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	#include <linux/crc32.h>
12	#include <linux/sched/mm.h>
13
14	#define DM_MSG_PREFIX "zoned metadata"
15
16	/*
17	* Metadata version.
18	*/
19	#define DMZ_META_VER 2
20
21	/*
22	* On-disk super block magic.
23	*/
24	#define DMZ_MAGIC ((((unsigned int)('D')) << 24) | \
25	(((unsigned int)('Z')) << 16) | \
26	(((unsigned int)('B')) << 8) | \
27	((unsigned int)('D')))
28
29	/*
30	* On disk super block.
31	* This uses only 512 B but uses on disk a full 4KB block. This block is
32	* followed on disk by the mapping table of chunks to zones and the bitmap
33	* blocks indicating zone block validity.
34	* The overall resulting metadata format is:
35	* (1) Super block (1 block)
36	* (2) Chunk mapping table (nr_map_blocks)
37	* (3) Bitmap blocks (nr_bitmap_blocks)
38	* All metadata blocks are stored in conventional zones, starting from
39	* the first conventional zone found on disk.
40	*/
41	struct dmz_super {
42	/* Magic number */
43	__le32 magic; /* 4 */
44
45	/* Metadata version number */
46	__le32 version; /* 8 */
47
48	/* Generation number */
49	__le64 gen; /* 16 */
50
51	/* This block number */
52	__le64 sb_block; /* 24 */
53
54	/* The number of metadata blocks, including this super block */
55	__le32 nr_meta_blocks; /* 28 */
56
57	/* The number of sequential zones reserved for reclaim */
58	__le32 nr_reserved_seq; /* 32 */
59
60	/* The number of entries in the mapping table */
61	__le32 nr_chunks; /* 36 */
62
63	/* The number of blocks used for the chunk mapping table */
64	__le32 nr_map_blocks; /* 40 */
65
66	/* The number of blocks used for the block bitmaps */
67	__le32 nr_bitmap_blocks; /* 44 */
68
69	/* Checksum */
70	__le32 crc; /* 48 */
71
72	/* DM-Zoned label */
73	u8 dmz_label[32]; /* 80 */
74
75	/* DM-Zoned UUID */
76	u8 dmz_uuid[16]; /* 96 */
77
78	/* Device UUID */
79	u8 dev_uuid[16]; /* 112 */
80
81	/* Padding to full 512B sector */
82	u8 reserved[400]; /* 512 */
83	};
84
85	/*
86	* Chunk mapping entry: entries are indexed by chunk number
87	* and give the zone ID (dzone_id) mapping the chunk on disk.
88	* This zone may be sequential or random. If it is a sequential
89	* zone, a second zone (bzone_id) used as a write buffer may
90	* also be specified. This second zone will always be a randomly
91	* writeable zone.
92	*/
93	struct dmz_map {
94	__le32 dzone_id;
95	__le32 bzone_id;
96	};
97
98	/*
99	* Chunk mapping table metadata: 512 8-bytes entries per 4KB block.
100	*/
101	#define DMZ_MAP_ENTRIES (DMZ_BLOCK_SIZE / sizeof(struct dmz_map))
102	#define DMZ_MAP_ENTRIES_SHIFT (ilog2(DMZ_MAP_ENTRIES))
103	#define DMZ_MAP_ENTRIES_MASK (DMZ_MAP_ENTRIES - 1)
104	#define DMZ_MAP_UNMAPPED UINT_MAX
105
106	/*
107	* Meta data block descriptor (for cached metadata blocks).
108	*/
109	struct dmz_mblock {
110	struct rb_node node;
111	struct list_head link;
112	sector_t no;
113	unsigned int ref;
114	unsigned long state;
115	struct page *page;
116	void *data;
117	};
118
119	/*
120	* Metadata block state flags.
121	*/
122	enum {
123	DMZ_META_DIRTY,
124	DMZ_META_READING,
125	DMZ_META_WRITING,
126	DMZ_META_ERROR,
127	};
128
129	/*
130	* Super block information (one per metadata set).
131	*/
132	struct dmz_sb {
133	sector_t block;
134	struct dmz_dev *dev;
135	struct dmz_mblock *mblk;
136	struct dmz_super *sb;
137	struct dm_zone *zone;
138	};
139
140	/*
141	* In-memory metadata.
142	*/
143	struct dmz_metadata {
144	struct dmz_dev *dev;
145	unsigned int nr_devs;
146
147	char devname[BDEVNAME_SIZE];
148	char label[BDEVNAME_SIZE];
149	uuid_t uuid;
150
151	sector_t zone_bitmap_size;
152	unsigned int zone_nr_bitmap_blocks;
153	unsigned int zone_bits_per_mblk;
154
155	sector_t zone_nr_blocks;
156	sector_t zone_nr_blocks_shift;
157
158	sector_t zone_nr_sectors;
159	sector_t zone_nr_sectors_shift;
160
161	unsigned int nr_bitmap_blocks;
162	unsigned int nr_map_blocks;
163
164	unsigned int nr_zones;
165	unsigned int nr_useable_zones;
166	unsigned int nr_meta_blocks;
167	unsigned int nr_meta_zones;
168	unsigned int nr_data_zones;
169	unsigned int nr_cache_zones;
170	unsigned int nr_rnd_zones;
171	unsigned int nr_reserved_seq;
172	unsigned int nr_chunks;
173
174	/* Zone information array */
175	struct xarray zones;
176
177	struct dmz_sb sb[2];
178	unsigned int mblk_primary;
179	unsigned int sb_version;
180	u64 sb_gen;
181	unsigned int min_nr_mblks;
182	unsigned int max_nr_mblks;
183	atomic_t nr_mblks;
184	struct rw_semaphore mblk_sem;
185	struct mutex mblk_flush_lock;
186	spinlock_t mblk_lock;
187	struct rb_root mblk_rbtree;
188	struct list_head mblk_lru_list;
189	struct list_head mblk_dirty_list;
190	struct shrinker *mblk_shrinker;
191
192	/* Zone allocation management */
193	struct mutex map_lock;
194	struct dmz_mblock **map_mblk;
195
196	unsigned int nr_cache;
197	atomic_t unmap_nr_cache;
198	struct list_head unmap_cache_list;
199	struct list_head map_cache_list;
200
201	atomic_t nr_reserved_seq_zones;
202	struct list_head reserved_seq_zones_list;
203
204	wait_queue_head_t free_wq;
205	};
206
207	#define dmz_zmd_info(zmd, format, args...) \
208	DMINFO("(%s): " format, (zmd)->label, ## args)
209
210	#define dmz_zmd_err(zmd, format, args...) \
211	DMERR("(%s): " format, (zmd)->label, ## args)
212
213	#define dmz_zmd_warn(zmd, format, args...) \
214	DMWARN("(%s): " format, (zmd)->label, ## args)
215
216	#define dmz_zmd_debug(zmd, format, args...) \
217	DMDEBUG("(%s): " format, (zmd)->label, ## args)
218	/*
219	* Various accessors
220	*/
221	static unsigned int dmz_dev_zone_id(struct dmz_metadata *zmd, struct dm_zone *zone)
222	{
223	if (WARN_ON(!zone))
224	return 0;
225
226	return zone->id - zone->dev->zone_offset;
227	}
228
229	sector_t dmz_start_sect(struct dmz_metadata *zmd, struct dm_zone *zone)
230	{
231	unsigned int zone_id = dmz_dev_zone_id(zmd, zone);
232
233	return (sector_t)zone_id << zmd->zone_nr_sectors_shift;
234	}
235
236	sector_t dmz_start_block(struct dmz_metadata *zmd, struct dm_zone *zone)
237	{
238	unsigned int zone_id = dmz_dev_zone_id(zmd, zone);
239
240	return (sector_t)zone_id << zmd->zone_nr_blocks_shift;
241	}
242
243	unsigned int dmz_zone_nr_blocks(struct dmz_metadata *zmd)
244	{
245	return zmd->zone_nr_blocks;
246	}
247
248	unsigned int dmz_zone_nr_blocks_shift(struct dmz_metadata *zmd)
249	{
250	return zmd->zone_nr_blocks_shift;
251	}
252
253	unsigned int dmz_zone_nr_sectors(struct dmz_metadata *zmd)
254	{
255	return zmd->zone_nr_sectors;
256	}
257
258	unsigned int dmz_zone_nr_sectors_shift(struct dmz_metadata *zmd)
259	{
260	return zmd->zone_nr_sectors_shift;
261	}
262
263	unsigned int dmz_nr_zones(struct dmz_metadata *zmd)
264	{
265	return zmd->nr_zones;
266	}
267
268	unsigned int dmz_nr_chunks(struct dmz_metadata *zmd)
269	{
270	return zmd->nr_chunks;
271	}
272
273	unsigned int dmz_nr_rnd_zones(struct dmz_metadata *zmd, int idx)
274	{
275	return zmd->dev[idx].nr_rnd;
276	}
277
278	unsigned int dmz_nr_unmap_rnd_zones(struct dmz_metadata *zmd, int idx)
279	{
280	return atomic_read(v: &zmd->dev[idx].unmap_nr_rnd);
281	}
282
283	unsigned int dmz_nr_cache_zones(struct dmz_metadata *zmd)
284	{
285	return zmd->nr_cache;
286	}
287
288	unsigned int dmz_nr_unmap_cache_zones(struct dmz_metadata *zmd)
289	{
290	return atomic_read(v: &zmd->unmap_nr_cache);
291	}
292
293	unsigned int dmz_nr_seq_zones(struct dmz_metadata *zmd, int idx)
294	{
295	return zmd->dev[idx].nr_seq;
296	}
297
298	unsigned int dmz_nr_unmap_seq_zones(struct dmz_metadata *zmd, int idx)
299	{
300	return atomic_read(v: &zmd->dev[idx].unmap_nr_seq);
301	}
302
303	static struct dm_zone *dmz_get(struct dmz_metadata *zmd, unsigned int zone_id)
304	{
305	return xa_load(&zmd->zones, index: zone_id);
306	}
307
308	static struct dm_zone *dmz_insert(struct dmz_metadata *zmd,
309	unsigned int zone_id, struct dmz_dev *dev)
310	{
311	struct dm_zone *zone = kzalloc(size: sizeof(struct dm_zone), GFP_KERNEL);
312
313	if (!zone)
314	return ERR_PTR(error: -ENOMEM);
315
316	if (xa_insert(xa: &zmd->zones, index: zone_id, entry: zone, GFP_KERNEL)) {
317	kfree(objp: zone);
318	return ERR_PTR(error: -EBUSY);
319	}
320
321	INIT_LIST_HEAD(list: &zone->link);
322	atomic_set(v: &zone->refcount, i: 0);
323	zone->id = zone_id;
324	zone->chunk = DMZ_MAP_UNMAPPED;
325	zone->dev = dev;
326
327	return zone;
328	}
329
330	const char *dmz_metadata_label(struct dmz_metadata *zmd)
331	{
332	return (const char *)zmd->label;
333	}
334
335	bool dmz_check_dev(struct dmz_metadata *zmd)
336	{
337	unsigned int i;
338
339	for (i = 0; i < zmd->nr_devs; i++) {
340	if (!dmz_check_bdev(dmz_dev: &zmd->dev[i]))
341	return false;
342	}
343	return true;
344	}
345
346	bool dmz_dev_is_dying(struct dmz_metadata *zmd)
347	{
348	unsigned int i;
349
350	for (i = 0; i < zmd->nr_devs; i++) {
351	if (dmz_bdev_is_dying(dmz_dev: &zmd->dev[i]))
352	return true;
353	}
354	return false;
355	}
356
357	/*
358	* Lock/unlock mapping table.
359	* The map lock also protects all the zone lists.
360	*/
361	void dmz_lock_map(struct dmz_metadata *zmd)
362	{
363	mutex_lock(&zmd->map_lock);
364	}
365
366	void dmz_unlock_map(struct dmz_metadata *zmd)
367	{
368	mutex_unlock(lock: &zmd->map_lock);
369	}
370
371	/*
372	* Lock/unlock metadata access. This is a "read" lock on a semaphore
373	* that prevents metadata flush from running while metadata are being
374	* modified. The actual metadata write mutual exclusion is achieved with
375	* the map lock and zone state management (active and reclaim state are
376	* mutually exclusive).
377	*/
378	void dmz_lock_metadata(struct dmz_metadata *zmd)
379	{
380	down_read(sem: &zmd->mblk_sem);
381	}
382
383	void dmz_unlock_metadata(struct dmz_metadata *zmd)
384	{
385	up_read(sem: &zmd->mblk_sem);
386	}
387
388	/*
389	* Lock/unlock flush: prevent concurrent executions
390	* of dmz_flush_metadata as well as metadata modification in reclaim
391	* while flush is being executed.
392	*/
393	void dmz_lock_flush(struct dmz_metadata *zmd)
394	{
395	mutex_lock(&zmd->mblk_flush_lock);
396	}
397
398	void dmz_unlock_flush(struct dmz_metadata *zmd)
399	{
400	mutex_unlock(lock: &zmd->mblk_flush_lock);
401	}
402
403	/*
404	* Allocate a metadata block.
405	*/
406	static struct dmz_mblock *dmz_alloc_mblock(struct dmz_metadata *zmd,
407	sector_t mblk_no)
408	{
409	struct dmz_mblock *mblk = NULL;
410
411	/* See if we can reuse cached blocks */
412	if (zmd->max_nr_mblks && atomic_read(v: &zmd->nr_mblks) > zmd->max_nr_mblks) {
413	spin_lock(lock: &zmd->mblk_lock);
414	mblk = list_first_entry_or_null(&zmd->mblk_lru_list,
415	struct dmz_mblock, link);
416	if (mblk) {
417	list_del_init(entry: &mblk->link);
418	rb_erase(&mblk->node, &zmd->mblk_rbtree);
419	mblk->no = mblk_no;
420	}
421	spin_unlock(lock: &zmd->mblk_lock);
422	if (mblk)
423	return mblk;
424	}
425
426	/* Allocate a new block */
427	mblk = kmalloc(size: sizeof(struct dmz_mblock), GFP_NOIO);
428	if (!mblk)
429	return NULL;
430
431	mblk->page = alloc_page(GFP_NOIO);
432	if (!mblk->page) {
433	kfree(objp: mblk);
434	return NULL;
435	}
436
437	RB_CLEAR_NODE(&mblk->node);
438	INIT_LIST_HEAD(list: &mblk->link);
439	mblk->ref = 0;
440	mblk->state = 0;
441	mblk->no = mblk_no;
442	mblk->data = page_address(mblk->page);
443
444	atomic_inc(v: &zmd->nr_mblks);
445
446	return mblk;
447	}
448
449	/*
450	* Free a metadata block.
