fs/btrfs/volumes.h

   1 /*
   2  * Copyright (C) 2007 Oracle.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #ifndef __BTRFS_VOLUMES_
  20 #define __BTRFS_VOLUMES_
  21
  22 #include <linux/bio.h>
  23 #include <linux/sort.h>
  24 #include <linux/btrfs.h>
  25 #include "async-thread.h"
  26
  27 #define BTRFS_MAX_DATA_CHUNK_SIZE       (10ULL * SZ_1G)
  28
  29 extern struct mutex uuid_mutex;
  30
  31 #define BTRFS_STRIPE_LEN        SZ_64K
  32
  33 struct buffer_head;
  34 struct btrfs_pending_bios {
  35         struct bio *head;
  36         struct bio *tail;
  37 };
  38
  39 /*
  40  * Use sequence counter to get consistent device stat data on
  41  * 32-bit processors.
  42  */
  43 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
  44 #include <linux/seqlock.h>
  45 #define __BTRFS_NEED_DEVICE_DATA_ORDERED
  46 #define btrfs_device_data_ordered_init(device)  \
  47         seqcount_init(&device->data_seqcount)
  48 #else
  49 #define btrfs_device_data_ordered_init(device) do { } while (0)
  50 #endif
  51
  52 struct btrfs_device {
  53         struct list_head dev_list;
  54         struct list_head dev_alloc_list;
  55         struct btrfs_fs_devices *fs_devices;
  56         struct btrfs_fs_info *fs_info;
  57
  58         struct rcu_string *name;
  59
  60         u64 generation;
  61
  62         spinlock_t io_lock ____cacheline_aligned;
  63         int running_pending;
  64         /* When true means this device has pending chunk alloc in
  65          * current transaction. Protected by chunk_mutex.
  66          */
  67         bool has_pending_chunks;
  68
  69         /* regular prio bios */
  70         struct btrfs_pending_bios pending_bios;
  71         /* sync bios */
  72         struct btrfs_pending_bios pending_sync_bios;
  73
  74         struct block_device *bdev;
  75
  76         /* the mode sent to blkdev_get */
  77         fmode_t mode;
  78
  79         int writeable;
  80         int in_fs_metadata;
  81         int missing;
  82         int can_discard;
  83         int is_tgtdev_for_dev_replace;
  84         blk_status_t last_flush_error;
  85         int flush_bio_sent;
  86
  87 #ifdef __BTRFS_NEED_DEVICE_DATA_ORDERED
  88         seqcount_t data_seqcount;
  89 #endif
  90
  91         /* the internal btrfs device id */
  92         u64 devid;
  93
  94         /* size of the device in memory */
  95         u64 total_bytes;
  96
  97         /* size of the device on disk */
  98         u64 disk_total_bytes;
  99
 100         /* bytes used */
 101         u64 bytes_used;
 102
 103         /* optimal io alignment for this device */
 104         u32 io_align;
 105
 106         /* optimal io width for this device */
 107         u32 io_width;
 108         /* type and info about this device */
 109         u64 type;
 110
 111         /* minimal io size for this device */
 112         u32 sector_size;
 113
 114         /* physical drive uuid (or lvm uuid) */
 115         u8 uuid[BTRFS_UUID_SIZE];
 116
 117         /*
 118          * size of the device on the current transaction
 119          *
 120          * This variant is update when committing the transaction,
 121          * and protected by device_list_mutex
 122          */
 123         u64 commit_total_bytes;
 124
 125         /* bytes used on the current transaction */
 126         u64 commit_bytes_used;
 127         /*
 128          * used to manage the device which is resized
 129          *
 130          * It is protected by chunk_lock.
 131          */
 132         struct list_head resized_list;
 133
 134         /* for sending down flush barriers */
 135         struct bio *flush_bio;
 136         struct completion flush_wait;
 137
 138         /* per-device scrub information */
 139         struct scrub_ctx *scrub_device;
 140
 141         struct btrfs_work work;
 142         struct rcu_head rcu;
 143         struct work_struct rcu_work;
 144
 145         /* readahead state */
 146         spinlock_t reada_lock;
 147         atomic_t reada_in_flight;
 148         u64 reada_next;
 149         struct reada_zone *reada_curr_zone;
 150         struct radix_tree_root reada_zones;
 151         struct radix_tree_root reada_extents;
 152
 153         /* disk I/O failure stats. For detailed description refer to
 154          * enum btrfs_dev_stat_values in ioctl.h */
 155         int dev_stats_valid;
 156
 157         /* Counter to record the change of device stats */
 158         atomic_t dev_stats_ccnt;
 159         atomic_t dev_stat_values[BTRFS_DEV_STAT_VALUES_MAX];
 160 };
 161
 162 /*
 163  * If we read those variants at the context of their own lock, we needn't
 164  * use the following helpers, reading them directly is safe.
