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