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