zone->id,
192		(unsigned long long)chunk_block, nr_blocks);
193
194	/* Check block validity to determine the read location */
195	bzone = zone->bzone;
196	while (chunk_block < end_block) {
197		nr_blocks = 0;
198		if (dmz_is_rnd(zone) || dmz_is_cache(zone) ||
199		    chunk_block < zone->wp_block) {
200			/* Test block validity in the data zone */
201			ret = dmz_block_valid(zmd, zone, chunk_block);
202			if (ret < 0)
203				return ret;
204			if (ret > 0) {
205				/* Read data zone blocks */
206				nr_blocks = ret;
207				rzone = zone;
208			}
209		}
210
211		/*
212		 * No valid blocks found in the data zone.
213		 * Check the buffer zone, if there is one.
214		 */
215		if (!nr_blocks && bzone) {
216			ret = dmz_block_valid(zmd, bzone, chunk_block);
217			if (ret < 0)
218				return ret;
219			if (ret > 0) {
220				/* Read buffer zone blocks */
221				nr_blocks = ret;
222				rzone = bzone;
223			}
224		}
225
226		if (nr_blocks) {
227			/* Valid blocks found: read them */
228			nr_blocks = min_t(unsigned int, nr_blocks,
229					  end_block - chunk_block);
230			ret = dmz_submit_bio(dmz, rzone, bio,
231					     chunk_block, nr_blocks);
232			if (ret)
233				return ret;
234			chunk_block += nr_blocks;
235		} else {
236			/* No valid block: zeroout the current BIO block */
237			dmz_handle_read_zero(dmz, bio, chunk_block, 1);
238			chunk_block++;
239		}
240	}
241
242	return 0;
243}
244
245/*
246 * Write blocks directly in a data zone, at the write pointer.
247 * If a buffer zone is assigned, invalidate the blocks written
248 * in place.
249 */
250static int dmz_handle_direct_write(struct dmz_target *dmz,
251				   struct dm_zone *zone, struct bio *bio,
252				   sector_t chunk_block,
253				   unsigned int nr_blocks)
254{
255	struct dmz_metadata *zmd = dmz->metadata;
256	struct dm_zone *bzone = zone->bzone;
257	int ret;
258
259	if (dmz_is_readonly(zone))
260		return -EROFS;
261
262	/* Submit write */
263	ret = dmz_submit_bio(dmz, zone, bio, chunk_block, nr_blocks);
264	if (ret)
265		return ret;
266
267	/*
268	 * Validate the blocks in the data zone and invalidate
269	 * in the buffer zone, if there is one.
270	 */
271	ret = dmz_validate_blocks(zmd, zone, chunk_block, nr_blocks);
272	if (ret == 0 && bzone)
273		ret = dmz_invalidate_blocks(zmd, bzone, chunk_block, nr_blocks);
274
275	return ret;
276}
277
278/*
279 * Write blocks in the buffer zone of @zone.
280 * If no buffer zone is assigned yet, get one.
281 * Called with @zone write locked.
282 */
283static int dmz_handle_buffered_write(struct dmz_target *dmz,
284				     struct dm_zone *zone, struct bio *bio,
285				     sector_t chunk_block,
286				     unsigned int nr_blocks)
287{
288	struct dmz_metadata *zmd = dmz->metadata;
289	struct dm_zone *bzone;
290	int ret;
291
292	/* Get the buffer zone. One will be allocated if needed */
293	bzone = dmz_get_chunk_buffer(zmd, zone);
294	if (IS_ERR(bzone))
295		return PTR_ERR(bzone);
296
297	if (dmz_is_readonly(bzone))
298		return -EROFS;
299
300	/* Submit write */
301	ret = dmz_submit_bio(dmz, bzone, bio, chunk_block, nr_blocks);
302	if (ret)
303		return ret;
304
305	/*
306	 * Validate the blocks in the buffer zone
307	 * and invalidate in the data zone.
308	 */
309	ret = dmz_validate_blocks(zmd, bzone, chunk_block, nr_blocks);
310	if (ret == 0 && chunk_block < zone->wp_block)
311		ret = dmz_invalidate_blocks(zmd, zone, chunk_block, nr_blocks);
312
313	return ret;
314}
315
316/*
317 * Process a write BIO.