 165  */
 166 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
 167 #define BTRFS_DEVICE_GETSET_FUNCS(name)                                 \
 168 static inline u64                                                       \
 169 btrfs_device_get_##name(const struct btrfs_device *dev)                 \
 170 {                                                                       \
 171         u64 size;                                                       \
 172         unsigned int seq;                                               \
 173                                                                         \
 174         do {                                                            \
 175                 seq = read_seqcount_begin(&dev->data_seqcount);         \
 176                 size = dev->name;                                       \
 177         } while (read_seqcount_retry(&dev->data_seqcount, seq));        \
 178         return size;                                                    \
 179 }                                                                       \
 180                                                                         \
 181 static inline void                                                      \
 182 btrfs_device_set_##name(struct btrfs_device *dev, u64 size)             \
 183 {                                                                       \
 184         preempt_disable();                                              \
 185         write_seqcount_begin(&dev->data_seqcount);                      \
 186         dev->name = size;                                               \
 187         write_seqcount_end(&dev->data_seqcount);                        \
 188         preempt_enable();                                               \
 189 }
 190 #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT)
 191 #define BTRFS_DEVICE_GETSET_FUNCS(name)                                 \
 192 static inline u64                                                       \
 193 btrfs_device_get_##name(const struct btrfs_device *dev)                 \
 194 {                                                                       \
 195         u64 size;                                                       \
 196                                                                         \
 197         preempt_disable();                                              \
 198         size = dev->name;                                               \
 199         preempt_enable();                                               \
 200         return size;                                                    \
 201 }                                                                       \
 202                                                                         \
 203 static inline void                                                      \
 204 btrfs_device_set_##name(struct btrfs_device *dev, u64 size)             \
 205 {                                                                       \
 206         preempt_disable();                                              \
 207         dev->name = size;                                               \
 208         preempt_enable();                                               \
 209 }
 210 #else
 211 #define BTRFS_DEVICE_GETSET_FUNCS(name)                                 \
 212 static inline u64                                                       \
 213 btrfs_device_get_##name(const struct btrfs_device *dev)                 \
 214 {                                                                       \
 215         return dev->name;                                               \
 216 }                                                                       \
 217                                                                         \
 218 static inline void                                                      \
 219 btrfs_device_set_##name(struct btrfs_device *dev, u64 size)             \
 220 {                                                                       \
 221         dev->name = size;                                               \
 222 }
 223 #endif
 224
 225 BTRFS_DEVICE_GETSET_FUNCS(total_bytes);
 226 BTRFS_DEVICE_GETSET_FUNCS(disk_total_bytes);
 227 BTRFS_DEVICE_GETSET_FUNCS(bytes_used);
 228
 229 struct btrfs_fs_devices {
 230         u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
 231
 232         u64 num_devices;
 233         u64 open_devices;
 234         u64 rw_devices;
 235         u64 missing_devices;
 236         u64 total_rw_bytes;
 237         u64 total_devices;
 238         struct block_device *latest_bdev;
 239
 240         /* all of the devices in the FS, protected by a mutex
 241          * so we can safely walk it to write out the supers without
 242          * worrying about add/remove by the multi-device code.
 243          * Scrubbing super can kick off supers writing by holding
 244          * this mutex lock.
 245          */
 246         struct mutex device_list_mutex;
 247         struct list_head devices;
 248
 249         struct list_head resized_devices;
 250         /* devices not currently being allocated */
 251         struct list_head alloc_list;
 252         struct list_head list;
 253
 254         struct btrfs_fs_devices *seed;
 255         int seeding;
 256
 257         int opened;
 258
 259         /* set when we find or add a device that doesn't have the
 260          * nonrot flag set
 261          */
 262         int rotating;
 263
 264         struct btrfs_fs_info *fs_info;
 265         /* sysfs kobjects */
 266         struct kobject fsid_kobj;
 267         struct kobject *device_dir_kobj;
 268         struct completion kobj_unregister;
 269 };
 270
 271 #define BTRFS_BIO_INLINE_CSUM_SIZE      64
 272
 273 /*
 274  * we need the mirror number and stripe index to be passed around
 275  * the call chain while we are processing end_io (especially errors).
