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   1// SPDX-License-Identifier: GPL-2.0
   2
   3#include <linux/bitops.h>
   4#include <linux/slab.h>
   5#include <linux/blkdev.h>
   6#include <linux/sched/mm.h>
   7#include <linux/atomic.h>
   8#include <linux/vmalloc.h>
   9#include "ctree.h"
  10#include "volumes.h"
  11#include "zoned.h"
  12#include "rcu-string.h"
  13#include "disk-io.h"
  14#include "block-group.h"
  15#include "transaction.h"
  16#include "dev-replace.h"
  17#include "space-info.h"
  18#include "super.h"
  19#include "fs.h"
  20#include "accessors.h"
  21#include "bio.h"
  22
  23/* Maximum number of zones to report per blkdev_report_zones() call */
  24#define BTRFS_REPORT_NR_ZONES   4096
  25/* Invalid allocation pointer value for missing devices */
  26#define WP_MISSING_DEV ((u64)-1)
  27/* Pseudo write pointer value for conventional zone */
  28#define WP_CONVENTIONAL ((u64)-2)
  29
  30/*
  31 * Location of the first zone of superblock logging zone pairs.
  32 *
  33 * - primary superblock:    0B (zone 0)
  34 * - first copy:          512G (zone starting at that offset)
  35 * - second copy:           4T (zone starting at that offset)
  36 */
  37#define BTRFS_SB_LOG_PRIMARY_OFFSET	(0ULL)
  38#define BTRFS_SB_LOG_FIRST_OFFSET	(512ULL * SZ_1G)
  39#define BTRFS_SB_LOG_SECOND_OFFSET	(4096ULL * SZ_1G)
  40
  41#define BTRFS_SB_LOG_FIRST_SHIFT	const_ilog2(BTRFS_SB_LOG_FIRST_OFFSET)
  42#define BTRFS_SB_LOG_SECOND_SHIFT	const_ilog2(BTRFS_SB_LOG_SECOND_OFFSET)
  43
  44/* Number of superblock log zones */
  45#define BTRFS_NR_SB_LOG_ZONES 2
  46
  47/*
  48 * Minimum of active zones we need:
  49 *
  50 * - BTRFS_SUPER_MIRROR_MAX zones for superblock mirrors
  51 * - 3 zones to ensure at least one zone per SYSTEM, META and DATA block group
  52 * - 1 zone for tree-log dedicated block group
  53 * - 1 zone for relocation
  54 */
  55#define BTRFS_MIN_ACTIVE_ZONES		(BTRFS_SUPER_MIRROR_MAX + 5)
  56
  57/*
  58 * Minimum / maximum supported zone size. Currently, SMR disks have a zone
  59 * size of 256MiB, and we are expecting ZNS drives to be in the 1-4GiB range.
  60 * We do not expect the zone size to become larger than 8GiB or smaller than
  61 * 4MiB in the near future.
  62 */
  63#define BTRFS_MAX_ZONE_SIZE		SZ_8G
  64#define BTRFS_MIN_ZONE_SIZE		SZ_4M
  65
  66#define SUPER_INFO_SECTORS	((u64)BTRFS_SUPER_INFO_SIZE >> SECTOR_SHIFT)
  67
  68static void wait_eb_writebacks(struct btrfs_block_group *block_group);
  69static int do_zone_finish(struct btrfs_block_group *block_group, bool fully_written);
  70
  71static inline bool sb_zone_is_full(const struct blk_zone *zone)
  72{
  73	return (zone->cond == BLK_ZONE_COND_FULL) ||
  74		(zone->wp + SUPER_INFO_SECTORS > zone->start + zone->capacity);
  75}
  76
  77static int copy_zone_info_cb(struct blk_zone *zone, unsigned int idx, void *data)
  78{
  79	struct blk_zone *zones = data;
  80
  81	memcpy(&zones[idx], zone, sizeof(*zone));
  82
  83	return 0;
  84}
  85
  86static int sb_write_pointer(struct block_device *bdev, struct blk_zone *zones,
  87			    u64 *wp_ret)
  88{
  89	bool empty[BTRFS_NR_SB_LOG_ZONES];
  90	bool full[BTRFS_NR_SB_LOG_ZONES];
  91	sector_t sector;
  92	int i;
  93
  94	for (i = 0; i < BTRFS_NR_SB_LOG_ZONES; i++) {
  95		ASSERT(zones[i].type != BLK_ZONE_TYPE_CONVENTIONAL);
  96		empty[i] = (zones[i].cond == BLK_ZONE_COND_EMPTY);
  97		full[i] = sb_zone_is_full(&zones[i]);
  98	}
  99
 100	/*
 101	 * Possible states of log buffer zones
 102	 *
 103	 *           Empty[0]  In use[0]  Full[0]
 104	 * Empty[1]         *          0        1
 105	 * In use[1]        x          x        1
 106	 * Full[1]          0          0        C
 107	 *
 108	 * Log position:
 109	 *   *: Special case, no superblock is written
 110	 *   0: Use write pointer of zones[0]
 111	 *   1: Use write pointer of zones[1]
 112	 *   C: Compare super blocks from zones[0] and zones[1], use the latest
 113	 *      one determined by generation
 114	 *   x: Invalid state
 115	 */
 116
 117	if (empty[0] && empty[1]) {
 118		/* Special case to distinguish no superblock to read */
 119		*wp_ret = zones[0].start << SECTOR_SHIFT;
 120		return -ENOENT;
 121	} else if (full[0] && full[1]) {
 122		/* Compare two super blocks */
 123		struct address_space *mapping = bdev->bd_inode->i_mapping;
 124		struct page *page[BTRFS_NR_SB_LOG_ZONES];
 125		struct btrfs_super_block *super[BTRFS_NR_SB_LOG_ZONES];
 126		int i;
 127
 128		for (i = 0; i < BTRFS_NR_SB_LOG_ZONES; i++) {
 129			u64 zone_end = (zones[i].start + zones[i].capacity) << SECTOR_SHIFT;
 130			u64 bytenr = ALIGN_DOWN(zone_end, BTRFS_SUPER_INFO_SIZE) -
 131						BTRFS_SUPER_INFO_SIZE;
 132
 133			page[i] = read_cache_page_gfp(mapping,
 134					bytenr >> PAGE_SHIFT, GFP_NOFS);
 135			if (IS_ERR(page[i])) {
 136				if (i == 1)
 137					btrfs_release_disk_super(super[0]);
 138				return PTR_ERR(page[i]);
 139			}
 140			super[i] = page_address(page[i]);
 141		}
 142
 143		if (btrfs_super_generation(super[0]) >
 144		    btrfs_super_generation(super[1]))
 145			sector = zones[1].start;
 146		else
 147			sector = zones[0].start;
 148
 149		for (i = 0; i < BTRFS_NR_SB_LOG_ZONES; i++)
 150			btrfs_release_disk_super(super[i]);
 151	} else if (!full[0] && (empty[1] || full[1])) {
 152		sector = zones[0].wp;
 153	} else if (full[0]) {
 154		sector = zones[1].wp;
 155	} else {
 156		return -EUCLEAN;
 157	}
 158	*wp_ret = sector << SECTOR_SHIFT;
 159	return 0;
 160}
 161
 162/*
 163 * Get the first zone number of the superblock mirror
 164 */
 165static inline u32 sb_zone_number(int shift, int mirror)
 166{
 167	u64 zone = U64_MAX;
 168
 169	ASSERT(mirror < BTRFS_SUPER_MIRROR_MAX);
 170	switch (mirror) {
 171	case 0: zone = 0; break;
 172	case 1: zone = 1ULL << (BTRFS_SB_LOG_FIRST_SHIFT - shift); break;
 173	case 2: zone = 1ULL << (BTRFS_SB_LOG_SECOND_SHIFT - shift); break;
 174	}
 175
 176	ASSERT(zone <= U32_MAX);
 177
 178	return (u32)zone;
 179}
 180
 181static inline sector_t zone_start_sector(u32 zone_number,
 182					 struct block_device *bdev)
 183{
 184	return (sector_t)zone_number << ilog2(bdev_zone_sectors(bdev));
 185}
 186
 187static inline u64 zone_start_physical(u32 zone_number,
 188				      struct btrfs_zoned_device_info *zone_info)
 189{
 190	return (u64)zone_number << zone_info->zone_size_shift;
 191}
 192
 193/*
 194 * Emulate blkdev_report_zones() for a non-zoned device. It slices up the block
 195 * device into static sized chunks and fake a conventional zone on each of
 196 * them.
 197 */
 198static int emulate_report_zones(struct btrfs_device *device, u64 pos,
 199				struct blk_zone *zones, unsigned int nr_zones)
 200{
 201	const sector_t zone_sectors = device->fs_info->zone_size >> SECTOR_SHIFT;
 202	sector_t bdev_size = bdev_nr_sectors(device->bdev);
 203	unsigned int i;
 204
 205	pos >>= SECTOR_SHIFT;
 206	for (i = 0; i < nr_zones; i++) {
 207		zones[i].start = i * zone_sectors + pos;
 208		zones[i].len = zone_sectors;
 209		zones[i].capacity = zone_sectors;
 210		zones[i].wp = zones[i].start + zone_sectors;
 211		zones[i].type = BLK_ZONE_TYPE_CONVENTIONAL;
 212		zones[i].cond = BLK_ZONE_COND_NOT_WP;
 213
 214		if (zones[i].wp >= bdev_size) {
 215			i++;
 216			break;
 217		}
 218	}
 219
 220	return i;
 221}
 222
 223static int btrfs_get_dev_zones(struct btrfs_device *device, u64 pos,
 224			       struct blk_zone *zones, unsigned int *nr_zones)
 225{
 226	struct btrfs_zoned_device_info *zinfo = device->zone_info;
 227	int ret;
 228
 229	if (!*nr_zones)
 230		return 0;
 231
 232	if (!bdev_is_zoned(device->bdev)) {
 233		ret = emulate_report_zones(device, pos, zones, *nr_zones);
 234		*nr_zones = ret;
 235		return 0;
 236	}
 237
 238	/* Check cache */
 239	if (zinfo->zone_cache) {
 240		unsigned int i;
 241		u32 zno;
 242
 243		ASSERT(IS_ALIGNED(pos, zinfo->zone_size));
 244		zno = pos >> zinfo->zone_size_shift;
 245		/*
 246		 * We cannot report zones beyond the zone end. So, it is OK to
 247		 * cap *nr_zones to at the end.
 248		 */
 249		*nr_zones = min_t(u32, *nr_zones, zinfo->nr_zones - zno);
 250
 251		for (i = 0; i < *nr_zones; i++) {
 252			struct blk_zone *zone_info;
 253
 254			zone_info = &zinfo->zone_cache[zno + i];
 255			if (!zone_info->len)
 256				break;
 257		}
 258
 259		if (i == *nr_zones) {
 260			/* Cache hit on all the zones */
 261			memcpy(zones, zinfo->zone_cache + zno,
 262			       sizeof(*zinfo->zone_cache) * *nr_zones);
 263			return 0;
 264		}
 265	}
 266
 267	ret = blkdev_report_zones(device->bdev, pos >> SECTOR_SHIFT, *nr_zones,
 268				  copy_zone_info_cb, zones);
 269	if (ret < 0) {
 270		btrfs_err_in_rcu(device->fs_info,
 271				 "zoned: failed to read zone %llu on %s (devid %llu)",
 272				 pos, rcu_str_deref(device->name),
 273				 device->devid);
 274		return ret;
 275	}
 276	*nr_zones = ret;
 277	if (!ret)
 278		return -EIO;
 279
 280	/* Populate cache */
 281	if (zinfo->zone_cache) {
 282		u32 zno = pos >> zinfo->zone_size_shift;
 283
 284		memcpy(zinfo->zone_cache + zno, zones,
 285		       sizeof(*zinfo->zone_cache) * *nr_zones);
 286	}
 287
 288	return 0;
 289}
 290
 291/* The emulated zone size is determined from the size of device extent */
 292static int calculate_emulated_zone_size(struct btrfs_fs_info *fs_info)
 293{
 294	struct btrfs_path *path;
 295	struct btrfs_root *root = fs_info->dev_root;
 296	struct btrfs_key key;
 297	struct extent_buffer *leaf;
 298	struct btrfs_dev_extent *dext;
 299	int ret = 0;
 300
 301	key.objectid = 1;
 302	key.type = BTRFS_DEV_EXTENT_KEY;
 303	key.offset = 0;
 304
 305	path = btrfs_alloc_path();
 306	if (!path)
 307		return -ENOMEM;
 308
 309	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
 310	if (ret < 0)
 311		goto out;
 312
 313	if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
 314		ret = btrfs_next_leaf(root, path);
 315		if (ret < 0)
 316			goto out;
 317		/* No dev extents at all? Not good */
 318		if (ret > 0) {
 319			ret = -EUCLEAN;
 320			goto out;
 321		}
 322	}
 323
 324	leaf = path->nodes[0];
 325	dext = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_extent);
 326	fs_info->zone_size = btrfs_dev_extent_length(leaf, dext);
 327	ret = 0;
 328
 329out:
 330	btrfs_free_path(path);
 331
 332	return ret;
 333}
 334
 335int btrfs_get_dev_zone_info_all_devices(struct btrfs_fs_info *fs_info)
 336{
 337	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
 338	struct btrfs_device *device;
 339	int ret = 0;
 340
 341	/* fs_info->zone_size might not set yet. Use the incomapt flag here. */
 342	if (!btrfs_fs_incompat(fs_info, ZONED))
 343		return 0;
 344
 345	mutex_lock(&fs_devices->device_list_mutex);
 346	list_for_each_entry(device, &fs_devices->devices, dev_list) {
 347		/* We can skip reading of zone info for missing devices */
 348		if (!device->bdev)
 349			continue;
 350
 351		ret = btrfs_get_dev_zone_info(device, true);
 352		if (ret)
 353			break;
 354	}
 355	mutex_unlock(&fs_devices->device_list_mutex);
 356
 357	return ret;
 358}
 359
 360int btrfs_get_dev_zone_info(struct btrfs_device *device, bool populate_cache)
 361{
 362	struct btrfs_fs_info *fs_info = device->fs_info;
 363	struct btrfs_zoned_device_info *zone_info = NULL;
 364	struct block_device *bdev = device->bdev;
 365	unsigned int max_active_zones;
 366	unsigned int nactive;
 367	sector_t nr_sectors;
 368	sector_t sector = 0;
 369	struct blk_zone *zones = NULL;
 370	unsigned int i, nreported = 0, nr_zones;
 371	sector_t zone_sectors;
 372	char *model, *emulated;
 373	int ret;
 374
 375	/*
 376	 * Cannot use btrfs_is_zoned here, since fs_info::zone_size might not
 377	 * yet be set.