318 */
319static int dmz_handle_write(struct dmz_target *dmz, struct dm_zone *zone,
320			    struct bio *bio)
321{
322	struct dmz_metadata *zmd = dmz->metadata;
323	sector_t chunk_block = dmz_chunk_block(zmd, dmz_bio_block(bio));
324	unsigned int nr_blocks = dmz_bio_blocks(bio);
325
326	if (!zone)
327		return -ENOSPC;
328
329	DMDEBUG("(%s): WRITE chunk %llu -> %s zone %u, block %llu, %u blocks",
330		dmz_metadata_label(zmd),
331		(unsigned long long)dmz_bio_chunk(zmd, bio),
332		(dmz_is_rnd(zone) ? "RND" :
333		 (dmz_is_cache(zone) ? "CACHE" : "SEQ")),
334		zone->id,
335		(unsigned long long)chunk_block, nr_blocks);
336
337	if (dmz_is_rnd(zone) || dmz_is_cache(zone) ||
338	    chunk_block == zone->wp_block) {
339		/*
340		 * zone is a random zone or it is a sequential zone
341		 * and the BIO is aligned to the zone write pointer:
342		 * direct write the zone.
343		 */
344		return dmz_handle_direct_write(dmz, zone, bio,
345					       chunk_block, nr_blocks);
346	}
347
348	/*
349	 * This is an unaligned write in a sequential zone:
350	 * use buffered write.
351	 */
352	return dmz_handle_buffered_write(dmz, zone, bio, chunk_block, nr_blocks);
353}
354
355/*
356 * Process a discard BIO.
357 */
358static int dmz_handle_discard(struct dmz_target *dmz, struct dm_zone *zone,
359			      struct bio *bio)
360{
361	struct dmz_metadata *zmd = dmz->metadata;
362	sector_t block = dmz_bio_block(bio);
363	unsigned int nr_blocks = dmz_bio_blocks(bio);
364	sector_t chunk_block = dmz_chunk_block(zmd, block);
365	int ret = 0;
366
367	/* For unmapped chunks, there is nothing to do */
368	if (!zone)
369		return 0;
370
371	if (dmz_is_readonly(zone))
372		return -EROFS;
373
374	DMDEBUG("(%s): DISCARD chunk %llu -> zone %u, block %llu, %u blocks",
375		dmz_metadata_label(dmz->metadata),
376		(unsigned long long)dmz_bio_chunk(zmd, bio),
377		zone->id,
378		(unsigned long long)chunk_block, nr_blocks);
379
380	/*
381	 * Invalidate blocks in the data zone and its
382	 * buffer zone if one is mapped.
383	 */
384	if (dmz_is_rnd(zone) || dmz_is_cache(zone) ||
385	    chunk_block < zone->wp_block)
386		ret = dmz_invalidate_blocks(zmd, zone, chunk_block, nr_blocks);
387	if (ret == 0 && zone->bzone)
388		ret = dmz_invalidate_blocks(zmd, zone->bzone,
389					    chunk_block, nr_blocks);
390	return ret;
391}
392
393/*
394 * Process a BIO.
395 */
396static void dmz_handle_bio(struct dmz_target *dmz, struct dm_chunk_work *cw,
397			   struct bio *bio)
398{
399	struct dmz_bioctx *bioctx =
400		dm_per_bio_data(bio, sizeof(struct dmz_bioctx));
401	struct dmz_metadata *zmd = dmz->metadata;
402	struct dm_zone *zone;
403	int ret;
404
405	dmz_lock_metadata(zmd);
406
407	/*
408	 * Get the data zone mapping the chunk. There may be no
409	 * mapping for read and discard. If a mapping is obtained,
410	 + the zone returned will be set to active state.
411	 */
412	zone = dmz_get_chunk_mapping(zmd, dmz_bio_chunk(zmd, bio),
413				     bio_op(bio));
414	if (IS_ERR(zone)) {
415		ret = PTR_ERR(zone);
416		goto out;
417	}
418
419	/* Process the BIO */
420	if (zone) {
421		dmz_activate_zone(zone);
422		bioctx->zone = zone;
423		dmz_reclaim_bio_acc(zone->dev->reclaim);
424	}
425
426	switch (bio_op(bio)) {
427	case REQ_OP_READ:
428		ret = dmz_handle_read(dmz, zone, bio);
429		break;
430	case REQ_OP_WRITE:
431		ret = dmz_handle_write(dmz, zone, bio);
432		break;
433	case REQ_OP_DISCARD:
434	case REQ_OP_WRITE_ZEROES:
435		ret = dmz_handle_discard(dmz, zone, bio);
436		break;
437	default:
438		DMERR("(%s): Unsupported BIO operation 0x%x",
439		      dmz_metadata_label(dmz->metadata), bio_op(bio));
440		ret = -EIO;
441	}
442
443	/*
444	 * Release the chunk mapping. This will check that the mapping
445	 * is still valid, that is, that the zone used still has valid blocks.