451	*/
452	static void dmz_free_mblock(struct dmz_metadata *zmd, struct dmz_mblock *mblk)
453	{
454	__free_pages(page: mblk->page, order: 0);
455	kfree(objp: mblk);
456
457	atomic_dec(v: &zmd->nr_mblks);
458	}
459
460	/*
461	* Insert a metadata block in the rbtree.
462	*/
463	static void dmz_insert_mblock(struct dmz_metadata *zmd, struct dmz_mblock *mblk)
464	{
465	struct rb_root *root = &zmd->mblk_rbtree;
466	struct rb_node **new = &(root->rb_node), *parent = NULL;
467	struct dmz_mblock *b;
468
469	/* Figure out where to put the new node */
470	while (*new) {
471	b = container_of(*new, struct dmz_mblock, node);
472	parent = *new;
473	new = (b->no < mblk->no) ? &((*new)->rb_left) : &((*new)->rb_right);
474	}
475
476	/* Add new node and rebalance tree */
477	rb_link_node(node: &mblk->node, parent, rb_link: new);
478	rb_insert_color(&mblk->node, root);
479	}
480
481	/*
482	* Lookup a metadata block in the rbtree. If the block is found, increment
483	* its reference count.
484	*/
485	static struct dmz_mblock *dmz_get_mblock_fast(struct dmz_metadata *zmd,
486	sector_t mblk_no)
487	{
488	struct rb_root *root = &zmd->mblk_rbtree;
489	struct rb_node *node = root->rb_node;
490	struct dmz_mblock *mblk;
491
492	while (node) {
493	mblk = container_of(node, struct dmz_mblock, node);
494	if (mblk->no == mblk_no) {
495	/*
496	* If this is the first reference to the block,
497	* remove it from the LRU list.
498	*/
499	mblk->ref++;
500	if (mblk->ref == 1 &&
501	!test_bit(DMZ_META_DIRTY, &mblk->state))
502	list_del_init(entry: &mblk->link);
503	return mblk;
504	}
505	node = (mblk->no < mblk_no) ? node->rb_left : node->rb_right;
506	}
507
508	return NULL;
509	}
510
511	/*
512	* Metadata block BIO end callback.
513	*/
514	static void dmz_mblock_bio_end_io(struct bio *bio)
515	{
516	struct dmz_mblock *mblk = bio->bi_private;
517	int flag;
518
519	if (bio->bi_status)
520	set_bit(nr: DMZ_META_ERROR, addr: &mblk->state);
521
522	if (bio_op(bio) == REQ_OP_WRITE)
523	flag = DMZ_META_WRITING;
524	else
525	flag = DMZ_META_READING;
526
527	clear_bit_unlock(nr: flag, addr: &mblk->state);
528	smp_mb__after_atomic();
529	wake_up_bit(word: &mblk->state, bit: flag);
530
531	bio_put(bio);
532	}
533
534	/*
535	* Read an uncached metadata block from disk and add it to the cache.
536	*/
537	static struct dmz_mblock *dmz_get_mblock_slow(struct dmz_metadata *zmd,
538	sector_t mblk_no)
539	{
540	struct dmz_mblock *mblk, *m;
541	sector_t block = zmd->sb[zmd->mblk_primary].block + mblk_no;
542	struct dmz_dev *dev = zmd->sb[zmd->mblk_primary].dev;
543	struct bio *bio;
544
545	if (dmz_bdev_is_dying(dmz_dev: dev))
546	return ERR_PTR(error: -EIO);
547
548	/* Get a new block and a BIO to read it */
549	mblk = dmz_alloc_mblock(zmd, mblk_no);
550	if (!mblk)
551	return ERR_PTR(error: -ENOMEM);
552
553	bio = bio_alloc(bdev: dev->bdev, nr_vecs: 1, opf: REQ_OP_READ | REQ_META | REQ_PRIO,
554	GFP_NOIO);
555
556	spin_lock(lock: &zmd->mblk_lock);
557
558	/*
559	* Make sure that another context did not start reading
560	* the block already.
561	*/
562	m = dmz_get_mblock_fast(zmd, mblk_no);
563	if (m) {
564	spin_unlock(lock: &zmd->mblk_lock);
565	dmz_free_mblock(zmd, mblk);
566	bio_put(bio);
567	return m;
568	}
569
570	mblk->ref++;
571	set_bit(nr: DMZ_META_READING, addr: &mblk->state);
572	dmz_insert_mblock(zmd, mblk);
573
574	spin_unlock(lock: &zmd->mblk_lock);
575
576	/* Submit read BIO */
577	bio->bi_iter.bi_sector = dmz_blk2sect(block);
578	bio->bi_private = mblk;
579	bio->bi_end_io = dmz_mblock_bio_end_io;
580	__bio_add_page(bio, page: mblk->page, DMZ_BLOCK_SIZE, off: 0);
581	submit_bio(bio);
582
583	return mblk;
584	}
585
586	/*
587	* Free metadata blocks.
588	*/
589	static unsigned long dmz_shrink_mblock_cache(struct dmz_metadata *zmd,
590	unsigned long limit)
591	{
592	struct dmz_mblock *mblk;
593	unsigned long count = 0;
594
595	if (!zmd->max_nr_mblks)
596	return 0;
597
598	while (!list_empty(head: &zmd->mblk_lru_list) &&
599	atomic_read(v: &zmd->nr_mblks) > zmd->min_nr_mblks &&
600	count < limit) {
601	mblk = list_first_entry(&zmd->mblk_lru_list,
602	struct dmz_mblock, link);
603	list_del_init(entry: &mblk->link);
604	rb_erase(&mblk->node, &zmd->mblk_rbtree);
605	dmz_free_mblock(zmd, mblk);
606	count++;
607	}
608
609	return count;
610	}
611
612	/*
613	* For mblock shrinker: get the number of unused metadata blocks in the cache.
614	*/
615	static unsigned long dmz_mblock_shrinker_count(struct shrinker *shrink,
616	struct shrink_control *sc)
617	{
618	struct dmz_metadata *zmd = shrink->private_data;
619
620	return atomic_read(v: &zmd->nr_mblks);
621	}
622
623	/*
624	* For mblock shrinker: scan unused metadata blocks and shrink the cache.
625	*/
626	static unsigned long dmz_mblock_shrinker_scan(struct shrinker *shrink,
627	struct shrink_control *sc)
628	{
629	struct dmz_metadata *zmd = shrink->private_data;
630	unsigned long count;
631
632	spin_lock(lock: &zmd->mblk_lock);
633	count = dmz_shrink_mblock_cache(zmd, limit: sc->nr_to_scan);
634	spin_unlock(lock: &zmd->mblk_lock);
635
636	return count ? count : SHRINK_STOP;
637	}
638
639	/*
640	* Release a metadata block.
641	*/
642	static void dmz_release_mblock(struct dmz_metadata *zmd,
643	struct dmz_mblock *mblk)
644	{
645
646	if (!mblk)
647	return;
648
649	spin_lock(lock: &zmd->mblk_lock);
650
651	mblk->ref--;
652	if (mblk->ref == 0) {
653	if (test_bit(DMZ_META_ERROR, &mblk->state)) {
654	rb_erase(&mblk->node, &zmd->mblk_rbtree);
655	dmz_free_mblock(zmd, mblk);
656	} else if (!test_bit(DMZ_META_DIRTY, &mblk->state)) {
657	list_add_tail(new: &mblk->link, head: &zmd->mblk_lru_list);
658	dmz_shrink_mblock_cache(zmd, limit: 1);
659	}
660	}
661
662	spin_unlock(lock: &zmd->mblk_lock);
663	}
664
665	/*
666	* Get a metadata block from the rbtree. If the block
667	* is not present, read it from disk.
668	*/
669	static struct dmz_mblock *dmz_get_mblock(struct dmz_metadata *zmd,
670	sector_t mblk_no)
671	{
672	struct dmz_mblock *mblk;
673	struct dmz_dev *dev = zmd->sb[zmd->mblk_primary].dev;
674
675	/* Check rbtree */
676	spin_lock(lock: &zmd->mblk_lock);
677	mblk = dmz_get_mblock_fast(zmd, mblk_no);
678	spin_unlock(lock: &zmd->mblk_lock);
679
680	if (!mblk) {
681	/* Cache miss: read the block from disk */
682	mblk = dmz_get_mblock_slow(zmd, mblk_no);
683	if (IS_ERR(ptr: mblk))
684	return mblk;
685	}
686
687	/* Wait for on-going read I/O and check for error */
688	wait_on_bit_io(word: &mblk->state, bit: DMZ_META_READING,
689	TASK_UNINTERRUPTIBLE);
690	if (test_bit(DMZ_META_ERROR, &mblk->state)) {
691	dmz_release_mblock(zmd, mblk);
692	dmz_check_bdev(dmz_dev: dev);
693	return ERR_PTR(error: -EIO);
694	}
695
696	return mblk;
697	}
698
699	/*
700	* Mark a metadata block dirty.
701	*/
702	static void dmz_dirty_mblock(struct dmz_metadata *zmd, struct dmz_mblock *mblk)
703	{
704	spin_lock(lock: &zmd->mblk_lock);
705	if (!test_and_set_bit(nr: DMZ_META_DIRTY, addr: &mblk->state))
706	list_add_tail(new: &mblk->link, head: &zmd->mblk_dirty_list);
707	spin_unlock(lock: &zmd->mblk_lock);
708	}
709
710	/*
711	* Issue a metadata block write BIO.
712	*/
713	static int dmz_write_mblock(struct dmz_metadata *zmd, struct dmz_mblock *mblk,
714	unsigned int set)
715	{
716	struct dmz_dev *dev = zmd->sb[set].dev;
717	sector_t block = zmd->sb[set].block + mblk->no;
718	struct bio *bio;
719
720	if (dmz_bdev_is_dying(dmz_dev: dev))
721	return -EIO;
722
723	bio = bio_alloc(bdev: dev->bdev, nr_vecs: 1, opf: REQ_OP_WRITE | REQ_META | REQ_PRIO,
724	GFP_NOIO);
725
726	set_bit(nr: DMZ_META_WRITING, addr: &mblk->state);
727
728	bio->bi_iter.bi_sector = dmz_blk2sect(block);
729	bio->bi_private = mblk;
730	bio->bi_end_io = dmz_mblock_bio_end_io;
731	__bio_add_page(bio, page: mblk->page, DMZ_BLOCK_SIZE, off: 0);
732	submit_bio(bio);
733
734	return 0;
735	}
736
737	/*
738	* Read/write a metadata block.
739	*/
740	static int dmz_rdwr_block(struct dmz_dev *dev, enum req_op op,
741	sector_t block, struct page *page)
742	{
743	struct bio *bio;
744	int ret;
745
746	if (WARN_ON(!dev))
747	return -EIO;
748
749	if (dmz_bdev_is_dying(dmz_dev: dev))
750	return -EIO;
751
752	bio = bio_alloc(bdev: dev->bdev, nr_vecs: 1, opf: op | REQ_SYNC | REQ_META | REQ_PRIO,
753	GFP_NOIO);
754	bio->bi_iter.bi_sector = dmz_blk2sect(block);
755	__bio_add_page(bio, page, DMZ_BLOCK_SIZE, off: 0);
756	ret = submit_bio_wait(bio);
757	bio_put(bio);
758
759	if (ret)
760	dmz_check_bdev(dmz_dev: dev);
761	return ret;
762	}
763
764	/*
765	* Write super block of the specified metadata set.
766	*/
767	static int dmz_write_sb(struct dmz_metadata *zmd, unsigned int set)
768	{
769	struct dmz_mblock *mblk = zmd->sb[set].mblk;
770	struct dmz_super *sb = zmd->sb[set].sb;
771	struct dmz_dev *dev = zmd->sb[set].dev;
772	sector_t sb_block;
773	u64 sb_gen = zmd->sb_gen + 1;
774	int ret;
775
776	sb->magic = cpu_to_le32(DMZ_MAGIC);
777
778	sb->version = cpu_to_le32(zmd->sb_version);
779	if (zmd->sb_version > 1) {
780	BUILD_BUG_ON(UUID_SIZE != 16);
781	export_uuid(dst: sb->dmz_uuid, src: &zmd->uuid);
782	memcpy(sb->dmz_label, zmd->label, BDEVNAME_SIZE);
783	export_uuid(dst: sb->dev_uuid, src: &dev->uuid);
784	}
785
786	sb->gen = cpu_to_le64(sb_gen);
787
788	/*
789	* The metadata always references the absolute block address,
790	* ie relative to the entire block range, not the per-device
791	* block address.
792	*/
793	sb_block = zmd->sb[set].zone->id << zmd->zone_nr_blocks_shift;
794	sb->sb_block = cpu_to_le64(sb_block);
795	sb->nr_meta_blocks = cpu_to_le32(zmd->nr_meta_blocks);
796	sb->nr_reserved_seq = cpu_to_le32(zmd->nr_reserved_seq);
797	sb->nr_chunks = cpu_to_le32(zmd->nr_chunks);
798
799	sb->nr_map_blocks = cpu_to_le32(zmd->nr_map_blocks);
800	sb->nr_bitmap_blocks = cpu_to_le32(zmd->nr_bitmap_blocks);
801
802	sb->crc = 0;
803	sb->crc = cpu_to_le32(crc32_le(sb_gen, (unsigned char *)sb, DMZ_BLOCK_SIZE));
804
805	ret = dmz_rdwr_block(dev, op: REQ_OP_WRITE, block: zmd->sb[set].block,
806	page: mblk->page);
807	if (ret == 0)
808	ret = blkdev_issue_flush(bdev: dev->bdev);
809
810	return ret;
811	}
812
813	/*
814	* Write dirty metadata blocks to the specified set.
815	*/
816	static int dmz_write_dirty_mblocks(struct dmz_metadata *zmd,
817	struct list_head *write_list,
818	unsigned int set)
819	{
820	struct dmz_mblock *mblk;
821	struct dmz_dev *dev = zmd->sb[set].dev;
822	struct blk_plug plug;
823	int ret = 0, nr_mblks_submitted = 0;
824
825	/* Issue writes */
826	blk_start_plug(&plug);
827	list_for_each_entry(mblk, write_list, link) {
828	ret = dmz_write_mblock(zmd, mblk, set);
829	if (ret)
830	break;
831	nr_mblks_submitted++;
832	}
833	blk_finish_plug(&plug);
834
835	/* Wait for completion */
836	list_for_each_entry(mblk, write_list, link) {
837	if (!nr_mblks_submitted)
838	break;
839	wait_on_bit_io(word: &mblk->state, bit: DMZ_META_WRITING,
840	TASK_UNINTERRUPTIBLE);
841	if (test_bit(DMZ_META_ERROR, &mblk->state)) {
842	clear_bit(nr: DMZ_META_ERROR, addr: &mblk->state);
843	dmz_check_bdev(dmz_dev: dev);
844	ret = -EIO;
845	}
846	nr_mblks_submitted--;
847	}
848
849	/* Flush drive cache (this will also sync data) */
850	if (ret == 0)
851	ret = blkdev_issue_flush(bdev: dev->bdev);
852
853	return ret;
854	}
855
856	/*
857	* Log dirty metadata blocks.
