fs/btrfs/zoned.c

   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
  68 static void wait_eb_writebacks(struct btrfs_block_group *block_group);
  69 static int do_zone_finish(struct btrfs_block_group *block_group, bool fully_written);
  70
  71 static 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
  77 static 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
  86 static 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  */
 165 static 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
 181 static 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
 187 static 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  */
 198 static 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
 223 static 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 */
 292 static 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
 329 out:
 330         btrfs_free_path(path);
 331
 332         return ret;
 333 }
 334
 335 int 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
 360 int 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         switch (bdev_zoned_model(bdev)) {
 582         case BLK_ZONED_HM:
 583                 model = "host-managed zoned";
 584                 emulated = "";
 585                 break;
 586         case BLK_ZONED_HA:
 587                 model = "host-aware zoned";
 588                 emulated = "";
 589                 break;
 590         case BLK_ZONED_NONE:
 591                 model = "regular";
 592                 emulated = "emulated ";
 593                 break;
 594         default:
 595                 /* Just in case */
 596                 btrfs_err_in_rcu(fs_info, "zoned: unsupported model %d on %s",
 597                                  bdev_zoned_model(bdev),
 598                                  rcu_str_deref(device->name));
 599                 ret = -EOPNOTSUPP;
 600                 goto out_free_zone_info;
 601         }
 602
 603         btrfs_info_in_rcu(fs_info,
 604                 "%s block device %s, %u %szones of %llu bytes",
 605                 model, rcu_str_deref(device->name), zone_info->nr_zones,
 606                 emulated, zone_info->zone_size);
 607
 608         return 0;
 609
 610 out:
 611         kvfree(zones);
 612 out_free_zone_info:
 613         btrfs_destroy_dev_zone_info(device);
 614
 615         return ret;
 616 }
 617
 618 void btrfs_destroy_dev_zone_info(struct btrfs_device *device)
 619 {
 620         struct btrfs_zoned_device_info *zone_info = device->zone_info;
 621
 622         if (!zone_info)
 623                 return;
 624
 625         bitmap_free(zone_info->active_zones);
 626         bitmap_free(zone_info->seq_zones);
 627         bitmap_free(zone_info->empty_zones);
 628         vfree(zone_info->zone_cache);
 629         kfree(zone_info);
 630         device->zone_info = NULL;
 631 }
 632
 633 struct btrfs_zoned_device_info *btrfs_clone_dev_zone_info(struct btrfs_device *orig_dev)
 634 {
 635         struct btrfs_zoned_device_info *zone_info;
 636
 637         zone_info = kmemdup(orig_dev->zone_info, sizeof(*zone_info), GFP_KERNEL);
 638         if (!zone_info)
 639                 return NULL;
 640
 641         zone_info->seq_zones = bitmap_zalloc(zone_info->nr_zones, GFP_KERNEL);
 642         if (!zone_info->seq_zones)
 643                 goto out;
 644
 645         bitmap_copy(zone_info->seq_zones, orig_dev->zone_info->seq_zones,
 646                     zone_info->nr_zones);
 647
 648         zone_info->empty_zones = bitmap_zalloc(zone_info->nr_zones, GFP_KERNEL);
 649         if (!zone_info->empty_zones)
 650                 goto out;
 651
 652         bitmap_copy(zone_info->empty_zones, orig_dev->zone_info->empty_zones,
 653                     zone_info->nr_zones);
 654
 655         zone_info->active_zones = bitmap_zalloc(zone_info->nr_zones, GFP_KERNEL);
 656         if (!zone_info->active_zones)
 657                 goto out;
 658
 659         bitmap_copy(zone_info->active_zones, orig_dev->zone_info->active_zones,
 660                     zone_info->nr_zones);
 661         zone_info->zone_cache = NULL;
 662
 663         return zone_info;
 664
 665 out:
 666         bitmap_free(zone_info->seq_zones);
 667         bitmap_free(zone_info->empty_zones);
 668         bitmap_free(zone_info->active_zones);
 669         kfree(zone_info);
 670         return NULL;
 671 }
 672
 673 int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
 674                        struct blk_zone *zone)
 675 {
 676         unsigned int nr_zones = 1;
 677         int ret;
 678
 679         ret = btrfs_get_dev_zones(device, pos, zone, &nr_zones);
 680         if (ret != 0 || !nr_zones)
 681                 return ret ? ret : -EIO;
 682
 683         return 0;
 684 }
 685
 686 static int btrfs_check_for_zoned_device(struct btrfs_fs_info *fs_info)
 687 {
 688         struct btrfs_device *device;
 689
 690         list_for_each_entry(device, &fs_info->fs_devices->devices, dev_list) {
 691                 if (device->bdev &&
 692                     bdev_zoned_model(device->bdev) == BLK_ZONED_HM) {
 693                         btrfs_err(fs_info,
 694                                 "zoned: mode not enabled but zoned device found: %pg",
 695                                 device->bdev);
 696                         return -EINVAL;
 697                 }
 698         }
 699
 700         return 0;
 701 }
 702
 703 int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info)
 704 {
 705         struct queue_limits *lim = &fs_info->limits;
 706         struct btrfs_device *device;
 707         u64 zone_size = 0;
 708         int ret;
 709
 710         /*
 711          * Host-Managed devices can't be used without the ZONED flag.  With the
 712          * ZONED all devices can be used, using zone emulation if required.
 713          */
 714         if (!btrfs_fs_incompat(fs_info, ZONED))
 715                 return btrfs_check_for_zoned_device(fs_info);
 716
 717         blk_set_stacking_limits(lim);
 718
 719         list_for_each_entry(device, &fs_info->fs_devices->devices, dev_list) {
 720                 struct btrfs_zoned_device_info *zone_info = device->zone_info;
 721
 722                 if (!device->bdev)
 723                         continue;
 724
 725                 if (!zone_size) {
 726                         zone_size = zone_info->zone_size;
 727                 } else if (zone_info->zone_size != zone_size) {
 728                         btrfs_err(fs_info,
 729                 "zoned: unequal block device zone sizes: have %llu found %llu",
 730                                   zone_info->zone_size, zone_size);
 731                         return -EINVAL;
 732                 }
 733
 734                 /*
 735                  * With the zoned emulation, we can have non-zoned device on the
 736                  * zoned mode. In this case, we don't have a valid max zone
 737                  * append size.
 738                  */
 739                 if (bdev_is_zoned(device->bdev)) {
 740                         blk_stack_limits(lim,
 741                                          &bdev_get_queue(device->bdev)->limits,
 742                                          0);
 743                 }
 744         }
 745
 746         /*
 747          * stripe_size is always aligned to BTRFS_STRIPE_LEN in
 748          * btrfs_create_chunk(). Since we want stripe_len == zone_size,
 749          * check the alignment here.
 750          */
 751         if (!IS_ALIGNED(zone_size, BTRFS_STRIPE_LEN)) {
 752                 btrfs_err(fs_info,
 753                           "zoned: zone size %llu not aligned to stripe %u",
 754                           zone_size, BTRFS_STRIPE_LEN);
 755                 return -EINVAL;
 756         }
 757
 758         if (btrfs_fs_incompat(fs_info, MIXED_GROUPS)) {
 759                 btrfs_err(fs_info, "zoned: mixed block groups not supported");
 760                 return -EINVAL;
 761         }
 762
 763         fs_info->zone_size = zone_size;
 764         /*
 765          * Also limit max_zone_append_size by max_segments * PAGE_SIZE.
 766          * Technically, we can have multiple pages per segment. But, since
 767          * we add the pages one by one to a bio, and cannot increase the
 768          * metadata reservation even if it increases the number of extents, it
 769          * is safe to stick with the limit.
 770          */
 771         fs_info->max_zone_append_size = ALIGN_DOWN(
 772                 min3((u64)lim->max_zone_append_sectors << SECTOR_SHIFT,
 773                      (u64)lim->max_sectors << SECTOR_SHIFT,
 774                      (u64)lim->max_segments << PAGE_SHIFT),
 775                 fs_info->sectorsize);
 776         fs_info->fs_devices->chunk_alloc_policy = BTRFS_CHUNK_ALLOC_ZONED;
 777         if (fs_info->max_zone_append_size < fs_info->max_extent_size)
 778                 fs_info->max_extent_size = fs_info->max_zone_append_size;
 779
 780         /*
 781          * Check mount options here, because we might change fs_info->zoned
 782          * from fs_info->zone_size.
 783          */
 784         ret = btrfs_check_mountopts_zoned(fs_info);
 785         if (ret)
 786                 return ret;
 787
 788         btrfs_info(fs_info, "zoned mode enabled with zone size %llu", zone_size);
 789         return 0;
 790 }
 791
 792 int btrfs_check_mountopts_zoned(struct btrfs_fs_info *info)
 793 {
 794         if (!btrfs_is_zoned(info))
 795                 return 0;
 796
 797         /*
 798          * Space cache writing is not COWed. Disable that to avoid write errors
 799          * in sequential zones.