 378	 */
 379	if (!btrfs_fs_incompat(fs_info, ZONED))
 380		return 0;
 381
 382	if (device->zone_info)
 383		return 0;
 384
 385	zone_info = kzalloc(sizeof(*zone_info), GFP_KERNEL);
 386	if (!zone_info)
 387		return -ENOMEM;
 388
 389	device->zone_info = zone_info;
 390
 391	if (!bdev_is_zoned(bdev)) {
 392		if (!fs_info->zone_size) {
 393			ret = calculate_emulated_zone_size(fs_info);
 394			if (ret)
 395				goto out;
 396		}
 397
 398		ASSERT(fs_info->zone_size);
 399		zone_sectors = fs_info->zone_size >> SECTOR_SHIFT;
 400	} else {
 401		zone_sectors = bdev_zone_sectors(bdev);
 402	}
 403
 404	ASSERT(is_power_of_two_u64(zone_sectors));
 405	zone_info->zone_size = zone_sectors << SECTOR_SHIFT;
 406
 407	/* We reject devices with a zone size larger than 8GB */
 408	if (zone_info->zone_size > BTRFS_MAX_ZONE_SIZE) {
 409		btrfs_err_in_rcu(fs_info,
 410		"zoned: %s: zone size %llu larger than supported maximum %llu",
 411				 rcu_str_deref(device->name),
 412				 zone_info->zone_size, BTRFS_MAX_ZONE_SIZE);
 413		ret = -EINVAL;
 414		goto out;
 415	} else if (zone_info->zone_size < BTRFS_MIN_ZONE_SIZE) {
 416		btrfs_err_in_rcu(fs_info,
 417		"zoned: %s: zone size %llu smaller than supported minimum %u",
 418				 rcu_str_deref(device->name),
 419				 zone_info->zone_size, BTRFS_MIN_ZONE_SIZE);
 420		ret = -EINVAL;
 421		goto out;
 422	}
 423
 424	nr_sectors = bdev_nr_sectors(bdev);
 425	zone_info->zone_size_shift = ilog2(zone_info->zone_size);
 426	zone_info->nr_zones = nr_sectors >> ilog2(zone_sectors);
 427	if (!IS_ALIGNED(nr_sectors, zone_sectors))
 428		zone_info->nr_zones++;
 429
 430	max_active_zones = bdev_max_active_zones(bdev);
 431	if (max_active_zones && max_active_zones < BTRFS_MIN_ACTIVE_ZONES) {
 432		btrfs_err_in_rcu(fs_info,
 433"zoned: %s: max active zones %u is too small, need at least %u active zones",
 434				 rcu_str_deref(device->name), max_active_zones,
 435				 BTRFS_MIN_ACTIVE_ZONES);
 436		ret = -EINVAL;
 437		goto out;
 438	}
 439	zone_info->max_active_zones = max_active_zones;
 440
 441	zone_info->seq_zones = bitmap_zalloc(zone_info->nr_zones, GFP_KERNEL);
 442	if (!zone_info->seq_zones) {
 443		ret = -ENOMEM;
 444		goto out;
 445	}
 446
 447	zone_info->empty_zones = bitmap_zalloc(zone_info->nr_zones, GFP_KERNEL);
 448	if (!zone_info->empty_zones) {
 449		ret = -ENOMEM;
 450		goto out;
 451	}
 452
 453	zone_info->active_zones = bitmap_zalloc(zone_info->nr_zones, GFP_KERNEL);
 454	if (!zone_info->active_zones) {
 455		ret = -ENOMEM;
 456		goto out;
 457	}
 458
 459	zones = kvcalloc(BTRFS_REPORT_NR_ZONES, sizeof(struct blk_zone), GFP_KERNEL);
 460	if (!zones) {
 461		ret = -ENOMEM;
 462		goto out;
 463	}
 464
 465	/*
 466	 * Enable zone cache only for a zoned device. On a non-zoned device, we
 467	 * fill the zone info with emulated CONVENTIONAL zones, so no need to
 468	 * use the cache.
 469	 */
 470	if (populate_cache && bdev_is_zoned(device->bdev)) {
 471		zone_info->zone_cache = vcalloc(zone_info->nr_zones,
 472						sizeof(struct blk_zone));
 473		if (!zone_info->zone_cache) {
 474			btrfs_err_in_rcu(device->fs_info,
 475				"zoned: failed to allocate zone cache for %s",
 476				rcu_str_deref(device->name));
 477			ret = -ENOMEM;
 478			goto out;
 479		}
 480	}
 481
 482	/* Get zones type */
 483	nactive = 0;
 484	while (sector < nr_sectors) {
 485		nr_zones = BTRFS_REPORT_NR_ZONES;
 486		ret = btrfs_get_dev_zones(device, sector << SECTOR_SHIFT, zones,
 487					  &nr_zones);
 488		if (ret)
 489			goto out;
 490
 491		for (i = 0; i < nr_zones; i++) {
 492			if (zones[i].type == BLK_ZONE_TYPE_SEQWRITE_REQ)
 493				__set_bit(nreported, zone_info->seq_zones);
 494			switch (zones[i].cond) {
 495			case BLK_ZONE_COND_EMPTY:
 496				__set_bit(nreported, zone_info->empty_zones);
 497				break;
 498			case BLK_ZONE_COND_IMP_OPEN:
 499			case BLK_ZONE_COND_EXP_OPEN:
 500			case BLK_ZONE_COND_CLOSED:
 501				__set_bit(nreported, zone_info->active_zones);
 502				nactive++;
 503				break;
 504			}
 505			nreported++;
 506		}
 507		sector = zones[nr_zones - 1].start + zones[nr_zones - 1].len;
 508	}
 509
 510	if (nreported != zone_info->nr_zones) {
 511		btrfs_err_in_rcu(device->fs_info,
 512				 "inconsistent number of zones on %s (%u/%u)",
 513				 rcu_str_deref(device->name), nreported,
 514				 zone_info->nr_zones);
 515		ret = -EIO;
 516		goto out;
 517	}
 518
 519	if (max_active_zones) {
 520		if (nactive > max_active_zones) {
 521			btrfs_err_in_rcu(device->fs_info,
 522			"zoned: %u active zones on %s exceeds max_active_zones %u",
 523					 nactive, rcu_str_deref(device->name),
 524					 max_active_zones);
 525			ret = -EIO;
 526			goto out;
 527		}
 528		atomic_set(&zone_info->active_zones_left,
 529			   max_active_zones - nactive);
 530		set_bit(BTRFS_FS_ACTIVE_ZONE_TRACKING, &fs_info->flags);
 531	}
 532
 533	/* Validate superblock log */
 534	nr_zones = BTRFS_NR_SB_LOG_ZONES;
 535	for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
 536		u32 sb_zone;
 537		u64 sb_wp;
 538		int sb_pos = BTRFS_NR_SB_LOG_ZONES * i;
 539
 540		sb_zone = sb_zone_number(zone_info->zone_size_shift, i);
 541		if (sb_zone + 1 >= zone_info->nr_zones)
 542			continue;
 543
 544		ret = btrfs_get_dev_zones(device,
 545					  zone_start_physical(sb_zone, zone_info),
 546					  &zone_info->sb_zones[sb_pos],
 547					  &nr_zones);
 548		if (ret)
 549			goto out;
 550
 551		if (nr_zones != BTRFS_NR_SB_LOG_ZONES) {
 552			btrfs_err_in_rcu(device->fs_info,
 553	"zoned: failed to read super block log zone info at devid %llu zone %u",
 554					 device->devid, sb_zone);
 555			ret = -EUCLEAN;
 556			goto out;
 557		}
 558
 559		/*
 560		 * If zones[0] is conventional, always use the beginning of the
 561		 * zone to record superblock. No need to validate in that case.
 562		 */
 563		if (zone_info->sb_zones[BTRFS_NR_SB_LOG_ZONES * i].type ==
 564		    BLK_ZONE_TYPE_CONVENTIONAL)
 565			continue;
 566
 567		ret = sb_write_pointer(device->bdev,
 568				       &zone_info->sb_zones[sb_pos], &sb_wp);
 569		if (ret != -ENOENT && ret) {
 570			btrfs_err_in_rcu(device->fs_info,
 571			"zoned: super block log zone corrupted devid %llu zone %u",
 572					 device->devid, sb_zone);
 573			ret = -EUCLEAN;
 574			goto out;
 575		}
 576	}
 577
 578
 579	kvfree(zones);
 580
 581	if (bdev_is_zoned(bdev)) {
 582		model = "host-managed zoned";
 583		emulated = "";
 584	} else {
 585		model = "regular";
 586		emulated = "emulated ";
 587	}
 588
 589	btrfs_info_in_rcu(fs_info,
 590		"%s block device %s, %u %szones of %llu bytes",
 591		model, rcu_str_deref(device->name), zone_info->nr_zones,
 592		emulated, zone_info->zone_size);
 593
 594	return 0;
 595
 596out:
 597	kvfree(zones);
 598	btrfs_destroy_dev_zone_info(device);
 599	return ret;
 600}
 601
 602void btrfs_destroy_dev_zone_info(struct btrfs_device *device)
 603{
 604	struct btrfs_zoned_device_info *zone_info = device->zone_info;
 605
 606	if (!zone_info)
 607		return;
 608
 609	bitmap_free(zone_info->active_zones);
 610	bitmap_free(zone_info->seq_zones);
 611	bitmap_free(zone_info->empty_zones);
 612	vfree(zone_info->zone_cache);
 613	kfree(zone_info);
 614	device->zone_info = NULL;
 615}
 616
 617struct btrfs_zoned_device_info *btrfs_clone_dev_zone_info(struct btrfs_device *orig_dev)
 618{
 619	struct btrfs_zoned_device_info *zone_info;
 620
 621	zone_info = kmemdup(orig_dev->zone_info, sizeof(*zone_info), GFP_KERNEL);
 622	if (!zone_info)
 623		return NULL;
 624
 625	zone_info->seq_zones = bitmap_zalloc(zone_info->nr_zones, GFP_KERNEL);
 626	if (!zone_info->seq_zones)
 627		goto out;
 628
 629	bitmap_copy(zone_info->seq_zones, orig_dev->zone_info->seq_zones,
 630		    zone_info->nr_zones);
 631
 632	zone_info->empty_zones = bitmap_zalloc(zone_info->nr_zones, GFP_KERNEL);
 633	if (!zone_info->empty_zones)
 634		goto out;
 635
 636	bitmap_copy(zone_info->empty_zones, orig_dev->zone_info->empty_zones,
 637		    zone_info->nr_zones);
 638
 639	zone_info->active_zones = bitmap_zalloc(zone_info->nr_zones, GFP_KERNEL);
 640	if (!zone_info->active_zones)
 641		goto out;
 642
 643	bitmap_copy(zone_info->active_zones, orig_dev->zone_info->active_zones,
 644		    zone_info->nr_zones);
 645	zone_info->zone_cache = NULL;
 646
 647	return zone_info;
 648
 649out:
 650	bitmap_free(zone_info->seq_zones);
 651	bitmap_free(zone_info->empty_zones);
 652	bitmap_free(zone_info->active_zones);
 653	kfree(zone_info);
 654	return NULL;
 655}
 656
 657int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
 658		       struct blk_zone *zone)
 659{
 660	unsigned int nr_zones = 1;
 661	int ret;
 662
 663	ret = btrfs_get_dev_zones(device, pos, zone, &nr_zones);
 664	if (ret != 0 || !nr_zones)
 665		return ret ? ret : -EIO;
 666
 667	return 0;
 668}
 669
 670static int btrfs_check_for_zoned_device(struct btrfs_fs_info *fs_info)
 671{
 672	struct btrfs_device *device;
 673
 674	list_for_each_entry(device, &fs_info->fs_devices->devices, dev_list) {
 675		if (device->bdev && bdev_is_zoned(device->bdev)) {
 676			btrfs_err(fs_info,
 677				"zoned: mode not enabled but zoned device found: %pg",
 678				device->bdev);
 679			return -EINVAL;
 680		}
 681	}
 682
 683	return 0;
 684}
 685
 686int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info)
 687{
 688	struct queue_limits *lim = &fs_info->limits;
 689	struct btrfs_device *device;
 690	u64 zone_size = 0;
 691	int ret;
 692
 693	/*
 694	 * Host-Managed devices can't be used without the ZONED flag.  With the
 695	 * ZONED all devices can be used, using zone emulation if required.
