fs/btrfs/volumes.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * Copyright (C) 2007 Oracle.  All rights reserved.
   4  */
   5
   6 #ifndef BTRFS_VOLUMES_H
   7 #define BTRFS_VOLUMES_H
   8
   9 #include <linux/bio.h>
  10 #include <linux/sort.h>
  11 #include <linux/btrfs.h>
  12 #include "async-thread.h"
  13
  14 #define BTRFS_MAX_DATA_CHUNK_SIZE       (10ULL * SZ_1G)
  15
  16 extern struct mutex uuid_mutex;
  17
  18 #define BTRFS_STRIPE_LEN        SZ_64K
  19
  20 struct btrfs_io_geometry {
  21         /* remaining bytes before crossing a stripe */
  22         u64 len;
  23         /* offset of logical address in chunk */
  24         u64 offset;
  25         /* length of single IO stripe */
  26         u64 stripe_len;
  27         /* number of stripe where address falls */
  28         u64 stripe_nr;
  29         /* offset of address in stripe */
  30         u64 stripe_offset;
  31         /* offset of raid56 stripe into the chunk */
  32         u64 raid56_stripe_offset;
  33 };
  34
  35 /*
  36  * Use sequence counter to get consistent device stat data on
  37  * 32-bit processors.
  38  */
  39 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
  40 #include <linux/seqlock.h>
  41 #define __BTRFS_NEED_DEVICE_DATA_ORDERED
  42 #define btrfs_device_data_ordered_init(device, info)                            \
  43         seqcount_mutex_init(&device->data_seqcount, &info->chunk_mutex)
  44 #else
  45 #define btrfs_device_data_ordered_init(device, info) do { } while (0)
  46 #endif
  47
  48 #define BTRFS_DEV_STATE_WRITEABLE       (0)
  49 #define BTRFS_DEV_STATE_IN_FS_METADATA  (1)
  50 #define BTRFS_DEV_STATE_MISSING         (2)
  51 #define BTRFS_DEV_STATE_REPLACE_TGT     (3)
  52 #define BTRFS_DEV_STATE_FLUSH_SENT      (4)
  53 #define BTRFS_DEV_STATE_NO_READA        (5)
  54
  55 struct btrfs_zoned_device_info;
  56
  57 struct btrfs_device {
  58         struct list_head dev_list; /* device_list_mutex */
  59         struct list_head dev_alloc_list; /* chunk mutex */
  60         struct list_head post_commit_list; /* chunk mutex */
  61         struct btrfs_fs_devices *fs_devices;
  62         struct btrfs_fs_info *fs_info;
  63
  64         struct rcu_string __rcu *name;
  65
  66         u64 generation;
  67
  68         struct block_device *bdev;
  69
  70         struct btrfs_zoned_device_info *zone_info;
  71
  72         /* the mode sent to blkdev_get */
  73         fmode_t mode;
  74
  75         unsigned long dev_state;
  76         blk_status_t last_flush_error;
  77
  78 #ifdef __BTRFS_NEED_DEVICE_DATA_ORDERED
  79         /* A seqcount_t with associated chunk_mutex (for lockdep) */
  80         seqcount_mutex_t data_seqcount;
  81 #endif
  82
  83         /* the internal btrfs device id */
  84         u64 devid;
  85
  86         /* size of the device in memory */
  87         u64 total_bytes;
  88
  89         /* size of the device on disk */
  90         u64 disk_total_bytes;
  91
  92         /* bytes used */
  93         u64 bytes_used;
  94
  95         /* optimal io alignment for this device */
  96         u32 io_align;
  97
  98         /* optimal io width for this device */
  99         u32 io_width;
 100         /* type and info about this device */
 101         u64 type;
 102
 103         /* minimal io size for this device */
 104         u32 sector_size;
 105
 106         /* physical drive uuid (or lvm uuid) */
 107         u8 uuid[BTRFS_UUID_SIZE];
 108
 109         /*
 110          * size of the device on the current transaction
 111          *
 112          * This variant is update when committing the transaction,
 113          * and protected by chunk mutex
 114          */
 115         u64 commit_total_bytes;
 116
 117         /* bytes used on the current transaction */
 118         u64 commit_bytes_used;
 119
 120         /* for sending down flush barriers */
 121         struct bio *flush_bio;
 122         struct completion flush_wait;
 123
 124         /* per-device scrub information */
 125         struct scrub_ctx *scrub_ctx;
 126
 127         /* readahead state */
 128         atomic_t reada_in_flight;
 129         u64 reada_next;
 130         struct reada_zone *reada_curr_zone;
 131         struct radix_tree_root reada_zones;
 132         struct radix_tree_root reada_extents;
 133
 134         /* disk I/O failure stats. For detailed description refer to
 135          * enum btrfs_dev_stat_values in ioctl.h */
 136         int dev_stats_valid;
 137
 138         /* Counter to record the change of device stats */
 139         atomic_t dev_stats_ccnt;
 140         atomic_t dev_stat_values[BTRFS_DEV_STAT_VALUES_MAX];
 141
 142         struct extent_io_tree alloc_state;