 276  * Really, what we need is a btrfs_bio structure that has this info
 277  * and is properly sized with its stripe array, but we're not there
 278  * quite yet.  We have our own btrfs bioset, and all of the bios
 279  * we allocate are actually btrfs_io_bios.  We'll cram as much of
 280  * struct btrfs_bio as we can into this over time.
 281  */
 282 typedef void (btrfs_io_bio_end_io_t) (struct btrfs_io_bio *bio, int err);
 283 struct btrfs_io_bio {
 284         unsigned int mirror_num;
 285         unsigned int stripe_index;
 286         u64 logical;
 287         u8 *csum;
 288         u8 csum_inline[BTRFS_BIO_INLINE_CSUM_SIZE];
 289         u8 *csum_allocated;
 290         btrfs_io_bio_end_io_t *end_io;
 291         struct bvec_iter iter;
 292         /*
 293          * This member must come last, bio_alloc_bioset will allocate enough
 294          * bytes for entire btrfs_io_bio but relies on bio being last.
 295          */
 296         struct bio bio;
 297 };
 298
 299 static inline struct btrfs_io_bio *btrfs_io_bio(struct bio *bio)
 300 {
 301         return container_of(bio, struct btrfs_io_bio, bio);
 302 }
 303
 304 struct btrfs_bio_stripe {
 305         struct btrfs_device *dev;
 306         u64 physical;
 307         u64 length; /* only used for discard mappings */
 308 };
 309
 310 struct btrfs_bio;
 311 typedef void (btrfs_bio_end_io_t) (struct btrfs_bio *bio, int err);
 312
 313 struct btrfs_bio {
 314         refcount_t refs;
 315         atomic_t stripes_pending;
 316         struct btrfs_fs_info *fs_info;
 317         u64 map_type; /* get from map_lookup->type */
 318         bio_end_io_t *end_io;
 319         struct bio *orig_bio;
 320         void *private;
 321         atomic_t error;
 322         int max_errors;
 323         int num_stripes;
 324         int mirror_num;
 325         int num_tgtdevs;
 326         int *tgtdev_map;
 327         /*
 328          * logical block numbers for the start of each stripe
 329          * The last one or two are p/q.  These are sorted,
 330          * so raid_map[0] is the start of our full stripe
 331          */
 332         u64 *raid_map;
 333         struct btrfs_bio_stripe stripes[];
 334 };
 335
 336 struct btrfs_device_info {
 337         struct btrfs_device *dev;
 338         u64 dev_offset;
 339         u64 max_avail;
 340         u64 total_avail;
 341 };
 342
 343 struct btrfs_raid_attr {
 344         int sub_stripes;        /* sub_stripes info for map */
 345         int dev_stripes;        /* stripes per dev */
 346         int devs_max;           /* max devs to use */
 347         int devs_min;           /* min devs needed */
 348         int tolerated_failures; /* max tolerated fail devs */
 349         int devs_increment;     /* ndevs has to be a multiple of this */
 350         int ncopies;            /* how many copies to data has */
 351 };
 352
 353 extern const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES];
 354 extern const int btrfs_raid_mindev_error[BTRFS_NR_RAID_TYPES];
 355 extern const u64 btrfs_raid_group[BTRFS_NR_RAID_TYPES];
 356
 357 struct map_lookup {
 358         u64 type;
 359         int io_align;
 360         int io_width;
 361         u64 stripe_len;
 362         int num_stripes;
 363         int sub_stripes;
 364         struct btrfs_bio_stripe stripes[];
 365 };
 366
 367 #define map_lookup_size(n) (sizeof(struct map_lookup) + \
 368                             (sizeof(struct btrfs_bio_stripe) * (n)))
 369
 370 struct btrfs_balance_args;
 371 struct btrfs_balance_progress;
 372 struct btrfs_balance_control {
 373         struct btrfs_fs_info *fs_info;
 374
 375         struct btrfs_balance_args data;
 376         struct btrfs_balance_args meta;
 377         struct btrfs_balance_args sys;
 378
 379         u64 flags;
 380
 381         struct btrfs_balance_progress stat;
 382 };
 383
 384 enum btrfs_map_op {
 385         BTRFS_MAP_READ,
 386         BTRFS_MAP_WRITE,
 387         BTRFS_MAP_DISCARD,
 388         BTRFS_MAP_GET_READ_MIRRORS,
 389 };
 390
 391 static inline enum btrfs_map_op btrfs_op(struct bio *bio)
 392 {
 393         switch (bio_op(bio)) {
 394         case REQ_OP_DISCARD:
 395                 return BTRFS_MAP_DISCARD;