446	 */
447	if (zone)
448		dmz_put_chunk_mapping(zmd, zone);
449out:
450	dmz_bio_endio(bio, errno_to_blk_status(ret));
451
452	dmz_unlock_metadata(zmd);
453}
454
455/*
456 * Increment a chunk reference counter.
457 */
458static inline void dmz_get_chunk_work(struct dm_chunk_work *cw)
459{
460	refcount_inc(&cw->refcount);
461}
462
463/*
464 * Decrement a chunk work reference count and
465 * free it if it becomes 0.
466 */
467static void dmz_put_chunk_work(struct dm_chunk_work *cw)
468{
469	if (refcount_dec_and_test(&cw->refcount)) {
470		WARN_ON(!bio_list_empty(&cw->bio_list));
471		radix_tree_delete(&cw->target->chunk_rxtree, cw->chunk);
472		kfree(cw);
473	}
474}
475
476/*
477 * Chunk BIO work function.
478 */
479static void dmz_chunk_work(struct work_struct *work)
480{
481	struct dm_chunk_work *cw = container_of(work, struct dm_chunk_work, work);
482	struct dmz_target *dmz = cw->target;
483	struct bio *bio;
484
485	mutex_lock(&dmz->chunk_lock);
486
487	/* Process the chunk BIOs */
488	while ((bio = bio_list_pop(&cw->bio_list))) {
489		mutex_unlock(&dmz->chunk_lock);
490		dmz_handle_bio(dmz, cw, bio);
491		mutex_lock(&dmz->chunk_lock);
492		dmz_put_chunk_work(cw);
493	}
494
495	/* Queueing the work incremented the work refcount */
496	dmz_put_chunk_work(cw);
497
498	mutex_unlock(&dmz->chunk_lock);
499}
500
501/*
502 * Flush work.
503 */
504static void dmz_flush_work(struct work_struct *work)
505{
506	struct dmz_target *dmz = container_of(work, struct dmz_target, flush_work.work);
507	struct bio *bio;
508	int ret;
509
510	/* Flush dirty metadata blocks */
511	ret = dmz_flush_metadata(dmz->metadata);
512	if (ret)
513		DMDEBUG("(%s): Metadata flush failed, rc=%d",
514			dmz_metadata_label(dmz->metadata), ret);
515
516	/* Process queued flush requests */
517	while (1) {
518		spin_lock(&dmz->flush_lock);
519		bio = bio_list_pop(&dmz->flush_list);
520		spin_unlock(&dmz->flush_lock);
521
522		if (!bio)
523			break;
524
525		dmz_bio_endio(bio, errno_to_blk_status(ret));
526	}
527
528	queue_delayed_work(dmz->flush_wq, &dmz->flush_work, DMZ_FLUSH_PERIOD);
529}
530
531/*
532 * Get a chunk work and start it to process a new BIO.
533 * If the BIO chunk has no work yet, create one.
534 */
535static int dmz_queue_chunk_work(struct dmz_target *dmz, struct bio *bio)
536{
537	unsigned int chunk = dmz_bio_chunk(dmz->metadata, bio);
538	struct dm_chunk_work *cw;
539	int ret = 0;
540
541	mutex_lock(&dmz->chunk_lock);
542
543	/* Get the BIO chunk work. If one is not active yet, create one */
544	cw = radix_tree_lookup(&dmz->chunk_rxtree, chunk);
545	if (cw) {
546		dmz_get_chunk_work(cw);
547	} else {
548		/* Create a new chunk work */
549		cw = kmalloc(sizeof(struct dm_chunk_work), GFP_NOIO);
550		if (unlikely(!cw)) {
551			ret = -ENOMEM;
552			goto out;
553		}
554
555		INIT_WORK(&cw->work, dmz_chunk_work);
556		refcount_set(&cw->refcount, 1);
557		cw->target = dmz;
558		cw->chunk = chunk;
559		bio_list_init(&cw->bio_list);
560
561		ret = radix_tree_insert(&dmz->chunk_rxtree, chunk, cw);
562		if (unlikely(ret)) {
563			kfree(cw);
564			goto out;
565		}
566	}
567
568	bio_list_add(&cw->bio_list, bio);
569
570	if (queue_work(dmz->chunk_wq, &cw->work))
571		dmz_get_chunk_work(cw);
572out:
573	mutex_unlock(&dmz->chunk_lock);
574	return ret;
575}
576
577/*
578 * Check if the backing device is being removed. If it's on the way out,
579 * start failing I/O. Reclaim and metadata components also call this
580 * function to cleanly abort operation in the event of such failure.
