LXR linux/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
  27extern struct mutex uuid_mutex;
  28
  29#define BTRFS_STRIPE_LEN        SZ_64K
  30
  31struct buffer_head;
  32struct 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
  50struct btrfs_device {
  51        struct list_head dev_list;
  52        struct list_head dev_alloc_list;
  53        struct btrfs_fs_devices *fs_devices;
  54
  55        struct btrfs_root *dev_root;
  56
  57        struct rcu_string *name;
  58
  59        u64 generation;
  60
  61        spinlock_t io_lock ____cacheline_aligned;
  62        int running_pending;
  63        /* regular prio bios */
  64        struct btrfs_pending_bios pending_bios;
  65        /* WRITE_SYNC bios */
  66        struct btrfs_pending_bios pending_sync_bios;
  67
  68        struct block_device *bdev;
  69
  70        /* the mode sent to blkdev_get */
  71        fmode_t mode;
  72
  73        int writeable;
  74        int in_fs_metadata;
  75        int missing;
  76        int can_discard;
  77        int is_tgtdev_for_dev_replace;
  78
  79#ifdef __BTRFS_NEED_DEVICE_DATA_ORDERED
  80        seqcount_t data_seqcount;
  81#endif
  82
  83        /* the internal btrfs device id */
  84        u64 devid;
  85
  86        /* size of the device in memory */
  87        u64 total_bytes;
  88
  89        /* size of the device on disk */
  90        u64 disk_total_bytes;
  91
  92        /* bytes used */
  93        u64 bytes_used;
  94
  95        /* optimal io alignment for this device */
  96        u32 io_align;
  97
  98        /* optimal io width for this device */
  99        u32 io_width;
 100        /* type and info about this device */
 101        u64 type;
 102
 103        /* minimal io size for this device */
 104        u32 sector_size;
 105
 106        /* physical drive uuid (or lvm uuid) */
 107        u8 uuid[BTRFS_UUID_SIZE];
 108
 109        /*
 110         * size of the device on the current transaction
 111         *
 112         * This variant is update when committing the transaction,
 113         * and protected by device_list_mutex
 114         */
 115        u64 commit_total_bytes;
 116
 117        /* bytes used on the current transaction */
 118        u64 commit_bytes_used;
 119        /*
 120         * used to manage the device which is resized
 121         *
 122         * It is protected by chunk_lock.
 123         */
 124        struct list_head resized_list;
 125
 126        /* for sending down flush barriers */
 127        int nobarriers;
 128        struct bio *flush_bio;
 129        struct completion flush_wait;
 130
 131        /* per-device scrub information */
 132        struct scrub_ctx *scrub_device;
 133
 134        struct btrfs_work work;
 135        struct rcu_head rcu;
 136        struct work_struct rcu_work;
 137
 138        /* readahead state */
 139        spinlock_t reada_lock;
 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)                                 \
 161static inline u64                                                       \
 162btrfs_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                                                                        \
 174static inline void                                                      \
 175btrfs_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)                                 \
 185static inline u64                                                       \
 186btrfs_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                                                                        \
 196static inline void                                                      \
 197btrfs_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)                                 \
 205static inline u64                                                       \
 206btrfs_device_get_##name(const struct btrfs_device *dev)                 \
 207{                                                                       \
 208        return dev->name;                                               \
 209}                                                                       \
 210                                                                        \
 211static inline void                                                      \
 212btrfs_device_set_##name(struct btrfs_device *dev, u64 size)             \
 213{                                                                       \
 214        dev->name = size;                                               \
 215}
 216#endif
 217
 218BTRFS_DEVICE_GETSET_FUNCS(total_bytes);
 219BTRFS_DEVICE_GETSET_FUNCS(disk_total_bytes);
 220BTRFS_DEVICE_GETSET_FUNCS(bytes_used);
 221
 222struct 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 */
 275typedef void (btrfs_io_bio_end_io_t) (struct btrfs_io_bio *bio, int err);
 276struct 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 bio bio;
 285};
 286
 287static inline struct btrfs_io_bio *btrfs_io_bio(struct bio *bio)
 288{
 289        return container_of(bio, struct btrfs_io_bio, bio);
 290}
 291
 292struct btrfs_bio_stripe {
 293        struct btrfs_device *dev;
 294        u64 physical;
 295        u64 length; /* only used for discard mappings */
 296};
 297
 298struct btrfs_bio;
 299typedef void (btrfs_bio_end_io_t) (struct btrfs_bio *bio, int err);
 300
 301struct btrfs_bio {
 302        atomic_t refs;
 303        atomic_t stripes_pending;
 304        struct btrfs_fs_info *fs_info;
 305        u64 map_type; /* get from map_lookup->type */
 306        bio_end_io_t *end_io;
 307        struct bio *orig_bio;
 308        unsigned long flags;
 309        void *private;
 310        atomic_t error;
 311        int max_errors;
 312        int num_stripes;
 313        int mirror_num;
