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