 396         case REQ_OP_WRITE:
 397                 return BTRFS_MAP_WRITE;
 398         default:
 399                 WARN_ON_ONCE(1);
 400         case REQ_OP_READ:
 401                 return BTRFS_MAP_READ;
 402         }
 403 }
 404
 405 int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
 406                                    u64 end, u64 *length);
 407 void btrfs_get_bbio(struct btrfs_bio *bbio);
 408 void btrfs_put_bbio(struct btrfs_bio *bbio);
 409 int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
 410                     u64 logical, u64 *length,
 411                     struct btrfs_bio **bbio_ret, int mirror_num);
 412 int btrfs_map_sblock(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
 413                      u64 logical, u64 *length,
 414                      struct btrfs_bio **bbio_ret);
 415 int btrfs_rmap_block(struct btrfs_fs_info *fs_info,
 416                      u64 chunk_start, u64 physical, u64 devid,
 417                      u64 **logical, int *naddrs, int *stripe_len);
 418 int btrfs_read_sys_array(struct btrfs_fs_info *fs_info);
 419 int btrfs_read_chunk_tree(struct btrfs_fs_info *fs_info);
 420 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
 421                       struct btrfs_fs_info *fs_info, u64 type);
 422 void btrfs_mapping_init(struct btrfs_mapping_tree *tree);
 423 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree);
 424 blk_status_t btrfs_map_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
 425                            int mirror_num, int async_submit);
 426 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
 427                        fmode_t flags, void *holder);
 428 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
 429                           struct btrfs_fs_devices **fs_devices_ret);
 430 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
 431 void btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices, int step);
 432 void btrfs_assign_next_active_device(struct btrfs_fs_info *fs_info,
 433                 struct btrfs_device *device, struct btrfs_device *this_dev);
 434 int btrfs_find_device_missing_or_by_path(struct btrfs_fs_info *fs_info,
 435                                          const char *device_path,
 436                                          struct btrfs_device **device);
 437 int btrfs_find_device_by_devspec(struct btrfs_fs_info *fs_info, u64 devid,
 438                                          const char *devpath,
 439                                          struct btrfs_device **device);
 440 struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info,
 441                                         const u64 *devid,
 442                                         const u8 *uuid);
 443 int btrfs_rm_device(struct btrfs_fs_info *fs_info,
 444                     const char *device_path, u64 devid);
 445 void btrfs_cleanup_fs_uuids(void);
 446 int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len);
 447 int btrfs_grow_device(struct btrfs_trans_handle *trans,
 448                       struct btrfs_device *device, u64 new_size);
 449 struct btrfs_device *btrfs_find_device(struct btrfs_fs_devices *fs_devices,
 450                                        u64 devid, u8 *uuid, u8 *fsid, bool seed);
 451 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size);
 452 int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *path);
 453 int btrfs_init_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
 454                                   const char *device_path,
 455                                   struct btrfs_device *srcdev,
 456                                   struct btrfs_device **device_out);
 457 int btrfs_balance(struct btrfs_balance_control *bctl,
 458                   struct btrfs_ioctl_balance_args *bargs);
 459 int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info);
 460 int btrfs_recover_balance(struct btrfs_fs_info *fs_info);
 461 int btrfs_pause_balance(struct btrfs_fs_info *fs_info);
 462 int btrfs_cancel_balance(struct btrfs_fs_info *fs_info);
 463 int btrfs_create_uuid_tree(struct btrfs_fs_info *fs_info);
 464 int btrfs_check_uuid_tree(struct btrfs_fs_info *fs_info);
 465 int btrfs_chunk_readonly(struct btrfs_fs_info *fs_info, u64 chunk_offset);