 800          */
 801         if (btrfs_test_opt(info, SPACE_CACHE)) {
 802                 btrfs_err(info, "zoned: space cache v1 is not supported");
 803                 return -EINVAL;
 804         }
 805
 806         if (btrfs_test_opt(info, NODATACOW)) {
 807                 btrfs_err(info, "zoned: NODATACOW not supported");
 808                 return -EINVAL;
 809         }
 810
 811         btrfs_clear_and_info(info, DISCARD_ASYNC,
 812                         "zoned: async discard ignored and disabled for zoned mode");
 813
 814         return 0;
 815 }
 816
 817 static int sb_log_location(struct block_device *bdev, struct blk_zone *zones,
 818                            int rw, u64 *bytenr_ret)
 819 {
 820         u64 wp;
 821         int ret;
 822
 823         if (zones[0].type == BLK_ZONE_TYPE_CONVENTIONAL) {
 824                 *bytenr_ret = zones[0].start << SECTOR_SHIFT;
 825                 return 0;
 826         }
 827
 828         ret = sb_write_pointer(bdev, zones, &wp);
 829         if (ret != -ENOENT && ret < 0)
 830                 return ret;
 831
 832         if (rw == WRITE) {
 833                 struct blk_zone *reset = NULL;
 834
 835                 if (wp == zones[0].start << SECTOR_SHIFT)
 836                         reset = &zones[0];
 837                 else if (wp == zones[1].start << SECTOR_SHIFT)
 838                         reset = &zones[1];
 839
 840                 if (reset && reset->cond != BLK_ZONE_COND_EMPTY) {
 841                         ASSERT(sb_zone_is_full(reset));
 842
 843                         ret = blkdev_zone_mgmt(bdev, REQ_OP_ZONE_RESET,
 844                                                reset->start, reset->len,
 845                                                GFP_NOFS);
 846                         if (ret)
 847                                 return ret;
 848
 849                         reset->cond = BLK_ZONE_COND_EMPTY;
 850                         reset->wp = reset->start;
 851                 }
 852         } else if (ret != -ENOENT) {
 853                 /*
 854                  * For READ, we want the previous one. Move write pointer to
 855                  * the end of a zone, if it is at the head of a zone.
 856                  */
 857                 u64 zone_end = 0;
 858
 859                 if (wp == zones[0].start << SECTOR_SHIFT)
 860                         zone_end = zones[1].start + zones[1].capacity;
 861                 else if (wp == zones[1].start << SECTOR_SHIFT)
 862                         zone_end = zones[0].start + zones[0].capacity;
 863                 if (zone_end)
 864                         wp = ALIGN_DOWN(zone_end << SECTOR_SHIFT,
 865                                         BTRFS_SUPER_INFO_SIZE);
 866
 867                 wp -= BTRFS_SUPER_INFO_SIZE;
 868         }
 869
 870         *bytenr_ret = wp;
 871         return 0;
 872
 873 }
 874
 875 int btrfs_sb_log_location_bdev(struct block_device *bdev, int mirror, int rw,
 876                                u64 *bytenr_ret)
 877 {
 878         struct blk_zone zones[BTRFS_NR_SB_LOG_ZONES];
 879         sector_t zone_sectors;
 880         u32 sb_zone;
 881         int ret;
 882         u8 zone_sectors_shift;
 883         sector_t nr_sectors;
 884         u32 nr_zones;
 885
 886         if (!bdev_is_zoned(bdev)) {
 887                 *bytenr_ret = btrfs_sb_offset(mirror);
 888                 return 0;
 889         }
 890
 891         ASSERT(rw == READ || rw == WRITE);
 892
 893         zone_sectors = bdev_zone_sectors(bdev);
 894         if (!is_power_of_2(zone_sectors))
 895                 return -EINVAL;
 896         zone_sectors_shift = ilog2(zone_sectors);
 897         nr_sectors = bdev_nr_sectors(bdev);
 898         nr_zones = nr_sectors >> zone_sectors_shift;
 899
 900         sb_zone = sb_zone_number(zone_sectors_shift + SECTOR_SHIFT, mirror);
 901         if (sb_zone + 1 >= nr_zones)
 902                 return -ENOENT;
 903
 904         ret = blkdev_report_zones(bdev, zone_start_sector(sb_zone, bdev),
 905                                   BTRFS_NR_SB_LOG_ZONES, copy_zone_info_cb,
 906                                   zones);
 907         if (ret < 0)
 908                 return ret;
 909         if (ret != BTRFS_NR_SB_LOG_ZONES)
 910                 return -EIO;
 911
 912         return sb_log_location(bdev, zones, rw, bytenr_ret);
 913 }
 914
 915 int btrfs_sb_log_location(struct btrfs_device *device, int mirror, int rw,
 916                           u64 *bytenr_ret)
 917 {
 918         struct btrfs_zoned_device_info *zinfo = device->zone_info;
 919         u32 zone_num;
 920
 921         /*
 922          * For a zoned filesystem on a non-zoned block device, use the same
 923          * super block locations as regular filesystem. Doing so, the super
 924          * block can always be retrieved and the zoned flag of the volume
 925          * detected from the super block information.
 926          */
 927         if (!bdev_is_zoned(device->bdev)) {
 928                 *bytenr_ret = btrfs_sb_offset(mirror);
 929                 return 0;
 930         }
 931
 932         zone_num = sb_zone_number(zinfo->zone_size_shift, mirror);
 933         if (zone_num + 1 >= zinfo->nr_zones)
 934                 return -ENOENT;
 935
 936         return sb_log_location(device->bdev,
 937                                &zinfo->sb_zones[BTRFS_NR_SB_LOG_ZONES * mirror],
 938                                rw, bytenr_ret);
 939 }
 940
 941 static inline bool is_sb_log_zone(struct btrfs_zoned_device_info *zinfo,
 942                                   int mirror)
 943 {
 944         u32 zone_num;
 945
 946         if (!zinfo)
 947                 return false;
 948
 949         zone_num = sb_zone_number(zinfo->zone_size_shift, mirror);
 950         if (zone_num + 1 >= zinfo->nr_zones)
 951                 return false;
 952
 953         if (!test_bit(zone_num, zinfo->seq_zones))
 954                 return false;
 955
 956         return true;
 957 }
 958
 959 int btrfs_advance_sb_log(struct btrfs_device *device, int mirror)
 960 {
 961         struct btrfs_zoned_device_info *zinfo = device->zone_info;
 962         struct blk_zone *zone;
 963         int i;
 964
 965         if (!is_sb_log_zone(zinfo, mirror))
 966                 return 0;
 967
 968         zone = &zinfo->sb_zones[BTRFS_NR_SB_LOG_ZONES * mirror];
 969         for (i = 0; i < BTRFS_NR_SB_LOG_ZONES; i++) {
 970                 /* Advance the next zone */
 971                 if (zone->cond == BLK_ZONE_COND_FULL) {
 972                         zone++;
 973                         continue;
 974                 }
 975
 976                 if (zone->cond == BLK_ZONE_COND_EMPTY)
 977                         zone->cond = BLK_ZONE_COND_IMP_OPEN;
 978
 979                 zone->wp += SUPER_INFO_SECTORS;
 980
 981                 if (sb_zone_is_full(zone)) {
 982                         /*
 983                          * No room left to write new superblock. Since
 984                          * superblock is written with REQ_SYNC, it is safe to
 985                          * finish the zone now.
 986                          *
 987                          * If the write pointer is exactly at the capacity,
 988                          * explicit ZONE_FINISH is not necessary.
 989                          */
 990                         if (zone->wp != zone->start + zone->capacity) {
 991                                 int ret;
 992
 993                                 ret = blkdev_zone_mgmt(device->bdev,
 994                                                 REQ_OP_ZONE_FINISH, zone->start,
 995                                                 zone->len, GFP_NOFS);
 996                                 if (ret)
 997                                         return ret;
 998                         }
 999
1000                         zone->wp = zone->start + zone->len;
1001                         zone->cond = BLK_ZONE_COND_FULL;
1002                 }
1003                 return 0;
1004         }
1005
1006         /* All the zones are FULL. Should not reach here. */
1007         ASSERT(0);
1008         return -EIO;
1009 }
1010
1011 int btrfs_reset_sb_log_zones(struct block_device *bdev, int mirror)
1012 {
1013         sector_t zone_sectors;
1014         sector_t nr_sectors;
1015         u8 zone_sectors_shift;
1016         u32 sb_zone;
1017         u32 nr_zones;
1018
1019         zone_sectors = bdev_zone_sectors(bdev);
1020         zone_sectors_shift = ilog2(zone_sectors);
1021         nr_sectors = bdev_nr_sectors(bdev);
1022         nr_zones = nr_sectors >> zone_sectors_shift;
1023
1024         sb_zone = sb_zone_number(zone_sectors_shift + SECTOR_SHIFT, mirror);
1025         if (sb_zone + 1 >= nr_zones)
1026                 return -ENOENT;
1027
1028         return blkdev_zone_mgmt(bdev, REQ_OP_ZONE_RESET,
1029                                 zone_start_sector(sb_zone, bdev),
1030                                 zone_sectors * BTRFS_NR_SB_LOG_ZONES, GFP_NOFS);
1031 }
1032
1033 /*
1034  * Find allocatable zones within a given region.
1035  *
1036  * @device:     the device to allocate a region on
1037  * @hole_start: the position of the hole to allocate the region
1038  * @num_bytes:  size of wanted region
1039  * @hole_end:   the end of the hole
1040  * @return:     position of allocatable zones
1041  *
1042  * Allocatable region should not contain any superblock locations.