858	*/
859	static int dmz_log_dirty_mblocks(struct dmz_metadata *zmd,
860	struct list_head *write_list)
861	{
862	unsigned int log_set = zmd->mblk_primary ^ 0x1;
863	int ret;
864
865	/* Write dirty blocks to the log */
866	ret = dmz_write_dirty_mblocks(zmd, write_list, set: log_set);
867	if (ret)
868	return ret;
869
870	/*
871	* No error so far: now validate the log by updating the
872	* log index super block generation.
873	*/
874	ret = dmz_write_sb(zmd, set: log_set);
875	if (ret)
876	return ret;
877
878	return 0;
879	}
880
881	/*
882	* Flush dirty metadata blocks.
883	*/
884	int dmz_flush_metadata(struct dmz_metadata *zmd)
885	{
886	struct dmz_mblock *mblk;
887	struct list_head write_list;
888	struct dmz_dev *dev;
889	int ret;
890
891	if (WARN_ON(!zmd))
892	return 0;
893
894	INIT_LIST_HEAD(list: &write_list);
895
896	/*
897	* Make sure that metadata blocks are stable before logging: take
898	* the write lock on the metadata semaphore to prevent target BIOs
899	* from modifying metadata.
900	*/
901	down_write(sem: &zmd->mblk_sem);
902	dev = zmd->sb[zmd->mblk_primary].dev;
903
904	/*
905	* This is called from the target flush work and reclaim work.
906	* Concurrent execution is not allowed.
907	*/
908	dmz_lock_flush(zmd);
909
910	if (dmz_bdev_is_dying(dmz_dev: dev)) {
911	ret = -EIO;
912	goto out;
913	}
914
915	/* Get dirty blocks */
916	spin_lock(lock: &zmd->mblk_lock);
917	list_splice_init(list: &zmd->mblk_dirty_list, head: &write_list);
918	spin_unlock(lock: &zmd->mblk_lock);
919
920	/* If there are no dirty metadata blocks, just flush the device cache */
921	if (list_empty(head: &write_list)) {
922	ret = blkdev_issue_flush(bdev: dev->bdev);
923	goto err;
924	}
925
926	/*
927	* The primary metadata set is still clean. Keep it this way until
928	* all updates are successful in the secondary set. That is, use
929	* the secondary set as a log.
930	*/
931	ret = dmz_log_dirty_mblocks(zmd, write_list: &write_list);
932	if (ret)
933	goto err;
934
935	/*
936	* The log is on disk. It is now safe to update in place
937	* in the primary metadata set.
938	*/
939	ret = dmz_write_dirty_mblocks(zmd, write_list: &write_list, set: zmd->mblk_primary);
940	if (ret)
941	goto err;
942
943	ret = dmz_write_sb(zmd, set: zmd->mblk_primary);
944	if (ret)
945	goto err;
946
947	while (!list_empty(head: &write_list)) {
948	mblk = list_first_entry(&write_list, struct dmz_mblock, link);
949	list_del_init(entry: &mblk->link);
950
951	spin_lock(lock: &zmd->mblk_lock);
952	clear_bit(nr: DMZ_META_DIRTY, addr: &mblk->state);
953	if (mblk->ref == 0)
954	list_add_tail(new: &mblk->link, head: &zmd->mblk_lru_list);
955	spin_unlock(lock: &zmd->mblk_lock);
956	}
957
958	zmd->sb_gen++;
959	out:
960	dmz_unlock_flush(zmd);
961	up_write(sem: &zmd->mblk_sem);
962
963	return ret;
964
965	err:
966	if (!list_empty(head: &write_list)) {
967	spin_lock(lock: &zmd->mblk_lock);
968	list_splice(list: &write_list, head: &zmd->mblk_dirty_list);
969	spin_unlock(lock: &zmd->mblk_lock);
970	}
971	if (!dmz_check_bdev(dmz_dev: dev))
972	ret = -EIO;
973	goto out;
974	}
975
976	/*
977	* Check super block.
978	*/
979	static int dmz_check_sb(struct dmz_metadata *zmd, struct dmz_sb *dsb,
980	bool tertiary)
981	{
982	struct dmz_super *sb = dsb->sb;
983	struct dmz_dev *dev = dsb->dev;
984	unsigned int nr_meta_zones, nr_data_zones;
985	u32 crc, stored_crc;
986	u64 gen, sb_block;
987
988	if (le32_to_cpu(sb->magic) != DMZ_MAGIC) {
989	dmz_dev_err(dev, "Invalid meta magic (needed 0x%08x, got 0x%08x)",
990	DMZ_MAGIC, le32_to_cpu(sb->magic));
991	return -ENXIO;
992	}
993
994	zmd->sb_version = le32_to_cpu(sb->version);
995	if (zmd->sb_version > DMZ_META_VER) {
996	dmz_dev_err(dev, "Invalid meta version (needed %d, got %d)",
997	DMZ_META_VER, zmd->sb_version);
998	return -EINVAL;
999	}
1000	if (zmd->sb_version < 2 && tertiary) {
1001	dmz_dev_err(dev, "Tertiary superblocks are not supported");
1002	return -EINVAL;
1003	}
1004
1005	gen = le64_to_cpu(sb->gen);
1006	stored_crc = le32_to_cpu(sb->crc);
1007	sb->crc = 0;
1008	crc = crc32_le(crc: gen, p: (unsigned char *)sb, DMZ_BLOCK_SIZE);
1009	if (crc != stored_crc) {
1010	dmz_dev_err(dev, "Invalid checksum (needed 0x%08x, got 0x%08x)",
1011	crc, stored_crc);
1012	return -ENXIO;
1013	}
1014
1015	sb_block = le64_to_cpu(sb->sb_block);
1016	if (sb_block != (u64)dsb->zone->id << zmd->zone_nr_blocks_shift) {
1017	dmz_dev_err(dev, "Invalid superblock position (is %llu expected %llu)",
1018	sb_block, (u64)dsb->zone->id << zmd->zone_nr_blocks_shift);
1019	return -EINVAL;
1020	}
1021	if (zmd->sb_version > 1) {
1022	uuid_t sb_uuid;
1023
1024	import_uuid(dst: &sb_uuid, src: sb->dmz_uuid);
1025	if (uuid_is_null(uuid: &sb_uuid)) {
1026	dmz_dev_err(dev, "NULL DM-Zoned uuid");
1027	return -ENXIO;
1028	} else if (uuid_is_null(uuid: &zmd->uuid)) {
1029	uuid_copy(dst: &zmd->uuid, src: &sb_uuid);
1030	} else if (!uuid_equal(u1: &zmd->uuid, u2: &sb_uuid)) {
1031	dmz_dev_err(dev, "mismatching DM-Zoned uuid, is %pUl expected %pUl",
1032	&sb_uuid, &zmd->uuid);
1033	return -ENXIO;
1034	}
1035	if (!strlen(zmd->label))
1036	memcpy(zmd->label, sb->dmz_label, BDEVNAME_SIZE);
1037	else if (memcmp(p: zmd->label, q: sb->dmz_label, BDEVNAME_SIZE)) {
1038	dmz_dev_err(dev, "mismatching DM-Zoned label, is %s expected %s",
1039	sb->dmz_label, zmd->label);
1040	return -ENXIO;
1041	}
1042	import_uuid(dst: &dev->uuid, src: sb->dev_uuid);
1043	if (uuid_is_null(uuid: &dev->uuid)) {
1044	dmz_dev_err(dev, "NULL device uuid");
1045	return -ENXIO;
1046	}
1047
1048	if (tertiary) {
1049	/*
1050	* Generation number should be 0, but it doesn't
1051	* really matter if it isn't.
1052	*/
1053	if (gen != 0)
1054	dmz_dev_warn(dev, "Invalid generation %llu",
1055	gen);
1056	return 0;
1057	}
1058	}
1059
1060	nr_meta_zones = (le32_to_cpu(sb->nr_meta_blocks) + zmd->zone_nr_blocks - 1)
1061	>> zmd->zone_nr_blocks_shift;
1062	if (!nr_meta_zones ||
1063	(zmd->nr_devs <= 1 && nr_meta_zones >= zmd->nr_rnd_zones) ||
1064	(zmd->nr_devs > 1 && nr_meta_zones >= zmd->nr_cache_zones)) {
1065	dmz_dev_err(dev, "Invalid number of metadata blocks");
1066	return -ENXIO;
1067	}
1068
1069	if (!le32_to_cpu(sb->nr_reserved_seq) ||
1070	le32_to_cpu(sb->nr_reserved_seq) >= (zmd->nr_useable_zones - nr_meta_zones)) {
1071	dmz_dev_err(dev, "Invalid number of reserved sequential zones");
1072	return -ENXIO;
1073	}
1074
1075	nr_data_zones = zmd->nr_useable_zones -
1076	(nr_meta_zones * 2 + le32_to_cpu(sb->nr_reserved_seq));
1077	if (le32_to_cpu(sb->nr_chunks) > nr_data_zones) {
1078	dmz_dev_err(dev, "Invalid number of chunks %u / %u",
1079	le32_to_cpu(sb->nr_chunks), nr_data_zones);
1080	return -ENXIO;
1081	}
1082
1083	/* OK */
1084	zmd->nr_meta_blocks = le32_to_cpu(sb->nr_meta_blocks);
1085	zmd->nr_reserved_seq = le32_to_cpu(sb->nr_reserved_seq);
1086	zmd->nr_chunks = le32_to_cpu(sb->nr_chunks);
1087	zmd->nr_map_blocks = le32_to_cpu(sb->nr_map_blocks);
1088	zmd->nr_bitmap_blocks = le32_to_cpu(sb->nr_bitmap_blocks);
1089	zmd->nr_meta_zones = nr_meta_zones;
1090	zmd->nr_data_zones = nr_data_zones;
1091
1092	return 0;
1093	}
1094
1095	/*
1096	* Read the first or second super block from disk.
1097	*/
1098	static int dmz_read_sb(struct dmz_metadata *zmd, struct dmz_sb *sb, int set)
1099	{
1100	dmz_zmd_debug(zmd, "read superblock set %d dev %pg block %llu",
1101	set, sb->dev->bdev, sb->block);
1102
1103	return dmz_rdwr_block(dev: sb->dev, op: REQ_OP_READ,
1104	block: sb->block, page: sb->mblk->page);
1105	}
1106
1107	/*
1108	* Determine the position of the secondary super blocks on disk.
1109	* This is used only if a corruption of the primary super block
1110	* is detected.
1111	*/
1112	static int dmz_lookup_secondary_sb(struct dmz_metadata *zmd)
1113	{
1114	unsigned int zone_nr_blocks = zmd->zone_nr_blocks;
1115	struct dmz_mblock *mblk;
1116	unsigned int zone_id = zmd->sb[0].zone->id;
1117	int i;
1118
1119	/* Allocate a block */
1120	mblk = dmz_alloc_mblock(zmd, mblk_no: 0);
1121	if (!mblk)
1122	return -ENOMEM;
1123
1124	zmd->sb[1].mblk = mblk;
1125	zmd->sb[1].sb = mblk->data;
1126
1127	/* Bad first super block: search for the second one */
1128	zmd->sb[1].block = zmd->sb[0].block + zone_nr_blocks;
1129	zmd->sb[1].zone = dmz_get(zmd, zone_id: zone_id + 1);
1130	zmd->sb[1].dev = zmd->sb[0].dev;
1131	for (i = 1; i < zmd->nr_rnd_zones; i++) {
1132	if (dmz_read_sb(zmd, sb: &zmd->sb[1], set: 1) != 0)
1133	break;
1134	if (le32_to_cpu(zmd->sb[1].sb->magic) == DMZ_MAGIC)
1135	return 0;
1136	zmd->sb[1].block += zone_nr_blocks;
1137	zmd->sb[1].zone = dmz_get(zmd, zone_id: zone_id + i);
1138	}
1139
1140	dmz_free_mblock(zmd, mblk);
1141	zmd->sb[1].mblk = NULL;
1142	zmd->sb[1].zone = NULL;
1143	zmd->sb[1].dev = NULL;
1144
1145	return -EIO;
1146	}
1147
1148	/*
1149	* Read a super block from disk.
1150	*/
1151	static int dmz_get_sb(struct dmz_metadata *zmd, struct dmz_sb *sb, int set)
1152	{
1153	struct dmz_mblock *mblk;
1154	int ret;
1155
1156	/* Allocate a block */
1157	mblk = dmz_alloc_mblock(zmd, mblk_no: 0);
1158	if (!mblk)
1159	return -ENOMEM;
1160
1161	sb->mblk = mblk;
1162	sb->sb = mblk->data;
1163
1164	/* Read super block */
1165	ret = dmz_read_sb(zmd, sb, set);
1166	if (ret) {
1167	dmz_free_mblock(zmd, mblk);
1168	sb->mblk = NULL;
1169	return ret;
1170	}
1171
1172	return 0;
1173	}
1174
1175	/*
1176	* Recover a metadata set.
1177	*/
1178	static int dmz_recover_mblocks(struct dmz_metadata *zmd, unsigned int dst_set)
1179	{
1180	unsigned int src_set = dst_set ^ 0x1;
1181	struct page *page;
1182	int i, ret;
1183
1184	dmz_dev_warn(zmd->sb[dst_set].dev,
1185	"Metadata set %u invalid: recovering", dst_set);
1186
1187	if (dst_set == 0)
1188	zmd->sb[0].block = dmz_start_block(zmd, zone: zmd->sb[0].zone);
1189	else
1190	zmd->sb[1].block = dmz_start_block(zmd, zone: zmd->sb[1].zone);
1191
1192	page = alloc_page(GFP_NOIO);
1193	if (!page)
1194	return -ENOMEM;
1195
1196	/* Copy metadata blocks */
1197	for (i = 1; i < zmd->nr_meta_blocks; i++) {
1198	ret = dmz_rdwr_block(dev: zmd->sb[src_set].dev, op: REQ_OP_READ,
1199	block: zmd->sb[src_set].block + i, page);
1200	if (ret)
1201	goto out;
1202	ret = dmz_rdwr_block(dev: zmd->sb[dst_set].dev, op: REQ_OP_WRITE,
1203	block: zmd->sb[dst_set].block + i, page);
1204	if (ret)
1205	goto out;
1206	}
1207
1208	/* Finalize with the super block */
1209	if (!zmd->sb[dst_set].mblk) {
1210	zmd->sb[dst_set].mblk = dmz_alloc_mblock(zmd, mblk_no: 0);
1211	if (!zmd->sb[dst_set].mblk) {
1212	ret = -ENOMEM;
1213	goto out;
1214	}
1215	zmd->sb[dst_set].sb = zmd->sb[dst_set].mblk->data;
1216	}
1217
1218	ret = dmz_write_sb(zmd, set: dst_set);
1219	out:
1220	__free_pages(page, order: 0);
1221
1222	return ret;
1223	}
1224
1225	/*
1226	* Get super block from disk.