581 */
582bool dmz_bdev_is_dying(struct dmz_dev *dmz_dev)
583{
584	if (dmz_dev->flags & DMZ_BDEV_DYING)
585		return true;
586
587	if (dmz_dev->flags & DMZ_CHECK_BDEV)
588		return !dmz_check_bdev(dmz_dev);
589
590	if (blk_queue_dying(bdev_get_queue(dmz_dev->bdev))) {
591		dmz_dev_warn(dmz_dev, "Backing device queue dying");
592		dmz_dev->flags |= DMZ_BDEV_DYING;
593	}
594
595	return dmz_dev->flags & DMZ_BDEV_DYING;
596}
597
598/*
599 * Check the backing device availability. This detects such events as
600 * backing device going offline due to errors, media removals, etc.
601 * This check is less efficient than dmz_bdev_is_dying() and should
602 * only be performed as a part of error handling.
603 */
604bool dmz_check_bdev(struct dmz_dev *dmz_dev)
605{
606	struct gendisk *disk;
607
608	dmz_dev->flags &= ~DMZ_CHECK_BDEV;
609
610	if (dmz_bdev_is_dying(dmz_dev))
611		return false;
612
613	disk = dmz_dev->bdev->bd_disk;
614	if (disk->fops->check_events &&
615	    disk->fops->check_events(disk, 0) & DISK_EVENT_MEDIA_CHANGE) {
616		dmz_dev_warn(dmz_dev, "Backing device offline");
617		dmz_dev->flags |= DMZ_BDEV_DYING;
618	}
619
620	return !(dmz_dev->flags & DMZ_BDEV_DYING);
621}
622
623/*
624 * Process a new BIO.
625 */
626static int dmz_map(struct dm_target *ti, struct bio *bio)
627{
628	struct dmz_target *dmz = ti->private;
629	struct dmz_metadata *zmd = dmz->metadata;
630	struct dmz_bioctx *bioctx = dm_per_bio_data(bio, sizeof(struct dmz_bioctx));
631	sector_t sector = bio->bi_iter.bi_sector;
632	unsigned int nr_sectors = bio_sectors(bio);
633	sector_t chunk_sector;
634	int ret;
635
636	if (dmz_dev_is_dying(zmd))
637		return DM_MAPIO_KILL;
638
639	DMDEBUG("(%s): BIO op %d sector %llu + %u => chunk %llu, block %llu, %u blocks",
640		dmz_metadata_label(zmd),
641		bio_op(bio), (unsigned long long)sector, nr_sectors,
642		(unsigned long long)dmz_bio_chunk(zmd, bio),
643		(unsigned long long)dmz_chunk_block(zmd, dmz_bio_block(bio)),
644		(unsigned int)dmz_bio_blocks(bio));
645
646	if (!nr_sectors && bio_op(bio) != REQ_OP_WRITE)
647		return DM_MAPIO_REMAPPED;
648
649	/* The BIO should be block aligned */
650	if ((nr_sectors & DMZ_BLOCK_SECTORS_MASK) || (sector & DMZ_BLOCK_SECTORS_MASK))
651		return DM_MAPIO_KILL;
652
653	/* Initialize the BIO context */
654	bioctx->dev = NULL;
655	bioctx->zone = NULL;
656	bioctx->bio = bio;
657	refcount_set(&bioctx->ref, 1);
658
659	/* Set the BIO pending in the flush list */
660	if (!nr_sectors && bio_op(bio) == REQ_OP_WRITE) {
661		spin_lock(&dmz->flush_lock);
662		bio_list_add(&dmz->flush_list, bio);
663		spin_unlock(&dmz->flush_lock);
664		mod_delayed_work(dmz->flush_wq, &dmz->flush_work, 0);
665		return DM_MAPIO_SUBMITTED;
666	}
667
668	/* Split zone BIOs to fit entirely into a zone */
669	chunk_sector = sector & (dmz_zone_nr_sectors(zmd) - 1);
670	if (chunk_sector + nr_sectors > dmz_zone_nr_sectors(zmd))
671		dm_accept_partial_bio(bio, dmz_zone_nr_sectors(zmd) - chunk_sector);
672
673	/* Now ready to handle this BIO */
674	ret = dmz_queue_chunk_work(dmz, bio);
675	if (ret) {
676		DMDEBUG("(%s): BIO op %d, can't process chunk %llu, err %i",
677			dmz_metadata_label(zmd),
678			bio_op(bio), (u64)dmz_bio_chunk(zmd, bio),
679			ret);
680		return DM_MAPIO_REQUEUE;
681	}
682
683	return DM_MAPIO_SUBMITTED;
684}
685
686/*
687 * Get zoned device information.