 143
 144         struct completion kobj_unregister;
 145         /* For sysfs/FSID/devinfo/devid/ */
 146         struct kobject devid_kobj;
 147 };
 148
 149 /*
 150  * If we read those variants at the context of their own lock, we needn't
 151  * use the following helpers, reading them directly is safe.
 152  */
 153 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
 154 #define BTRFS_DEVICE_GETSET_FUNCS(name)                                 \
 155 static inline u64                                                       \
 156 btrfs_device_get_##name(const struct btrfs_device *dev)                 \
 157 {                                                                       \
 158         u64 size;                                                       \
 159         unsigned int seq;                                               \
 160                                                                         \
 161         do {                                                            \
 162                 seq = read_seqcount_begin(&dev->data_seqcount);         \
 163                 size = dev->name;                                       \
 164         } while (read_seqcount_retry(&dev->data_seqcount, seq));        \
 165         return size;                                                    \
 166 }                                                                       \
 167                                                                         \
 168 static inline void                                                      \
 169 btrfs_device_set_##name(struct btrfs_device *dev, u64 size)             \
 170 {                                                                       \
 171         write_seqcount_begin(&dev->data_seqcount);                      \
 172         dev->name = size;                                               \
 173         write_seqcount_end(&dev->data_seqcount);                        \
 174 }
 175 #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION)
 176 #define BTRFS_DEVICE_GETSET_FUNCS(name)                                 \
 177 static inline u64                                                       \
 178 btrfs_device_get_##name(const struct btrfs_device *dev)                 \
 179 {                                                                       \
 180         u64 size;                                                       \
 181                                                                         \
 182         preempt_disable();                                              \
 183         size = dev->name;                                               \
 184         preempt_enable();                                               \
 185         return size;                                                    \
 186 }                                                                       \
 187                                                                         \
 188 static inline void                                                      \
 189 btrfs_device_set_##name(struct btrfs_device *dev, u64 size)             \
 190 {                                                                       \
 191         preempt_disable();                                              \
 192         dev->name = size;                                               \
 193         preempt_enable();                                               \
 194 }
 195 #else
 196 #define BTRFS_DEVICE_GETSET_FUNCS(name)                                 \
 197 static inline u64                                                       \
 198 btrfs_device_get_##name(const struct btrfs_device *dev)                 \
 199 {                                                                       \
 200         return dev->name;                                               \
 201 }                                                                       \
 202                                                                         \
 203 static inline void                                                      \
 204 btrfs_device_set_##name(struct btrfs_device *dev, u64 size)             \
 205 {                                                                       \
 206         dev->name = size;                                               \
 207 }
 208 #endif
 209
 210 BTRFS_DEVICE_GETSET_FUNCS(total_bytes);
 211 BTRFS_DEVICE_GETSET_FUNCS(disk_total_bytes);
 212 BTRFS_DEVICE_GETSET_FUNCS(bytes_used);
 213
 214 enum btrfs_chunk_allocation_policy {
 215         BTRFS_CHUNK_ALLOC_REGULAR,
 216 };
 217
 218 /*
 219  * Read policies for mirrored block group profiles, read picks the stripe based
 220  * on these policies.