 466 int find_free_dev_extent_start(struct btrfs_transaction *transaction,
 467                          struct btrfs_device *device, u64 num_bytes,
 468                          u64 search_start, u64 *start, u64 *max_avail);
 469 int find_free_dev_extent(struct btrfs_trans_handle *trans,
 470                          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                         struct btrfs_fs_info *fs_info);
 479 void btrfs_rm_dev_replace_remove_srcdev(struct btrfs_fs_info *fs_info,
 480                                         struct btrfs_device *srcdev);
 481 void btrfs_rm_dev_replace_free_srcdev(struct btrfs_fs_info *fs_info,
 482                                       struct btrfs_device *srcdev);
 483 void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
 484                                       struct btrfs_device *tgtdev);
 485 void btrfs_init_dev_replace_tgtdev_for_resume(struct btrfs_fs_info *fs_info,
 486                                               struct btrfs_device *tgtdev);
 487 void btrfs_scratch_superblocks(struct block_device *bdev, const char *device_path);
 488 int btrfs_is_parity_mirror(struct btrfs_fs_info *fs_info,
 489                            u64 logical, u64 len);
 490 unsigned long btrfs_full_stripe_len(struct btrfs_fs_info *fs_info,
 491                                     u64 logical);
 492 int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans,
 493                                 struct btrfs_fs_info *fs_info,
 494                                 u64 chunk_offset, u64 chunk_size);
 495 int btrfs_remove_chunk(struct btrfs_trans_handle *trans,
 496                        struct btrfs_fs_info *fs_info, u64 chunk_offset);
 497
 498 static inline int btrfs_dev_stats_dirty(struct btrfs_device *dev)
 499 {
 500         return atomic_read(&dev->dev_stats_ccnt);
 501 }
 502
 503 static inline void btrfs_dev_stat_inc(struct btrfs_device *dev,
 504                                       int index)
 505 {
 506         atomic_inc(dev->dev_stat_values + index);
 507         /*
 508          * This memory barrier orders stores updating statistics before stores
 509          * updating dev_stats_ccnt.
 510          *
 511          * It pairs with smp_rmb() in btrfs_run_dev_stats().
 512          */
 513         smp_mb__before_atomic();
 514         atomic_inc(&dev->dev_stats_ccnt);
 515 }
 516
 517 static inline int btrfs_dev_stat_read(struct btrfs_device *dev,
 518                                       int index)
 519 {
 520         return atomic_read(dev->dev_stat_values + index);
 521 }
 522
 523 static inline int btrfs_dev_stat_read_and_reset(struct btrfs_device *dev,
 524                                                 int index)
 525 {
 526         int ret;
 527
 528         ret = atomic_xchg(dev->dev_stat_values + index, 0);
 529         smp_mb__before_atomic();
 530         atomic_inc(&dev->dev_stats_ccnt);
 531         return ret;
 532 }
 533
 534 static inline void btrfs_dev_stat_set(struct btrfs_device *dev,
 535                                       int index, unsigned long val)
 536 {
 537         atomic_set(dev->dev_stat_values + index, val);
 538         /*
 539          * This memory barrier orders stores updating statistics before stores
 540          * updating dev_stats_ccnt.
 541          *
 542          * It pairs with smp_rmb() in btrfs_run_dev_stats().
 543          */
 544         smp_mb__before_atomic();
 545         atomic_inc(&dev->dev_stats_ccnt);
 546 }
 547
 548 static inline void btrfs_dev_stat_reset(struct btrfs_device *dev,
 549                                         int index)
 550 {
 551         btrfs_dev_stat_set(dev, index, 0);
 552 }
 553
 554 void btrfs_update_commit_device_size(struct btrfs_fs_info *fs_info);
 555 void btrfs_update_commit_device_bytes_used(struct btrfs_fs_info *fs_info,
 556                                         struct btrfs_transaction *transaction);
 557
 558 struct list_head *btrfs_get_fs_uuids(void);
 559 void btrfs_set_fs_info_ptr(struct btrfs_fs_info *fs_info);
 560 void btrfs_reset_fs_info_ptr(struct btrfs_fs_info *fs_info);
 561
 562 bool btrfs_check_rw_degradable(struct btrfs_fs_info *fs_info);
 563
 564 #endif