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