 221  */
 222 enum btrfs_read_policy {
 223         /* Use process PID to choose the stripe */
 224         BTRFS_READ_POLICY_PID,
 225         BTRFS_NR_READ_POLICY,
 226 };
 227
 228 struct btrfs_fs_devices {
 229         u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
 230         u8 metadata_uuid[BTRFS_FSID_SIZE];
 231         bool fsid_change;
 232         struct list_head fs_list;
 233
 234         u64 num_devices;
 235         u64 open_devices;
 236         u64 rw_devices;
 237         u64 missing_devices;
 238         u64 total_rw_bytes;
 239         u64 total_devices;
 240
 241         /* Highest generation number of seen devices */
 242         u64 latest_generation;
 243
 244         struct block_device *latest_bdev;
 245
 246         /* all of the devices in the FS, protected by a mutex
 247          * so we can safely walk it to write out the supers without
 248          * worrying about add/remove by the multi-device code.
 249          * Scrubbing super can kick off supers writing by holding
 250          * this mutex lock.
 251          */
 252         struct mutex device_list_mutex;
 253
 254         /* List of all devices, protected by device_list_mutex */
 255         struct list_head devices;
 256
 257         /*
 258          * Devices which can satisfy space allocation. Protected by
 259          * chunk_mutex
 260          */
 261         struct list_head alloc_list;
 262
 263         struct list_head seed_list;
 264         bool seeding;
 265
 266         int opened;
 267
 268         /* set when we find or add a device that doesn't have the
 269          * nonrot flag set
 270          */
 271         bool rotating;
 272
 273         struct btrfs_fs_info *fs_info;
 274         /* sysfs kobjects */
 275         struct kobject fsid_kobj;
 276         struct kobject *devices_kobj;
 277         struct kobject *devinfo_kobj;
 278         struct completion kobj_unregister;
 279
 280         enum btrfs_chunk_allocation_policy chunk_alloc_policy;
 281
 282         /* Policy used to read the mirrored stripes */
 283         enum btrfs_read_policy read_policy;
 284 };
 285
 286 #define BTRFS_BIO_INLINE_CSUM_SIZE      64
 287
 288 #define BTRFS_MAX_DEVS(info) ((BTRFS_MAX_ITEM_SIZE(info)        \
 289                         - sizeof(struct btrfs_chunk))           \
 290                         / sizeof(struct btrfs_stripe) + 1)
 291
 292 #define BTRFS_MAX_DEVS_SYS_CHUNK ((BTRFS_SYSTEM_CHUNK_ARRAY_SIZE        \
 293                                 - 2 * sizeof(struct btrfs_disk_key)     \
 294                                 - 2 * sizeof(struct btrfs_chunk))       \
 295                                 / sizeof(struct btrfs_stripe) + 1)
 296
 297 /*
 298  * we need the mirror number and stripe index to be passed around
 299  * the call chain while we are processing end_io (especially errors).
 300  * Really, what we need is a btrfs_bio structure that has this info
 301  * and is properly sized with its stripe array, but we're not there
 302  * quite yet.  We have our own btrfs bioset, and all of the bios
 303  * we allocate are actually btrfs_io_bios.  We'll cram as much of
 304  * struct btrfs_bio as we can into this over time.
 305  */
 306 struct btrfs_io_bio {
 307         unsigned int mirror_num;
 308         struct btrfs_device *device;
 309         u64 logical;
 310         u8 *csum;
 311         u8 csum_inline[BTRFS_BIO_INLINE_CSUM_SIZE];
 312         struct bvec_iter iter;
 313         /*
 314          * This member must come last, bio_alloc_bioset will allocate enough
 315          * bytes for entire btrfs_io_bio but relies on bio being last.