 696	 */
 697	if (!btrfs_fs_incompat(fs_info, ZONED))
 698		return btrfs_check_for_zoned_device(fs_info);
 699
 700	blk_set_stacking_limits(lim);
 701
 702	list_for_each_entry(device, &fs_info->fs_devices->devices, dev_list) {
 703		struct btrfs_zoned_device_info *zone_info = device->zone_info;
 704
 705		if (!device->bdev)
 706			continue;
 707
 708		if (!zone_size) {
 709			zone_size = zone_info->zone_size;
 710		} else if (zone_info->zone_size != zone_size) {
 711			btrfs_err(fs_info,
 712		"zoned: unequal block device zone sizes: have %llu found %llu",
 713				  zone_info->zone_size, zone_size);
 714			return -EINVAL;
 715		}
 716
 717		/*
 718		 * With the zoned emulation, we can have non-zoned device on the
 719		 * zoned mode. In this case, we don't have a valid max zone
 720		 * append size.
 721		 */
 722		if (bdev_is_zoned(device->bdev)) {
 723			blk_stack_limits(lim,
 724					 &bdev_get_queue(device->bdev)->limits,
 725					 0);
 726		}
 727	}
 728
 729	/*
 730	 * stripe_size is always aligned to BTRFS_STRIPE_LEN in
 731	 * btrfs_create_chunk(). Since we want stripe_len == zone_size,
 732	 * check the alignment here.
 733	 */
 734	if (!IS_ALIGNED(zone_size, BTRFS_STRIPE_LEN)) {
 735		btrfs_err(fs_info,
 736			  "zoned: zone size %llu not aligned to stripe %u",
 737			  zone_size, BTRFS_STRIPE_LEN);
 738		return -EINVAL;
 739	}
 740
 741	if (btrfs_fs_incompat(fs_info, MIXED_GROUPS)) {
 742		btrfs_err(fs_info, "zoned: mixed block groups not supported");
 743		return -EINVAL;
 744	}
 745
 746	fs_info->zone_size = zone_size;
 747	/*
 748	 * Also limit max_zone_append_size by max_segments * PAGE_SIZE.
 749	 * Technically, we can have multiple pages per segment. But, since
 750	 * we add the pages one by one to a bio, and cannot increase the
 751	 * metadata reservation even if it increases the number of extents, it
 752	 * is safe to stick with the limit.
 753	 */
 754	fs_info->max_zone_append_size = ALIGN_DOWN(
 755		min3((u64)lim->max_zone_append_sectors << SECTOR_SHIFT,
 756		     (u64)lim->max_sectors << SECTOR_SHIFT,
 757		     (u64)lim->max_segments << PAGE_SHIFT),
 758		fs_info->sectorsize);
 759	fs_info->fs_devices->chunk_alloc_policy = BTRFS_CHUNK_ALLOC_ZONED;
 760	if (fs_info->max_zone_append_size < fs_info->max_extent_size)
 761		fs_info->max_extent_size = fs_info->max_zone_append_size;
 762
 763	/*
 764	 * Check mount options here, because we might change fs_info->zoned
 765	 * from fs_info->zone_size.
 766	 */
 767	ret = btrfs_check_mountopts_zoned(fs_info, &fs_info->mount_opt);
 768	if (ret)
 769		return ret;
 770
 771	btrfs_info(fs_info, "zoned mode enabled with zone size %llu", zone_size);
 772	return 0;
 773}
 774
 775int btrfs_check_mountopts_zoned(struct btrfs_fs_info *info, unsigned long *mount_opt)
 776{
 777	if (!btrfs_is_zoned(info))
 778		return 0;
 779
 780	/*
 781	 * Space cache writing is not COWed. Disable that to avoid write errors
 782	 * in sequential zones.
 783	 */
 784	if (btrfs_raw_test_opt(*mount_opt, SPACE_CACHE)) {
 785		btrfs_err(info, "zoned: space cache v1 is not supported");
 786		return -EINVAL;
 787	}
 788
 789	if (btrfs_raw_test_opt(*mount_opt, NODATACOW)) {
 790		btrfs_err(info, "zoned: NODATACOW not supported");
 791		return -EINVAL;
 792	}
 793
 794	if (btrfs_raw_test_opt(*mount_opt, DISCARD_ASYNC)) {
 795		btrfs_info(info,
 796			   "zoned: async discard ignored and disabled for zoned mode");
 797		btrfs_clear_opt(*mount_opt, DISCARD_ASYNC);
 798	}
 799
 800	return 0;
 801}
 802
 803static int sb_log_location(struct block_device *bdev, struct blk_zone *zones,
 804			   int rw, u64 *bytenr_ret)
 805{
 806	u64 wp;
 807	int ret;
 808
 809	if (zones[0].type == BLK_ZONE_TYPE_CONVENTIONAL) {
 810		*bytenr_ret = zones[0].start << SECTOR_SHIFT;
 811		return 0;
 812	}
 813
 814	ret = sb_write_pointer(bdev, zones, &wp);
 815	if (ret != -ENOENT && ret < 0)
 816		return ret;
 817
 818	if (rw == WRITE) {
 819		struct blk_zone *reset = NULL;
 820
 821		if (wp == zones[0].start << SECTOR_SHIFT)
 822			reset = &zones[0];
 823		else if (wp == zones[1].start << SECTOR_SHIFT)
 824			reset = &zones[1];
 825
 826		if (reset && reset->cond != BLK_ZONE_COND_EMPTY) {
 827			ASSERT(sb_zone_is_full(reset));
 828
 829			ret = blkdev_zone_mgmt(bdev, REQ_OP_ZONE_RESET,
 830					       reset->start, reset->len,
 831					       GFP_NOFS);
 832			if (ret)
 833				return ret;
 834
 835			reset->cond = BLK_ZONE_COND_EMPTY;
 836			reset->wp = reset->start;
 837		}
 838	} else if (ret != -ENOENT) {
 839		/*
 840		 * For READ, we want the previous one. Move write pointer to
 841		 * the end of a zone, if it is at the head of a zone.
 842		 */
 843		u64 zone_end = 0;
 844
 845		if (wp == zones[0].start << SECTOR_SHIFT)
 846			zone_end = zones[1].start + zones[1].capacity;
 847		else if (wp == zones[1].start << SECTOR_SHIFT)
 848			zone_end = zones[0].start + zones[0].capacity;
 849		if (zone_end)
 850			wp = ALIGN_DOWN(zone_end << SECTOR_SHIFT,
 851					BTRFS_SUPER_INFO_SIZE);
 852
 853		wp -= BTRFS_SUPER_INFO_SIZE;
 854	}
 855
 856	*bytenr_ret = wp;
 857	return 0;
 858
 859}
 860
 861int btrfs_sb_log_location_bdev(struct block_device *bdev, int mirror, int rw,
 862			       u64 *bytenr_ret)
 863{
 864	struct blk_zone zones[BTRFS_NR_SB_LOG_ZONES];
 865	sector_t zone_sectors;
 866	u32 sb_zone;
 867	int ret;
 868	u8 zone_sectors_shift;
 869	sector_t nr_sectors;
 870	u32 nr_zones;
 871
 872	if (!bdev_is_zoned(bdev)) {
 873		*bytenr_ret = btrfs_sb_offset(mirror);
 874		return 0;
 875	}
 876
 877	ASSERT(rw == READ || rw == WRITE);
 878
 879	zone_sectors = bdev_zone_sectors(bdev);
 880	if (!is_power_of_2(zone_sectors))
 881		return -EINVAL;
 882	zone_sectors_shift = ilog2(zone_sectors);
 883	nr_sectors = bdev_nr_sectors(bdev);
 884	nr_zones = nr_sectors >> zone_sectors_shift;
 885
 886	sb_zone = sb_zone_number(zone_sectors_shift + SECTOR_SHIFT, mirror);
 887	if (sb_zone + 1 >= nr_zones)
 888		return -ENOENT;
 889
 890	ret = blkdev_report_zones(bdev, zone_start_sector(sb_zone, bdev),
 891				  BTRFS_NR_SB_LOG_ZONES, copy_zone_info_cb,
 892				  zones);
 893	if (ret < 0)
 894		return ret;
 895	if (ret != BTRFS_NR_SB_LOG_ZONES)
 896		return -EIO;
 897
 898	return sb_log_location(bdev, zones, rw, bytenr_ret);
 899}
 900
 901int btrfs_sb_log_location(struct btrfs_device *device, int mirror, int rw,
 902			  u64 *bytenr_ret)
 903{
 904	struct btrfs_zoned_device_info *zinfo = device->zone_info;
 905	u32 zone_num;
 906
 907	/*
 908	 * For a zoned filesystem on a non-zoned block device, use the same
 909	 * super block locations as regular filesystem. Doing so, the super
 910	 * block can always be retrieved and the zoned flag of the volume
 911	 * detected from the super block information.
 912	 */
 913	if (!bdev_is_zoned(device->bdev)) {
 914		*bytenr_ret = btrfs_sb_offset(mirror);
 915		return 0;
 916	}
 917
 918	zone_num = sb_zone_number(zinfo->zone_size_shift, mirror);
 919	if (zone_num + 1 >= zinfo->nr_zones)
 920		return -ENOENT;
 921
 922	return sb_log_location(device->bdev,
 923			       &zinfo->sb_zones[BTRFS_NR_SB_LOG_ZONES * mirror],
 924			       rw, bytenr_ret);
 925}
 926
 927static inline bool is_sb_log_zone(struct btrfs_zoned_device_info *zinfo,
 928				  int mirror)
 929{
 930	u32 zone_num;
 931
 932	if (!zinfo)
 933		return false;
 934
 935	zone_num = sb_zone_number(zinfo->zone_size_shift, mirror);
 936	if (zone_num + 1 >= zinfo->nr_zones)
 937		return false;
 938
 939	if (!test_bit(zone_num, zinfo->seq_zones))
 940		return false;
 941
 942	return true;
 943}
 944
 945int btrfs_advance_sb_log(struct btrfs_device *device, int mirror)
 946{
 947	struct btrfs_zoned_device_info *zinfo = device->zone_info;
 948	struct blk_zone *zone;
 949	int i;
 950
 951	if (!is_sb_log_zone(zinfo, mirror))
 952		return 0;
 953
 954	zone = &zinfo->sb_zones[BTRFS_NR_SB_LOG_ZONES * mirror];
 955	for (i = 0; i < BTRFS_NR_SB_LOG_ZONES; i++) {
 956		/* Advance the next zone */
 957		if (zone->cond == BLK_ZONE_COND_FULL) {
 958			zone++;
 959			continue;
 960		}
 961
 962		if (zone->cond == BLK_ZONE_COND_EMPTY)
 963			zone->cond = BLK_ZONE_COND_IMP_OPEN;
 964
 965		zone->wp += SUPER_INFO_SECTORS;
 966
 967		if (sb_zone_is_full(zone)) {
 968			/*
 969			 * No room left to write new superblock. Since
 970			 * superblock is written with REQ_SYNC, it is safe to
 971			 * finish the zone now.
 972			 *
 973			 * If the write pointer is exactly at the capacity,
 974			 * explicit ZONE_FINISH is not necessary.