1043  */
1044 u64 btrfs_find_allocatable_zones(struct btrfs_device *device, u64 hole_start,
1045                                  u64 hole_end, u64 num_bytes)
1046 {
1047         struct btrfs_zoned_device_info *zinfo = device->zone_info;
1048         const u8 shift = zinfo->zone_size_shift;
1049         u64 nzones = num_bytes >> shift;
1050         u64 pos = hole_start;
1051         u64 begin, end;
1052         bool have_sb;
1053         int i;
1054
1055         ASSERT(IS_ALIGNED(hole_start, zinfo->zone_size));
1056         ASSERT(IS_ALIGNED(num_bytes, zinfo->zone_size));
1057
1058         while (pos < hole_end) {
1059                 begin = pos >> shift;
1060                 end = begin + nzones;
1061
1062                 if (end > zinfo->nr_zones)
1063                         return hole_end;
1064
1065                 /* Check if zones in the region are all empty */
1066                 if (btrfs_dev_is_sequential(device, pos) &&
1067                     !bitmap_test_range_all_set(zinfo->empty_zones, begin, nzones)) {
1068                         pos += zinfo->zone_size;
1069                         continue;
1070                 }
1071
1072                 have_sb = false;
1073                 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
1074                         u32 sb_zone;
1075                         u64 sb_pos;
1076
1077                         sb_zone = sb_zone_number(shift, i);
1078                         if (!(end <= sb_zone ||
1079                               sb_zone + BTRFS_NR_SB_LOG_ZONES <= begin)) {
1080                                 have_sb = true;
1081                                 pos = zone_start_physical(
1082                                         sb_zone + BTRFS_NR_SB_LOG_ZONES, zinfo);
1083                                 break;
1084                         }
1085
1086                         /* We also need to exclude regular superblock positions */
1087                         sb_pos = btrfs_sb_offset(i);
1088                         if (!(pos + num_bytes <= sb_pos ||
1089                               sb_pos + BTRFS_SUPER_INFO_SIZE <= pos)) {
1090                                 have_sb = true;
1091                                 pos = ALIGN(sb_pos + BTRFS_SUPER_INFO_SIZE,
1092                                             zinfo->zone_size);
1093                                 break;
1094                         }
1095                 }
1096                 if (!have_sb)
1097                         break;
1098         }
1099
1100         return pos;
1101 }
1102
1103 static bool btrfs_dev_set_active_zone(struct btrfs_device *device, u64 pos)
1104 {
1105         struct btrfs_zoned_device_info *zone_info = device->zone_info;
1106         unsigned int zno = (pos >> zone_info->zone_size_shift);
1107
1108         /* We can use any number of zones */
1109         if (zone_info->max_active_zones == 0)
1110                 return true;
1111
1112         if (!test_bit(zno, zone_info->active_zones)) {
1113                 /* Active zone left? */
1114                 if (atomic_dec_if_positive(&zone_info->active_zones_left) < 0)
1115                         return false;
1116                 if (test_and_set_bit(zno, zone_info->active_zones)) {
1117                         /* Someone already set the bit */
1118                         atomic_inc(&zone_info->active_zones_left);
1119                 }
1120         }
1121
1122         return true;
1123 }
1124
1125 static void btrfs_dev_clear_active_zone(struct btrfs_device *device, u64 pos)
1126 {
1127         struct btrfs_zoned_device_info *zone_info = device->zone_info;
1128         unsigned int zno = (pos >> zone_info->zone_size_shift);
1129
1130         /* We can use any number of zones */
1131         if (zone_info->max_active_zones == 0)
1132                 return;
1133
1134         if (test_and_clear_bit(zno, zone_info->active_zones))
1135                 atomic_inc(&zone_info->active_zones_left);
1136 }
1137
1138 int btrfs_reset_device_zone(struct btrfs_device *device, u64 physical,
1139                             u64 length, u64 *bytes)
1140 {
1141         int ret;
1142
1143         *bytes = 0;
1144         ret = blkdev_zone_mgmt(device->bdev, REQ_OP_ZONE_RESET,
1145                                physical >> SECTOR_SHIFT, length >> SECTOR_SHIFT,
1146                                GFP_NOFS);
1147         if (ret)
1148                 return ret;
1149
1150         *bytes = length;
1151         while (length) {
1152                 btrfs_dev_set_zone_empty(device, physical);
1153                 btrfs_dev_clear_active_zone(device, physical);
1154                 physical += device->zone_info->zone_size;
1155                 length -= device->zone_info->zone_size;
1156         }
1157
1158         return 0;
1159 }
1160
1161 int btrfs_ensure_empty_zones(struct btrfs_device *device, u64 start, u64 size)
1162 {
1163         struct btrfs_zoned_device_info *zinfo = device->zone_info;
1164         const u8 shift = zinfo->zone_size_shift;
1165         unsigned long begin = start >> shift;
1166         unsigned long nbits = size >> shift;
1167         u64 pos;
1168         int ret;
1169
1170         ASSERT(IS_ALIGNED(start, zinfo->zone_size));
1171         ASSERT(IS_ALIGNED(size, zinfo->zone_size));
1172
1173         if (begin + nbits > zinfo->nr_zones)
1174                 return -ERANGE;
1175
1176         /* All the zones are conventional */
1177         if (bitmap_test_range_all_zero(zinfo->seq_zones, begin, nbits))
1178                 return 0;
1179
1180         /* All the zones are sequential and empty */
1181         if (bitmap_test_range_all_set(zinfo->seq_zones, begin, nbits) &&
1182             bitmap_test_range_all_set(zinfo->empty_zones, begin, nbits))
1183                 return 0;
1184
1185         for (pos = start; pos < start + size; pos += zinfo->zone_size) {
1186                 u64 reset_bytes;
1187
1188                 if (!btrfs_dev_is_sequential(device, pos) ||
1189                     btrfs_dev_is_empty_zone(device, pos))
1190                         continue;
1191
1192                 /* Free regions should be empty */
1193                 btrfs_warn_in_rcu(
1194                         device->fs_info,
1195                 "zoned: resetting device %s (devid %llu) zone %llu for allocation",
1196                         rcu_str_deref(device->name), device->devid, pos >> shift);
1197                 WARN_ON_ONCE(1);
1198
1199                 ret = btrfs_reset_device_zone(device, pos, zinfo->zone_size,
1200                                               &reset_bytes);
1201                 if (ret)
1202                         return ret;
1203         }
1204
1205         return 0;
1206 }
1207
1208 /*
1209  * Calculate an allocation pointer from the extent allocation information
1210  * for a block group consist of conventional zones. It is pointed to the
1211  * end of the highest addressed extent in the block group as an allocation
1212  * offset.
1213  */
1214 static int calculate_alloc_pointer(struct btrfs_block_group *cache,
1215                                    u64 *offset_ret, bool new)
1216 {
1217         struct btrfs_fs_info *fs_info = cache->fs_info;
1218         struct btrfs_root *root;
1219         struct btrfs_path *path;
1220         struct btrfs_key key;
1221         struct btrfs_key found_key;
1222         int ret;
1223         u64 length;
1224
1225         /*
1226          * Avoid  tree lookups for a new block group, there's no use for it.
1227          * It must always be 0.
1228          *
1229          * Also, we have a lock chain of extent buffer lock -> chunk mutex.
1230          * For new a block group, this function is called from
1231          * btrfs_make_block_group() which is already taking the chunk mutex.
1232          * Thus, we cannot call calculate_alloc_pointer() which takes extent
1233          * buffer locks to avoid deadlock.
1234          */
1235         if (new) {
1236                 *offset_ret = 0;
1237                 return 0;
1238         }
1239
1240         path = btrfs_alloc_path();
1241         if (!path)
1242                 return -ENOMEM;
1243
1244         key.objectid = cache->start + cache->length;
1245         key.type = 0;
1246         key.offset = 0;
1247
1248         root = btrfs_extent_root(fs_info, key.objectid);
1249         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1250         /* We should not find the exact match */
1251         if (!ret)
1252                 ret = -EUCLEAN;
1253         if (ret < 0)
1254                 goto out;
1255
1256         ret = btrfs_previous_extent_item(root, path, cache->start);
1257         if (ret) {
1258                 if (ret == 1) {
1259                         ret = 0;
1260                         *offset_ret = 0;
1261                 }
1262                 goto out;
1263         }
1264
1265         btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
1266
1267         if (found_key.type == BTRFS_EXTENT_ITEM_KEY)
1268                 length = found_key.offset;
1269         else
1270                 length = fs_info->nodesize;
1271
1272         if (!(found_key.objectid >= cache->start &&
1273                found_key.objectid + length <= cache->start + cache->length)) {
1274                 ret = -EUCLEAN;
1275                 goto out;
1276         }
1277         *offset_ret = found_key.objectid + length - cache->start;
1278         ret = 0;
1279
1280 out:
1281         btrfs_free_path(path);
1282         return ret;
1283 }
1284
1285 int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache, bool new)
1286 {
1287         struct btrfs_fs_info *fs_info = cache->fs_info;
1288         struct extent_map_tree *em_tree = &fs_info->mapping_tree;
1289         struct extent_map *em;
1290         struct map_lookup *map;
1291         struct btrfs_device *device;
1292         u64 logical = cache->start;
1293         u64 length = cache->length;
1294         int ret;
1295         int i;
1296         unsigned int nofs_flag;
1297         u64 *alloc_offsets = NULL;
1298         u64 *caps = NULL;
1299         u64 *physical = NULL;
1300         unsigned long *active = NULL;
1301         u64 last_alloc = 0;
1302         u32 num_sequential = 0, num_conventional = 0;
1303
1304         if (!btrfs_is_zoned(fs_info))
1305                 return 0;
1306
1307         /* Sanity check */
1308         if (!IS_ALIGNED(length, fs_info->zone_size)) {
1309                 btrfs_err(fs_info,
1310                 "zoned: block group %llu len %llu unaligned to zone size %llu",
1311                           logical, length, fs_info->zone_size);
1312                 return -EIO;
1313         }
1314
1315         /* Get the chunk mapping */
1316         read_lock(&em_tree->lock);
1317         em = lookup_extent_mapping(em_tree, logical, length);
1318         read_unlock(&em_tree->lock);
1319
1320         if (!em)
1321                 return -EINVAL;
1322
1323         map = em->map_lookup;
1324
1325         cache->physical_map = kmemdup(map, map_lookup_size(map->num_stripes), GFP_NOFS);
1326         if (!cache->physical_map) {
1327                 ret = -ENOMEM;
1328                 goto out;
1329         }
1330
1331         alloc_offsets = kcalloc(map->num_stripes, sizeof(*alloc_offsets), GFP_NOFS);
1332         if (!alloc_offsets) {
1333                 ret = -ENOMEM;
1334                 goto out;
1335         }
1336
1337         caps = kcalloc(map->num_stripes, sizeof(*caps), GFP_NOFS);
1338         if (!caps) {
1339                 ret = -ENOMEM;
1340                 goto out;
1341         }
1342
1343         physical = kcalloc(map->num_stripes, sizeof(*physical), GFP_NOFS);
1344         if (!physical) {
1345                 ret = -ENOMEM;
1346                 goto out;
1347         }
1348
1349         active = bitmap_zalloc(map->num_stripes, GFP_NOFS);
1350         if (!active) {
1351                 ret = -ENOMEM;
1352                 goto out;
1353         }
1354
1355         for (i = 0; i < map->num_stripes; i++) {
1356                 bool is_sequential;
1357                 struct blk_zone zone;
1358                 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
1359                 int dev_replace_is_ongoing = 0;
1360
1361                 device = map->stripes[i].dev;
1362                 physical[i] = map->stripes[i].physical;
1363
1364                 if (device->bdev == NULL) {
1365                         alloc_offsets[i] = WP_MISSING_DEV;
1366                         continue;
1367                 }
1368
1369                 is_sequential = btrfs_dev_is_sequential(device, physical[i]);
1370                 if (is_sequential)
1371                         num_sequential++;
1372                 else
1373                         num_conventional++;
1374
1375                 /*
1376                  * Consider a zone as active if we can allow any number of
1377                  * active zones.