 316          */
 317         struct bio bio;
 318 };
 319
 320 static inline struct btrfs_io_bio *btrfs_io_bio(struct bio *bio)
 321 {
 322         return container_of(bio, struct btrfs_io_bio, bio);
 323 }
 324
 325 static inline void btrfs_io_bio_free_csum(struct btrfs_io_bio *io_bio)
 326 {
 327         if (io_bio->csum != io_bio->csum_inline) {
 328                 kfree(io_bio->csum);
 329                 io_bio->csum = NULL;
 330         }
 331 }
 332
 333 struct btrfs_bio_stripe {
 334         struct btrfs_device *dev;
 335         u64 physical;
 336         u64 length; /* only used for discard mappings */
 337 };
 338
 339 struct btrfs_bio {
 340         refcount_t refs;
 341         atomic_t stripes_pending;
 342         struct btrfs_fs_info *fs_info;
 343         u64 map_type; /* get from map_lookup->type */
 344         bio_end_io_t *end_io;
 345         struct bio *orig_bio;
 346         void *private;
 347         atomic_t error;
 348         int max_errors;
 349         int num_stripes;
 350         int mirror_num;
 351         int num_tgtdevs;
 352         int *tgtdev_map;
 353         /*
 354          * logical block numbers for the start of each stripe
 355          * The last one or two are p/q.  These are sorted,
 356          * so raid_map[0] is the start of our full stripe
 357          */
 358         u64 *raid_map;
 359         struct btrfs_bio_stripe stripes[];
 360 };
 361
 362 struct btrfs_device_info {
 363         struct btrfs_device *dev;
 364         u64 dev_offset;
 365         u64 max_avail;
 366         u64 total_avail;
 367 };
 368
 369 struct btrfs_raid_attr {
 370         u8 sub_stripes;         /* sub_stripes info for map */
 371         u8 dev_stripes;         /* stripes per dev */
 372         u8 devs_max;            /* max devs to use */
 373         u8 devs_min;            /* min devs needed */
 374         u8 tolerated_failures;  /* max tolerated fail devs */
 375         u8 devs_increment;      /* ndevs has to be a multiple of this */
 376         u8 ncopies;             /* how many copies to data has */
 377         u8 nparity;             /* number of stripes worth of bytes to store
 378                                  * parity information */
 379         u8 mindev_error;        /* error code if min devs requisite is unmet */
 380         const char raid_name[8]; /* name of the raid */
 381         u64 bg_flag;            /* block group flag of the raid */
 382 };
 383
 384 extern const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES];
 385
 386 struct map_lookup {
 387         u64 type;
 388         int io_align;
 389         int io_width;
 390         u64 stripe_len;
 391         int num_stripes;
 392         int sub_stripes;
 393         int verified_stripes; /* For mount time dev extent verification */
 394         struct btrfs_bio_stripe stripes[];
 395 };
 396
 397 #define map_lookup_size(n) (sizeof(struct map_lookup) + \
 398                             (sizeof(struct btrfs_bio_stripe) * (n)))
 399
 400 struct btrfs_balance_args;
 401 struct btrfs_balance_progress;
 402 struct btrfs_balance_control {
 403         struct btrfs_balance_args data;
 404         struct btrfs_balance_args meta;
 405         struct btrfs_balance_args sys;
 406
 407         u64 flags;
 408
 409         struct btrfs_balance_progress stat;
 410 };
 411
 412 enum btrfs_map_op {
 413         BTRFS_MAP_READ,
 414         BTRFS_MAP_WRITE,
 415         BTRFS_MAP_DISCARD,
 416         BTRFS_MAP_GET_READ_MIRRORS,
 417 };
 418
 419 static inline enum btrfs_map_op btrfs_op(struct bio *bio)
 420 {
 421         switch (bio_op(bio)) {
 422         case REQ_OP_DISCARD:
 423                 return BTRFS_MAP_DISCARD;
 424         case REQ_OP_WRITE:
 425                 return BTRFS_MAP_WRITE;
 426         default:
 427                 WARN_ON_ONCE(1);
 428                 fallthrough;
 429         case REQ_OP_READ:
 430                 return BTRFS_MAP_READ;
 431         }
 432 }
 433
 434 void btrfs_get_bbio(struct btrfs_bio *bbio);
 435 void btrfs_put_bbio(struct btrfs_bio *bbio);
 436 int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
 437                     u64 logical, u64 *length,
 438                     struct btrfs_bio **bbio_ret, int mirror_num);
 439 int btrfs_map_sblock(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
 440                      u64 logical, u64 *length,
 441                      struct btrfs_bio **bbio_ret);
 442 int btrfs_get_io_geometry(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
 443                 u64 logical, u64 len, struct btrfs_io_geometry *io_geom);