 975			 */
 976			if (zone->wp != zone->start + zone->capacity) {
 977				int ret;
 978
 979				ret = blkdev_zone_mgmt(device->bdev,
 980						REQ_OP_ZONE_FINISH, zone->start,
 981						zone->len, GFP_NOFS);
 982				if (ret)
 983					return ret;
 984			}
 985
 986			zone->wp = zone->start + zone->len;
 987			zone->cond = BLK_ZONE_COND_FULL;
 988		}
 989		return 0;
 990	}
 991
 992	/* All the zones are FULL. Should not reach here. */
 993	ASSERT(0);
 994	return -EIO;
 995}
 996
 997int btrfs_reset_sb_log_zones(struct block_device *bdev, int mirror)
 998{
 999	sector_t zone_sectors;
1000	sector_t nr_sectors;
1001	u8 zone_sectors_shift;
1002	u32 sb_zone;
1003	u32 nr_zones;
1004
1005	zone_sectors = bdev_zone_sectors(bdev);
1006	zone_sectors_shift = ilog2(zone_sectors);
1007	nr_sectors = bdev_nr_sectors(bdev);
1008	nr_zones = nr_sectors >> zone_sectors_shift;
1009
1010	sb_zone = sb_zone_number(zone_sectors_shift + SECTOR_SHIFT, mirror);
1011	if (sb_zone + 1 >= nr_zones)
1012		return -ENOENT;
1013
1014	return blkdev_zone_mgmt(bdev, REQ_OP_ZONE_RESET,
1015				zone_start_sector(sb_zone, bdev),
1016				zone_sectors * BTRFS_NR_SB_LOG_ZONES, GFP_NOFS);
1017}
1018
1019/*
1020 * Find allocatable zones within a given region.
1021 *
1022 * @device:	the device to allocate a region on
1023 * @hole_start: the position of the hole to allocate the region
1024 * @num_bytes:	size of wanted region
1025 * @hole_end:	the end of the hole
1026 * @return:	position of allocatable zones
1027 *
1028 * Allocatable region should not contain any superblock locations.
1029 */
1030u64 btrfs_find_allocatable_zones(struct btrfs_device *device, u64 hole_start,
1031				 u64 hole_end, u64 num_bytes)
1032{
1033	struct btrfs_zoned_device_info *zinfo = device->zone_info;
1034	const u8 shift = zinfo->zone_size_shift;
1035	u64 nzones = num_bytes >> shift;
1036	u64 pos = hole_start;
1037	u64 begin, end;
1038	bool have_sb;
1039	int i;
1040
1041	ASSERT(IS_ALIGNED(hole_start, zinfo->zone_size));
1042	ASSERT(IS_ALIGNED(num_bytes, zinfo->zone_size));
1043
1044	while (pos < hole_end) {
1045		begin = pos >> shift;
1046		end = begin + nzones;
1047
1048		if (end > zinfo->nr_zones)
1049			return hole_end;
1050
1051		/* Check if zones in the region are all empty */
1052		if (btrfs_dev_is_sequential(device, pos) &&
1053		    !bitmap_test_range_all_set(zinfo->empty_zones, begin, nzones)) {
1054			pos += zinfo->zone_size;
1055			continue;
1056		}
1057
1058		have_sb = false;
1059		for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
1060			u32 sb_zone;
1061			u64 sb_pos;
1062
1063			sb_zone = sb_zone_number(shift, i);
1064			if (!(end <= sb_zone ||
1065			      sb_zone + BTRFS_NR_SB_LOG_ZONES <= begin)) {
1066				have_sb = true;
1067				pos = zone_start_physical(
1068					sb_zone + BTRFS_NR_SB_LOG_ZONES, zinfo);
1069				break;
1070			}
1071
1072			/* We also need to exclude regular superblock positions */
1073			sb_pos = btrfs_sb_offset(i);
1074			if (!(pos + num_bytes <= sb_pos ||
1075			      sb_pos + BTRFS_SUPER_INFO_SIZE <= pos)) {
1076				have_sb = true;
1077				pos = ALIGN(sb_pos + BTRFS_SUPER_INFO_SIZE,
1078					    zinfo->zone_size);
1079				break;
1080			}
1081		}
1082		if (!have_sb)
1083			break;
1084	}
1085
1086	return pos;
1087}
1088
1089static bool btrfs_dev_set_active_zone(struct btrfs_device *device, u64 pos)
1090{
1091	struct btrfs_zoned_device_info *zone_info = device->zone_info;
1092	unsigned int zno = (pos >> zone_info->zone_size_shift);
1093
1094	/* We can use any number of zones */
1095	if (zone_info->max_active_zones == 0)
1096		return true;
1097
1098	if (!test_bit(zno, zone_info->active_zones)) {
1099		/* Active zone left? */
1100		if (atomic_dec_if_positive(&zone_info->active_zones_left) < 0)
1101			return false;
1102		if (test_and_set_bit(zno, zone_info->active_zones)) {
1103			/* Someone already set the bit */
1104			atomic_inc(&zone_info->active_zones_left);
1105		}
1106	}
1107
1108	return true;
1109}
1110
1111static void btrfs_dev_clear_active_zone(struct btrfs_device *device, u64 pos)
1112{
1113	struct btrfs_zoned_device_info *zone_info = device->zone_info;
1114	unsigned int zno = (pos >> zone_info->zone_size_shift);
1115
1116	/* We can use any number of zones */
1117	if (zone_info->max_active_zones == 0)
1118		return;
1119
1120	if (test_and_clear_bit(zno, zone_info->active_zones))
1121		atomic_inc(&zone_info->active_zones_left);
1122}
1123
1124int btrfs_reset_device_zone(struct btrfs_device *device, u64 physical,
1125			    u64 length, u64 *bytes)
1126{
1127	int ret;
1128
1129	*bytes = 0;
1130	ret = blkdev_zone_mgmt(device->bdev, REQ_OP_ZONE_RESET,
1131			       physical >> SECTOR_SHIFT, length >> SECTOR_SHIFT,
1132			       GFP_NOFS);
1133	if (ret)
1134		return ret;
1135
1136	*bytes = length;
1137	while (length) {
1138		btrfs_dev_set_zone_empty(device, physical);
1139		btrfs_dev_clear_active_zone(device, physical);
1140		physical += device->zone_info->zone_size;
1141		length -= device->zone_info->zone_size;
1142	}
1143
1144	return 0;
1145}
1146
1147int btrfs_ensure_empty_zones(struct btrfs_device *device, u64 start, u64 size)
1148{
1149	struct btrfs_zoned_device_info *zinfo = device->zone_info;
1150	const u8 shift = zinfo->zone_size_shift;
1151	unsigned long begin = start >> shift;
1152	unsigned long nbits = size >> shift;
1153	u64 pos;
1154	int ret;
1155
1156	ASSERT(IS_ALIGNED(start, zinfo->zone_size));
1157	ASSERT(IS_ALIGNED(size, zinfo->zone_size));
1158
1159	if (begin + nbits > zinfo->nr_zones)
1160		return -ERANGE;
1161
1162	/* All the zones are conventional */
1163	if (bitmap_test_range_all_zero(zinfo->seq_zones, begin, nbits))
1164		return 0;
1165
1166	/* All the zones are sequential and empty */
1167	if (bitmap_test_range_all_set(zinfo->seq_zones, begin, nbits) &&
1168	    bitmap_test_range_all_set(zinfo->empty_zones, begin, nbits))
1169		return 0;
1170
1171	for (pos = start; pos < start + size; pos += zinfo->zone_size) {
1172		u64 reset_bytes;
1173
1174		if (!btrfs_dev_is_sequential(device, pos) ||
1175		    btrfs_dev_is_empty_zone(device, pos))
1176			continue;
1177
1178		/* Free regions should be empty */
1179		btrfs_warn_in_rcu(
1180			device->fs_info,
1181		"zoned: resetting device %s (devid %llu) zone %llu for allocation",
1182			rcu_str_deref(device->name), device->devid, pos >> shift);
1183		WARN_ON_ONCE(1);
1184
1185		ret = btrfs_reset_device_zone(device, pos, zinfo->zone_size,
1186					      &reset_bytes);
1187		if (ret)
1188			return ret;
1189	}
1190
1191	return 0;
1192}
1193
1194/*
1195 * Calculate an allocation pointer from the extent allocation information
1196 * for a block group consist of conventional zones. It is pointed to the
1197 * end of the highest addressed extent in the block group as an allocation
1198 * offset.
1199 */
1200static int calculate_alloc_pointer(struct btrfs_block_group *cache,
1201				   u64 *offset_ret, bool new)
1202{
1203	struct btrfs_fs_info *fs_info = cache->fs_info;
1204	struct btrfs_root *root;
1205	struct btrfs_path *path;
1206	struct btrfs_key key;
1207	struct btrfs_key found_key;
1208	int ret;
1209	u64 length;
1210
1211	/*
1212	 * Avoid  tree lookups for a new block group, there's no use for it.
1213	 * It must always be 0.
1214	 *
1215	 * Also, we have a lock chain of extent buffer lock -> chunk mutex.
1216	 * For new a block group, this function is called from
1217	 * btrfs_make_block_group() which is already taking the chunk mutex.
1218	 * Thus, we cannot call calculate_alloc_pointer() which takes extent
1219	 * buffer locks to avoid deadlock.
1220	 */
1221	if (new) {
1222		*offset_ret = 0;
1223		return 0;
1224	}
1225
1226	path = btrfs_alloc_path();
1227	if (!path)
1228		return -ENOMEM;
1229
1230	key.objectid = cache->start + cache->length;
1231	key.type = 0;
1232	key.offset = 0;
1233
1234	root = btrfs_extent_root(fs_info, key.objectid);
1235	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1236	/* We should not find the exact match */
1237	if (!ret)
1238		ret = -EUCLEAN;
1239	if (ret < 0)
1240		goto out;
1241
1242	ret = btrfs_previous_extent_item(root, path, cache->start);
1243	if (ret) {
1244		if (ret == 1) {
1245			ret = 0;
1246			*offset_ret = 0;
1247		}
1248		goto out;
1249	}
1250
1251	btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
1252
1253	if (found_key.type == BTRFS_EXTENT_ITEM_KEY)
1254		length = found_key.offset;
1255	else
1256		length = fs_info->nodesize;
1257
1258	if (!(found_key.objectid >= cache->start &&
1259	       found_key.objectid + length <= cache->start + cache->length)) {
1260		ret = -EUCLEAN;
1261		goto out;
1262	}
1263	*offset_ret = found_key.objectid + length - cache->start;
1264	ret = 0;
1265
1266out:
1267	btrfs_free_path(path);
1268	return ret;
1269}
1270
1271struct zone_info {
1272	u64 physical;
1273	u64 capacity;
1274	u64 alloc_offset;
1275};
1276
1277static int btrfs_load_zone_info(struct btrfs_fs_info *fs_info, int zone_idx,
1278				struct zone_info *info, unsigned long *active,
1279				struct btrfs_chunk_map *map)
1280{
1281	struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
1282	struct btrfs_device *device = map->stripes[zone_idx].dev;
1283	int dev_replace_is_ongoing = 0;
1284	unsigned int nofs_flag;
1285	struct blk_zone zone;
1286	int ret;
1287
1288	info->physical = map->stripes[zone_idx].physical;
1289
1290	if (!device->bdev) {
1291		info->alloc_offset = WP_MISSING_DEV;
1292		return 0;
1293	}
1294
1295	/* Consider a zone as active if we can allow any number of active zones. */
1296	if (!device->zone_info->max_active_zones)
1297		__set_bit(zone_idx, active);
1298
1299	if (!btrfs_dev_is_sequential(device, info->physical)) {
1300		info->alloc_offset = WP_CONVENTIONAL;
1301		return 0;
1302	}
1303
1304	/* This zone will be used for allocation, so mark this zone non-empty. */
1305	btrfs_dev_clear_zone_empty(device, info->physical);
1306
1307	down_read(&dev_replace->rwsem);
1308	dev_replace_is_ongoing = btrfs_dev_replace_is_ongoing(dev_replace);
1309	if (dev_replace_is_ongoing && dev_replace->tgtdev != NULL)
1310		btrfs_dev_clear_zone_empty(dev_replace->tgtdev, info->physical);
1311	up_read(&dev_replace->rwsem);
1312
1313	/*
1314	 * The group is mapped to a sequential zone. Get the zone write pointer
1315	 * to determine the allocation offset within the zone.