1378                  */
1379                 if (!device->zone_info->max_active_zones)
1380                         __set_bit(i, active);
1381
1382                 if (!is_sequential) {
1383                         alloc_offsets[i] = WP_CONVENTIONAL;
1384                         continue;
1385                 }
1386
1387                 /*
1388                  * This zone will be used for allocation, so mark this zone
1389                  * non-empty.
1390                  */
1391                 btrfs_dev_clear_zone_empty(device, physical[i]);
1392
1393                 down_read(&dev_replace->rwsem);
1394                 dev_replace_is_ongoing = btrfs_dev_replace_is_ongoing(dev_replace);
1395                 if (dev_replace_is_ongoing && dev_replace->tgtdev != NULL)
1396                         btrfs_dev_clear_zone_empty(dev_replace->tgtdev, physical[i]);
1397                 up_read(&dev_replace->rwsem);
1398
1399                 /*
1400                  * The group is mapped to a sequential zone. Get the zone write
1401                  * pointer to determine the allocation offset within the zone.
1402                  */
1403                 WARN_ON(!IS_ALIGNED(physical[i], fs_info->zone_size));
1404                 nofs_flag = memalloc_nofs_save();
1405                 ret = btrfs_get_dev_zone(device, physical[i], &zone);
1406                 memalloc_nofs_restore(nofs_flag);
1407                 if (ret == -EIO || ret == -EOPNOTSUPP) {
1408                         ret = 0;
1409                         alloc_offsets[i] = WP_MISSING_DEV;
1410                         continue;
1411                 } else if (ret) {
1412                         goto out;
1413                 }
1414
1415                 if (zone.type == BLK_ZONE_TYPE_CONVENTIONAL) {
1416                         btrfs_err_in_rcu(fs_info,
1417         "zoned: unexpected conventional zone %llu on device %s (devid %llu)",
1418                                 zone.start << SECTOR_SHIFT,
1419                                 rcu_str_deref(device->name), device->devid);
1420                         ret = -EIO;
1421                         goto out;
1422                 }
1423
1424                 caps[i] = (zone.capacity << SECTOR_SHIFT);
1425
1426                 switch (zone.cond) {
1427                 case BLK_ZONE_COND_OFFLINE:
1428                 case BLK_ZONE_COND_READONLY:
1429                         btrfs_err(fs_info,
1430                 "zoned: offline/readonly zone %llu on device %s (devid %llu)",
1431                                   physical[i] >> device->zone_info->zone_size_shift,
1432                                   rcu_str_deref(device->name), device->devid);
1433                         alloc_offsets[i] = WP_MISSING_DEV;
1434                         break;
1435                 case BLK_ZONE_COND_EMPTY:
1436                         alloc_offsets[i] = 0;
1437                         break;
1438                 case BLK_ZONE_COND_FULL:
1439                         alloc_offsets[i] = caps[i];
1440                         break;
1441                 default:
1442                         /* Partially used zone */
1443                         alloc_offsets[i] =
1444                                         ((zone.wp - zone.start) << SECTOR_SHIFT);
1445                         __set_bit(i, active);
1446                         break;
1447                 }
1448         }
1449
1450         if (num_sequential > 0)
1451                 set_bit(BLOCK_GROUP_FLAG_SEQUENTIAL_ZONE, &cache->runtime_flags);
1452
1453         if (num_conventional > 0) {
1454                 /* Zone capacity is always zone size in emulation */
1455                 cache->zone_capacity = cache->length;
1456                 ret = calculate_alloc_pointer(cache, &last_alloc, new);
1457                 if (ret) {
1458                         btrfs_err(fs_info,
1459                         "zoned: failed to determine allocation offset of bg %llu",
1460                                   cache->start);
1461                         goto out;
1462                 } else if (map->num_stripes == num_conventional) {
1463                         cache->alloc_offset = last_alloc;
1464                         set_bit(BLOCK_GROUP_FLAG_ZONE_IS_ACTIVE, &cache->runtime_flags);
1465                         goto out;
1466                 }
1467         }
1468
1469         switch (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
1470         case 0: /* single */
1471                 if (alloc_offsets[0] == WP_MISSING_DEV) {
1472                         btrfs_err(fs_info,
1473                         "zoned: cannot recover write pointer for zone %llu",
1474                                 physical[0]);
1475                         ret = -EIO;
1476                         goto out;
1477                 }
1478                 cache->alloc_offset = alloc_offsets[0];
1479                 cache->zone_capacity = caps[0];
1480                 if (test_bit(0, active))
1481                         set_bit(BLOCK_GROUP_FLAG_ZONE_IS_ACTIVE, &cache->runtime_flags);
1482                 break;
1483         case BTRFS_BLOCK_GROUP_DUP:
1484                 if (map->type & BTRFS_BLOCK_GROUP_DATA) {
1485                         btrfs_err(fs_info, "zoned: profile DUP not yet supported on data bg");
1486                         ret = -EINVAL;
1487                         goto out;
1488                 }
1489                 if (alloc_offsets[0] == WP_MISSING_DEV) {
1490                         btrfs_err(fs_info,
1491                         "zoned: cannot recover write pointer for zone %llu",
1492                                 physical[0]);
1493                         ret = -EIO;
1494                         goto out;
1495                 }
1496                 if (alloc_offsets[1] == WP_MISSING_DEV) {
1497                         btrfs_err(fs_info,
1498                         "zoned: cannot recover write pointer for zone %llu",
1499                                 physical[1]);
1500                         ret = -EIO;
1501                         goto out;
1502                 }
1503                 if (alloc_offsets[0] != alloc_offsets[1]) {
1504                         btrfs_err(fs_info,
1505                         "zoned: write pointer offset mismatch of zones in DUP profile");
1506                         ret = -EIO;
1507                         goto out;
1508                 }
1509                 if (test_bit(0, active) != test_bit(1, active)) {
1510                         if (!btrfs_zone_activate(cache)) {
1511                                 ret = -EIO;
1512                                 goto out;
1513                         }
1514                 } else {
1515                         if (test_bit(0, active))
1516                                 set_bit(BLOCK_GROUP_FLAG_ZONE_IS_ACTIVE,
1517                                         &cache->runtime_flags);
1518                 }
1519                 cache->alloc_offset = alloc_offsets[0];
1520                 cache->zone_capacity = min(caps[0], caps[1]);
1521                 break;
1522         case BTRFS_BLOCK_GROUP_RAID1:
1523         case BTRFS_BLOCK_GROUP_RAID0:
1524         case BTRFS_BLOCK_GROUP_RAID10:
1525         case BTRFS_BLOCK_GROUP_RAID5:
1526         case BTRFS_BLOCK_GROUP_RAID6:
1527                 /* non-single profiles are not supported yet */
1528         default:
1529                 btrfs_err(fs_info, "zoned: profile %s not yet supported",
1530                           btrfs_bg_type_to_raid_name(map->type));
1531                 ret = -EINVAL;
1532                 goto out;
1533         }
1534
1535 out:
1536         if (cache->alloc_offset > fs_info->zone_size) {
1537                 btrfs_err(fs_info,
1538                         "zoned: invalid write pointer %llu in block group %llu",
1539                         cache->alloc_offset, cache->start);
1540                 ret = -EIO;
1541         }
1542
1543         if (cache->alloc_offset > cache->zone_capacity) {
1544                 btrfs_err(fs_info,
1545 "zoned: invalid write pointer %llu (larger than zone capacity %llu) in block group %llu",
1546                           cache->alloc_offset, cache->zone_capacity,
1547                           cache->start);
1548                 ret = -EIO;
1549         }
1550
1551         /* An extent is allocated after the write pointer */
1552         if (!ret && num_conventional && last_alloc > cache->alloc_offset) {
1553                 btrfs_err(fs_info,
1554                           "zoned: got wrong write pointer in BG %llu: %llu > %llu",
1555                           logical, last_alloc, cache->alloc_offset);
1556                 ret = -EIO;
1557         }
1558
1559         if (!ret) {
1560                 cache->meta_write_pointer = cache->alloc_offset + cache->start;
1561                 if (test_bit(BLOCK_GROUP_FLAG_ZONE_IS_ACTIVE, &cache->runtime_flags)) {
1562                         btrfs_get_block_group(cache);
1563                         spin_lock(&fs_info->zone_active_bgs_lock);