 444 int btrfs_read_sys_array(struct btrfs_fs_info *fs_info);
 445 int btrfs_read_chunk_tree(struct btrfs_fs_info *fs_info);
 446 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans, u64 type);
 447 void btrfs_mapping_tree_free(struct extent_map_tree *tree);
 448 blk_status_t btrfs_map_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
 449                            int mirror_num);
 450 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
 451                        fmode_t flags, void *holder);
 452 struct btrfs_device *btrfs_scan_one_device(const char *path,
 453                                            fmode_t flags, void *holder);
 454 int btrfs_forget_devices(const char *path);
 455 void btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
 456 void btrfs_free_extra_devids(struct btrfs_fs_devices *fs_devices);
 457 void btrfs_assign_next_active_device(struct btrfs_device *device,
 458                                      struct btrfs_device *this_dev);
 459 struct btrfs_device *btrfs_find_device_by_devspec(struct btrfs_fs_info *fs_info,
 460                                                   u64 devid,
 461                                                   const char *devpath);
 462 struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info,
 463                                         const u64 *devid,
 464                                         const u8 *uuid);
 465 void btrfs_free_device(struct btrfs_device *device);
 466 int btrfs_rm_device(struct btrfs_fs_info *fs_info,
 467                     const char *device_path, u64 devid);
 468 void __exit btrfs_cleanup_fs_uuids(void);
 469 int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len);
 470 int btrfs_grow_device(struct btrfs_trans_handle *trans,
 471                       struct btrfs_device *device, u64 new_size);
 472 struct btrfs_device *btrfs_find_device(struct btrfs_fs_devices *fs_devices,
 473                                        u64 devid, u8 *uuid, u8 *fsid);
 474 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size);
 475 int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *path);
 476 int btrfs_balance(struct btrfs_fs_info *fs_info,
 477                   struct btrfs_balance_control *bctl,
 478                   struct btrfs_ioctl_balance_args *bargs);
 479 void btrfs_describe_block_groups(u64 flags, char *buf, u32 size_buf);
 480 int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info);
 481 int btrfs_recover_balance(struct btrfs_fs_info *fs_info);
 482 int btrfs_pause_balance(struct btrfs_fs_info *fs_info);
 483 int btrfs_cancel_balance(struct btrfs_fs_info *fs_info);
 484 int btrfs_create_uuid_tree(struct btrfs_fs_info *fs_info);
 485 int btrfs_uuid_scan_kthread(void *data);
 486 int btrfs_chunk_readonly(struct btrfs_fs_info *fs_info, u64 chunk_offset);
 487 int find_free_dev_extent(struct btrfs_device *device, u64 num_bytes,
 488                          u64 *start, u64 *max_avail);
 489 void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index);
 490 int btrfs_get_dev_stats(struct btrfs_fs_info *fs_info,
 491                         struct btrfs_ioctl_get_dev_stats *stats);
 492 void btrfs_init_devices_late(struct btrfs_fs_info *fs_info);
 493 int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info);
 494 int btrfs_run_dev_stats(struct btrfs_trans_handle *trans);
 495 void btrfs_rm_dev_replace_remove_srcdev(struct btrfs_device *srcdev);
 496 void btrfs_rm_dev_replace_free_srcdev(struct btrfs_device *srcdev);
 497 void btrfs_destroy_dev_replace_tgtdev(struct btrfs_device *tgtdev);
 498 int btrfs_is_parity_mirror(struct btrfs_fs_info *fs_info,
 499                            u64 logical, u64 len);
 500 unsigned long btrfs_full_stripe_len(struct btrfs_fs_info *fs_info,
 501                                     u64 logical);
 502 int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans,
 503                              u64 chunk_offset, u64 chunk_size);
 504 int btrfs_remove_chunk(struct btrfs_trans_handle *trans, u64 chunk_offset);
 505 struct extent_map *btrfs_get_chunk_map(struct btrfs_fs_info *fs_info,
 506                                        u64 logical, u64 length);
 507 void btrfs_release_disk_super(struct btrfs_super_block *super);
 508
 509 static inline void btrfs_dev_stat_inc(struct btrfs_device *dev,
 510                                       int index)
 511 {
 512         atomic_inc(dev->dev_stat_values + index);
 513         /*
 514          * This memory barrier orders stores updating statistics before stores
 515          * updating dev_stats_ccnt.