1316	 */
1317	WARN_ON(!IS_ALIGNED(info->physical, fs_info->zone_size));
1318	nofs_flag = memalloc_nofs_save();
1319	ret = btrfs_get_dev_zone(device, info->physical, &zone);
1320	memalloc_nofs_restore(nofs_flag);
1321	if (ret) {
1322		if (ret != -EIO && ret != -EOPNOTSUPP)
1323			return ret;
1324		info->alloc_offset = WP_MISSING_DEV;
1325		return 0;
1326	}
1327
1328	if (zone.type == BLK_ZONE_TYPE_CONVENTIONAL) {
1329		btrfs_err_in_rcu(fs_info,
1330		"zoned: unexpected conventional zone %llu on device %s (devid %llu)",
1331			zone.start << SECTOR_SHIFT, rcu_str_deref(device->name),
1332			device->devid);
1333		return -EIO;
1334	}
1335
1336	info->capacity = (zone.capacity << SECTOR_SHIFT);
1337
1338	switch (zone.cond) {
1339	case BLK_ZONE_COND_OFFLINE:
1340	case BLK_ZONE_COND_READONLY:
1341		btrfs_err(fs_info,
1342		"zoned: offline/readonly zone %llu on device %s (devid %llu)",
1343			  (info->physical >> device->zone_info->zone_size_shift),
1344			  rcu_str_deref(device->name), device->devid);
1345		info->alloc_offset = WP_MISSING_DEV;
1346		break;
1347	case BLK_ZONE_COND_EMPTY:
1348		info->alloc_offset = 0;
1349		break;
1350	case BLK_ZONE_COND_FULL:
1351		info->alloc_offset = info->capacity;
1352		break;
1353	default:
1354		/* Partially used zone. */
1355		info->alloc_offset = ((zone.wp - zone.start) << SECTOR_SHIFT);
1356		__set_bit(zone_idx, active);
1357		break;
1358	}
1359
1360	return 0;
1361}
1362
1363static int btrfs_load_block_group_single(struct btrfs_block_group *bg,
1364					 struct zone_info *info,
1365					 unsigned long *active)
1366{
1367	if (info->alloc_offset == WP_MISSING_DEV) {
1368		btrfs_err(bg->fs_info,
1369			"zoned: cannot recover write pointer for zone %llu",
1370			info->physical);
1371		return -EIO;
1372	}
1373
1374	bg->alloc_offset = info->alloc_offset;
1375	bg->zone_capacity = info->capacity;
1376	if (test_bit(0, active))
1377		set_bit(BLOCK_GROUP_FLAG_ZONE_IS_ACTIVE, &bg->runtime_flags);
1378	return 0;
1379}
1380
1381static int btrfs_load_block_group_dup(struct btrfs_block_group *bg,
1382				      struct btrfs_chunk_map *map,
1383				      struct zone_info *zone_info,
1384				      unsigned long *active)
1385{
1386	struct btrfs_fs_info *fs_info = bg->fs_info;
1387
1388	if ((map->type & BTRFS_BLOCK_GROUP_DATA) && !fs_info->stripe_root) {
1389		btrfs_err(fs_info, "zoned: data DUP profile needs raid-stripe-tree");
1390		return -EINVAL;
1391	}
1392
1393	if (zone_info[0].alloc_offset == WP_MISSING_DEV) {
1394		btrfs_err(bg->fs_info,
1395			  "zoned: cannot recover write pointer for zone %llu",
1396			  zone_info[0].physical);
1397		return -EIO;
1398	}
1399	if (zone_info[1].alloc_offset == WP_MISSING_DEV) {
1400		btrfs_err(bg->fs_info,
1401			  "zoned: cannot recover write pointer for zone %llu",
1402			  zone_info[1].physical);
1403		return -EIO;
1404	}
1405	if (zone_info[0].alloc_offset != zone_info[1].alloc_offset) {
1406		btrfs_err(bg->fs_info,
1407			  "zoned: write pointer offset mismatch of zones in DUP profile");
1408		return -EIO;
1409	}
1410
1411	if (test_bit(0, active) != test_bit(1, active)) {
1412		if (!btrfs_zone_activate(bg))
1413			return -EIO;
1414	} else if (test_bit(0, active)) {
1415		set_bit(BLOCK_GROUP_FLAG_ZONE_IS_ACTIVE, &bg->runtime_flags);
1416	}
1417
1418	bg->alloc_offset = zone_info[0].alloc_offset;
1419	bg->zone_capacity = min(zone_info[0].capacity, zone_info[1].capacity);
1420	return 0;
1421}
1422
1423static int btrfs_load_block_group_raid1(struct btrfs_block_group *bg,
1424					struct btrfs_chunk_map *map,
1425					struct zone_info *zone_info,
1426					unsigned long *active)
1427{
1428	struct btrfs_fs_info *fs_info = bg->fs_info;
1429	int i;
1430
1431	if ((map->type & BTRFS_BLOCK_GROUP_DATA) && !fs_info->stripe_root) {
1432		btrfs_err(fs_info, "zoned: data %s needs raid-stripe-tree",
1433			  btrfs_bg_type_to_raid_name(map->type));
1434		return -EINVAL;
1435	}
1436
1437	for (i = 0; i < map->num_stripes; i++) {
1438		if (zone_info[i].alloc_offset == WP_MISSING_DEV ||
1439		    zone_info[i].alloc_offset == WP_CONVENTIONAL)
1440			continue;
1441
1442		if ((zone_info[0].alloc_offset != zone_info[i].alloc_offset) &&
1443		    !btrfs_test_opt(fs_info, DEGRADED)) {
1444			btrfs_err(fs_info,
1445			"zoned: write pointer offset mismatch of zones in %s profile",
1446				  btrfs_bg_type_to_raid_name(map->type));
1447			return -EIO;
1448		}
1449		if (test_bit(0, active) != test_bit(i, active)) {
1450			if (!btrfs_test_opt(fs_info, DEGRADED) &&
1451			    !btrfs_zone_activate(bg)) {
1452				return -EIO;
1453			}
1454		} else {
1455			if (test_bit(0, active))
1456				set_bit(BLOCK_GROUP_FLAG_ZONE_IS_ACTIVE, &bg->runtime_flags);
1457		}
1458		/* In case a device is missing we have a cap of 0, so don't use it. */
1459		bg->zone_capacity = min_not_zero(zone_info[0].capacity,
1460						 zone_info[1].capacity);
1461	}
1462
1463	if (zone_info[0].alloc_offset != WP_MISSING_DEV)
1464		bg->alloc_offset = zone_info[0].alloc_offset;
1465	else
1466		bg->alloc_offset = zone_info[i - 1].alloc_offset;
1467
1468	return 0;
1469}
1470
1471static int btrfs_load_block_group_raid0(struct btrfs_block_group *bg,
1472					struct btrfs_chunk_map *map,
1473					struct zone_info *zone_info,
1474					unsigned long *active)
1475{
1476	struct btrfs_fs_info *fs_info = bg->fs_info;
1477
1478	if ((map->type & BTRFS_BLOCK_GROUP_DATA) && !fs_info->stripe_root) {
1479		btrfs_err(fs_info, "zoned: data %s needs raid-stripe-tree",
1480			  btrfs_bg_type_to_raid_name(map->type));
1481		return -EINVAL;
1482	}
1483
1484	for (int i = 0; i < map->num_stripes; i++) {
1485		if (zone_info[i].alloc_offset == WP_MISSING_DEV ||
1486		    zone_info[i].alloc_offset == WP_CONVENTIONAL)
1487			continue;
1488
1489		if (test_bit(0, active) != test_bit(i, active)) {
1490			if (!btrfs_zone_activate(bg))
1491				return -EIO;
1492		} else {
1493			if (test_bit(0, active))
1494				set_bit(BLOCK_GROUP_FLAG_ZONE_IS_ACTIVE, &bg->runtime_flags);
1495		}
1496		bg->zone_capacity += zone_info[i].capacity;
1497		bg->alloc_offset += zone_info[i].alloc_offset;
1498	}
1499
1500	return 0;
1501}
1502
1503static int btrfs_load_block_group_raid10(struct btrfs_block_group *bg,
1504					 struct btrfs_chunk_map *map,
1505					 struct zone_info *zone_info,
1506					 unsigned long *active)
1507{
1508	struct btrfs_fs_info *fs_info = bg->fs_info;
1509
1510	if ((map->type & BTRFS_BLOCK_GROUP_DATA) && !fs_info->stripe_root) {
1511		btrfs_err(fs_info, "zoned: data %s needs raid-stripe-tree",
1512			  btrfs_bg_type_to_raid_name(map->type));
1513		return -EINVAL;
1514	}
1515
1516	for (int i = 0; i < map->num_stripes; i++) {
1517		if (zone_info[i].alloc_offset == WP_MISSING_DEV ||
1518		    zone_info[i].alloc_offset == WP_CONVENTIONAL)
1519			continue;
1520
1521		if (test_bit(0, active) != test_bit(i, active)) {
1522			if (!btrfs_zone_activate(bg))
1523				return -EIO;
1524		} else {
1525			if (test_bit(0, active))
1526				set_bit(BLOCK_GROUP_FLAG_ZONE_IS_ACTIVE, &bg->runtime_flags);
1527		}
1528
1529		if ((i % map->sub_stripes) == 0) {
1530			bg->zone_capacity += zone_info[i].capacity;
1531			bg->alloc_offset += zone_info[i].alloc_offset;
1532		}
1533	}
1534
1535	return 0;
1536}
1537
1538int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache, bool new)
1539{
1540	struct btrfs_fs_info *fs_info = cache->fs_info;
1541	struct btrfs_chunk_map *map;
1542	u64 logical = cache->start;
1543	u64 length = cache->length;
1544	struct zone_info *zone_info = NULL;
1545	int ret;
1546	int i;
1547	unsigned long *active = NULL;
1548	u64 last_alloc = 0;
1549	u32 num_sequential = 0, num_conventional = 0;
1550
1551	if (!btrfs_is_zoned(fs_info))
1552		return 0;
1553
1554	/* Sanity check */
1555	if (!IS_ALIGNED(length, fs_info->zone_size)) {
1556		btrfs_err(fs_info,
1557		"zoned: block group %llu len %llu unaligned to zone size %llu",
1558			  logical, length, fs_info->zone_size);
1559		return -EIO;
1560	}
1561
1562	map = btrfs_find_chunk_map(fs_info, logical, length);
1563	if (!map)
1564		return -EINVAL;
1565
1566	cache->physical_map = btrfs_clone_chunk_map(map, GFP_NOFS);
1567	if (!cache->physical_map) {
1568		ret = -ENOMEM;
1569		goto out;
1570	}
1571
1572	zone_info = kcalloc(map->num_stripes, sizeof(*zone_info), GFP_NOFS);
1573	if (!zone_info) {
1574		ret = -ENOMEM;
1575		goto out;
1576	}
1577
1578	active = bitmap_zalloc(map->num_stripes, GFP_NOFS);
1579	if (!active) {
1580		ret = -ENOMEM;
1581		goto out;
1582	}
1583
1584	for (i = 0; i < map->num_stripes; i++) {
1585		ret = btrfs_load_zone_info(fs_info, i, &zone_info[i], active, map);
1586		if (ret)
1587			goto out;
1588
1589		if (zone_info[i].alloc_offset == WP_CONVENTIONAL)
1590			num_conventional++;
1591		else
1592			num_sequential++;
1593	}
1594
1595	if (num_sequential > 0)
1596		set_bit(BLOCK_GROUP_FLAG_SEQUENTIAL_ZONE, &cache->runtime_flags);
1597
1598	if (num_conventional > 0) {
1599		/* Zone capacity is always zone size in emulation */
1600		cache->zone_capacity = cache->length;
1601		ret = calculate_alloc_pointer(cache, &last_alloc, new);
1602		if (ret) {
1603			btrfs_err(fs_info,
1604			"zoned: failed to determine allocation offset of bg %llu",
1605				  cache->start);
1606			goto out;
1607		} else if (map->num_stripes == num_conventional) {
1608			cache->alloc_offset = last_alloc;
1609			set_bit(BLOCK_GROUP_FLAG_ZONE_IS_ACTIVE, &cache->runtime_flags);
1610			goto out;
1611		}
1612	}
1613
1614	switch (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
1615	case 0: /* single */
1616		ret = btrfs_load_block_group_single(cache, &zone_info[0], active);
1617		break;
1618	case BTRFS_BLOCK_GROUP_DUP:
1619		ret = btrfs_load_block_group_dup(cache, map, zone_info, active);
1620		break;
1621	case BTRFS_BLOCK_GROUP_RAID1:
1622	case BTRFS_BLOCK_GROUP_RAID1C3:
1623	case BTRFS_BLOCK_GROUP_RAID1C4:
1624		ret = btrfs_load_block_group_raid1(cache, map, zone_info, active);
1625		break;
1626	case BTRFS_BLOCK_GROUP_RAID0:
1627		ret = btrfs_load_block_group_raid0(cache, map, zone_info, active);
1628		break;
1629	case BTRFS_BLOCK_GROUP_RAID10:
1630		ret = btrfs_load_block_group_raid10(cache, map, zone_info, active);
1631		break;
1632	case BTRFS_BLOCK_GROUP_RAID5:
1633	case BTRFS_BLOCK_GROUP_RAID6:
1634	default:
1635		btrfs_err(fs_info, "zoned: profile %s not yet supported",
1636			  btrfs_bg_type_to_raid_name(map->type));