688 */
689static int dmz_get_zoned_device(struct dm_target *ti, char *path,
690				int idx, int nr_devs)
691{
692	struct dmz_target *dmz = ti->private;
693	struct dm_dev *ddev;
694	struct dmz_dev *dev;
695	int ret;
696	struct block_device *bdev;
697
698	/* Get the target device */
699	ret = dm_get_device(ti, path, dm_table_get_mode(ti->table), &ddev);
700	if (ret) {
701		ti->error = "Get target device failed";
702		return ret;
703	}
704
705	bdev = ddev->bdev;
706	if (bdev_zoned_model(bdev) == BLK_ZONED_NONE) {
707		if (nr_devs == 1) {
708			ti->error = "Invalid regular device";
709			goto err;
710		}
711		if (idx != 0) {
712			ti->error = "First device must be a regular device";
713			goto err;
714		}
715		if (dmz->ddev[0]) {
716			ti->error = "Too many regular devices";
717			goto err;
718		}
719		dev = &dmz->dev[idx];
720		dev->flags = DMZ_BDEV_REGULAR;
721	} else {
722		if (dmz->ddev[idx]) {
723			ti->error = "Too many zoned devices";
724			goto err;
725		}
726		if (nr_devs > 1 && idx == 0) {
727			ti->error = "First device must be a regular device";
728			goto err;
729		}
730		dev = &dmz->dev[idx];
731	}
732	dev->bdev = bdev;
733	dev->dev_idx = idx;
734	(void)bdevname(dev->bdev, dev->name);
735
736	dev->capacity = i_size_read(bdev->bd_inode) >> SECTOR_SHIFT;
737	if (ti->begin) {
738		ti->error = "Partial mapping is not supported";
739		goto err;
740	}
741
742	dmz->ddev[idx] = ddev;
743
744	return 0;
745err:
746	dm_put_device(ti, ddev);
747	return -EINVAL;
748}
749
750/*
751 * Cleanup zoned device information.
752 */
753static void dmz_put_zoned_devices(struct dm_target *ti)
754{
755	struct dmz_target *dmz = ti->private;
756	int i;
757
758	for (i = 0; i < dmz->nr_ddevs; i++)
759		if (dmz->ddev[i])
760			dm_put_device(ti, dmz->ddev[i]);
761
762	kfree(dmz->ddev);
763}
764
765static int dmz_fixup_devices(struct dm_target *ti)
766{
767	struct dmz_target *dmz = ti->private;
768	struct dmz_dev *reg_dev, *zoned_dev;
769	struct request_queue *q;
770	sector_t zone_nr_sectors = 0;
771	int i;
772
773	/*
774	 * When we have more than on devices, the first one must be a
775	 * regular block device and the others zoned block devices.
776	 */
777	if (dmz->nr_ddevs > 1) {
778		reg_dev = &dmz->dev[0];
779		if (!(reg_dev->flags & DMZ_BDEV_REGULAR)) {
780			ti->error = "Primary disk is not a regular device";
781			return -EINVAL;
782		}
783		for (i = 1; i < dmz->nr_ddevs; i++) {
784			zoned_dev = &dmz->dev[i];
785			if (zoned_dev->flags & DMZ_BDEV_REGULAR) {
786				ti->error = "Secondary disk is not a zoned device";
787				return -EINVAL;
788			}
789			q = bdev_get_queue(zoned_dev->bdev);
790			if (zone_nr_sectors &&
791			    zone_nr_sectors != blk_queue_zone_sectors(q)) {
792				ti->error = "Zone nr sectors mismatch";
793				return -EINVAL;
794			}
795			zone_nr_sectors = blk_queue_zone_sectors(q);
796			zoned_dev->zone_nr_sectors = zone_nr_sectors;
797			zoned_dev->nr_zones =
798				blkdev_nr_zones(zoned_dev->bdev->bd_disk);
799		}
800	} else {
801		reg_dev = NULL;
802		zoned_dev = &dmz->dev[0];
803		if (zoned_dev->flags & DMZ_BDEV_REGULAR) {
804			ti->error = "Disk is not a zoned device";
805			return -EINVAL;
806		}
807		q = bdev_get_queue(zoned_dev->bdev);
808		zoned_dev->zone_nr_sectors = blk_queue_zone_sectors(q);
809		zoned_dev->nr_zones = blkdev_nr_zones(zoned_dev->bdev->bd_disk);
810	}
811
812	if (reg_dev) {
813		sector_t zone_offset;
814
815		reg_dev->zone_nr_sectors = zone_nr_sectors;
816		reg_dev->nr_zones =
817			DIV_ROUND_UP_SECTOR_T(reg_dev->capacity,
818					      reg_dev->zone_nr_sectors);
819		reg_dev->zone_offset = 0;
820		zone_offset = reg_dev->nr_zones;
821		for (i = 1; i < dmz->nr_ddevs; i++) {
822			dmz->dev[i].zone_offset = zone_offset;
823			zone_offset += dmz->dev[i].nr_zones;
824		}
825	}
826	return 0;
827}
828
829/*
830 * Setup target.