1227	*/
1228	static int dmz_load_sb(struct dmz_metadata *zmd)
1229	{
1230	bool sb_good[2] = {false, false};
1231	u64 sb_gen[2] = {0, 0};
1232	int ret;
1233
1234	if (!zmd->sb[0].zone) {
1235	dmz_zmd_err(zmd, "Primary super block zone not set");
1236	return -ENXIO;
1237	}
1238
1239	/* Read and check the primary super block */
1240	zmd->sb[0].block = dmz_start_block(zmd, zone: zmd->sb[0].zone);
1241	zmd->sb[0].dev = zmd->sb[0].zone->dev;
1242	ret = dmz_get_sb(zmd, sb: &zmd->sb[0], set: 0);
1243	if (ret) {
1244	dmz_dev_err(zmd->sb[0].dev, "Read primary super block failed");
1245	return ret;
1246	}
1247
1248	ret = dmz_check_sb(zmd, dsb: &zmd->sb[0], tertiary: false);
1249
1250	/* Read and check secondary super block */
1251	if (ret == 0) {
1252	sb_good[0] = true;
1253	if (!zmd->sb[1].zone) {
1254	unsigned int zone_id =
1255	zmd->sb[0].zone->id + zmd->nr_meta_zones;
1256
1257	zmd->sb[1].zone = dmz_get(zmd, zone_id);
1258	}
1259	zmd->sb[1].block = dmz_start_block(zmd, zone: zmd->sb[1].zone);
1260	zmd->sb[1].dev = zmd->sb[0].dev;
1261	ret = dmz_get_sb(zmd, sb: &zmd->sb[1], set: 1);
1262	} else
1263	ret = dmz_lookup_secondary_sb(zmd);
1264
1265	if (ret) {
1266	dmz_dev_err(zmd->sb[1].dev, "Read secondary super block failed");
1267	return ret;
1268	}
1269
1270	ret = dmz_check_sb(zmd, dsb: &zmd->sb[1], tertiary: false);
1271	if (ret == 0)
1272	sb_good[1] = true;
1273
1274	/* Use highest generation sb first */
1275	if (!sb_good[0] && !sb_good[1]) {
1276	dmz_zmd_err(zmd, "No valid super block found");
1277	return -EIO;
1278	}
1279
1280	if (sb_good[0])
1281	sb_gen[0] = le64_to_cpu(zmd->sb[0].sb->gen);
1282	else {
1283	ret = dmz_recover_mblocks(zmd, dst_set: 0);
1284	if (ret) {
1285	dmz_dev_err(zmd->sb[0].dev,
1286	"Recovery of superblock 0 failed");
1287	return -EIO;
1288	}
1289	}
1290
1291	if (sb_good[1])
1292	sb_gen[1] = le64_to_cpu(zmd->sb[1].sb->gen);
1293	else {
1294	ret = dmz_recover_mblocks(zmd, dst_set: 1);
1295
1296	if (ret) {
1297	dmz_dev_err(zmd->sb[1].dev,
1298	"Recovery of superblock 1 failed");
1299	return -EIO;
1300	}
1301	}
1302
1303	if (sb_gen[0] >= sb_gen[1]) {
1304	zmd->sb_gen = sb_gen[0];
1305	zmd->mblk_primary = 0;
1306	} else {
1307	zmd->sb_gen = sb_gen[1];
1308	zmd->mblk_primary = 1;
1309	}
1310
1311	dmz_dev_debug(zmd->sb[zmd->mblk_primary].dev,
1312	"Using super block %u (gen %llu)",
1313	zmd->mblk_primary, zmd->sb_gen);
1314
1315	if (zmd->sb_version > 1) {
1316	int i;
1317	struct dmz_sb *sb;
1318
1319	sb = kzalloc(size: sizeof(struct dmz_sb), GFP_KERNEL);
1320	if (!sb)
1321	return -ENOMEM;
1322	for (i = 1; i < zmd->nr_devs; i++) {
1323	sb->block = 0;
1324	sb->zone = dmz_get(zmd, zone_id: zmd->dev[i].zone_offset);
1325	sb->dev = &zmd->dev[i];
1326	if (!dmz_is_meta(sb->zone)) {
1327	dmz_dev_err(sb->dev,
1328	"Tertiary super block zone %u not marked as metadata zone",
1329	sb->zone->id);
1330	ret = -EINVAL;
1331	goto out_kfree;
1332	}
1333	ret = dmz_get_sb(zmd, sb, set: i + 1);
1334	if (ret) {
1335	dmz_dev_err(sb->dev,
1336	"Read tertiary super block failed");
1337	dmz_free_mblock(zmd, mblk: sb->mblk);
1338	goto out_kfree;
1339	}
1340	ret = dmz_check_sb(zmd, dsb: sb, tertiary: true);
1341	dmz_free_mblock(zmd, mblk: sb->mblk);
1342	if (ret == -EINVAL)
1343	goto out_kfree;
1344	}
1345	out_kfree:
1346	kfree(objp: sb);
1347	}
1348	return ret;
1349	}
1350
1351	/*
1352	* Initialize a zone descriptor.
1353	*/
1354	static int dmz_init_zone(struct blk_zone *blkz, unsigned int num, void *data)
1355	{
1356	struct dmz_dev *dev = data;
1357	struct dmz_metadata *zmd = dev->metadata;
1358	int idx = num + dev->zone_offset;
1359	struct dm_zone *zone;
1360
1361	zone = dmz_insert(zmd, zone_id: idx, dev);
1362	if (IS_ERR(ptr: zone))
1363	return PTR_ERR(ptr: zone);
1364
1365	if (blkz->len != zmd->zone_nr_sectors) {
1366	if (zmd->sb_version > 1) {
1367	/* Ignore the eventual runt (smaller) zone */
1368	set_bit(nr: DMZ_OFFLINE, addr: &zone->flags);
1369	return 0;
1370	} else if (blkz->start + blkz->len == dev->capacity)
1371	return 0;
1372	return -ENXIO;
1373	}
1374
1375	/*
1376	* Devices that have zones with a capacity smaller than the zone size
1377	* (e.g. NVMe zoned namespaces) are not supported.
1378	*/
1379	if (blkz->capacity != blkz->len)
1380	return -ENXIO;
1381
1382	switch (blkz->type) {
1383	case BLK_ZONE_TYPE_CONVENTIONAL:
1384	set_bit(nr: DMZ_RND, addr: &zone->flags);
1385	break;
1386	case BLK_ZONE_TYPE_SEQWRITE_REQ:
1387	case BLK_ZONE_TYPE_SEQWRITE_PREF:
1388	set_bit(nr: DMZ_SEQ, addr: &zone->flags);
1389	break;
1390	default:
1391	return -ENXIO;
1392	}
1393
1394	if (dmz_is_rnd(zone))
1395	zone->wp_block = 0;
1396	else
1397	zone->wp_block = dmz_sect2blk(blkz->wp - blkz->start);
1398
1399	if (blkz->cond == BLK_ZONE_COND_OFFLINE)
1400	set_bit(nr: DMZ_OFFLINE, addr: &zone->flags);
1401	else if (blkz->cond == BLK_ZONE_COND_READONLY)
1402	set_bit(nr: DMZ_READ_ONLY, addr: &zone->flags);
1403	else {
1404	zmd->nr_useable_zones++;
1405	if (dmz_is_rnd(zone)) {
1406	zmd->nr_rnd_zones++;
1407	if (zmd->nr_devs == 1 && !zmd->sb[0].zone) {
1408	/* Primary super block zone */
1409	zmd->sb[0].zone = zone;
1410	}
1411	}
1412	if (zmd->nr_devs > 1 && num == 0) {
1413	/*
1414	* Tertiary superblock zones are always at the
1415	* start of the zoned devices, so mark them
1416	* as metadata zone.
1417	*/
1418	set_bit(nr: DMZ_META, addr: &zone->flags);
1419	}
1420	}
1421	return 0;
1422	}
1423
1424	static int dmz_emulate_zones(struct dmz_metadata *zmd, struct dmz_dev *dev)
1425	{
1426	int idx;
1427	sector_t zone_offset = 0;
1428
1429	for (idx = 0; idx < dev->nr_zones; idx++) {
1430	struct dm_zone *zone;
1431
1432	zone = dmz_insert(zmd, zone_id: idx, dev);
1433	if (IS_ERR(ptr: zone))
1434	return PTR_ERR(ptr: zone);
1435	set_bit(nr: DMZ_CACHE, addr: &zone->flags);
1436	zone->wp_block = 0;
1437	zmd->nr_cache_zones++;
1438	zmd->nr_useable_zones++;
1439	if (dev->capacity - zone_offset < zmd->zone_nr_sectors) {
1440	/* Disable runt zone */
1441	set_bit(nr: DMZ_OFFLINE, addr: &zone->flags);
1442	break;
1443	}
1444	zone_offset += zmd->zone_nr_sectors;
1445	}
1446	return 0;
1447	}
1448
1449	/*
1450	* Free zones descriptors.
1451	*/
1452	static void dmz_drop_zones(struct dmz_metadata *zmd)
1453	{
1454	int idx;
1455
1456	for (idx = 0; idx < zmd->nr_zones; idx++) {
1457	struct dm_zone *zone = xa_load(&zmd->zones, index: idx);
1458
1459	kfree(objp: zone);
1460	xa_erase(&zmd->zones, index: idx);
1461	}
1462	xa_destroy(&zmd->zones);
1463	}
1464
1465	/*
1466	* Allocate and initialize zone descriptors using the zone
1467	* information from disk.
1468	*/
1469	static int dmz_init_zones(struct dmz_metadata *zmd)
1470	{
1471	int i, ret;
1472	struct dmz_dev *zoned_dev = &zmd->dev[0];
1473
1474	/* Init */
1475	zmd->zone_nr_sectors = zmd->dev[0].zone_nr_sectors;
1476	zmd->zone_nr_sectors_shift = ilog2(zmd->zone_nr_sectors);
1477	zmd->zone_nr_blocks = dmz_sect2blk(zmd->zone_nr_sectors);
1478	zmd->zone_nr_blocks_shift = ilog2(zmd->zone_nr_blocks);
1479	zmd->zone_bitmap_size = zmd->zone_nr_blocks >> 3;
1480	zmd->zone_nr_bitmap_blocks =
1481	max_t(sector_t, 1, zmd->zone_bitmap_size >> DMZ_BLOCK_SHIFT);
1482	zmd->zone_bits_per_mblk = min_t(sector_t, zmd->zone_nr_blocks,
1483	DMZ_BLOCK_SIZE_BITS);
1484
1485	/* Allocate zone array */
1486	zmd->nr_zones = 0;
1487	for (i = 0; i < zmd->nr_devs; i++) {
1488	struct dmz_dev *dev = &zmd->dev[i];
1489
1490	dev->metadata = zmd;
1491	zmd->nr_zones += dev->nr_zones;
1492
1493	atomic_set(v: &dev->unmap_nr_rnd, i: 0);
1494	INIT_LIST_HEAD(list: &dev->unmap_rnd_list);
1495	INIT_LIST_HEAD(list: &dev->map_rnd_list);
1496
1497	atomic_set(v: &dev->unmap_nr_seq, i: 0);
1498	INIT_LIST_HEAD(list: &dev->unmap_seq_list);
1499	INIT_LIST_HEAD(list: &dev->map_seq_list);
1500	}
1501
1502	if (!zmd->nr_zones) {
1503	DMERR("(%s): No zones found", zmd->devname);
1504	return -ENXIO;
1505	}
1506	xa_init(xa: &zmd->zones);
1507
1508	DMDEBUG("(%s): Using %zu B for zone information",
1509	zmd->devname, sizeof(struct dm_zone) * zmd->nr_zones);
1510
1511	if (zmd->nr_devs > 1) {
1512	ret = dmz_emulate_zones(zmd, dev: &zmd->dev[0]);
1513	if (ret < 0) {
1514	DMDEBUG("(%s): Failed to emulate zones, error %d",
1515	zmd->devname, ret);
1516	dmz_drop_zones(zmd);
1517	return ret;
1518	}
1519
1520	/*
1521	* Primary superblock zone is always at zone 0 when multiple
1522	* drives are present.
1523	*/
1524	zmd->sb[0].zone = dmz_get(zmd, zone_id: 0);
1525
1526	for (i = 1; i < zmd->nr_devs; i++) {
1527	zoned_dev = &zmd->dev[i];
1528
1529	ret = blkdev_report_zones(bdev: zoned_dev->bdev, sector: 0,
1530	BLK_ALL_ZONES,
1531	cb: dmz_init_zone, data: zoned_dev);
1532	if (ret < 0) {
1533	DMDEBUG("(%s): Failed to report zones, error %d",
1534	zmd->devname, ret);
1535	dmz_drop_zones(zmd);
1536	return ret;
1537	}
1538	}
1539	return 0;
1540	}
1541
1542	/*
1543	* Get zone information and initialize zone descriptors. At the same
1544	* time, determine where the super block should be: first block of the
1545	* first randomly writable zone.
1546	*/
1547	ret = blkdev_report_zones(bdev: zoned_dev->bdev, sector: 0, BLK_ALL_ZONES,
1548	cb: dmz_init_zone, data: zoned_dev);
1549	if (ret < 0) {
1550	DMDEBUG("(%s): Failed to report zones, error %d",
1551	zmd->devname, ret);
1552	dmz_drop_zones(zmd);
1553	return ret;
1554	}
1555
1556	return 0;
1557	}
1558
1559	static int dmz_update_zone_cb(struct blk_zone *blkz, unsigned int idx,
1560	void *data)
1561	{
1562	struct dm_zone *zone = data;
1563
1564	clear_bit(nr: DMZ_OFFLINE, addr: &zone->flags);
1565	clear_bit(nr: DMZ_READ_ONLY, addr: &zone->flags);
1566	if (blkz->cond == BLK_ZONE_COND_OFFLINE)
1567	set_bit(nr: DMZ_OFFLINE, addr: &zone->flags);
1568	else if (blkz->cond == BLK_ZONE_COND_READONLY)
1569	set_bit(nr: DMZ_READ_ONLY, addr: &zone->flags);
1570
1571	if (dmz_is_seq(zone))
1572	zone->wp_block = dmz_sect2blk(blkz->wp - blkz->start);
1573	else
1574	zone->wp_block = 0;
1575	return 0;
1576	}
1577
1578	/*
1579	* Update a zone information.