1637		ret = -EINVAL;
1638		goto out;
1639	}
1640
1641out:
1642	/* Reject non SINGLE data profiles without RST */
1643	if ((map->type & BTRFS_BLOCK_GROUP_DATA) &&
1644	    (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) &&
1645	    !fs_info->stripe_root) {
1646		btrfs_err(fs_info, "zoned: data %s needs raid-stripe-tree",
1647			  btrfs_bg_type_to_raid_name(map->type));
1648		return -EINVAL;
1649	}
1650
1651	if (cache->alloc_offset > cache->zone_capacity) {
1652		btrfs_err(fs_info,
1653"zoned: invalid write pointer %llu (larger than zone capacity %llu) in block group %llu",
1654			  cache->alloc_offset, cache->zone_capacity,
1655			  cache->start);
1656		ret = -EIO;
1657	}
1658
1659	/* An extent is allocated after the write pointer */
1660	if (!ret && num_conventional && last_alloc > cache->alloc_offset) {
1661		btrfs_err(fs_info,
1662			  "zoned: got wrong write pointer in BG %llu: %llu > %llu",
1663			  logical, last_alloc, cache->alloc_offset);
1664		ret = -EIO;
1665	}
1666
1667	if (!ret) {
1668		cache->meta_write_pointer = cache->alloc_offset + cache->start;
1669		if (test_bit(BLOCK_GROUP_FLAG_ZONE_IS_ACTIVE, &cache->runtime_flags)) {
1670			btrfs_get_block_group(cache);
1671			spin_lock(&fs_info->zone_active_bgs_lock);
1672			list_add_tail(&cache->active_bg_list,
1673				      &fs_info->zone_active_bgs);
1674			spin_unlock(&fs_info->zone_active_bgs_lock);
1675		}
1676	} else {
1677		btrfs_free_chunk_map(cache->physical_map);
1678		cache->physical_map = NULL;
1679	}
1680	bitmap_free(active);
1681	kfree(zone_info);
1682	btrfs_free_chunk_map(map);
1683
1684	return ret;
1685}
1686
1687void btrfs_calc_zone_unusable(struct btrfs_block_group *cache)
1688{
1689	u64 unusable, free;
1690
1691	if (!btrfs_is_zoned(cache->fs_info))
1692		return;
1693
1694	WARN_ON(cache->bytes_super != 0);
1695	unusable = (cache->alloc_offset - cache->used) +
1696		   (cache->length - cache->zone_capacity);
1697	free = cache->zone_capacity - cache->alloc_offset;
1698
1699	/* We only need ->free_space in ALLOC_SEQ block groups */
1700	cache->cached = BTRFS_CACHE_FINISHED;
1701	cache->free_space_ctl->free_space = free;
1702	cache->zone_unusable = unusable;
1703}
1704
1705bool btrfs_use_zone_append(struct btrfs_bio *bbio)
1706{
1707	u64 start = (bbio->bio.bi_iter.bi_sector << SECTOR_SHIFT);
1708	struct btrfs_inode *inode = bbio->inode;
1709	struct btrfs_fs_info *fs_info = bbio->fs_info;
1710	struct btrfs_block_group *cache;
1711	bool ret = false;
1712
1713	if (!btrfs_is_zoned(fs_info))
1714		return false;
1715
1716	if (!inode || !is_data_inode(&inode->vfs_inode))
1717		return false;
1718
1719	if (btrfs_op(&bbio->bio) != BTRFS_MAP_WRITE)
1720		return false;
1721
1722	/*
1723	 * Using REQ_OP_ZONE_APPNED for relocation can break assumptions on the
1724	 * extent layout the relocation code has.
1725	 * Furthermore we have set aside own block-group from which only the
1726	 * relocation "process" can allocate and make sure only one process at a
1727	 * time can add pages to an extent that gets relocated, so it's safe to
1728	 * use regular REQ_OP_WRITE for this special case.
1729	 */
1730	if (btrfs_is_data_reloc_root(inode->root))
1731		return false;
1732
1733	cache = btrfs_lookup_block_group(fs_info, start);
1734	ASSERT(cache);
1735	if (!cache)
1736		return false;
1737
1738	ret = !!test_bit(BLOCK_GROUP_FLAG_SEQUENTIAL_ZONE, &cache->runtime_flags);
1739	btrfs_put_block_group(cache);
1740
1741	return ret;
1742}
1743
1744void btrfs_record_physical_zoned(struct btrfs_bio *bbio)
1745{
1746	const u64 physical = bbio->bio.bi_iter.bi_sector << SECTOR_SHIFT;
1747	struct btrfs_ordered_sum *sum = bbio->sums;
1748
1749	if (physical < bbio->orig_physical)
1750		sum->logical -= bbio->orig_physical - physical;
1751	else
1752		sum->logical += physical - bbio->orig_physical;
1753}
1754
1755static void btrfs_rewrite_logical_zoned(struct btrfs_ordered_extent *ordered,
1756					u64 logical)
1757{
1758	struct extent_map_tree *em_tree = &BTRFS_I(ordered->inode)->extent_tree;
1759	struct extent_map *em;
1760
1761	ordered->disk_bytenr = logical;
1762
1763	write_lock(&em_tree->lock);
1764	em = search_extent_mapping(em_tree, ordered->file_offset,
1765				   ordered->num_bytes);
1766	em->block_start = logical;
1767	free_extent_map(em);
1768	write_unlock(&em_tree->lock);
1769}
1770
1771static bool btrfs_zoned_split_ordered(struct btrfs_ordered_extent *ordered,
1772				      u64 logical, u64 len)
1773{
1774	struct btrfs_ordered_extent *new;
1775
1776	if (!test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags) &&
1777	    split_extent_map(BTRFS_I(ordered->inode), ordered->file_offset,
1778			     ordered->num_bytes, len, logical))
1779		return false;
1780
1781	new = btrfs_split_ordered_extent(ordered, len);
1782	if (IS_ERR(new))
1783		return false;
1784	new->disk_bytenr = logical;
1785	btrfs_finish_one_ordered(new);
1786	return true;
1787}
1788
1789void btrfs_finish_ordered_zoned(struct btrfs_ordered_extent *ordered)
1790{
1791	struct btrfs_inode *inode = BTRFS_I(ordered->inode);
1792	struct btrfs_fs_info *fs_info = inode->root->fs_info;
1793	struct btrfs_ordered_sum *sum;
1794	u64 logical, len;
1795
1796	/*
1797	 * Write to pre-allocated region is for the data relocation, and so
1798	 * it should use WRITE operation. No split/rewrite are necessary.
1799	 */
1800	if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags))
1801		return;
1802
1803	ASSERT(!list_empty(&ordered->list));
1804	/* The ordered->list can be empty in the above pre-alloc case. */
1805	sum = list_first_entry(&ordered->list, struct btrfs_ordered_sum, list);
1806	logical = sum->logical;
1807	len = sum->len;
1808
1809	while (len < ordered->disk_num_bytes) {
1810		sum = list_next_entry(sum, list);
1811		if (sum->logical == logical + len) {
1812			len += sum->len;
1813			continue;
1814		}
1815		if (!btrfs_zoned_split_ordered(ordered, logical, len)) {
1816			set_bit(BTRFS_ORDERED_IOERR, &ordered->flags);
1817			btrfs_err(fs_info, "failed to split ordered extent");
1818			goto out;
1819		}
1820		logical = sum->logical;
1821		len = sum->len;
1822	}
1823
1824	if (ordered->disk_bytenr != logical)
1825		btrfs_rewrite_logical_zoned(ordered, logical);
1826
1827out:
1828	/*
1829	 * If we end up here for nodatasum I/O, the btrfs_ordered_sum structures
1830	 * were allocated by btrfs_alloc_dummy_sum only to record the logical
1831	 * addresses and don't contain actual checksums.  We thus must free them
1832	 * here so that we don't attempt to log the csums later.
1833	 */
1834	if ((inode->flags & BTRFS_INODE_NODATASUM) ||
1835	    test_bit(BTRFS_FS_STATE_NO_CSUMS, &fs_info->fs_state)) {
1836		while ((sum = list_first_entry_or_null(&ordered->list,
1837						       typeof(*sum), list))) {
1838			list_del(&sum->list);
1839			kfree(sum);
1840		}
1841	}
1842}
1843
1844static bool check_bg_is_active(struct btrfs_eb_write_context *ctx,
1845			       struct btrfs_block_group **active_bg)
1846{
1847	const struct writeback_control *wbc = ctx->wbc;
1848	struct btrfs_block_group *block_group = ctx->zoned_bg;
1849	struct btrfs_fs_info *fs_info = block_group->fs_info;
1850
1851	if (test_bit(BLOCK_GROUP_FLAG_ZONE_IS_ACTIVE, &block_group->runtime_flags))
1852		return true;
1853
1854	if (fs_info->treelog_bg == block_group->start) {
1855		if (!btrfs_zone_activate(block_group)) {
1856			int ret_fin = btrfs_zone_finish_one_bg(fs_info);
1857
1858			if (ret_fin != 1 || !btrfs_zone_activate(block_group))
1859				return false;
1860		}
1861	} else if (*active_bg != block_group) {
1862		struct btrfs_block_group *tgt = *active_bg;
1863
1864		/* zoned_meta_io_lock protects fs_info->active_{meta,system}_bg. */
1865		lockdep_assert_held(&fs_info->zoned_meta_io_lock);
1866
1867		if (tgt) {
1868			/*
1869			 * If there is an unsent IO left in the allocated area,
1870			 * we cannot wait for them as it may cause a deadlock.
1871			 */
1872			if (tgt->meta_write_pointer < tgt->start + tgt->alloc_offset) {
1873				if (wbc->sync_mode == WB_SYNC_NONE ||
1874				    (wbc->sync_mode == WB_SYNC_ALL && !wbc->for_sync))
1875					return false;
1876			}
1877
1878			/* Pivot active metadata/system block group. */
1879			btrfs_zoned_meta_io_unlock(fs_info);
1880			wait_eb_writebacks(tgt);
1881			do_zone_finish(tgt, true);
1882			btrfs_zoned_meta_io_lock(fs_info);
1883			if (*active_bg == tgt) {
1884				btrfs_put_block_group(tgt);
1885				*active_bg = NULL;
1886			}
1887		}
1888		if (!btrfs_zone_activate(block_group))
1889			return false;
1890		if (*active_bg != block_group) {
1891			ASSERT(*active_bg == NULL);
1892			*active_bg = block_group;
1893			btrfs_get_block_group(block_group);
1894		}
1895	}
1896
1897	return true;
1898}
1899
1900/*
1901 * Check if @ctx->eb is aligned to the write pointer.
1902 *
1903 * Return:
1904 *   0:        @ctx->eb is at the write pointer. You can write it.
1905 *   -EAGAIN:  There is a hole. The caller should handle the case.
1906 *   -EBUSY:   There is a hole, but the caller can just bail out.
1907 */
1908int btrfs_check_meta_write_pointer(struct btrfs_fs_info *fs_info,
1909				   struct btrfs_eb_write_context *ctx)
1910{
1911	const struct writeback_control *wbc = ctx->wbc;
1912	const struct extent_buffer *eb = ctx->eb;
1913	struct btrfs_block_group *block_group = ctx->zoned_bg;
1914
1915	if (!btrfs_is_zoned(fs_info))
1916		return 0;
1917
1918	if (block_group) {
1919		if (block_group->start > eb->start ||
1920		    block_group->start + block_group->length <= eb->start) {
1921			btrfs_put_block_group(block_group);
1922			block_group = NULL;
1923			ctx->zoned_bg = NULL;
1924		}
1925	}
1926
1927	if (!block_group) {
1928		block_group = btrfs_lookup_block_group(fs_info, eb->start);
1929		if (!block_group)
1930			return 0;
1931		ctx->zoned_bg = block_group;
1932	}
1933
1934	if (block_group->meta_write_pointer == eb->start) {
1935		struct btrfs_block_group **tgt;
1936
1937		if (!test_bit(BTRFS_FS_ACTIVE_ZONE_TRACKING, &fs_info->flags))
1938			return 0;
1939
1940		if (block_group->flags & BTRFS_BLOCK_GROUP_SYSTEM)
1941			tgt = &fs_info->active_system_bg;
1942		else
1943			tgt = &fs_info->active_meta_bg;
1944		if (check_bg_is_active(ctx, tgt))
1945			return 0;
1946	}
1947
1948	/*
1949	 * Since we may release fs_info->zoned_meta_io_lock, someone can already
1950	 * start writing this eb. In that case, we can just bail out.