831 */
832static int dmz_ctr(struct dm_target *ti, unsigned int argc, char **argv)
833{
834	struct dmz_target *dmz;
835	int ret, i;
836
837	/* Check arguments */
838	if (argc < 1) {
839		ti->error = "Invalid argument count";
840		return -EINVAL;
841	}
842
843	/* Allocate and initialize the target descriptor */
844	dmz = kzalloc(sizeof(struct dmz_target), GFP_KERNEL);
845	if (!dmz) {
846		ti->error = "Unable to allocate the zoned target descriptor";
847		return -ENOMEM;
848	}
849	dmz->dev = kcalloc(argc, sizeof(struct dmz_dev), GFP_KERNEL);
850	if (!dmz->dev) {
851		ti->error = "Unable to allocate the zoned device descriptors";
852		kfree(dmz);
853		return -ENOMEM;
854	}
855	dmz->ddev = kcalloc(argc, sizeof(struct dm_dev *), GFP_KERNEL);
856	if (!dmz->ddev) {
857		ti->error = "Unable to allocate the dm device descriptors";
858		ret = -ENOMEM;
859		goto err;
860	}
861	dmz->nr_ddevs = argc;
862
863	ti->private = dmz;
864
865	/* Get the target zoned block device */
866	for (i = 0; i < argc; i++) {
867		ret = dmz_get_zoned_device(ti, argv[i], i, argc);
868		if (ret)
869			goto err_dev;
870	}
871	ret = dmz_fixup_devices(ti);
872	if (ret)
873		goto err_dev;
874
875	/* Initialize metadata */
876	ret = dmz_ctr_metadata(dmz->dev, argc, &dmz->metadata,
877			       dm_table_device_name(ti->table));
878	if (ret) {
879		ti->error = "Metadata initialization failed";
880		goto err_dev;
881	}
882
883	/* Set target (no write same support) */
884	ti->max_io_len = dmz_zone_nr_sectors(dmz->metadata);
885	ti->num_flush_bios = 1;
886	ti->num_discard_bios = 1;
887	ti->num_write_zeroes_bios = 1;
888	ti->per_io_data_size = sizeof(struct dmz_bioctx);
889	ti->flush_supported = true;
890	ti->discards_supported = true;
891
892	/* The exposed capacity is the number of chunks that can be mapped */
893	ti->len = (sector_t)dmz_nr_chunks(dmz->metadata) <<
894		dmz_zone_nr_sectors_shift(dmz->metadata);
895
896	/* Zone BIO */
897	ret = bioset_init(&dmz->bio_set, DMZ_MIN_BIOS, 0, 0);
898	if (ret) {
899		ti->error = "Create BIO set failed";
900		goto err_meta;
901	}
902
903	/* Chunk BIO work */
904	mutex_init(&dmz->chunk_lock);
905	INIT_RADIX_TREE(&dmz->chunk_rxtree, GFP_NOIO);
906	dmz->chunk_wq = alloc_workqueue("dmz_cwq_%s",
907					WQ_MEM_RECLAIM | WQ_UNBOUND, 0,
908					dmz_metadata_label(dmz->metadata));
909	if (!dmz->chunk_wq) {
910		ti->error = "Create chunk workqueue failed";
911		ret = -ENOMEM;
912		goto err_bio;
913	}
914
915	/* Flush work */
916	spin_lock_init(&dmz->flush_lock);
917	bio_list_init(&dmz->flush_list);
918	INIT_DELAYED_WORK(&dmz->flush_work, dmz_flush_work);
919	dmz->flush_wq = alloc_ordered_workqueue("dmz_fwq_%s", WQ_MEM_RECLAIM,
920						dmz_metadata_label(dmz->metadata));
921	if (!dmz->flush_wq) {
922		ti->error = "Create flush workqueue failed";
923		ret = -ENOMEM;
924		goto err_cwq;
925	}
926	mod_delayed_work(dmz->flush_wq, &dmz->flush_work, DMZ_FLUSH_PERIOD);
927
928	/* Initialize reclaim */
929	for (i = 0; i < dmz->nr_ddevs; i++) {
930		ret = dmz_ctr_reclaim(dmz->metadata, &dmz->dev[i].reclaim, i);
931		if (ret) {
932			ti->error = "Zone reclaim initialization failed";
933			goto err_fwq;
934		}
935	}
936
937	DMINFO("(%s): Target device: %llu 512-byte logical sectors (%llu blocks)",
938	       dmz_metadata_label(dmz->metadata),
939	       (unsigned long long)ti->len,
940	       (unsigned long long)dmz_sect2blk(ti->len));
941
942	return 0;
943err_fwq:
944	destroy_workqueue(dmz->flush_wq);
945err_cwq:
946	destroy_workqueue(dmz->chunk_wq);
947err_bio:
948	mutex_destroy(&dmz->chunk_lock);
949	bioset_exit(&dmz->bio_set);
950err_meta:
951	dmz_dtr_metadata(dmz->metadata);
952err_dev:
953	dmz_put_zoned_devices(ti);
954err:
955	kfree(dmz->dev);
956	kfree(dmz);
957
958	return ret;
959}
960
961/*
962 * Cleanup target.