1564                         list_add_tail(&cache->active_bg_list,
1565                                       &fs_info->zone_active_bgs);
1566                         spin_unlock(&fs_info->zone_active_bgs_lock);
1567                 }
1568         } else {
1569                 kfree(cache->physical_map);
1570                 cache->physical_map = NULL;
1571         }
1572         bitmap_free(active);
1573         kfree(physical);
1574         kfree(caps);
1575         kfree(alloc_offsets);
1576         free_extent_map(em);
1577
1578         return ret;
1579 }
1580
1581 void btrfs_calc_zone_unusable(struct btrfs_block_group *cache)
1582 {
1583         u64 unusable, free;
1584
1585         if (!btrfs_is_zoned(cache->fs_info))
1586                 return;
1587
1588         WARN_ON(cache->bytes_super != 0);
1589         unusable = (cache->alloc_offset - cache->used) +
1590                    (cache->length - cache->zone_capacity);
1591         free = cache->zone_capacity - cache->alloc_offset;
1592
1593         /* We only need ->free_space in ALLOC_SEQ block groups */
1594         cache->cached = BTRFS_CACHE_FINISHED;
1595         cache->free_space_ctl->free_space = free;
1596         cache->zone_unusable = unusable;
1597 }
1598
1599 void btrfs_redirty_list_add(struct btrfs_transaction *trans,
1600                             struct extent_buffer *eb)
1601 {
1602         if (!btrfs_is_zoned(eb->fs_info) ||
1603             btrfs_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN))
1604                 return;
1605
1606         ASSERT(!test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
1607
1608         memzero_extent_buffer(eb, 0, eb->len);
1609         set_bit(EXTENT_BUFFER_NO_CHECK, &eb->bflags);
1610         set_extent_buffer_dirty(eb);
1611         set_extent_bit(&trans->dirty_pages, eb->start, eb->start + eb->len - 1,
1612                         EXTENT_DIRTY | EXTENT_NOWAIT, NULL);
1613 }
1614
1615 bool btrfs_use_zone_append(struct btrfs_bio *bbio)
1616 {
1617         u64 start = (bbio->bio.bi_iter.bi_sector << SECTOR_SHIFT);
1618         struct btrfs_inode *inode = bbio->inode;
1619         struct btrfs_fs_info *fs_info = bbio->fs_info;
1620         struct btrfs_block_group *cache;
1621         bool ret = false;
1622
1623         if (!btrfs_is_zoned(fs_info))
1624                 return false;
1625
1626         if (!inode || !is_data_inode(&inode->vfs_inode))
1627                 return false;
1628
1629         if (btrfs_op(&bbio->bio) != BTRFS_MAP_WRITE)
1630                 return false;
1631
1632         /*
1633          * Using REQ_OP_ZONE_APPNED for relocation can break assumptions on the
1634          * extent layout the relocation code has.
1635          * Furthermore we have set aside own block-group from which only the
1636          * relocation "process" can allocate and make sure only one process at a
1637          * time can add pages to an extent that gets relocated, so it's safe to
1638          * use regular REQ_OP_WRITE for this special case.
1639          */
1640         if (btrfs_is_data_reloc_root(inode->root))
1641                 return false;
1642
1643         cache = btrfs_lookup_block_group(fs_info, start);
1644         ASSERT(cache);
1645         if (!cache)
1646                 return false;
1647
1648         ret = !!test_bit(BLOCK_GROUP_FLAG_SEQUENTIAL_ZONE, &cache->runtime_flags);
1649         btrfs_put_block_group(cache);
1650
1651         return ret;
1652 }
1653
1654 void btrfs_record_physical_zoned(struct btrfs_bio *bbio)
1655 {
1656         const u64 physical = bbio->bio.bi_iter.bi_sector << SECTOR_SHIFT;
1657         struct btrfs_ordered_sum *sum = bbio->sums;
1658
1659         if (physical < bbio->orig_physical)
1660                 sum->logical -= bbio->orig_physical - physical;
1661         else
1662                 sum->logical += physical - bbio->orig_physical;
1663 }
1664
1665 static void btrfs_rewrite_logical_zoned(struct btrfs_ordered_extent *ordered,
1666                                         u64 logical)
1667 {
1668         struct extent_map_tree *em_tree = &BTRFS_I(ordered->inode)->extent_tree;
1669         struct extent_map *em;
1670
1671         ordered->disk_bytenr = logical;
1672
1673         write_lock(&em_tree->lock);
1674         em = search_extent_mapping(em_tree, ordered->file_offset,
1675                                    ordered->num_bytes);
1676         em->block_start = logical;
1677         free_extent_map(em);
1678         write_unlock(&em_tree->lock);
1679 }
1680
1681 static bool btrfs_zoned_split_ordered(struct btrfs_ordered_extent *ordered,
1682                                       u64 logical, u64 len)
1683 {
1684         struct btrfs_ordered_extent *new;
1685
1686         if (!test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags) &&
1687             split_extent_map(BTRFS_I(ordered->inode), ordered->file_offset,
1688                              ordered->num_bytes, len, logical))
1689                 return false;
1690
1691         new = btrfs_split_ordered_extent(ordered, len);
1692         if (IS_ERR(new))
1693                 return false;
1694         new->disk_bytenr = logical;
1695         btrfs_finish_one_ordered(new);
1696         return true;
1697 }
1698
1699 void btrfs_finish_ordered_zoned(struct btrfs_ordered_extent *ordered)
1700 {
1701         struct btrfs_inode *inode = BTRFS_I(ordered->inode);
1702         struct btrfs_fs_info *fs_info = inode->root->fs_info;
1703         struct btrfs_ordered_sum *sum;
1704         u64 logical, len;
1705
1706         /*
1707          * Write to pre-allocated region is for the data relocation, and so
1708          * it should use WRITE operation. No split/rewrite are necessary.
1709          */
1710         if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags))
1711                 return;
1712
1713         ASSERT(!list_empty(&ordered->list));
1714         /* The ordered->list can be empty in the above pre-alloc case. */
1715         sum = list_first_entry(&ordered->list, struct btrfs_ordered_sum, list);
1716         logical = sum->logical;
1717         len = sum->len;
1718
1719         while (len < ordered->disk_num_bytes) {
1720                 sum = list_next_entry(sum, list);
1721                 if (sum->logical == logical + len) {
1722                         len += sum->len;
1723                         continue;
1724                 }
1725                 if (!btrfs_zoned_split_ordered(ordered, logical, len)) {
1726                         set_bit(BTRFS_ORDERED_IOERR, &ordered->flags);
1727                         btrfs_err(fs_info, "failed to split ordered extent");
1728                         goto out;
1729                 }
1730                 logical = sum->logical;
1731                 len = sum->len;
1732         }
1733
1734         if (ordered->disk_bytenr != logical)
1735                 btrfs_rewrite_logical_zoned(ordered, logical);
1736
1737 out:
1738         /*
1739          * If we end up here for nodatasum I/O, the btrfs_ordered_sum structures
1740          * were allocated by btrfs_alloc_dummy_sum only to record the logical
1741          * addresses and don't contain actual checksums.  We thus must free them
1742          * here so that we don't attempt to log the csums later.
1743          */
1744         if ((inode->flags & BTRFS_INODE_NODATASUM) ||
1745             test_bit(BTRFS_FS_STATE_NO_CSUMS, &fs_info->fs_state)) {
1746                 while ((sum = list_first_entry_or_null(&ordered->list,
1747                                                        typeof(*sum), list))) {
1748                         list_del(&sum->list);
1749                         kfree(sum);
1750                 }
1751         }
1752 }
1753
1754 static bool check_bg_is_active(struct btrfs_eb_write_context *ctx,
1755                                struct btrfs_block_group **active_bg)
1756 {
1757         const struct writeback_control *wbc = ctx->wbc;
1758         struct btrfs_block_group *block_group = ctx->zoned_bg;
1759         struct btrfs_fs_info *fs_info = block_group->fs_info;
1760
1761         if (test_bit(BLOCK_GROUP_FLAG_ZONE_IS_ACTIVE, &block_group->runtime_flags))
1762                 return true;
1763
1764         if (fs_info->treelog_bg == block_group->start) {
1765                 if (!btrfs_zone_activate(block_group)) {
1766                         int ret_fin = btrfs_zone_finish_one_bg(fs_info);
1767
1768                         if (ret_fin != 1 || !btrfs_zone_activate(block_group))
1769                                 return false;
1770                 }
1771         } else if (*active_bg != block_group) {
1772                 struct btrfs_block_group *tgt = *active_bg;
1773
1774                 /* zoned_meta_io_lock protects fs_info->active_{meta,system}_bg. */
1775                 lockdep_assert_held(&fs_info->zoned_meta_io_lock);
1776
1777                 if (tgt) {
1778                         /*
1779                          * If there is an unsent IO left in the allocated area,
1780                          * we cannot wait for them as it may cause a deadlock.