1951	 */
1952	if (block_group->meta_write_pointer > eb->start)
1953		return -EBUSY;
1954
1955	/* If for_sync, this hole will be filled with trasnsaction commit. */
1956	if (wbc->sync_mode == WB_SYNC_ALL && !wbc->for_sync)
1957		return -EAGAIN;
1958	return -EBUSY;
1959}
1960
1961int btrfs_zoned_issue_zeroout(struct btrfs_device *device, u64 physical, u64 length)
1962{
1963	if (!btrfs_dev_is_sequential(device, physical))
1964		return -EOPNOTSUPP;
1965
1966	return blkdev_issue_zeroout(device->bdev, physical >> SECTOR_SHIFT,
1967				    length >> SECTOR_SHIFT, GFP_NOFS, 0);
1968}
1969
1970static int read_zone_info(struct btrfs_fs_info *fs_info, u64 logical,
1971			  struct blk_zone *zone)
1972{
1973	struct btrfs_io_context *bioc = NULL;
1974	u64 mapped_length = PAGE_SIZE;
1975	unsigned int nofs_flag;
1976	int nmirrors;
1977	int i, ret;
1978
1979	ret = btrfs_map_block(fs_info, BTRFS_MAP_GET_READ_MIRRORS, logical,
1980			      &mapped_length, &bioc, NULL, NULL);
1981	if (ret || !bioc || mapped_length < PAGE_SIZE) {
1982		ret = -EIO;
1983		goto out_put_bioc;
1984	}
1985
1986	if (bioc->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
1987		ret = -EINVAL;
1988		goto out_put_bioc;
1989	}
1990
1991	nofs_flag = memalloc_nofs_save();
1992	nmirrors = (int)bioc->num_stripes;
1993	for (i = 0; i < nmirrors; i++) {
1994		u64 physical = bioc->stripes[i].physical;
1995		struct btrfs_device *dev = bioc->stripes[i].dev;
1996
1997		/* Missing device */
1998		if (!dev->bdev)
1999			continue;
2000
2001		ret = btrfs_get_dev_zone(dev, physical, zone);
2002		/* Failing device */
2003		if (ret == -EIO || ret == -EOPNOTSUPP)
2004			continue;
2005		break;
2006	}
2007	memalloc_nofs_restore(nofs_flag);
2008out_put_bioc:
2009	btrfs_put_bioc(bioc);
2010	return ret;
2011}
2012
2013/*
2014 * Synchronize write pointer in a zone at @physical_start on @tgt_dev, by
2015 * filling zeros between @physical_pos to a write pointer of dev-replace
2016 * source device.
2017 */
2018int btrfs_sync_zone_write_pointer(struct btrfs_device *tgt_dev, u64 logical,
2019				    u64 physical_start, u64 physical_pos)
2020{
2021	struct btrfs_fs_info *fs_info = tgt_dev->fs_info;
2022	struct blk_zone zone;
2023	u64 length;
2024	u64 wp;
2025	int ret;
2026
2027	if (!btrfs_dev_is_sequential(tgt_dev, physical_pos))
2028		return 0;
2029
2030	ret = read_zone_info(fs_info, logical, &zone);
2031	if (ret)
2032		return ret;
2033
2034	wp = physical_start + ((zone.wp - zone.start) << SECTOR_SHIFT);
2035
2036	if (physical_pos == wp)
2037		return 0;
2038
2039	if (physical_pos > wp)
2040		return -EUCLEAN;
2041
2042	length = wp - physical_pos;
2043	return btrfs_zoned_issue_zeroout(tgt_dev, physical_pos, length);
2044}
2045
2046/*
2047 * Activate block group and underlying device zones
2048 *
2049 * @block_group: the block group to activate
2050 *
2051 * Return: true on success, false otherwise
2052 */
2053bool btrfs_zone_activate(struct btrfs_block_group *block_group)
2054{
2055	struct btrfs_fs_info *fs_info = block_group->fs_info;
2056	struct btrfs_chunk_map *map;
2057	struct btrfs_device *device;
2058	u64 physical;
2059	const bool is_data = (block_group->flags & BTRFS_BLOCK_GROUP_DATA);
2060	bool ret;
2061	int i;
2062
2063	if (!btrfs_is_zoned(block_group->fs_info))
2064		return true;
2065
2066	map = block_group->physical_map;
2067
2068	spin_lock(&fs_info->zone_active_bgs_lock);
2069	spin_lock(&block_group->lock);
2070	if (test_bit(BLOCK_GROUP_FLAG_ZONE_IS_ACTIVE, &block_group->runtime_flags)) {
2071		ret = true;
2072		goto out_unlock;
2073	}
2074
2075	/* No space left */
2076	if (btrfs_zoned_bg_is_full(block_group)) {
2077		ret = false;
2078		goto out_unlock;
2079	}
2080
2081	for (i = 0; i < map->num_stripes; i++) {
2082		struct btrfs_zoned_device_info *zinfo;
2083		int reserved = 0;
2084
2085		device = map->stripes[i].dev;
2086		physical = map->stripes[i].physical;
2087		zinfo = device->zone_info;
2088
2089		if (zinfo->max_active_zones == 0)
2090			continue;
2091
2092		if (is_data)
2093			reserved = zinfo->reserved_active_zones;
2094		/*
2095		 * For the data block group, leave active zones for one
2096		 * metadata block group and one system block group.
2097		 */
2098		if (atomic_read(&zinfo->active_zones_left) <= reserved) {
2099			ret = false;
2100			goto out_unlock;
2101		}
2102
2103		if (!btrfs_dev_set_active_zone(device, physical)) {
2104			/* Cannot activate the zone */
2105			ret = false;
2106			goto out_unlock;
2107		}
2108		if (!is_data)
2109			zinfo->reserved_active_zones--;
2110	}
2111
2112	/* Successfully activated all the zones */
2113	set_bit(BLOCK_GROUP_FLAG_ZONE_IS_ACTIVE, &block_group->runtime_flags);
2114	spin_unlock(&block_group->lock);
2115
2116	/* For the active block group list */
2117	btrfs_get_block_group(block_group);
2118	list_add_tail(&block_group->active_bg_list, &fs_info->zone_active_bgs);
2119	spin_unlock(&fs_info->zone_active_bgs_lock);
2120
2121	return true;
2122
2123out_unlock:
2124	spin_unlock(&block_group->lock);
2125	spin_unlock(&fs_info->zone_active_bgs_lock);
2126	return ret;
2127}
2128
2129static void wait_eb_writebacks(struct btrfs_block_group *block_group)
2130{
2131	struct btrfs_fs_info *fs_info = block_group->fs_info;
2132	const u64 end = block_group->start + block_group->length;
2133	struct radix_tree_iter iter;
2134	struct extent_buffer *eb;
2135	void __rcu **slot;
2136
2137	rcu_read_lock();
2138	radix_tree_for_each_slot(slot, &fs_info->buffer_radix, &iter,
2139				 block_group->start >> fs_info->sectorsize_bits) {
2140		eb = radix_tree_deref_slot(slot);
2141		if (!eb)
2142			continue;
2143		if (radix_tree_deref_retry(eb)) {
2144			slot = radix_tree_iter_retry(&iter);
2145			continue;
2146		}
2147
2148		if (eb->start < block_group->start)
2149			continue;
2150		if (eb->start >= end)
2151			break;
2152
2153		slot = radix_tree_iter_resume(slot, &iter);
2154		rcu_read_unlock();
2155		wait_on_extent_buffer_writeback(eb);
2156		rcu_read_lock();
2157	}
2158	rcu_read_unlock();
2159}
2160
2161static int do_zone_finish(struct btrfs_block_group *block_group, bool fully_written)
2162{
2163	struct btrfs_fs_info *fs_info = block_group->fs_info;
2164	struct btrfs_chunk_map *map;
2165	const bool is_metadata = (block_group->flags &
2166			(BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_SYSTEM));
2167	int ret = 0;
2168	int i;
2169
2170	spin_lock(&block_group->lock);
2171	if (!test_bit(BLOCK_GROUP_FLAG_ZONE_IS_ACTIVE, &block_group->runtime_flags)) {
2172		spin_unlock(&block_group->lock);
2173		return 0;
2174	}
2175
2176	/* Check if we have unwritten allocated space */
2177	if (is_metadata &&
2178	    block_group->start + block_group->alloc_offset > block_group->meta_write_pointer) {
2179		spin_unlock(&block_group->lock);
2180		return -EAGAIN;
2181	}
2182
2183	/*
2184	 * If we are sure that the block group is full (= no more room left for
2185	 * new allocation) and the IO for the last usable block is completed, we
2186	 * don't need to wait for the other IOs. This holds because we ensure
2187	 * the sequential IO submissions using the ZONE_APPEND command for data
2188	 * and block_group->meta_write_pointer for metadata.
2189	 */
2190	if (!fully_written) {
2191		if (test_bit(BLOCK_GROUP_FLAG_ZONED_DATA_RELOC, &block_group->runtime_flags)) {
2192			spin_unlock(&block_group->lock);
2193			return -EAGAIN;
2194		}
2195		spin_unlock(&block_group->lock);
2196
2197		ret = btrfs_inc_block_group_ro(block_group, false);
2198		if (ret)
2199			return ret;
2200
2201		/* Ensure all writes in this block group finish */
2202		btrfs_wait_block_group_reservations(block_group);
2203		/* No need to wait for NOCOW writers. Zoned mode does not allow that */
2204		btrfs_wait_ordered_roots(fs_info, U64_MAX, block_group->start,
2205					 block_group->length);
2206		/* Wait for extent buffers to be written. */
2207		if (is_metadata)
2208			wait_eb_writebacks(block_group);
2209
2210		spin_lock(&block_group->lock);
2211
2212		/*
2213		 * Bail out if someone already deactivated the block group, or
2214		 * allocated space is left in the block group.