1580	*/
1581	static int dmz_update_zone(struct dmz_metadata *zmd, struct dm_zone *zone)
1582	{
1583	struct dmz_dev *dev = zone->dev;
1584	unsigned int noio_flag;
1585	int ret;
1586
1587	if (dev->flags & DMZ_BDEV_REGULAR)
1588	return 0;
1589
1590	/*
1591	* Get zone information from disk. Since blkdev_report_zones() uses
1592	* GFP_KERNEL by default for memory allocations, set the per-task
1593	* PF_MEMALLOC_NOIO flag so that all allocations are done as if
1594	* GFP_NOIO was specified.
1595	*/
1596	noio_flag = memalloc_noio_save();
1597	ret = blkdev_report_zones(bdev: dev->bdev, sector: dmz_start_sect(zmd, zone), nr_zones: 1,
1598	cb: dmz_update_zone_cb, data: zone);
1599	memalloc_noio_restore(flags: noio_flag);
1600
1601	if (ret == 0)
1602	ret = -EIO;
1603	if (ret < 0) {
1604	dmz_dev_err(dev, "Get zone %u report failed",
1605	zone->id);
1606	dmz_check_bdev(dmz_dev: dev);
1607	return ret;
1608	}
1609
1610	return 0;
1611	}
1612
1613	/*
1614	* Check a zone write pointer position when the zone is marked
1615	* with the sequential write error flag.
1616	*/
1617	static int dmz_handle_seq_write_err(struct dmz_metadata *zmd,
1618	struct dm_zone *zone)
1619	{
1620	struct dmz_dev *dev = zone->dev;
1621	unsigned int wp = 0;
1622	int ret;
1623
1624	wp = zone->wp_block;
1625	ret = dmz_update_zone(zmd, zone);
1626	if (ret)
1627	return ret;
1628
1629	dmz_dev_warn(dev, "Processing zone %u write error (zone wp %u/%u)",
1630	zone->id, zone->wp_block, wp);
1631
1632	if (zone->wp_block < wp) {
1633	dmz_invalidate_blocks(zmd, zone, chunk_block: zone->wp_block,
1634	nr_blocks: wp - zone->wp_block);
1635	}
1636
1637	return 0;
1638	}
1639
1640	/*
1641	* Reset a zone write pointer.
1642	*/
1643	static int dmz_reset_zone(struct dmz_metadata *zmd, struct dm_zone *zone)
1644	{
1645	int ret;
1646
1647	/*
1648	* Ignore offline zones, read only zones,
1649	* and conventional zones.
1650	*/
1651	if (dmz_is_offline(zone) ||
1652	dmz_is_readonly(zone) ||
1653	dmz_is_rnd(zone))
1654	return 0;
1655
1656	if (!dmz_is_empty(zone) || dmz_seq_write_err(zone)) {
1657	struct dmz_dev *dev = zone->dev;
1658
1659	ret = blkdev_zone_mgmt(bdev: dev->bdev, op: REQ_OP_ZONE_RESET,
1660	sectors: dmz_start_sect(zmd, zone),
1661	nr_sectors: zmd->zone_nr_sectors, GFP_NOIO);
1662	if (ret) {
1663	dmz_dev_err(dev, "Reset zone %u failed %d",
1664	zone->id, ret);
1665	return ret;
1666	}
1667	}
1668
1669	/* Clear write error bit and rewind write pointer position */
1670	clear_bit(nr: DMZ_SEQ_WRITE_ERR, addr: &zone->flags);
1671	zone->wp_block = 0;
1672
1673	return 0;
1674	}
1675
1676	static void dmz_get_zone_weight(struct dmz_metadata *zmd, struct dm_zone *zone);
1677
1678	/*
1679	* Initialize chunk mapping.
1680	*/
1681	static int dmz_load_mapping(struct dmz_metadata *zmd)
1682	{
1683	struct dm_zone *dzone, *bzone;
1684	struct dmz_mblock *dmap_mblk = NULL;
1685	struct dmz_map *dmap;
1686	unsigned int i = 0, e = 0, chunk = 0;
1687	unsigned int dzone_id;
1688	unsigned int bzone_id;
1689
1690	/* Metadata block array for the chunk mapping table */
1691	zmd->map_mblk = kcalloc(n: zmd->nr_map_blocks,
1692	size: sizeof(struct dmz_mblk *), GFP_KERNEL);
1693	if (!zmd->map_mblk)
1694	return -ENOMEM;
1695
1696	/* Get chunk mapping table blocks and initialize zone mapping */
1697	while (chunk < zmd->nr_chunks) {
1698	if (!dmap_mblk) {
1699	/* Get mapping block */
1700	dmap_mblk = dmz_get_mblock(zmd, mblk_no: i + 1);
1701	if (IS_ERR(ptr: dmap_mblk))
1702	return PTR_ERR(ptr: dmap_mblk);
1703	zmd->map_mblk[i] = dmap_mblk;
1704	dmap = dmap_mblk->data;
1705	i++;
1706	e = 0;
1707	}
1708
1709	/* Check data zone */
1710	dzone_id = le32_to_cpu(dmap[e].dzone_id);
1711	if (dzone_id == DMZ_MAP_UNMAPPED)
1712	goto next;
1713
1714	if (dzone_id >= zmd->nr_zones) {
1715	dmz_zmd_err(zmd, "Chunk %u mapping: invalid data zone ID %u",
1716	chunk, dzone_id);
1717	return -EIO;
1718	}
1719
1720	dzone = dmz_get(zmd, zone_id: dzone_id);
1721	if (!dzone) {
1722	dmz_zmd_err(zmd, "Chunk %u mapping: data zone %u not present",
1723	chunk, dzone_id);
1724	return -EIO;
1725	}
1726	set_bit(nr: DMZ_DATA, addr: &dzone->flags);
1727	dzone->chunk = chunk;
1728	dmz_get_zone_weight(zmd, zone: dzone);
1729
1730	if (dmz_is_cache(dzone))
1731	list_add_tail(new: &dzone->link, head: &zmd->map_cache_list);
1732	else if (dmz_is_rnd(dzone))
1733	list_add_tail(new: &dzone->link, head: &dzone->dev->map_rnd_list);
1734	else
1735	list_add_tail(new: &dzone->link, head: &dzone->dev->map_seq_list);
1736
1737	/* Check buffer zone */
1738	bzone_id = le32_to_cpu(dmap[e].bzone_id);
1739	if (bzone_id == DMZ_MAP_UNMAPPED)
1740	goto next;
1741
1742	if (bzone_id >= zmd->nr_zones) {
1743	dmz_zmd_err(zmd, "Chunk %u mapping: invalid buffer zone ID %u",
1744	chunk, bzone_id);
1745	return -EIO;
1746	}
1747
1748	bzone = dmz_get(zmd, zone_id: bzone_id);
1749	if (!bzone) {
1750	dmz_zmd_err(zmd, "Chunk %u mapping: buffer zone %u not present",
1751	chunk, bzone_id);
1752	return -EIO;
1753	}
1754	if (!dmz_is_rnd(bzone) && !dmz_is_cache(bzone)) {
1755	dmz_zmd_err(zmd, "Chunk %u mapping: invalid buffer zone %u",
1756	chunk, bzone_id);
1757	return -EIO;
1758	}
1759
1760	set_bit(nr: DMZ_DATA, addr: &bzone->flags);
1761	set_bit(nr: DMZ_BUF, addr: &bzone->flags);
1762	bzone->chunk = chunk;
1763	bzone->bzone = dzone;
1764	dzone->bzone = bzone;
1765	dmz_get_zone_weight(zmd, zone: bzone);
1766	if (dmz_is_cache(bzone))
1767	list_add_tail(new: &bzone->link, head: &zmd->map_cache_list);
1768	else
1769	list_add_tail(new: &bzone->link, head: &bzone->dev->map_rnd_list);
1770	next:
1771	chunk++;
1772	e++;
1773	if (e >= DMZ_MAP_ENTRIES)
1774	dmap_mblk = NULL;
1775	}
1776
1777	/*
1778	* At this point, only meta zones and mapped data zones were
1779	* fully initialized. All remaining zones are unmapped data
1780	* zones. Finish initializing those here.
1781	*/
1782	for (i = 0; i < zmd->nr_zones; i++) {
1783	dzone = dmz_get(zmd, zone_id: i);
1784	if (!dzone)
1785	continue;
1786	if (dmz_is_meta(dzone))
1787	continue;
1788	if (dmz_is_offline(dzone))
1789	continue;
1790
1791	if (dmz_is_cache(dzone))
1792	zmd->nr_cache++;
1793	else if (dmz_is_rnd(dzone))
1794	dzone->dev->nr_rnd++;
1795	else
1796	dzone->dev->nr_seq++;
1797
1798	if (dmz_is_data(dzone)) {
1799	/* Already initialized */
1800	continue;
1801	}
1802
1803	/* Unmapped data zone */
1804	set_bit(nr: DMZ_DATA, addr: &dzone->flags);
1805	dzone->chunk = DMZ_MAP_UNMAPPED;
1806	if (dmz_is_cache(dzone)) {
1807	list_add_tail(new: &dzone->link, head: &zmd->unmap_cache_list);
1808	atomic_inc(v: &zmd->unmap_nr_cache);
1809	} else if (dmz_is_rnd(dzone)) {
1810	list_add_tail(new: &dzone->link,
1811	head: &dzone->dev->unmap_rnd_list);
1812	atomic_inc(v: &dzone->dev->unmap_nr_rnd);
1813	} else if (atomic_read(v: &zmd->nr_reserved_seq_zones) < zmd->nr_reserved_seq) {
1814	list_add_tail(new: &dzone->link, head: &zmd->reserved_seq_zones_list);
1815	set_bit(nr: DMZ_RESERVED, addr: &dzone->flags);
1816	atomic_inc(v: &zmd->nr_reserved_seq_zones);
1817	dzone->dev->nr_seq--;
1818	} else {
1819	list_add_tail(new: &dzone->link,
1820	head: &dzone->dev->unmap_seq_list);
1821	atomic_inc(v: &dzone->dev->unmap_nr_seq);
1822	}
1823	}
1824
1825	return 0;
1826	}
1827
1828	/*
1829	* Set a data chunk mapping.
1830	*/
1831	static void dmz_set_chunk_mapping(struct dmz_metadata *zmd, unsigned int chunk,
1832	unsigned int dzone_id, unsigned int bzone_id)
1833	{
1834	struct dmz_mblock *dmap_mblk = zmd->map_mblk[chunk >> DMZ_MAP_ENTRIES_SHIFT];
1835	struct dmz_map *dmap = dmap_mblk->data;
1836	int map_idx = chunk & DMZ_MAP_ENTRIES_MASK;
1837
1838	dmap[map_idx].dzone_id = cpu_to_le32(dzone_id);
1839	dmap[map_idx].bzone_id = cpu_to_le32(bzone_id);
1840	dmz_dirty_mblock(zmd, mblk: dmap_mblk);
1841	}
1842
1843	/*
1844	* The list of mapped zones is maintained in LRU order.
1845	* This rotates a zone at the end of its map list.
1846	*/
1847	static void __dmz_lru_zone(struct dmz_metadata *zmd, struct dm_zone *zone)
1848	{
1849	if (list_empty(head: &zone->link))
1850	return;
1851
1852	list_del_init(entry: &zone->link);
1853	if (dmz_is_seq(zone)) {
1854	/* LRU rotate sequential zone */
1855	list_add_tail(new: &zone->link, head: &zone->dev->map_seq_list);
1856	} else if (dmz_is_cache(zone)) {
1857	/* LRU rotate cache zone */
1858	list_add_tail(new: &zone->link, head: &zmd->map_cache_list);
1859	} else {
1860	/* LRU rotate random zone */
1861	list_add_tail(new: &zone->link, head: &zone->dev->map_rnd_list);
1862	}
1863	}
1864
1865	/*
1866	* The list of mapped random zones is maintained
1867	* in LRU order. This rotates a zone at the end of the list.
1868	*/
1869	static void dmz_lru_zone(struct dmz_metadata *zmd, struct dm_zone *zone)
1870	{
1871	__dmz_lru_zone(zmd, zone);
1872	if (zone->bzone)
1873	__dmz_lru_zone(zmd, zone: zone->bzone);
1874	}
1875
1876	/*
1877	* Wait for any zone to be freed.
1878	*/
1879	static void dmz_wait_for_free_zones(struct dmz_metadata *zmd)
1880	{
1881	DEFINE_WAIT(wait);
1882
1883	prepare_to_wait(wq_head: &zmd->free_wq, wq_entry: &wait, TASK_UNINTERRUPTIBLE);
1884	dmz_unlock_map(zmd);
1885	dmz_unlock_metadata(zmd);
1886
1887	io_schedule_timeout(HZ);
1888
1889	dmz_lock_metadata(zmd);
1890	dmz_lock_map(zmd);
1891	finish_wait(wq_head: &zmd->free_wq, wq_entry: &wait);
1892	}
1893
1894	/*
1895	* Lock a zone for reclaim (set the zone RECLAIM bit).
1896	* Returns false if the zone cannot be locked or if it is already locked
1897	* and 1 otherwise.
1898	*/
1899	int dmz_lock_zone_reclaim(struct dm_zone *zone)
1900	{
1901	/* Active zones cannot be reclaimed */
1902	if (dmz_is_active(zone))
1903	return 0;
1904
1905	return !test_and_set_bit(nr: DMZ_RECLAIM, addr: &zone->flags);
1906	}
1907
1908	/*
1909	* Clear a zone reclaim flag.
1910	*/
1911	void dmz_unlock_zone_reclaim(struct dm_zone *zone)
1912	{
1913	WARN_ON(dmz_is_active(zone));
1914	WARN_ON(!dmz_in_reclaim(zone));
1915
1916	clear_bit_unlock(nr: DMZ_RECLAIM, addr: &zone->flags);
1917	smp_mb__after_atomic();
1918	wake_up_bit(word: &zone->flags, bit: DMZ_RECLAIM);
1919	}
1920
1921	/*
1922	* Wait for a zone reclaim to complete.
1923	*/
1924	static void dmz_wait_for_reclaim(struct dmz_metadata *zmd, struct dm_zone *zone)
1925	{
1926	dmz_unlock_map(zmd);
1927	dmz_unlock_metadata(zmd);
1928	set_bit(nr: DMZ_RECLAIM_TERMINATE, addr: &zone->flags);
1929	wait_on_bit_timeout(word: &zone->flags, bit: DMZ_RECLAIM, TASK_UNINTERRUPTIBLE, HZ);
1930	clear_bit(nr: DMZ_RECLAIM_TERMINATE, addr: &zone->flags);
1931	dmz_lock_metadata(zmd);
1932	dmz_lock_map(zmd);
1933	}
1934
1935	/*
1936	* Select a cache or random write zone for reclaim.