1781                          */
1782                         if (tgt->meta_write_pointer < tgt->start + tgt->alloc_offset) {
1783                                 if (wbc->sync_mode == WB_SYNC_NONE ||
1784                                     (wbc->sync_mode == WB_SYNC_ALL && !wbc->for_sync))
1785                                         return false;
1786                         }
1787
1788                         /* Pivot active metadata/system block group. */
1789                         btrfs_zoned_meta_io_unlock(fs_info);
1790                         wait_eb_writebacks(tgt);
1791                         do_zone_finish(tgt, true);
1792                         btrfs_zoned_meta_io_lock(fs_info);
1793                         if (*active_bg == tgt) {
1794                                 btrfs_put_block_group(tgt);
1795                                 *active_bg = NULL;
1796                         }
1797                 }
1798                 if (!btrfs_zone_activate(block_group))
1799                         return false;
1800                 if (*active_bg != block_group) {
1801                         ASSERT(*active_bg == NULL);
1802                         *active_bg = block_group;
1803                         btrfs_get_block_group(block_group);
1804                 }
1805         }
1806
1807         return true;
1808 }
1809
1810 /*
1811  * Check if @ctx->eb is aligned to the write pointer.
1812  *
1813  * Return:
1814  *   0:        @ctx->eb is at the write pointer. You can write it.
1815  *   -EAGAIN:  There is a hole. The caller should handle the case.
1816  *   -EBUSY:   There is a hole, but the caller can just bail out.
1817  */
1818 int btrfs_check_meta_write_pointer(struct btrfs_fs_info *fs_info,
1819                                    struct btrfs_eb_write_context *ctx)
1820 {
1821         const struct writeback_control *wbc = ctx->wbc;
1822         const struct extent_buffer *eb = ctx->eb;
1823         struct btrfs_block_group *block_group = ctx->zoned_bg;
1824
1825         if (!btrfs_is_zoned(fs_info))
1826                 return 0;
1827
1828         if (block_group) {
1829                 if (block_group->start > eb->start ||
1830                     block_group->start + block_group->length <= eb->start) {
1831                         btrfs_put_block_group(block_group);
1832                         block_group = NULL;
1833                         ctx->zoned_bg = NULL;
1834                 }
1835         }
1836
1837         if (!block_group) {
1838                 block_group = btrfs_lookup_block_group(fs_info, eb->start);
1839                 if (!block_group)
1840                         return 0;
1841                 ctx->zoned_bg = block_group;
1842         }
1843
1844         if (block_group->meta_write_pointer == eb->start) {
1845                 struct btrfs_block_group **tgt;
1846
1847                 if (!test_bit(BTRFS_FS_ACTIVE_ZONE_TRACKING, &fs_info->flags))
1848                         return 0;
1849
1850                 if (block_group->flags & BTRFS_BLOCK_GROUP_SYSTEM)
1851                         tgt = &fs_info->active_system_bg;
1852                 else
1853                         tgt = &fs_info->active_meta_bg;
1854                 if (check_bg_is_active(ctx, tgt))
1855                         return 0;
1856         }
1857
1858         /*
1859          * Since we may release fs_info->zoned_meta_io_lock, someone can already
1860          * start writing this eb. In that case, we can just bail out.
1861          */
1862         if (block_group->meta_write_pointer > eb->start)
1863                 return -EBUSY;
1864
1865         /* If for_sync, this hole will be filled with trasnsaction commit. */
1866         if (wbc->sync_mode == WB_SYNC_ALL && !wbc->for_sync)
1867                 return -EAGAIN;
1868         return -EBUSY;
1869 }
1870
1871 int btrfs_zoned_issue_zeroout(struct btrfs_device *device, u64 physical, u64 length)
1872 {
1873         if (!btrfs_dev_is_sequential(device, physical))
1874                 return -EOPNOTSUPP;
1875
1876         return blkdev_issue_zeroout(device->bdev, physical >> SECTOR_SHIFT,
1877                                     length >> SECTOR_SHIFT, GFP_NOFS, 0);
1878 }
1879
1880 static int read_zone_info(struct btrfs_fs_info *fs_info, u64 logical,
1881                           struct blk_zone *zone)
1882 {
1883         struct btrfs_io_context *bioc = NULL;
1884         u64 mapped_length = PAGE_SIZE;
1885         unsigned int nofs_flag;
1886         int nmirrors;
1887         int i, ret;
1888
1889         ret = btrfs_map_block(fs_info, BTRFS_MAP_GET_READ_MIRRORS, logical,
1890                               &mapped_length, &bioc, NULL, NULL, 1);
1891         if (ret || !bioc || mapped_length < PAGE_SIZE) {
1892                 ret = -EIO;
1893                 goto out_put_bioc;
1894         }
1895
1896         if (bioc->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
1897                 ret = -EINVAL;
1898                 goto out_put_bioc;
1899         }
1900
1901         nofs_flag = memalloc_nofs_save();
1902         nmirrors = (int)bioc->num_stripes;
1903         for (i = 0; i < nmirrors; i++) {
1904                 u64 physical = bioc->stripes[i].physical;
1905                 struct btrfs_device *dev = bioc->stripes[i].dev;
1906
1907                 /* Missing device */
1908                 if (!dev->bdev)
1909                         continue;
1910
1911                 ret = btrfs_get_dev_zone(dev, physical, zone);
1912                 /* Failing device */
1913                 if (ret == -EIO || ret == -EOPNOTSUPP)
1914                         continue;
1915                 break;
1916         }
1917         memalloc_nofs_restore(nofs_flag);
1918 out_put_bioc:
1919         btrfs_put_bioc(bioc);
1920         return ret;
1921 }
1922
1923 /*
1924  * Synchronize write pointer in a zone at @physical_start on @tgt_dev, by
1925  * filling zeros between @physical_pos to a write pointer of dev-replace
1926  * source device.
1927  */
1928 int btrfs_sync_zone_write_pointer(struct btrfs_device *tgt_dev, u64 logical,
1929                                     u64 physical_start, u64 physical_pos)
1930 {
1931         struct btrfs_fs_info *fs_info = tgt_dev->fs_info;
1932         struct blk_zone zone;
1933         u64 length;
1934         u64 wp;
1935         int ret;
1936
1937         if (!btrfs_dev_is_sequential(tgt_dev, physical_pos))
1938                 return 0;
1939
1940         ret = read_zone_info(fs_info, logical, &zone);
1941         if (ret)
1942                 return ret;
1943
1944         wp = physical_start + ((zone.wp - zone.start) << SECTOR_SHIFT);
1945
1946         if (physical_pos == wp)
1947                 return 0;
1948
1949         if (physical_pos > wp)
1950                 return -EUCLEAN;
1951
1952         length = wp - physical_pos;
1953         return btrfs_zoned_issue_zeroout(tgt_dev, physical_pos, length);
1954 }
1955
1956 /*
1957  * Activate block group and underlying device zones
1958  *
1959  * @block_group: the block group to activate
1960  *
1961  * Return: true on success, false otherwise
1962  */
1963 bool btrfs_zone_activate(struct btrfs_block_group *block_group)
1964 {
1965         struct btrfs_fs_info *fs_info = block_group->fs_info;
1966         struct map_lookup *map;
1967         struct btrfs_device *device;
1968         u64 physical;
1969         const bool is_data = (block_group->flags & BTRFS_BLOCK_GROUP_DATA);
1970         bool ret;
1971         int i;
1972
1973         if (!btrfs_is_zoned(block_group->fs_info))
1974                 return true;
1975
1976         map = block_group->physical_map;
1977
1978         spin_lock(&block_group->lock);
1979         if (test_bit(BLOCK_GROUP_FLAG_ZONE_IS_ACTIVE, &block_group->runtime_flags)) {
1980                 ret = true;
1981                 goto out_unlock;
1982         }
1983
1984         /* No space left */
1985         if (btrfs_zoned_bg_is_full(block_group)) {
1986                 ret = false;
1987                 goto out_unlock;
1988         }
1989
1990         spin_lock(&fs_info->zone_active_bgs_lock);
1991         for (i = 0; i < map->num_stripes; i++) {
1992                 struct btrfs_zoned_device_info *zinfo;
1993                 int reserved = 0;
1994
1995                 device = map->stripes[i].dev;
1996                 physical = map->stripes[i].physical;
1997                 zinfo = device->zone_info;
1998
1999                 if (zinfo->max_active_zones == 0)
2000                         continue;
2001
2002                 if (is_data)
2003                         reserved = zinfo->reserved_active_zones;
2004                 /*
2005                  * For the data block group, leave active zones for one
2006                  * metadata block group and one system block group.