2215		 */
2216		if (!test_bit(BLOCK_GROUP_FLAG_ZONE_IS_ACTIVE,
2217			      &block_group->runtime_flags)) {
2218			spin_unlock(&block_group->lock);
2219			btrfs_dec_block_group_ro(block_group);
2220			return 0;
2221		}
2222
2223		if (block_group->reserved ||
2224		    test_bit(BLOCK_GROUP_FLAG_ZONED_DATA_RELOC,
2225			     &block_group->runtime_flags)) {
2226			spin_unlock(&block_group->lock);
2227			btrfs_dec_block_group_ro(block_group);
2228			return -EAGAIN;
2229		}
2230	}
2231
2232	clear_bit(BLOCK_GROUP_FLAG_ZONE_IS_ACTIVE, &block_group->runtime_flags);
2233	block_group->alloc_offset = block_group->zone_capacity;
2234	if (block_group->flags & (BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_SYSTEM))
2235		block_group->meta_write_pointer = block_group->start +
2236						  block_group->zone_capacity;
2237	block_group->free_space_ctl->free_space = 0;
2238	btrfs_clear_treelog_bg(block_group);
2239	btrfs_clear_data_reloc_bg(block_group);
2240	spin_unlock(&block_group->lock);
2241
2242	map = block_group->physical_map;
2243	for (i = 0; i < map->num_stripes; i++) {
2244		struct btrfs_device *device = map->stripes[i].dev;
2245		const u64 physical = map->stripes[i].physical;
2246		struct btrfs_zoned_device_info *zinfo = device->zone_info;
2247
2248		if (zinfo->max_active_zones == 0)
2249			continue;
2250
2251		ret = blkdev_zone_mgmt(device->bdev, REQ_OP_ZONE_FINISH,
2252				       physical >> SECTOR_SHIFT,
2253				       zinfo->zone_size >> SECTOR_SHIFT,
2254				       GFP_NOFS);
2255
2256		if (ret)
2257			return ret;
2258
2259		if (!(block_group->flags & BTRFS_BLOCK_GROUP_DATA))
2260			zinfo->reserved_active_zones++;
2261		btrfs_dev_clear_active_zone(device, physical);
2262	}
2263
2264	if (!fully_written)
2265		btrfs_dec_block_group_ro(block_group);
2266
2267	spin_lock(&fs_info->zone_active_bgs_lock);
2268	ASSERT(!list_empty(&block_group->active_bg_list));
2269	list_del_init(&block_group->active_bg_list);
2270	spin_unlock(&fs_info->zone_active_bgs_lock);
2271
2272	/* For active_bg_list */
2273	btrfs_put_block_group(block_group);
2274
2275	clear_and_wake_up_bit(BTRFS_FS_NEED_ZONE_FINISH, &fs_info->flags);
2276
2277	return 0;
2278}
2279
2280int btrfs_zone_finish(struct btrfs_block_group *block_group)
2281{
2282	if (!btrfs_is_zoned(block_group->fs_info))
2283		return 0;
2284
2285	return do_zone_finish(block_group, false);
2286}
2287
2288bool btrfs_can_activate_zone(struct btrfs_fs_devices *fs_devices, u64 flags)
2289{
2290	struct btrfs_fs_info *fs_info = fs_devices->fs_info;
2291	struct btrfs_device *device;
2292	bool ret = false;
2293
2294	if (!btrfs_is_zoned(fs_info))
2295		return true;
2296
2297	/* Check if there is a device with active zones left */
2298	mutex_lock(&fs_info->chunk_mutex);
2299	spin_lock(&fs_info->zone_active_bgs_lock);
2300	list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) {
2301		struct btrfs_zoned_device_info *zinfo = device->zone_info;
2302		int reserved = 0;
2303
2304		if (!device->bdev)
2305			continue;
2306
2307		if (!zinfo->max_active_zones) {
2308			ret = true;
2309			break;
2310		}
2311
2312		if (flags & BTRFS_BLOCK_GROUP_DATA)
2313			reserved = zinfo->reserved_active_zones;
2314
2315		switch (flags & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
2316		case 0: /* single */
2317			ret = (atomic_read(&zinfo->active_zones_left) >= (1 + reserved));
2318			break;
2319		case BTRFS_BLOCK_GROUP_DUP:
2320			ret = (atomic_read(&zinfo->active_zones_left) >= (2 + reserved));
2321			break;
2322		}
2323		if (ret)
2324			break;
2325	}
2326	spin_unlock(&fs_info->zone_active_bgs_lock);
2327	mutex_unlock(&fs_info->chunk_mutex);
2328
2329	if (!ret)
2330		set_bit(BTRFS_FS_NEED_ZONE_FINISH, &fs_info->flags);
2331
2332	return ret;
2333}
2334
2335void btrfs_zone_finish_endio(struct btrfs_fs_info *fs_info, u64 logical, u64 length)
2336{
2337	struct btrfs_block_group *block_group;
2338	u64 min_alloc_bytes;
2339
2340	if (!btrfs_is_zoned(fs_info))
2341		return;
2342
2343	block_group = btrfs_lookup_block_group(fs_info, logical);
2344	ASSERT(block_group);
2345
2346	/* No MIXED_BG on zoned btrfs. */
2347	if (block_group->flags & BTRFS_BLOCK_GROUP_DATA)
2348		min_alloc_bytes = fs_info->sectorsize;
2349	else
2350		min_alloc_bytes = fs_info->nodesize;
2351
2352	/* Bail out if we can allocate more data from this block group. */
2353	if (logical + length + min_alloc_bytes <=
2354	    block_group->start + block_group->zone_capacity)
2355		goto out;
2356
2357	do_zone_finish(block_group, true);
2358
2359out:
2360	btrfs_put_block_group(block_group);
2361}
2362
2363static void btrfs_zone_finish_endio_workfn(struct work_struct *work)
2364{
2365	struct btrfs_block_group *bg =
2366		container_of(work, struct btrfs_block_group, zone_finish_work);
2367
2368	wait_on_extent_buffer_writeback(bg->last_eb);
2369	free_extent_buffer(bg->last_eb);
2370	btrfs_zone_finish_endio(bg->fs_info, bg->start, bg->length);
2371	btrfs_put_block_group(bg);
2372}
2373
2374void btrfs_schedule_zone_finish_bg(struct btrfs_block_group *bg,
2375				   struct extent_buffer *eb)
2376{
2377	if (!test_bit(BLOCK_GROUP_FLAG_SEQUENTIAL_ZONE, &bg->runtime_flags) ||
2378	    eb->start + eb->len * 2 <= bg->start + bg->zone_capacity)
2379		return;
2380
2381	if (WARN_ON(bg->zone_finish_work.func == btrfs_zone_finish_endio_workfn)) {
2382		btrfs_err(bg->fs_info, "double scheduling of bg %llu zone finishing",
2383			  bg->start);
2384		return;
2385	}
2386
2387	/* For the work */
2388	btrfs_get_block_group(bg);
2389	atomic_inc(&eb->refs);
2390	bg->last_eb = eb;
2391	INIT_WORK(&bg->zone_finish_work, btrfs_zone_finish_endio_workfn);
2392	queue_work(system_unbound_wq, &bg->zone_finish_work);
2393}
2394
2395void btrfs_clear_data_reloc_bg(struct btrfs_block_group *bg)
2396{
2397	struct btrfs_fs_info *fs_info = bg->fs_info;
2398
2399	spin_lock(&fs_info->relocation_bg_lock);
2400	if (fs_info->data_reloc_bg == bg->start)
2401		fs_info->data_reloc_bg = 0;
2402	spin_unlock(&fs_info->relocation_bg_lock);
2403}
2404
2405void btrfs_free_zone_cache(struct btrfs_fs_info *fs_info)
2406{
2407	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
2408	struct btrfs_device *device;
2409
2410	if (!btrfs_is_zoned(fs_info))
2411		return;
2412
2413	mutex_lock(&fs_devices->device_list_mutex);
2414	list_for_each_entry(device, &fs_devices->devices, dev_list) {
2415		if (device->zone_info) {
2416			vfree(device->zone_info->zone_cache);
2417			device->zone_info->zone_cache = NULL;
2418		}
2419	}
2420	mutex_unlock(&fs_devices->device_list_mutex);
2421}
2422
2423bool btrfs_zoned_should_reclaim(struct btrfs_fs_info *fs_info)
2424{
2425	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
2426	struct btrfs_device *device;
2427	u64 used = 0;
2428	u64 total = 0;
2429	u64 factor;
2430
2431	ASSERT(btrfs_is_zoned(fs_info));
2432
2433	if (fs_info->bg_reclaim_threshold == 0)
2434		return false;
2435
2436	mutex_lock(&fs_devices->device_list_mutex);
2437	list_for_each_entry(device, &fs_devices->devices, dev_list) {
2438		if (!device->bdev)
2439			continue;
2440
2441		total += device->disk_total_bytes;
2442		used += device->bytes_used;
2443	}
2444	mutex_unlock(&fs_devices->device_list_mutex);
2445
2446	factor = div64_u64(used * 100, total);
2447	return factor >= fs_info->bg_reclaim_threshold;
2448}
2449
2450void btrfs_zoned_release_data_reloc_bg(struct btrfs_fs_info *fs_info, u64 logical,
2451				       u64 length)
2452{
2453	struct btrfs_block_group *block_group;
2454
2455	if (!btrfs_is_zoned(fs_info))
2456		return;
2457
2458	block_group = btrfs_lookup_block_group(fs_info, logical);
2459	/* It should be called on a previous data relocation block group. */
2460	ASSERT(block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA));
2461
2462	spin_lock(&block_group->lock);
2463	if (!test_bit(BLOCK_GROUP_FLAG_ZONED_DATA_RELOC, &block_group->runtime_flags))
2464		goto out;
2465
2466	/* All relocation extents are written. */
2467	if (block_group->start + block_group->alloc_offset == logical + length) {
2468		/*
2469		 * Now, release this block group for further allocations and
2470		 * zone finish.
2471		 */
2472		clear_bit(BLOCK_GROUP_FLAG_ZONED_DATA_RELOC,
2473			  &block_group->runtime_flags);
2474	}
2475
2476out:
2477	spin_unlock(&block_group->lock);
2478	btrfs_put_block_group(block_group);
2479}
2480
2481int btrfs_zone_finish_one_bg(struct btrfs_fs_info *fs_info)
2482{
2483	struct btrfs_block_group *block_group;
2484	struct btrfs_block_group *min_bg = NULL;
2485	u64 min_avail = U64_MAX;
2486	int ret;
2487
2488	spin_lock(&fs_info->zone_active_bgs_lock);
2489	list_for_each_entry(block_group, &fs_info->zone_active_bgs,
2490			    active_bg_list) {
2491		u64 avail;
2492
2493		spin_lock(&block_group->lock);
2494		if (block_group->reserved || block_group->alloc_offset == 0 ||
2495		    (block_group->flags & BTRFS_BLOCK_GROUP_SYSTEM) ||
2496		    test_bit(BLOCK_GROUP_FLAG_ZONED_DATA_RELOC, &block_group->runtime_flags)) {
2497			spin_unlock(&block_group->lock);
2498			continue;
2499		}
2500
2501		avail = block_group->zone_capacity - block_group->alloc_offset;
2502		if (min_avail > avail) {
2503			if (min_bg)
2504				btrfs_put_block_group(min_bg);
2505			min_bg = block_group;
2506			min_avail = avail;
2507			btrfs_get_block_group(min_bg);
2508		}
2509		spin_unlock(&block_group->lock);
2510	}
2511	spin_unlock(&fs_info->zone_active_bgs_lock);
2512
2513	if (!min_bg)
2514		return 0;
2515
2516	ret = btrfs_zone_finish(min_bg);
2517	btrfs_put_block_group(min_bg);
2518
2519	return ret < 0 ? ret : 1;
2520}
2521
2522int btrfs_zoned_activate_one_bg(struct btrfs_fs_info *fs_info,
2523				struct btrfs_space_info *space_info,
2524				bool do_finish)
2525{
2526	struct btrfs_block_group *bg;
2527	int index;
2528
2529	if (!btrfs_is_zoned(fs_info) || (space_info->flags & BTRFS_BLOCK_GROUP_DATA))
2530		return 0;
2531
2532	for (;;) {
2533		int ret;
2534		bool need_finish = false;
2535
2536		down_read(&space_info->groups_sem);
2537		for (index = 0; index < BTRFS_NR_RAID_TYPES; index++) {
2538			list_for_each_entry(bg, &space_info->block_groups[index],
2539					    list) {
2540				if (!spin_trylock(&bg->lock))
2541					continue;
2542				if (btrfs_zoned_bg_is_full(bg) ||
2543				    test_bit(BLOCK_GROUP_FLAG_ZONE_IS_ACTIVE,
2544					     &bg->runtime_flags)) {
2545					spin_unlock(&bg->lock);
2546					continue;
2547				}
2548				spin_unlock(&bg->lock);
2549
2550				if (btrfs_zone_activate(bg)) {
2551					up_read(&space_info->groups_sem);
2552					return 1;
2553				}
2554
2555				need_finish = true;
2556			}
2557		}
2558		up_read(&space_info->groups_sem);
2559
2560		if (!do_finish || !need_finish)
2561			break;
2562
2563		ret = btrfs_zone_finish_one_bg(fs_info);
2564		if (ret == 0)
2565			break;
2566		if (ret < 0)
2567			return ret;
2568	}
2569
2570	return 0;
2571}
2572
2573/*
2574 * Reserve zones for one metadata block group, one tree-log block group, and one
2575 * system block group.
2576 */
2577void btrfs_check_active_zone_reservation(struct btrfs_fs_info *fs_info)
2578{
2579	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
2580	struct btrfs_block_group *block_group;
2581	struct btrfs_device *device;
2582	/* Reserve zones for normal SINGLE metadata and tree-log block group. */
2583	unsigned int metadata_reserve = 2;
2584	/* Reserve a zone for SINGLE system block group. */
2585	unsigned int system_reserve = 1;
2586
2587	if (!test_bit(BTRFS_FS_ACTIVE_ZONE_TRACKING, &fs_info->flags))
2588		return;
2589
2590	/*
2591	 * This function is called from the mount context. So, there is no
2592	 * parallel process touching the bits. No need for read_seqretry().
2593	 */
2594	if (fs_info->avail_metadata_alloc_bits & BTRFS_BLOCK_GROUP_DUP)
2595		metadata_reserve = 4;
2596	if (fs_info->avail_system_alloc_bits & BTRFS_BLOCK_GROUP_DUP)
2597		system_reserve = 2;
2598
2599	/* Apply the reservation on all the devices. */
2600	mutex_lock(&fs_devices->device_list_mutex);
2601	list_for_each_entry(device, &fs_devices->devices, dev_list) {
2602		if (!device->bdev)
2603			continue;
2604
2605		device->zone_info->reserved_active_zones =
2606			metadata_reserve + system_reserve;
2607	}
2608	mutex_unlock(&fs_devices->device_list_mutex);
2609
2610	/* Release reservation for currently active block groups. */
2611	spin_lock(&fs_info->zone_active_bgs_lock);
2612	list_for_each_entry(block_group, &fs_info->zone_active_bgs, active_bg_list) {
2613		struct btrfs_chunk_map *map = block_group->physical_map;
2614
2615		if (!(block_group->flags &
2616		      (BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_SYSTEM)))
2617			continue;
2618
2619		for (int i = 0; i < map->num_stripes; i++)
2620			map->stripes[i].dev->zone_info->reserved_active_zones--;
2621	}
2622	spin_unlock(&fs_info->zone_active_bgs_lock);
2623}