1937	*/
1938	static struct dm_zone *dmz_get_rnd_zone_for_reclaim(struct dmz_metadata *zmd,
1939	unsigned int idx, bool idle)
1940	{
1941	struct dm_zone *dzone = NULL;
1942	struct dm_zone *zone, *maxw_z = NULL;
1943	struct list_head *zone_list;
1944
1945	/* If we have cache zones select from the cache zone list */
1946	if (zmd->nr_cache) {
1947	zone_list = &zmd->map_cache_list;
1948	/* Try to relaim random zones, too, when idle */
1949	if (idle && list_empty(head: zone_list))
1950	zone_list = &zmd->dev[idx].map_rnd_list;
1951	} else
1952	zone_list = &zmd->dev[idx].map_rnd_list;
1953
1954	/*
1955	* Find the buffer zone with the heaviest weight or the first (oldest)
1956	* data zone that can be reclaimed.
1957	*/
1958	list_for_each_entry(zone, zone_list, link) {
1959	if (dmz_is_buf(zone)) {
1960	dzone = zone->bzone;
1961	if (dmz_is_rnd(dzone) && dzone->dev->dev_idx != idx)
1962	continue;
1963	if (!maxw_z || maxw_z->weight < dzone->weight)
1964	maxw_z = dzone;
1965	} else {
1966	dzone = zone;
1967	if (dmz_lock_zone_reclaim(zone: dzone))
1968	return dzone;
1969	}
1970	}
1971
1972	if (maxw_z && dmz_lock_zone_reclaim(zone: maxw_z))
1973	return maxw_z;
1974
1975	/*
1976	* If we come here, none of the zones inspected could be locked for
1977	* reclaim. Try again, being more aggressive, that is, find the
1978	* first zone that can be reclaimed regardless of its weitght.
1979	*/
1980	list_for_each_entry(zone, zone_list, link) {
1981	if (dmz_is_buf(zone)) {
1982	dzone = zone->bzone;
1983	if (dmz_is_rnd(dzone) && dzone->dev->dev_idx != idx)
1984	continue;
1985	} else
1986	dzone = zone;
1987	if (dmz_lock_zone_reclaim(zone: dzone))
1988	return dzone;
1989	}
1990
1991	return NULL;
1992	}
1993
1994	/*
1995	* Select a buffered sequential zone for reclaim.
1996	*/
1997	static struct dm_zone *dmz_get_seq_zone_for_reclaim(struct dmz_metadata *zmd,
1998	unsigned int idx)
1999	{
2000	struct dm_zone *zone;
2001
2002	list_for_each_entry(zone, &zmd->dev[idx].map_seq_list, link) {
2003	if (!zone->bzone)
2004	continue;
2005	if (dmz_lock_zone_reclaim(zone))
2006	return zone;
2007	}
2008
2009	return NULL;
2010	}
2011
2012	/*
2013	* Select a zone for reclaim.
2014	*/
2015	struct dm_zone *dmz_get_zone_for_reclaim(struct dmz_metadata *zmd,
2016	unsigned int dev_idx, bool idle)
2017	{
2018	struct dm_zone *zone = NULL;
2019
2020	/*
2021	* Search for a zone candidate to reclaim: 2 cases are possible.
2022	* (1) There is no free sequential zones. Then a random data zone
2023	* cannot be reclaimed. So choose a sequential zone to reclaim so
2024	* that afterward a random zone can be reclaimed.
2025	* (2) At least one free sequential zone is available, then choose
2026	* the oldest random zone (data or buffer) that can be locked.
2027	*/
2028	dmz_lock_map(zmd);
2029	if (list_empty(head: &zmd->reserved_seq_zones_list))
2030	zone = dmz_get_seq_zone_for_reclaim(zmd, idx: dev_idx);
2031	if (!zone)
2032	zone = dmz_get_rnd_zone_for_reclaim(zmd, idx: dev_idx, idle);
2033	dmz_unlock_map(zmd);
2034
2035	return zone;
2036	}
2037
2038	/*
2039	* Get the zone mapping a chunk, if the chunk is mapped already.
2040	* If no mapping exist and the operation is WRITE, a zone is
2041	* allocated and used to map the chunk.
2042	* The zone returned will be set to the active state.
2043	*/
2044	struct dm_zone *dmz_get_chunk_mapping(struct dmz_metadata *zmd,
2045	unsigned int chunk, enum req_op op)
2046	{
2047	struct dmz_mblock *dmap_mblk = zmd->map_mblk[chunk >> DMZ_MAP_ENTRIES_SHIFT];
2048	struct dmz_map *dmap = dmap_mblk->data;
2049	int dmap_idx = chunk & DMZ_MAP_ENTRIES_MASK;
2050	unsigned int dzone_id;
2051	struct dm_zone *dzone = NULL;
2052	int ret = 0;
2053	int alloc_flags = zmd->nr_cache ? DMZ_ALLOC_CACHE : DMZ_ALLOC_RND;
2054
2055	dmz_lock_map(zmd);
2056	again:
2057	/* Get the chunk mapping */
2058	dzone_id = le32_to_cpu(dmap[dmap_idx].dzone_id);
2059	if (dzone_id == DMZ_MAP_UNMAPPED) {
2060	/*
2061	* Read or discard in unmapped chunks are fine. But for
2062	* writes, we need a mapping, so get one.
2063	*/
2064	if (op != REQ_OP_WRITE)
2065	goto out;
2066
2067	/* Allocate a random zone */
2068	dzone = dmz_alloc_zone(zmd, dev_idx: 0, flags: alloc_flags);
2069	if (!dzone) {
2070	if (dmz_dev_is_dying(zmd)) {
2071	dzone = ERR_PTR(error: -EIO);
2072	goto out;
2073	}
2074	dmz_wait_for_free_zones(zmd);
2075	goto again;
2076	}
2077
2078	dmz_map_zone(zmd, zone: dzone, chunk);
2079
2080	} else {
2081	/* The chunk is already mapped: get the mapping zone */
2082	dzone = dmz_get(zmd, zone_id: dzone_id);
2083	if (!dzone) {
2084	dzone = ERR_PTR(error: -EIO);
2085	goto out;
2086	}
2087	if (dzone->chunk != chunk) {
2088	dzone = ERR_PTR(error: -EIO);
2089	goto out;
2090	}
2091
2092	/* Repair write pointer if the sequential dzone has error */
2093	if (dmz_seq_write_err(dzone)) {
2094	ret = dmz_handle_seq_write_err(zmd, zone: dzone);
2095	if (ret) {
2096	dzone = ERR_PTR(error: -EIO);
2097	goto out;
2098	}
2099	clear_bit(nr: DMZ_SEQ_WRITE_ERR, addr: &dzone->flags);
2100	}
2101	}
2102
2103	/*
2104	* If the zone is being reclaimed, the chunk mapping may change
2105	* to a different zone. So wait for reclaim and retry. Otherwise,
2106	* activate the zone (this will prevent reclaim from touching it).
2107	*/
2108	if (dmz_in_reclaim(dzone)) {
2109	dmz_wait_for_reclaim(zmd, zone: dzone);
2110	goto again;
2111	}
2112	dmz_activate_zone(zone: dzone);
2113	dmz_lru_zone(zmd, zone: dzone);
2114	out:
2115	dmz_unlock_map(zmd);
2116
2117	return dzone;
2118	}
2119
2120	/*
2121	* Write and discard change the block validity of data zones and their buffer
2122	* zones. Check here that valid blocks are still present. If all blocks are
2123	* invalid, the zones can be unmapped on the fly without waiting for reclaim
2124	* to do it.
2125	*/
2126	void dmz_put_chunk_mapping(struct dmz_metadata *zmd, struct dm_zone *dzone)
2127	{
2128	struct dm_zone *bzone;
2129
2130	dmz_lock_map(zmd);
2131
2132	bzone = dzone->bzone;
2133	if (bzone) {
2134	if (dmz_weight(bzone))
2135	dmz_lru_zone(zmd, zone: bzone);
2136	else {
2137	/* Empty buffer zone: reclaim it */
2138	dmz_unmap_zone(zmd, zone: bzone);
2139	dmz_free_zone(zmd, zone: bzone);
2140	bzone = NULL;
2141	}
2142	}
2143
2144	/* Deactivate the data zone */
2145	dmz_deactivate_zone(zone: dzone);
2146	if (dmz_is_active(zone: dzone) || bzone || dmz_weight(dzone))
2147	dmz_lru_zone(zmd, zone: dzone);
2148	else {
2149	/* Unbuffered inactive empty data zone: reclaim it */
2150	dmz_unmap_zone(zmd, zone: dzone);
2151	dmz_free_zone(zmd, zone: dzone);
2152	}
2153
2154	dmz_unlock_map(zmd);
2155	}
2156
2157	/*
2158	* Allocate and map a random zone to buffer a chunk
2159	* already mapped to a sequential zone.
2160	*/
2161	struct dm_zone *dmz_get_chunk_buffer(struct dmz_metadata *zmd,
2162	struct dm_zone *dzone)
2163	{
2164	struct dm_zone *bzone;
2165	int alloc_flags = zmd->nr_cache ? DMZ_ALLOC_CACHE : DMZ_ALLOC_RND;
2166
2167	dmz_lock_map(zmd);
2168	again:
2169	bzone = dzone->bzone;
2170	if (bzone)
2171	goto out;
2172
2173	/* Allocate a random zone */
2174	bzone = dmz_alloc_zone(zmd, dev_idx: 0, flags: alloc_flags);
2175	if (!bzone) {
2176	if (dmz_dev_is_dying(zmd)) {
2177	bzone = ERR_PTR(error: -EIO);
2178	goto out;
2179	}
2180	dmz_wait_for_free_zones(zmd);
2181	goto again;
2182	}
2183
2184	/* Update the chunk mapping */
2185	dmz_set_chunk_mapping(zmd, chunk: dzone->chunk, dzone_id: dzone->id, bzone_id: bzone->id);
2186
2187	set_bit(nr: DMZ_BUF, addr: &bzone->flags);
2188	bzone->chunk = dzone->chunk;
2189	bzone->bzone = dzone;
2190	dzone->bzone = bzone;
2191	if (dmz_is_cache(bzone))
2192	list_add_tail(new: &bzone->link, head: &zmd->map_cache_list);
2193	else
2194	list_add_tail(new: &bzone->link, head: &bzone->dev->map_rnd_list);
2195	out:
2196	dmz_unlock_map(zmd);
2197
2198	return bzone;
2199	}
2200
2201	/*
2202	* Get an unmapped (free) zone.
2203	* This must be called with the mapping lock held.
2204	*/
2205	struct dm_zone *dmz_alloc_zone(struct dmz_metadata *zmd, unsigned int dev_idx,
2206	unsigned long flags)
2207	{
2208	struct list_head *list;
2209	struct dm_zone *zone;
2210	int i;
2211
2212	/* Schedule reclaim to ensure free zones are available */
2213	if (!(flags & DMZ_ALLOC_RECLAIM)) {
2214	for (i = 0; i < zmd->nr_devs; i++)
2215	dmz_schedule_reclaim(zrc: zmd->dev[i].reclaim);
2216	}
2217
2218	i = 0;
2219	again:
2220	if (flags & DMZ_ALLOC_CACHE)
2221	list = &zmd->unmap_cache_list;
2222	else if (flags & DMZ_ALLOC_RND)
2223	list = &zmd->dev[dev_idx].unmap_rnd_list;
2224	else
2225	list = &zmd->dev[dev_idx].unmap_seq_list;
2226
2227	if (list_empty(head: list)) {
2228	/*
2229	* No free zone: return NULL if this is for not reclaim.
2230	*/
2231	if (!(flags & DMZ_ALLOC_RECLAIM))
2232	return NULL;
2233	/*
2234	* Try to allocate from other devices
2235	*/
2236	if (i < zmd->nr_devs) {
2237	dev_idx = (dev_idx + 1) % zmd->nr_devs;
2238	i++;
2239	goto again;
2240	}
2241
2242	/*
2243	* Fallback to the reserved sequential zones
2244	*/
2245	zone = list_first_entry_or_null(&zmd->reserved_seq_zones_list,
2246	struct dm_zone, link);
2247	if (zone) {
2248	list_del_init(entry: &zone->link);
2249	atomic_dec(v: &zmd->nr_reserved_seq_zones);
2250	}
2251	return zone;
2252	}
2253
2254	zone = list_first_entry(list, struct dm_zone, link);
2255	list_del_init(entry: &zone->link);
2256
2257	if (dmz_is_cache(zone))
2258	atomic_dec(v: &zmd->unmap_nr_cache);
2259	else if (dmz_is_rnd(zone))
2260	atomic_dec(v: &zone->dev->unmap_nr_rnd);
2261	else
2262	atomic_dec(v: &zone->dev->unmap_nr_seq);
2263
2264	if (dmz_is_offline(zone)) {
2265	dmz_zmd_warn(zmd, "Zone %u is offline", zone->id);
2266	zone = NULL;
2267	goto again;
2268	}
2269	if (dmz_is_meta(zone)) {
2270	dmz_zmd_warn(zmd, "Zone %u has metadata", zone->id);
2271	zone = NULL;
2272	goto again;
2273	}
2274	return zone;
2275	}
2276
2277	/*
2278	* Free a zone.
2279	* This must be called with the mapping lock held.
2280	*/
2281	void dmz_free_zone(struct dmz_metadata *zmd, struct dm_zone *zone)
2282	{
2283	/* If this is a sequential zone, reset it */
2284	if (dmz_is_seq(zone))
2285	dmz_reset_zone(zmd, zone);
2286
2287	/* Return the zone to its type unmap list */
2288	if (dmz_is_cache(zone)) {
2289	list_add_tail(new: &zone->link, head: &zmd->unmap_cache_list);
2290	atomic_inc(v: &zmd->unmap_nr_cache);
2291	} else if (dmz_is_rnd(zone)) {
2292	list_add_tail(new: &zone->link, head: &zone->dev->unmap_rnd_list);
2293	atomic_inc(v: &zone->dev->unmap_nr_rnd);
2294	} else if (dmz_is_reserved(zone)) {
2295	list_add_tail(new: &zone->link, head: &zmd->reserved_seq_zones_list);
2296	atomic_inc(v: &zmd->nr_reserved_seq_zones);
2297	} else {
2298	list_add_tail(new: &zone->link, head: &zone->dev->unmap_seq_list);
2299	atomic_inc(v: &zone->dev->unmap_nr_seq);
2300	}
2301
2302	wake_up_all(&zmd->free_wq);
2303	}
2304
2305	/*
2306	* Map a chunk to a zone.
2307	* This must be called with the mapping lock held.