2007                  */
2008                 if (atomic_read(&zinfo->active_zones_left) <= reserved) {
2009                         ret = false;
2010                         spin_unlock(&fs_info->zone_active_bgs_lock);
2011                         goto out_unlock;
2012                 }
2013
2014                 if (!btrfs_dev_set_active_zone(device, physical)) {
2015                         /* Cannot activate the zone */
2016                         ret = false;
2017                         spin_unlock(&fs_info->zone_active_bgs_lock);
2018                         goto out_unlock;
2019                 }
2020                 if (!is_data)
2021                         zinfo->reserved_active_zones--;
2022         }
2023         spin_unlock(&fs_info->zone_active_bgs_lock);
2024
2025         /* Successfully activated all the zones */
2026         set_bit(BLOCK_GROUP_FLAG_ZONE_IS_ACTIVE, &block_group->runtime_flags);
2027         spin_unlock(&block_group->lock);
2028
2029         /* For the active block group list */
2030         btrfs_get_block_group(block_group);
2031
2032         spin_lock(&fs_info->zone_active_bgs_lock);
2033         list_add_tail(&block_group->active_bg_list, &fs_info->zone_active_bgs);
2034         spin_unlock(&fs_info->zone_active_bgs_lock);
2035
2036         return true;
2037
2038 out_unlock:
2039         spin_unlock(&block_group->lock);
2040         return ret;
2041 }
2042
2043 static void wait_eb_writebacks(struct btrfs_block_group *block_group)
2044 {
2045         struct btrfs_fs_info *fs_info = block_group->fs_info;
2046         const u64 end = block_group->start + block_group->length;
2047         struct radix_tree_iter iter;
2048         struct extent_buffer *eb;
2049         void __rcu **slot;
2050
2051         rcu_read_lock();
2052         radix_tree_for_each_slot(slot, &fs_info->buffer_radix, &iter,
2053                                  block_group->start >> fs_info->sectorsize_bits) {
2054                 eb = radix_tree_deref_slot(slot);
2055                 if (!eb)
2056                         continue;
2057                 if (radix_tree_deref_retry(eb)) {
2058                         slot = radix_tree_iter_retry(&iter);
2059                         continue;
2060                 }
2061
2062                 if (eb->start < block_group->start)
2063                         continue;
2064                 if (eb->start >= end)
2065                         break;
2066
2067                 slot = radix_tree_iter_resume(slot, &iter);
2068                 rcu_read_unlock();
2069                 wait_on_extent_buffer_writeback(eb);
2070                 rcu_read_lock();
2071         }
2072         rcu_read_unlock();
2073 }
2074
2075 static int do_zone_finish(struct btrfs_block_group *block_group, bool fully_written)
2076 {
2077         struct btrfs_fs_info *fs_info = block_group->fs_info;
2078         struct map_lookup *map;
2079         const bool is_metadata = (block_group->flags &
2080                         (BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_SYSTEM));
2081         int ret = 0;
2082         int i;
2083
2084         spin_lock(&block_group->lock);
2085         if (!test_bit(BLOCK_GROUP_FLAG_ZONE_IS_ACTIVE, &block_group->runtime_flags)) {
2086                 spin_unlock(&block_group->lock);
2087                 return 0;
2088         }
2089
2090         /* Check if we have unwritten allocated space */
2091         if (is_metadata &&
2092             block_group->start + block_group->alloc_offset > block_group->meta_write_pointer) {
2093                 spin_unlock(&block_group->lock);
2094                 return -EAGAIN;
2095         }
2096
2097         /*
2098          * If we are sure that the block group is full (= no more room left for
2099          * new allocation) and the IO for the last usable block is completed, we
2100          * don't need to wait for the other IOs. This holds because we ensure
2101          * the sequential IO submissions using the ZONE_APPEND command for data
2102          * and block_group->meta_write_pointer for metadata.
2103          */
2104         if (!fully_written) {
2105                 if (test_bit(BLOCK_GROUP_FLAG_ZONED_DATA_RELOC, &block_group->runtime_flags)) {
2106                         spin_unlock(&block_group->lock);
2107                         return -EAGAIN;
2108                 }
2109                 spin_unlock(&block_group->lock);
2110
2111                 ret = btrfs_inc_block_group_ro(block_group, false);
2112                 if (ret)
2113                         return ret;
2114
2115                 /* Ensure all writes in this block group finish */
2116                 btrfs_wait_block_group_reservations(block_group);
2117                 /* No need to wait for NOCOW writers. Zoned mode does not allow that */
2118                 btrfs_wait_ordered_roots(fs_info, U64_MAX, block_group->start,
2119                                          block_group->length);
2120                 /* Wait for extent buffers to be written. */
2121                 if (is_metadata)
2122                         wait_eb_writebacks(block_group);
2123
2124                 spin_lock(&block_group->lock);
2125
2126                 /*
2127                  * Bail out if someone already deactivated the block group, or
2128                  * allocated space is left in the block group.
2129                  */
2130                 if (!test_bit(BLOCK_GROUP_FLAG_ZONE_IS_ACTIVE,
2131                               &block_group->runtime_flags)) {
2132                         spin_unlock(&block_group->lock);
2133                         btrfs_dec_block_group_ro(block_group);
2134                         return 0;
2135                 }
2136
2137                 if (block_group->reserved ||
2138                     test_bit(BLOCK_GROUP_FLAG_ZONED_DATA_RELOC,
2139                              &block_group->runtime_flags)) {
2140                         spin_unlock(&block_group->lock);
2141                         btrfs_dec_block_group_ro(block_group);
2142                         return -EAGAIN;
2143                 }
2144         }
2145
2146         clear_bit(BLOCK_GROUP_FLAG_ZONE_IS_ACTIVE, &block_group->runtime_flags);
2147         block_group->alloc_offset = block_group->zone_capacity;
2148         if (block_group->flags & (BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_SYSTEM))
2149                 block_group->meta_write_pointer = block_group->start +
2150                                                   block_group->zone_capacity;
2151         block_group->free_space_ctl->free_space = 0;
2152         btrfs_clear_treelog_bg(block_group);
2153         btrfs_clear_data_reloc_bg(block_group);
2154         spin_unlock(&block_group->lock);
2155
2156         map = block_group->physical_map;
2157         for (i = 0; i < map->num_stripes; i++) {
2158                 struct btrfs_device *device = map->stripes[i].dev;
2159                 const u64 physical = map->stripes[i].physical;
2160                 struct btrfs_zoned_device_info *zinfo = device->zone_info;
2161
2162                 if (zinfo->max_active_zones == 0)
2163                         continue;
2164
2165                 ret = blkdev_zone_mgmt(device->bdev, REQ_OP_ZONE_FINISH,
2166                                        physical >> SECTOR_SHIFT,
2167                                        zinfo->zone_size >> SECTOR_SHIFT,
2168                                        GFP_NOFS);
2169
2170                 if (ret)
2171                         return ret;
2172
2173                 if (!(block_group->flags & BTRFS_BLOCK_GROUP_DATA))
2174                         zinfo->reserved_active_zones++;
2175                 btrfs_dev_clear_active_zone(device, physical);
2176         }
2177
2178         if (!fully_written)
2179                 btrfs_dec_block_group_ro(block_group);
2180
2181         spin_lock(&fs_info->zone_active_bgs_lock);
2182         ASSERT(!list_empty(&block_group->active_bg_list));
2183         list_del_init(&block_group->active_bg_list);
2184         spin_unlock(&fs_info->zone_active_bgs_lock);
2185
2186         /* For active_bg_list */
2187         btrfs_put_block_group(block_group);
2188
2189         clear_and_wake_up_bit(BTRFS_FS_NEED_ZONE_FINISH, &fs_info->flags);
2190
2191         return 0;
2192 }
2193
2194 int btrfs_zone_finish(struct btrfs_block_group *block_group)
2195 {
2196         if (!btrfs_is_zoned(block_group->fs_info))
2197                 return 0;
2198
2199         return do_zone_finish(block_group, false);
2200 }
2201
2202 bool btrfs_can_activate_zone(struct btrfs_fs_devices *fs_devices, u64 flags)
2203 {
2204         struct btrfs_fs_info *fs_info = fs_devices->fs_info;
2205         struct btrfs_device *device;
2206         bool ret = false;
2207
2208         if (!btrfs_is_zoned(fs_info))
2209                 return true;
2210
2211         /* Check if there is a device with active zones left */
2212         mutex_lock(&fs_info->chunk_mutex);
2213         spin_lock(&fs_info->zone_active_bgs_lock);
2214         list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) {
2215                 struct btrfs_zoned_device_info *zinfo = device->zone_info;
2216                 int reserved = 0;
2217
2218                 if (!device->bdev)
2219                         continue;
2220
2221                 if (!zinfo->max_active_zones) {
2222                         ret = true;
2223                         break;
2224                 }
2225
2226                 if (flags & BTRFS_BLOCK_GROUP_DATA)
2227                         reserved = zinfo->reserved_active_zones;
2228
2229                 switch (flags & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
2230                 case 0: /* single */
2231                         ret = (atomic_read(&zinfo->active_zones_left) >= (1 + reserved));
2232                         break;
2233                 case BTRFS_BLOCK_GROUP_DUP:
2234                         ret = (atomic_read(&zinfo->active_zones_left) >= (2 + reserved));
2235                         break;
2236                 }
2237                 if (ret)
2238                         break;
2239         }
2240         spin_unlock(&fs_info->zone_active_bgs_lock);
2241         mutex_unlock(&fs_info->chunk_mutex);
2242
2243         if (!ret)
2244                 set_bit(BTRFS_FS_NEED_ZONE_FINISH, &fs_info->flags);
2245
2246         return ret;
2247 }
2248
2249 void btrfs_zone_finish_endio(struct btrfs_fs_info *fs_info, u64 logical, u64 length)
2250 {
2251         struct btrfs_block_group *block_group;
2252         u64 min_alloc_bytes;
2253
2254         if (!btrfs_is_zoned(fs_info))
2255                 return;
2256
2257         block_group = btrfs_lookup_block_group(fs_info, logical);
2258         ASSERT(block_group);
2259
2260         /* No MIXED_BG on zoned btrfs. */
2261         if (block_group->flags & BTRFS_BLOCK_GROUP_DATA)
2262                 min_alloc_bytes = fs_info->sectorsize;
2263         else
2264                 min_alloc_bytes = fs_info->nodesize;
2265
2266         /* Bail out if we can allocate more data from this block group. */
