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