963 */
964static void dmz_dtr(struct dm_target *ti)
965{
966	struct dmz_target *dmz = ti->private;
967	int i;
968
969	flush_workqueue(dmz->chunk_wq);
970	destroy_workqueue(dmz->chunk_wq);
971
972	for (i = 0; i < dmz->nr_ddevs; i++)
973		dmz_dtr_reclaim(dmz->dev[i].reclaim);
974
975	cancel_delayed_work_sync(&dmz->flush_work);
976	destroy_workqueue(dmz->flush_wq);
977
978	(void) dmz_flush_metadata(dmz->metadata);
979
980	dmz_dtr_metadata(dmz->metadata);
981
982	bioset_exit(&dmz->bio_set);
983
984	dmz_put_zoned_devices(ti);
985
986	mutex_destroy(&dmz->chunk_lock);
987
988	kfree(dmz->dev);
989	kfree(dmz);
990}
991
992/*
993 * Setup target request queue limits.
994 */
995static void dmz_io_hints(struct dm_target *ti, struct queue_limits *limits)
996{
997	struct dmz_target *dmz = ti->private;
998	unsigned int chunk_sectors = dmz_zone_nr_sectors(dmz->metadata);
999
1000	limits->logical_block_size = DMZ_BLOCK_SIZE;
1001	limits->physical_block_size = DMZ_BLOCK_SIZE;
1002
1003	blk_limits_io_min(limits, DMZ_BLOCK_SIZE);
1004	blk_limits_io_opt(limits, DMZ_BLOCK_SIZE);
1005
1006	limits->discard_alignment = DMZ_BLOCK_SIZE;
1007	limits->discard_granularity = DMZ_BLOCK_SIZE;
1008	limits->max_discard_sectors = chunk_sectors;
1009	limits->max_hw_discard_sectors = chunk_sectors;
1010	limits->max_write_zeroes_sectors = chunk_sectors;
1011
1012	/* FS hint to try to align to the device zone size */
1013	limits->chunk_sectors = chunk_sectors;
1014	limits->max_sectors = chunk_sectors;
1015
1016	/* We are exposing a drive-managed zoned block device */
1017	limits->zoned = BLK_ZONED_NONE;
1018}
1019
1020/*
1021 * Pass on ioctl to the backend device.
1022 */
1023static int dmz_prepare_ioctl(struct dm_target *ti, struct block_device **bdev)
1024{
1025	struct dmz_target *dmz = ti->private;
1026	struct dmz_dev *dev = &dmz->dev[0];
1027
1028	if (!dmz_check_bdev(dev))
1029		return -EIO;
1030
1031	*bdev = dev->bdev;
1032
1033	return 0;
1034}
1035
1036/*
1037 * Stop works on suspend.
1038 */
1039static void dmz_suspend(struct dm_target *ti)
1040{
1041	struct dmz_target *dmz = ti->private;
1042	int i;
1043
1044	flush_workqueue(dmz->chunk_wq);
1045	for (i = 0; i < dmz->nr_ddevs; i++)
1046		dmz_suspend_reclaim(dmz->dev[i].reclaim);
1047	cancel_delayed_work_sync(&dmz->flush_work);
1048}
1049
1050/*
1051 * Restart works on resume or if suspend failed.