2308	*/
2309	void dmz_map_zone(struct dmz_metadata *zmd, struct dm_zone *dzone,
2310	unsigned int chunk)
2311	{
2312	/* Set the chunk mapping */
2313	dmz_set_chunk_mapping(zmd, chunk, dzone_id: dzone->id,
2314	DMZ_MAP_UNMAPPED);
2315	dzone->chunk = chunk;
2316	if (dmz_is_cache(dzone))
2317	list_add_tail(new: &dzone->link, head: &zmd->map_cache_list);
2318	else if (dmz_is_rnd(dzone))
2319	list_add_tail(new: &dzone->link, head: &dzone->dev->map_rnd_list);
2320	else
2321	list_add_tail(new: &dzone->link, head: &dzone->dev->map_seq_list);
2322	}
2323
2324	/*
2325	* Unmap a zone.
2326	* This must be called with the mapping lock held.
2327	*/
2328	void dmz_unmap_zone(struct dmz_metadata *zmd, struct dm_zone *zone)
2329	{
2330	unsigned int chunk = zone->chunk;
2331	unsigned int dzone_id;
2332
2333	if (chunk == DMZ_MAP_UNMAPPED) {
2334	/* Already unmapped */
2335	return;
2336	}
2337
2338	if (test_and_clear_bit(nr: DMZ_BUF, addr: &zone->flags)) {
2339	/*
2340	* Unmapping the chunk buffer zone: clear only
2341	* the chunk buffer mapping
2342	*/
2343	dzone_id = zone->bzone->id;
2344	zone->bzone->bzone = NULL;
2345	zone->bzone = NULL;
2346
2347	} else {
2348	/*
2349	* Unmapping the chunk data zone: the zone must
2350	* not be buffered.
2351	*/
2352	if (WARN_ON(zone->bzone)) {
2353	zone->bzone->bzone = NULL;
2354	zone->bzone = NULL;
2355	}
2356	dzone_id = DMZ_MAP_UNMAPPED;
2357	}
2358
2359	dmz_set_chunk_mapping(zmd, chunk, dzone_id, DMZ_MAP_UNMAPPED);
2360
2361	zone->chunk = DMZ_MAP_UNMAPPED;
2362	list_del_init(entry: &zone->link);
2363	}
2364
2365	/*
2366	* Set @nr_bits bits in @bitmap starting from @bit.
2367	* Return the number of bits changed from 0 to 1.
2368	*/
2369	static unsigned int dmz_set_bits(unsigned long *bitmap,
2370	unsigned int bit, unsigned int nr_bits)
2371	{
2372	unsigned long *addr;
2373	unsigned int end = bit + nr_bits;
2374	unsigned int n = 0;
2375
2376	while (bit < end) {
2377	if (((bit & (BITS_PER_LONG - 1)) == 0) &&
2378	((end - bit) >= BITS_PER_LONG)) {
2379	/* Try to set the whole word at once */
2380	addr = bitmap + BIT_WORD(bit);
2381	if (*addr == 0) {
2382	*addr = ULONG_MAX;
2383	n += BITS_PER_LONG;
2384	bit += BITS_PER_LONG;
2385	continue;
2386	}
2387	}
2388
2389	if (!test_and_set_bit(nr: bit, addr: bitmap))
2390	n++;
2391	bit++;
2392	}
2393
2394	return n;
2395	}
2396
2397	/*
2398	* Get the bitmap block storing the bit for chunk_block in zone.
2399	*/
2400	static struct dmz_mblock *dmz_get_bitmap(struct dmz_metadata *zmd,
2401	struct dm_zone *zone,
2402	sector_t chunk_block)
2403	{
2404	sector_t bitmap_block = 1 + zmd->nr_map_blocks +
2405	(sector_t)(zone->id * zmd->zone_nr_bitmap_blocks) +
2406	(chunk_block >> DMZ_BLOCK_SHIFT_BITS);
2407
2408	return dmz_get_mblock(zmd, mblk_no: bitmap_block);
2409	}
2410
2411	/*
2412	* Copy the valid blocks bitmap of from_zone to the bitmap of to_zone.
2413	*/
2414	int dmz_copy_valid_blocks(struct dmz_metadata *zmd, struct dm_zone *from_zone,
2415	struct dm_zone *to_zone)
2416	{
2417	struct dmz_mblock *from_mblk, *to_mblk;
2418	sector_t chunk_block = 0;
2419
2420	/* Get the zones bitmap blocks */
2421	while (chunk_block < zmd->zone_nr_blocks) {
2422	from_mblk = dmz_get_bitmap(zmd, zone: from_zone, chunk_block);
2423	if (IS_ERR(ptr: from_mblk))
2424	return PTR_ERR(ptr: from_mblk);
2425	to_mblk = dmz_get_bitmap(zmd, zone: to_zone, chunk_block);
2426	if (IS_ERR(ptr: to_mblk)) {
2427	dmz_release_mblock(zmd, mblk: from_mblk);
2428	return PTR_ERR(ptr: to_mblk);
2429	}
2430
2431	memcpy(to_mblk->data, from_mblk->data, DMZ_BLOCK_SIZE);
2432	dmz_dirty_mblock(zmd, mblk: to_mblk);
2433
2434	dmz_release_mblock(zmd, mblk: to_mblk);
2435	dmz_release_mblock(zmd, mblk: from_mblk);
2436
2437	chunk_block += zmd->zone_bits_per_mblk;
2438	}
2439
2440	to_zone->weight = from_zone->weight;
2441
2442	return 0;
2443	}
2444
2445	/*
2446	* Merge the valid blocks bitmap of from_zone into the bitmap of to_zone,
2447	* starting from chunk_block.
2448	*/
2449	int dmz_merge_valid_blocks(struct dmz_metadata *zmd, struct dm_zone *from_zone,
2450	struct dm_zone *to_zone, sector_t chunk_block)
2451	{
2452	unsigned int nr_blocks;
2453	int ret;
2454
2455	/* Get the zones bitmap blocks */
2456	while (chunk_block < zmd->zone_nr_blocks) {
2457	/* Get a valid region from the source zone */
2458	ret = dmz_first_valid_block(zmd, zone: from_zone, chunk_block: &chunk_block);
2459	if (ret <= 0)
2460	return ret;
2461
2462	nr_blocks = ret;
2463	ret = dmz_validate_blocks(zmd, zone: to_zone, chunk_block, nr_blocks);
2464	if (ret)
2465	return ret;
2466
2467	chunk_block += nr_blocks;
2468	}
2469
2470	return 0;
2471	}
2472
2473	/*
2474	* Validate all the blocks in the range [block..block+nr_blocks-1].
2475	*/
2476	int dmz_validate_blocks(struct dmz_metadata *zmd, struct dm_zone *zone,
2477	sector_t chunk_block, unsigned int nr_blocks)
2478	{
2479	unsigned int count, bit, nr_bits;
2480	unsigned int zone_nr_blocks = zmd->zone_nr_blocks;
2481	struct dmz_mblock *mblk;
2482	unsigned int n = 0;
2483
2484	dmz_zmd_debug(zmd, "=> VALIDATE zone %u, block %llu, %u blocks",
2485	zone->id, (unsigned long long)chunk_block,
2486	nr_blocks);
2487
2488	WARN_ON(chunk_block + nr_blocks > zone_nr_blocks);
2489
2490	while (nr_blocks) {
2491	/* Get bitmap block */
2492	mblk = dmz_get_bitmap(zmd, zone, chunk_block);
2493	if (IS_ERR(ptr: mblk))
2494	return PTR_ERR(ptr: mblk);
2495
2496	/* Set bits */
2497	bit = chunk_block & DMZ_BLOCK_MASK_BITS;
2498	nr_bits = min(nr_blocks, zmd->zone_bits_per_mblk - bit);
2499
2500	count = dmz_set_bits(bitmap: (unsigned long *)mblk->data, bit, nr_bits);
2501	if (count) {
2502	dmz_dirty_mblock(zmd, mblk);
2503	n += count;
2504	}
2505	dmz_release_mblock(zmd, mblk);
2506
2507	nr_blocks -= nr_bits;
2508	chunk_block += nr_bits;
2509	}
2510
2511	if (likely(zone->weight + n <= zone_nr_blocks))
2512	zone->weight += n;
2513	else {
2514	dmz_zmd_warn(zmd, "Zone %u: weight %u should be <= %u",
2515	zone->id, zone->weight,
2516	zone_nr_blocks - n);
2517	zone->weight = zone_nr_blocks;
2518	}
2519
2520	return 0;
2521	}
2522
2523	/*
2524	* Clear nr_bits bits in bitmap starting from bit.
2525	* Return the number of bits cleared.
2526	*/
2527	static int dmz_clear_bits(unsigned long *bitmap, int bit, int nr_bits)
2528	{
2529	unsigned long *addr;
2530	int end = bit + nr_bits;
2531	int n = 0;
2532
2533	while (bit < end) {
2534	if (((bit & (BITS_PER_LONG - 1)) == 0) &&
2535	((end - bit) >= BITS_PER_LONG)) {
2536	/* Try to clear whole word at once */
2537	addr = bitmap + BIT_WORD(bit);
2538	if (*addr == ULONG_MAX) {
2539	*addr = 0;
2540	n += BITS_PER_LONG;
2541	bit += BITS_PER_LONG;
2542	continue;
2543	}
2544	}
2545
2546	if (test_and_clear_bit(nr: bit, addr: bitmap))
2547	n++;
2548	bit++;
2549	}
2550
2551	return n;
2552	}
2553
2554	/*
2555	* Invalidate all the blocks in the range [block..block+nr_blocks-1].
2556	*/
2557	int dmz_invalidate_blocks(struct dmz_metadata *zmd, struct dm_zone *zone,
2558	sector_t chunk_block, unsigned int nr_blocks)
2559	{
2560	unsigned int count, bit, nr_bits;
2561	struct dmz_mblock *mblk;
2562	unsigned int n = 0;
2563
2564	dmz_zmd_debug(zmd, "=> INVALIDATE zone %u, block %llu, %u blocks",
2565	zone->id, (u64)chunk_block, nr_blocks);
2566
2567	WARN_ON(chunk_block + nr_blocks > zmd->zone_nr_blocks);
2568
2569	while (nr_blocks) {
2570	/* Get bitmap block */
2571	mblk = dmz_get_bitmap(zmd, zone, chunk_block);
2572	if (IS_ERR(ptr: mblk))
2573	return PTR_ERR(ptr: mblk);
2574
2575	/* Clear bits */
2576	bit = chunk_block & DMZ_BLOCK_MASK_BITS;
2577	nr_bits = min(nr_blocks, zmd->zone_bits_per_mblk - bit);
2578
2579	count = dmz_clear_bits(bitmap: (unsigned long *)mblk->data,
2580	bit, nr_bits);
2581	if (count) {
2582	dmz_dirty_mblock(zmd, mblk);
2583	n += count;
2584	}
2585	dmz_release_mblock(zmd, mblk);
2586
2587	nr_blocks -= nr_bits;
2588	chunk_block += nr_bits;
2589	}
2590
2591	if (zone->weight >= n)
2592	zone->weight -= n;
2593	else {
2594	dmz_zmd_warn(zmd, "Zone %u: weight %u should be >= %u",
2595	zone->id, zone->weight, n);
2596	zone->weight = 0;
2597	}
2598
2599	return 0;
2600	}
2601
2602	/*
2603	* Get a block bit value.
2604	*/
2605	static int dmz_test_block(struct dmz_metadata *zmd, struct dm_zone *zone,
2606	sector_t chunk_block)
2607	{
2608	struct dmz_mblock *mblk;
2609	int ret;
2610
2611	WARN_ON(chunk_block >= zmd->zone_nr_blocks);
2612
2613	/* Get bitmap block */
2614	mblk = dmz_get_bitmap(zmd, zone, chunk_block);
2615	if (IS_ERR(ptr: mblk))
2616	return PTR_ERR(ptr: mblk);
2617
2618	/* Get offset */
2619	ret = test_bit(chunk_block & DMZ_BLOCK_MASK_BITS,
2620	(unsigned long *) mblk->data) != 0;
2621
2622	dmz_release_mblock(zmd, mblk);
2623
2624	return ret;
2625	}
2626
2627	/*
2628	* Return the number of blocks from chunk_block to the first block with a bit
2629	* value specified by set. Search at most nr_blocks blocks from chunk_block.
2630	*/
2631	static int dmz_to_next_set_block(struct dmz_metadata *zmd, struct dm_zone *zone,
2632	sector_t chunk_block, unsigned int nr_blocks,
2633	int set)
2634	{
2635	struct dmz_mblock *mblk;
2636	unsigned int bit, set_bit, nr_bits;
2637	unsigned int zone_bits = zmd->zone_bits_per_mblk;
2638	unsigned long *bitmap;
2639	int n = 0;
2640
2641	WARN_ON(chunk_block + nr_blocks > zmd->zone_nr_blocks);
2642
2643	while (nr_blocks) {
2644	/* Get bitmap block */
2645	mblk = dmz_get_bitmap(zmd, zone, chunk_block);
2646	if (IS_ERR(ptr: mblk))
2647	return PTR_ERR(ptr: mblk);
2648
2649	/* Get offset */
2650	bitmap = (unsigned long *) mblk->data;
2651	bit = chunk_block & DMZ_BLOCK_MASK_BITS;
2652	nr_bits = min(nr_blocks, zone_bits - bit);
2653	if (set)
2654	set_bit = find_next_bit(addr: bitmap, size: zone_bits, offset: bit);
2655	else
2656	set_bit = find_next_zero_bit(addr: bitmap, size: zone_bits, offset: bit);
2657	dmz_release_mblock(zmd, mblk);
2658
2659	n += set_bit - bit;
2660	if (set_bit < zone_bits)
2661	break;
2662
2663	nr_blocks -= nr_bits;
2664	chunk_block += nr_bits;
2665	}
2666
2667	return n;
2668	}
2669
2670	/*
2671	* Test if chunk_block is valid. If it is, the number of consecutive
2672	* valid blocks from chunk_block will be returned.
2673	*/
2674	int dmz_block_valid(struct dmz_metadata *zmd, struct dm_zone *zone,
2675	sector_t chunk_block)
2676	{
2677	int valid;
2678
2679	valid = dmz_test_block(zmd, zone, chunk_block);
2680	if (valid <= 0)
2681	return valid;
2682
2683	/* The block is valid: get the number of valid blocks from block */
2684	return dmz_to_next_set_block(zmd, zone, chunk_block,
2685	nr_blocks: zmd->zone_nr_blocks - chunk_block, set: 0);
2686	}
2687
2688	/*
2689	* Find the first valid block from @chunk_block in @zone.
2690	* If such a block is found, its number is returned using
2691	* @chunk_block and the total number of valid blocks from @chunk_block
2692	* is returned.