2267         if (logical + length + min_alloc_bytes <=
2268             block_group->start + block_group->zone_capacity)
2269                 goto out;
2270
2271         do_zone_finish(block_group, true);
2272
2273 out:
2274         btrfs_put_block_group(block_group);
2275 }
2276
2277 static void btrfs_zone_finish_endio_workfn(struct work_struct *work)
2278 {
2279         struct btrfs_block_group *bg =
2280                 container_of(work, struct btrfs_block_group, zone_finish_work);
2281
2282         wait_on_extent_buffer_writeback(bg->last_eb);
2283         free_extent_buffer(bg->last_eb);
2284         btrfs_zone_finish_endio(bg->fs_info, bg->start, bg->length);
2285         btrfs_put_block_group(bg);
2286 }
2287
2288 void btrfs_schedule_zone_finish_bg(struct btrfs_block_group *bg,
2289                                    struct extent_buffer *eb)
2290 {
2291         if (!test_bit(BLOCK_GROUP_FLAG_SEQUENTIAL_ZONE, &bg->runtime_flags) ||
2292             eb->start + eb->len * 2 <= bg->start + bg->zone_capacity)
2293                 return;
2294
2295         if (WARN_ON(bg->zone_finish_work.func == btrfs_zone_finish_endio_workfn)) {
2296                 btrfs_err(bg->fs_info, "double scheduling of bg %llu zone finishing",
2297                           bg->start);
2298                 return;
2299         }
2300
2301         /* For the work */
2302         btrfs_get_block_group(bg);
2303         atomic_inc(&eb->refs);
2304         bg->last_eb = eb;
2305         INIT_WORK(&bg->zone_finish_work, btrfs_zone_finish_endio_workfn);
2306         queue_work(system_unbound_wq, &bg->zone_finish_work);
2307 }
2308
2309 void btrfs_clear_data_reloc_bg(struct btrfs_block_group *bg)
2310 {
2311         struct btrfs_fs_info *fs_info = bg->fs_info;
2312
2313         spin_lock(&fs_info->relocation_bg_lock);
2314         if (fs_info->data_reloc_bg == bg->start)
2315                 fs_info->data_reloc_bg = 0;
2316         spin_unlock(&fs_info->relocation_bg_lock);
2317 }
2318
2319 void btrfs_free_zone_cache(struct btrfs_fs_info *fs_info)
2320 {
2321         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
2322         struct btrfs_device *device;
2323
2324         if (!btrfs_is_zoned(fs_info))
2325                 return;
2326
2327         mutex_lock(&fs_devices->device_list_mutex);
2328         list_for_each_entry(device, &fs_devices->devices, dev_list) {
2329                 if (device->zone_info) {
2330                         vfree(device->zone_info->zone_cache);
2331                         device->zone_info->zone_cache = NULL;
2332                 }
2333         }
2334         mutex_unlock(&fs_devices->device_list_mutex);
2335 }
2336
2337 bool btrfs_zoned_should_reclaim(struct btrfs_fs_info *fs_info)
2338 {
2339         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
2340         struct btrfs_device *device;
2341         u64 used = 0;
2342         u64 total = 0;
2343         u64 factor;
2344
2345         ASSERT(btrfs_is_zoned(fs_info));
2346
2347         if (fs_info->bg_reclaim_threshold == 0)
2348                 return false;
2349
2350         mutex_lock(&fs_devices->device_list_mutex);
2351         list_for_each_entry(device, &fs_devices->devices, dev_list) {
2352                 if (!device->bdev)
2353                         continue;
2354
2355                 total += device->disk_total_bytes;
2356                 used += device->bytes_used;
2357         }
2358         mutex_unlock(&fs_devices->device_list_mutex);
2359
2360         factor = div64_u64(used * 100, total);
2361         return factor >= fs_info->bg_reclaim_threshold;
2362 }
2363
2364 void btrfs_zoned_release_data_reloc_bg(struct btrfs_fs_info *fs_info, u64 logical,
2365                                        u64 length)
2366 {
2367         struct btrfs_block_group *block_group;
2368
2369         if (!btrfs_is_zoned(fs_info))
2370                 return;
2371
2372         block_group = btrfs_lookup_block_group(fs_info, logical);
2373         /* It should be called on a previous data relocation block group. */
2374         ASSERT(block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA));
2375
2376         spin_lock(&block_group->lock);
2377         if (!test_bit(BLOCK_GROUP_FLAG_ZONED_DATA_RELOC, &block_group->runtime_flags))
2378                 goto out;
2379
2380         /* All relocation extents are written. */
2381         if (block_group->start + block_group->alloc_offset == logical + length) {
2382                 /*
2383                  * Now, release this block group for further allocations and
2384                  * zone finish.
2385                  */
2386                 clear_bit(BLOCK_GROUP_FLAG_ZONED_DATA_RELOC,
2387                           &block_group->runtime_flags);
2388         }
2389
2390 out:
2391         spin_unlock(&block_group->lock);
2392         btrfs_put_block_group(block_group);
2393 }
2394
2395 int btrfs_zone_finish_one_bg(struct btrfs_fs_info *fs_info)
2396 {
2397         struct btrfs_block_group *block_group;
2398         struct btrfs_block_group *min_bg = NULL;
2399         u64 min_avail = U64_MAX;
2400         int ret;
2401
2402         spin_lock(&fs_info->zone_active_bgs_lock);
2403         list_for_each_entry(block_group, &fs_info->zone_active_bgs,
2404                             active_bg_list) {
2405                 u64 avail;
2406
2407                 spin_lock(&block_group->lock);
2408                 if (block_group->reserved || block_group->alloc_offset == 0 ||
2409                     (block_group->flags & BTRFS_BLOCK_GROUP_SYSTEM) ||
2410                     test_bit(BLOCK_GROUP_FLAG_ZONED_DATA_RELOC, &block_group->runtime_flags)) {
2411                         spin_unlock(&block_group->lock);
2412                         continue;
2413                 }
2414
2415                 avail = block_group->zone_capacity - block_group->alloc_offset;
2416                 if (min_avail > avail) {
2417                         if (min_bg)
2418                                 btrfs_put_block_group(min_bg);
2419                         min_bg = block_group;
2420                         min_avail = avail;
2421                         btrfs_get_block_group(min_bg);
2422                 }
2423                 spin_unlock(&block_group->lock);
2424         }
2425         spin_unlock(&fs_info->zone_active_bgs_lock);
2426
2427         if (!min_bg)
2428                 return 0;
2429
2430         ret = btrfs_zone_finish(min_bg);
2431         btrfs_put_block_group(min_bg);
2432
2433         return ret < 0 ? ret : 1;
2434 }
2435
2436 int btrfs_zoned_activate_one_bg(struct btrfs_fs_info *fs_info,
2437                                 struct btrfs_space_info *space_info,
2438                                 bool do_finish)
2439 {
2440         struct btrfs_block_group *bg;
2441         int index;
2442
2443         if (!btrfs_is_zoned(fs_info) || (space_info->flags & BTRFS_BLOCK_GROUP_DATA))
2444                 return 0;
2445
2446         for (;;) {
2447                 int ret;
2448                 bool need_finish = false;
2449
2450                 down_read(&space_info->groups_sem);
2451                 for (index = 0; index < BTRFS_NR_RAID_TYPES; index++) {
2452                         list_for_each_entry(bg, &space_info->block_groups[index],
2453                                             list) {
2454                                 if (!spin_trylock(&bg->lock))
2455                                         continue;
2456                                 if (btrfs_zoned_bg_is_full(bg) ||
2457                                     test_bit(BLOCK_GROUP_FLAG_ZONE_IS_ACTIVE,
2458                                              &bg->runtime_flags)) {
2459                                         spin_unlock(&bg->lock);
2460                                         continue;
2461                                 }
2462                                 spin_unlock(&bg->lock);
2463
2464                                 if (btrfs_zone_activate(bg)) {
2465                                         up_read(&space_info->groups_sem);
2466                                         return 1;
2467                                 }
2468
2469                                 need_finish = true;
2470                         }
2471                 }
2472                 up_read(&space_info->groups_sem);
2473
2474                 if (!do_finish || !need_finish)
2475                         break;
2476
2477                 ret = btrfs_zone_finish_one_bg(fs_info);
2478                 if (ret == 0)
2479                         break;
2480                 if (ret < 0)
2481                         return ret;
2482         }
2483
2484         return 0;
2485 }
2486
2487 /*
2488  * Reserve zones for one metadata block group, one tree-log block group, and one
2489  * system block group.
2490  */
2491 void btrfs_check_active_zone_reservation(struct btrfs_fs_info *fs_info)
2492 {
2493         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
2494         struct btrfs_block_group *block_group;
2495         struct btrfs_device *device;
2496         /* Reserve zones for normal SINGLE metadata and tree-log block group. */
2497         unsigned int metadata_reserve = 2;
2498         /* Reserve a zone for SINGLE system block group. */
2499         unsigned int system_reserve = 1;
2500
2501         if (!test_bit(BTRFS_FS_ACTIVE_ZONE_TRACKING, &fs_info->flags))
2502                 return;
2503
2504         /*
2505          * This function is called from the mount context. So, there is no
2506          * parallel process touching the bits. No need for read_seqretry().
2507          */
2508         if (fs_info->avail_metadata_alloc_bits & BTRFS_BLOCK_GROUP_DUP)
2509                 metadata_reserve = 4;
2510         if (fs_info->avail_system_alloc_bits & BTRFS_BLOCK_GROUP_DUP)
2511                 system_reserve = 2;
2512
2513         /* Apply the reservation on all the devices. */
2514         mutex_lock(&fs_devices->device_list_mutex);
2515         list_for_each_entry(device, &fs_devices->devices, dev_list) {
2516                 if (!device->bdev)
2517                         continue;
2518
2519                 device->zone_info->reserved_active_zones =
2520                         metadata_reserve + system_reserve;
2521         }
2522         mutex_unlock(&fs_devices->device_list_mutex);
2523
2524         /* Release reservation for currently active block groups. */
2525         spin_lock(&fs_info->zone_active_bgs_lock);
2526         list_for_each_entry(block_group, &fs_info->zone_active_bgs, active_bg_list) {
2527                 struct map_lookup *map = block_group->physical_map;
2528
2529                 if (!(block_group->flags &
2530                       (BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_SYSTEM)))
2531                         continue;
2532
2533                 for (int i = 0; i < map->num_stripes; i++)
2534                         map->stripes[i].dev->zone_info->reserved_active_zones--;
2535         }
2536         spin_unlock(&fs_info->zone_active_bgs_lock);
2537 }