 516          *
 517          * It pairs with smp_rmb() in btrfs_run_dev_stats().
 518          */
 519         smp_mb__before_atomic();
 520         atomic_inc(&dev->dev_stats_ccnt);
 521 }
 522
 523 static inline int btrfs_dev_stat_read(struct btrfs_device *dev,
 524                                       int index)
 525 {
 526         return atomic_read(dev->dev_stat_values + index);
 527 }
 528
 529 static inline int btrfs_dev_stat_read_and_reset(struct btrfs_device *dev,
 530                                                 int index)
 531 {
 532         int ret;
 533
 534         ret = atomic_xchg(dev->dev_stat_values + index, 0);
 535         /*
 536          * atomic_xchg implies a full memory barriers as per atomic_t.txt:
 537          * - RMW operations that have a return value are fully ordered;
 538          *
 539          * This implicit memory barriers is paired with the smp_rmb in
 540          * btrfs_run_dev_stats
 541          */
 542         atomic_inc(&dev->dev_stats_ccnt);
 543         return ret;
 544 }
 545
 546 static inline void btrfs_dev_stat_set(struct btrfs_device *dev,
 547                                       int index, unsigned long val)
 548 {
 549         atomic_set(dev->dev_stat_values + index, val);
 550         /*
 551          * This memory barrier orders stores updating statistics before stores
 552          * updating dev_stats_ccnt.
 553          *
 554          * It pairs with smp_rmb() in btrfs_run_dev_stats().
 555          */
 556         smp_mb__before_atomic();
 557         atomic_inc(&dev->dev_stats_ccnt);
 558 }
 559
 560 /*
 561  * Convert block group flags (BTRFS_BLOCK_GROUP_*) to btrfs_raid_types, which
 562  * can be used as index to access btrfs_raid_array[].
 563  */
 564 static inline enum btrfs_raid_types btrfs_bg_flags_to_raid_index(u64 flags)
 565 {
 566         if (flags & BTRFS_BLOCK_GROUP_RAID10)
 567                 return BTRFS_RAID_RAID10;
 568         else if (flags & BTRFS_BLOCK_GROUP_RAID1)
 569                 return BTRFS_RAID_RAID1;
 570         else if (flags & BTRFS_BLOCK_GROUP_RAID1C3)
 571                 return BTRFS_RAID_RAID1C3;
 572         else if (flags & BTRFS_BLOCK_GROUP_RAID1C4)
 573                 return BTRFS_RAID_RAID1C4;
 574         else if (flags & BTRFS_BLOCK_GROUP_DUP)
 575                 return BTRFS_RAID_DUP;
 576         else if (flags & BTRFS_BLOCK_GROUP_RAID0)
 577                 return BTRFS_RAID_RAID0;
 578         else if (flags & BTRFS_BLOCK_GROUP_RAID5)
 579                 return BTRFS_RAID_RAID5;
 580         else if (flags & BTRFS_BLOCK_GROUP_RAID6)
 581                 return BTRFS_RAID_RAID6;
 582
 583         return BTRFS_RAID_SINGLE; /* BTRFS_BLOCK_GROUP_SINGLE */
 584 }
 585
 586 void btrfs_commit_device_sizes(struct btrfs_transaction *trans);
 587
 588 struct list_head * __attribute_const__ btrfs_get_fs_uuids(void);
 589 bool btrfs_check_rw_degradable(struct btrfs_fs_info *fs_info,
 590                                         struct btrfs_device *failing_dev);
 591 void btrfs_scratch_superblocks(struct btrfs_fs_info *fs_info,
 592                                struct block_device *bdev,
 593                                const char *device_path);
 594
 595 int btrfs_bg_type_to_factor(u64 flags);
 596 const char *btrfs_bg_type_to_raid_name(u64 flags);
 597 int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info);
 598
 599 #endif