2693	*/
2694	int dmz_first_valid_block(struct dmz_metadata *zmd, struct dm_zone *zone,
2695	sector_t *chunk_block)
2696	{
2697	sector_t start_block = *chunk_block;
2698	int ret;
2699
2700	ret = dmz_to_next_set_block(zmd, zone, chunk_block: start_block,
2701	nr_blocks: zmd->zone_nr_blocks - start_block, set: 1);
2702	if (ret < 0)
2703	return ret;
2704
2705	start_block += ret;
2706	*chunk_block = start_block;
2707
2708	return dmz_to_next_set_block(zmd, zone, chunk_block: start_block,
2709	nr_blocks: zmd->zone_nr_blocks - start_block, set: 0);
2710	}
2711
2712	/*
2713	* Count the number of bits set starting from bit up to bit + nr_bits - 1.
2714	*/
2715	static int dmz_count_bits(void *bitmap, int bit, int nr_bits)
2716	{
2717	unsigned long *addr;
2718	int end = bit + nr_bits;
2719	int n = 0;
2720
2721	while (bit < end) {
2722	if (((bit & (BITS_PER_LONG - 1)) == 0) &&
2723	((end - bit) >= BITS_PER_LONG)) {
2724	addr = (unsigned long *)bitmap + BIT_WORD(bit);
2725	if (*addr == ULONG_MAX) {
2726	n += BITS_PER_LONG;
2727	bit += BITS_PER_LONG;
2728	continue;
2729	}
2730	}
2731
2732	if (test_bit(bit, bitmap))
2733	n++;
2734	bit++;
2735	}
2736
2737	return n;
2738	}
2739
2740	/*
2741	* Get a zone weight.
2742	*/
2743	static void dmz_get_zone_weight(struct dmz_metadata *zmd, struct dm_zone *zone)
2744	{
2745	struct dmz_mblock *mblk;
2746	sector_t chunk_block = 0;
2747	unsigned int bit, nr_bits;
2748	unsigned int nr_blocks = zmd->zone_nr_blocks;
2749	void *bitmap;
2750	int n = 0;
2751
2752	while (nr_blocks) {
2753	/* Get bitmap block */
2754	mblk = dmz_get_bitmap(zmd, zone, chunk_block);
2755	if (IS_ERR(ptr: mblk)) {
2756	n = 0;
2757	break;
2758	}
2759
2760	/* Count bits in this block */
2761	bitmap = mblk->data;
2762	bit = chunk_block & DMZ_BLOCK_MASK_BITS;
2763	nr_bits = min(nr_blocks, zmd->zone_bits_per_mblk - bit);
2764	n += dmz_count_bits(bitmap, bit, nr_bits);
2765
2766	dmz_release_mblock(zmd, mblk);
2767
2768	nr_blocks -= nr_bits;
2769	chunk_block += nr_bits;
2770	}
2771
2772	zone->weight = n;
2773	}
2774
2775	/*
2776	* Cleanup the zoned metadata resources.
2777	*/
2778	static void dmz_cleanup_metadata(struct dmz_metadata *zmd)
2779	{
2780	struct rb_root *root;
2781	struct dmz_mblock *mblk, *next;
2782	int i;
2783
2784	/* Release zone mapping resources */
2785	if (zmd->map_mblk) {
2786	for (i = 0; i < zmd->nr_map_blocks; i++)
2787	dmz_release_mblock(zmd, mblk: zmd->map_mblk[i]);
2788	kfree(objp: zmd->map_mblk);
2789	zmd->map_mblk = NULL;
2790	}
2791
2792	/* Release super blocks */
2793	for (i = 0; i < 2; i++) {
2794	if (zmd->sb[i].mblk) {
2795	dmz_free_mblock(zmd, mblk: zmd->sb[i].mblk);
2796	zmd->sb[i].mblk = NULL;
2797	}
2798	}
2799
2800	/* Free cached blocks */
2801	while (!list_empty(head: &zmd->mblk_dirty_list)) {
2802	mblk = list_first_entry(&zmd->mblk_dirty_list,
2803	struct dmz_mblock, link);
2804	dmz_zmd_warn(zmd, "mblock %llu still in dirty list (ref %u)",
2805	(u64)mblk->no, mblk->ref);
2806	list_del_init(entry: &mblk->link);
2807	rb_erase(&mblk->node, &zmd->mblk_rbtree);
2808	dmz_free_mblock(zmd, mblk);
2809	}
2810
2811	while (!list_empty(head: &zmd->mblk_lru_list)) {
2812	mblk = list_first_entry(&zmd->mblk_lru_list,
2813	struct dmz_mblock, link);
2814	list_del_init(entry: &mblk->link);
2815	rb_erase(&mblk->node, &zmd->mblk_rbtree);
2816	dmz_free_mblock(zmd, mblk);
2817	}
2818
2819	/* Sanity checks: the mblock rbtree should now be empty */
2820	root = &zmd->mblk_rbtree;
2821	rbtree_postorder_for_each_entry_safe(mblk, next, root, node) {
2822	dmz_zmd_warn(zmd, "mblock %llu ref %u still in rbtree",
2823	(u64)mblk->no, mblk->ref);
2824	mblk->ref = 0;
2825	dmz_free_mblock(zmd, mblk);
2826	}
2827
2828	/* Free the zone descriptors */
2829	dmz_drop_zones(zmd);
2830
2831	mutex_destroy(lock: &zmd->mblk_flush_lock);
2832	mutex_destroy(lock: &zmd->map_lock);
2833	}
2834
2835	static void dmz_print_dev(struct dmz_metadata *zmd, int num)
2836	{
2837	struct dmz_dev *dev = &zmd->dev[num];
2838
2839	if (bdev_zoned_model(bdev: dev->bdev) == BLK_ZONED_NONE)
2840	dmz_dev_info(dev, "Regular block device");
2841	else
2842	dmz_dev_info(dev, "Host-%s zoned block device",
2843	bdev_zoned_model(dev->bdev) == BLK_ZONED_HA ?
2844	"aware" : "managed");
2845	if (zmd->sb_version > 1) {
2846	sector_t sector_offset =
2847	dev->zone_offset << zmd->zone_nr_sectors_shift;
2848
2849	dmz_dev_info(dev, " %llu 512-byte logical sectors (offset %llu)",
2850	(u64)dev->capacity, (u64)sector_offset);
2851	dmz_dev_info(dev, " %u zones of %llu 512-byte logical sectors (offset %llu)",
2852	dev->nr_zones, (u64)zmd->zone_nr_sectors,
2853	(u64)dev->zone_offset);
2854	} else {
2855	dmz_dev_info(dev, " %llu 512-byte logical sectors",
2856	(u64)dev->capacity);
2857	dmz_dev_info(dev, " %u zones of %llu 512-byte logical sectors",
2858	dev->nr_zones, (u64)zmd->zone_nr_sectors);
2859	}
2860	}
2861
2862	/*
2863	* Initialize the zoned metadata.
2864	*/
2865	int dmz_ctr_metadata(struct dmz_dev *dev, int num_dev,
2866	struct dmz_metadata **metadata,
2867	const char *devname)
2868	{
2869	struct dmz_metadata *zmd;
2870	unsigned int i;
2871	struct dm_zone *zone;
2872	int ret;
2873
2874	zmd = kzalloc(size: sizeof(struct dmz_metadata), GFP_KERNEL);
2875	if (!zmd)
2876	return -ENOMEM;
2877
2878	strcpy(p: zmd->devname, q: devname);
2879	zmd->dev = dev;
2880	zmd->nr_devs = num_dev;
2881	zmd->mblk_rbtree = RB_ROOT;
2882	init_rwsem(&zmd->mblk_sem);
2883	mutex_init(&zmd->mblk_flush_lock);
2884	spin_lock_init(&zmd->mblk_lock);
2885	INIT_LIST_HEAD(list: &zmd->mblk_lru_list);
2886	INIT_LIST_HEAD(list: &zmd->mblk_dirty_list);
2887
2888	mutex_init(&zmd->map_lock);
2889
2890	atomic_set(v: &zmd->unmap_nr_cache, i: 0);
2891	INIT_LIST_HEAD(list: &zmd->unmap_cache_list);
2892	INIT_LIST_HEAD(list: &zmd->map_cache_list);
2893
2894	atomic_set(v: &zmd->nr_reserved_seq_zones, i: 0);
2895	INIT_LIST_HEAD(list: &zmd->reserved_seq_zones_list);
2896
2897	init_waitqueue_head(&zmd->free_wq);
2898
2899	/* Initialize zone descriptors */
2900	ret = dmz_init_zones(zmd);
2901	if (ret)
2902	goto err;
2903
2904	/* Get super block */
2905	ret = dmz_load_sb(zmd);
2906	if (ret)
2907	goto err;
2908
2909	/* Set metadata zones starting from sb_zone */
2910	for (i = 0; i < zmd->nr_meta_zones << 1; i++) {
2911	zone = dmz_get(zmd, zone_id: zmd->sb[0].zone->id + i);
2912	if (!zone) {
2913	dmz_zmd_err(zmd,
2914	"metadata zone %u not present", i);
2915	ret = -ENXIO;
2916	goto err;
2917	}
2918	if (!dmz_is_rnd(zone) && !dmz_is_cache(zone)) {
2919	dmz_zmd_err(zmd,
2920	"metadata zone %d is not random", i);
2921	ret = -ENXIO;
2922	goto err;
2923	}
2924	set_bit(nr: DMZ_META, addr: &zone->flags);
2925	}
2926	/* Load mapping table */
2927	ret = dmz_load_mapping(zmd);
2928	if (ret)
2929	goto err;
2930
2931	/*
2932	* Cache size boundaries: allow at least 2 super blocks, the chunk map
2933	* blocks and enough blocks to be able to cache the bitmap blocks of
2934	* up to 16 zones when idle (min_nr_mblks). Otherwise, if busy, allow
2935	* the cache to add 512 more metadata blocks.
2936	*/
2937	zmd->min_nr_mblks = 2 + zmd->nr_map_blocks + zmd->zone_nr_bitmap_blocks * 16;
2938	zmd->max_nr_mblks = zmd->min_nr_mblks + 512;
2939
2940	/* Metadata cache shrinker */
2941	zmd->mblk_shrinker = shrinker_alloc(flags: 0, fmt: "dm-zoned-meta:(%u:%u)",
2942	MAJOR(dev->bdev->bd_dev),
2943	MINOR(dev->bdev->bd_dev));
2944	if (!zmd->mblk_shrinker) {
2945	ret = -ENOMEM;
2946	dmz_zmd_err(zmd, "Allocate metadata cache shrinker failed");
2947	goto err;
2948	}
2949
2950	zmd->mblk_shrinker->count_objects = dmz_mblock_shrinker_count;
2951	zmd->mblk_shrinker->scan_objects = dmz_mblock_shrinker_scan;
2952	zmd->mblk_shrinker->private_data = zmd;
2953
2954	shrinker_register(shrinker: zmd->mblk_shrinker);
2955
2956	dmz_zmd_info(zmd, "DM-Zoned metadata version %d", zmd->sb_version);
2957	for (i = 0; i < zmd->nr_devs; i++)
2958	dmz_print_dev(zmd, num: i);
2959
2960	dmz_zmd_info(zmd, " %u zones of %llu 512-byte logical sectors",
2961	zmd->nr_zones, (u64)zmd->zone_nr_sectors);
2962	dmz_zmd_debug(zmd, " %u metadata zones",
2963	zmd->nr_meta_zones * 2);
2964	dmz_zmd_debug(zmd, " %u data zones for %u chunks",
2965	zmd->nr_data_zones, zmd->nr_chunks);
2966	dmz_zmd_debug(zmd, " %u cache zones (%u unmapped)",
2967	zmd->nr_cache, atomic_read(&zmd->unmap_nr_cache));
2968	for (i = 0; i < zmd->nr_devs; i++) {
2969	dmz_zmd_debug(zmd, " %u random zones (%u unmapped)",
2970	dmz_nr_rnd_zones(zmd, i),
2971	dmz_nr_unmap_rnd_zones(zmd, i));
2972	dmz_zmd_debug(zmd, " %u sequential zones (%u unmapped)",
2973	dmz_nr_seq_zones(zmd, i),
2974	dmz_nr_unmap_seq_zones(zmd, i));
2975	}
2976	dmz_zmd_debug(zmd, " %u reserved sequential data zones",
2977	zmd->nr_reserved_seq);
2978	dmz_zmd_debug(zmd, "Format:");
2979	dmz_zmd_debug(zmd, "%u metadata blocks per set (%u max cache)",
2980	zmd->nr_meta_blocks, zmd->max_nr_mblks);
2981	dmz_zmd_debug(zmd, " %u data zone mapping blocks",
2982	zmd->nr_map_blocks);
2983	dmz_zmd_debug(zmd, " %u bitmap blocks",
2984	zmd->nr_bitmap_blocks);
2985
2986	*metadata = zmd;
2987
2988	return 0;
2989	err:
2990	dmz_cleanup_metadata(zmd);
2991	kfree(objp: zmd);
2992	*metadata = NULL;
2993
2994	return ret;
2995	}
2996
2997	/*
2998	* Cleanup the zoned metadata resources.
2999	*/
3000	void dmz_dtr_metadata(struct dmz_metadata *zmd)
3001	{
3002	shrinker_free(shrinker: zmd->mblk_shrinker);
3003	dmz_cleanup_metadata(zmd);
3004	kfree(objp: zmd);
3005	}
3006
3007	/*
3008	* Check zone information on resume.
3009	*/
3010	int dmz_resume_metadata(struct dmz_metadata *zmd)
3011	{
3012	struct dm_zone *zone;
3013	sector_t wp_block;
3014	unsigned int i;
3015	int ret;
3016
3017	/* Check zones */
3018	for (i = 0; i < zmd->nr_zones; i++) {
3019	zone = dmz_get(zmd, zone_id: i);
3020	if (!zone) {
3021	dmz_zmd_err(zmd, "Unable to get zone %u", i);
3022	return -EIO;
3023	}
3024	wp_block = zone->wp_block;
3025
3026	ret = dmz_update_zone(zmd, zone);
3027	if (ret) {
3028	dmz_zmd_err(zmd, "Broken zone %u", i);
3029	return ret;
3030	}
3031
3032	if (dmz_is_offline(zone)) {
3033	dmz_zmd_warn(zmd, "Zone %u is offline", i);
3034	continue;
3035	}
3036
3037	/* Check write pointer */
3038	if (!dmz_is_seq(zone))
3039	zone->wp_block = 0;
3040	else if (zone->wp_block != wp_block) {
3041	dmz_zmd_err(zmd, "Zone %u: Invalid wp (%llu / %llu)",
3042	i, (u64)zone->wp_block, (u64)wp_block);
3043	zone->wp_block = wp_block;
3044	dmz_invalidate_blocks(zmd, zone, chunk_block: zone->wp_block,
3045	nr_blocks: zmd->zone_nr_blocks - zone->wp_block);
3046	}
3047	}
3048
3049	return 0;
3050	}
3051