1052 */
1053static void dmz_resume(struct dm_target *ti)
1054{
1055	struct dmz_target *dmz = ti->private;
1056	int i;
1057
1058	queue_delayed_work(dmz->flush_wq, &dmz->flush_work, DMZ_FLUSH_PERIOD);
1059	for (i = 0; i < dmz->nr_ddevs; i++)
1060		dmz_resume_reclaim(dmz->dev[i].reclaim);
1061}
1062
1063static int dmz_iterate_devices(struct dm_target *ti,
1064			       iterate_devices_callout_fn fn, void *data)
1065{
1066	struct dmz_target *dmz = ti->private;
1067	unsigned int zone_nr_sectors = dmz_zone_nr_sectors(dmz->metadata);
1068	sector_t capacity;
1069	int i, r;
1070
1071	for (i = 0; i < dmz->nr_ddevs; i++) {
1072		capacity = dmz->dev[i].capacity & ~(zone_nr_sectors - 1);
1073		r = fn(ti, dmz->ddev[i], 0, capacity, data);
1074		if (r)
1075			break;
1076	}
1077	return r;
1078}
1079
1080static void dmz_status(struct dm_target *ti, status_type_t type,
1081		       unsigned int status_flags, char *result,
1082		       unsigned int maxlen)
1083{
1084	struct dmz_target *dmz = ti->private;
1085	ssize_t sz = 0;
1086	char buf[BDEVNAME_SIZE];
1087	struct dmz_dev *dev;
1088	int i;
1089
1090	switch (type) {
1091	case STATUSTYPE_INFO:
1092		DMEMIT("%u zones %u/%u cache",
1093		       dmz_nr_zones(dmz->metadata),
1094		       dmz_nr_unmap_cache_zones(dmz->metadata),
1095		       dmz_nr_cache_zones(dmz->metadata));
1096		for (i = 0; i < dmz->nr_ddevs; i++) {
1097			/*
1098			 * For a multi-device setup the first device
1099			 * contains only cache zones.
1100			 */
1101			if ((i == 0) &&
1102			    (dmz_nr_cache_zones(dmz->metadata) > 0))
1103				continue;
1104			DMEMIT(" %u/%u random %u/%u sequential",
1105			       dmz_nr_unmap_rnd_zones(dmz->metadata, i),
1106			       dmz_nr_rnd_zones(dmz->metadata, i),
1107			       dmz_nr_unmap_seq_zones(dmz->metadata, i),
1108			       dmz_nr_seq_zones(dmz->metadata, i));
1109		}
1110		break;
1111	case STATUSTYPE_TABLE:
1112		dev = &dmz->dev[0];
1113		format_dev_t(buf, dev->bdev->bd_dev);
1114		DMEMIT("%s", buf);
1115		for (i = 1; i < dmz->nr_ddevs; i++) {
1116			dev = &dmz->dev[i];
1117			format_dev_t(buf, dev->bdev->bd_dev);
1118			DMEMIT(" %s", buf);
1119		}
1120		break;
1121	}
1122	return;
1123}
1124
1125static int dmz_message(struct dm_target *ti, unsigned int argc, char **argv,
1126		       char *result, unsigned int maxlen)
1127{
1128	struct dmz_target *dmz = ti->private;
1129	int r = -EINVAL;
1130
1131	if (!strcasecmp(argv[0], "reclaim")) {
1132		int i;
1133
1134		for (i = 0; i < dmz->nr_ddevs; i++)
1135			dmz_schedule_reclaim(dmz->dev[i].reclaim);
1136		r = 0;
1137	} else
1138		DMERR("unrecognized message %s", argv[0]);
1139	return r;
1140}
1141
1142static struct target_type dmz_type = {
1143	.name		 = "zoned",
1144	.version	 = {2, 0, 0},
1145	.features	 = DM_TARGET_SINGLETON | DM_TARGET_MIXED_ZONED_MODEL,
1146	.module		 = THIS_MODULE,
1147	.ctr		 = dmz_ctr,
1148	.dtr		 = dmz_dtr,
1149	.map		 = dmz_map,
1150	.io_hints	 = dmz_io_hints,
1151	.prepare_ioctl	 = dmz_prepare_ioctl,
1152	.postsuspend	 = dmz_suspend,
1153	.resume		 = dmz_resume,
1154	.iterate_devices = dmz_iterate_devices,
1155	.status		 = dmz_status,
1156	.message	 = dmz_message,
1157};
1158
1159static int __init dmz_init(void)
1160{
1161	return dm_register_target(&dmz_type);
1162}
1163
1164static void __exit dmz_exit(void)
1165{
1166	dm_unregister_target(&dmz_type);
1167}
1168
1169module_init(dmz_init);
1170module_exit(dmz_exit);
1171
1172MODULE_DESCRIPTION(DM_NAME " target for zoned block devices");
1173MODULE_AUTHOR("Damien Le Moal <damien.lemoal@wdc.com>");
1174MODULE_LICENSE("GPL");
1175