 314        int num_tgtdevs;
 315        int *tgtdev_map;
 316        /*
 317         * logical block numbers for the start of each stripe
 318         * The last one or two are p/q.  These are sorted,
 319         * so raid_map[0] is the start of our full stripe
 320         */
 321        u64 *raid_map;
 322        struct btrfs_bio_stripe stripes[];
 323};
 324
 325struct btrfs_device_info {
 326        struct btrfs_device *dev;
 327        u64 dev_offset;
 328        u64 max_avail;
 329        u64 total_avail;
 330};
 331
 332struct btrfs_raid_attr {
 333        int sub_stripes;        /* sub_stripes info for map */
 334        int dev_stripes;        /* stripes per dev */
 335        int devs_max;           /* max devs to use */
 336        int devs_min;           /* min devs needed */
 337        int tolerated_failures; /* max tolerated fail devs */
 338        int devs_increment;     /* ndevs has to be a multiple of this */
 339        int ncopies;            /* how many copies to data has */
 340};
 341
 342extern const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES];
 343extern const int btrfs_raid_mindev_error[BTRFS_NR_RAID_TYPES];
 344extern const u64 btrfs_raid_group[BTRFS_NR_RAID_TYPES];
 345
 346struct map_lookup {
 347        u64 type;
 348        int io_align;
 349        int io_width;
 350        u64 stripe_len;
 351        int sector_size;
 352        int num_stripes;
 353        int sub_stripes;
 354        struct btrfs_bio_stripe stripes[];
 355};
 356
 357#define map_lookup_size(n) (sizeof(struct map_lookup) + \
 358                            (sizeof(struct btrfs_bio_stripe) * (n)))
 359
 360struct btrfs_balance_args;
 361struct btrfs_balance_progress;
 362struct btrfs_balance_control {
 363        struct btrfs_fs_info *fs_info;
 364
 365        struct btrfs_balance_args data;
 366        struct btrfs_balance_args meta;
 367        struct btrfs_balance_args sys;
 368
 369        u64 flags;
 370
 371        struct btrfs_balance_progress stat;
 372};
 373
 374int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
 375                                   u64 end, u64 *length);
 376void btrfs_get_bbio(struct btrfs_bio *bbio);
 377void btrfs_put_bbio(struct btrfs_bio *bbio);
 378int btrfs_map_block(struct btrfs_fs_info *fs_info, int op,
 379                    u64 logical, u64 *length,
 380                    struct btrfs_bio **bbio_ret, int mirror_num);
 381int btrfs_map_sblock(struct btrfs_fs_info *fs_info, int op,
 382                     u64 logical, u64 *length,
 383                     struct btrfs_bio **bbio_ret, int mirror_num,
 384                     int need_raid_map);
 385int btrfs_rmap_block(struct btrfs_fs_info *fs_info,
 386                     u64 chunk_start, u64 physical, u64 devid,
 387                     u64 **logical, int *naddrs, int *stripe_len);
 388int btrfs_read_sys_array(struct btrfs_root *root);
 389int btrfs_read_chunk_tree(struct btrfs_root *root);
 390int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
 391                      struct btrfs_root *extent_root, u64 type);
 392void btrfs_mapping_init(struct btrfs_mapping_tree *tree);
 393void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree);
 394int btrfs_map_bio(struct btrfs_root *root, struct bio *bio,
 395                  int mirror_num, int async_submit);
 396int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
 397                       fmode_t flags, void *holder);
 398int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
 399                          struct btrfs_fs_devices **fs_devices_ret);
 400int btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
 401void btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices, int step);
 402void btrfs_assign_next_active_device(struct btrfs_fs_info *fs_info,
 403                struct btrfs_device *device, struct btrfs_device *this_dev);
 404int btrfs_find_device_missing_or_by_path(struct btrfs_root *root,
 405                                         char *device_path,
 406                                         struct btrfs_device **device);
 407int btrfs_find_device_by_devspec(struct btrfs_root *root, u64 devid,
 408                                         char *devpath,
 409                                         struct btrfs_device **device);
 410struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info,
 411                                        const u64 *devid,
 412                                        const u8 *uuid);
 413int btrfs_rm_device(struct btrfs_root *root, char *device_path, u64 devid);
 414void btrfs_cleanup_fs_uuids(void);
 415int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len);
 416int btrfs_grow_device(struct btrfs_trans_handle *trans,
 417                      struct btrfs_device *device, u64 new_size);
 418struct btrfs_device *btrfs_find_device(struct btrfs_fs_info *fs_info, u64 devid,
 419                                       u8 *uuid, u8 *fsid);
 420int btrfs_shrink_device(struct btrfs_device *device, u64 new_size);
 421int btrfs_init_new_device(struct btrfs_root *root, char *path);
 422int btrfs_init_dev_replace_tgtdev(struct btrfs_root *root, char *device_path,
 423                                  struct btrfs_device *srcdev,
 424                                  struct btrfs_device **device_out);
 425int btrfs_balance(struct btrfs_balance_control *bctl,
 426                  struct btrfs_ioctl_balance_args *bargs);
 427int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info);
 428int btrfs_recover_balance(struct btrfs_fs_info *fs_info);
 429int btrfs_pause_balance(struct btrfs_fs_info *fs_info);
 430int btrfs_cancel_balance(struct btrfs_fs_info *fs_info);
 431int btrfs_create_uuid_tree(struct btrfs_fs_info *fs_info);
 432int btrfs_check_uuid_tree(struct btrfs_fs_info *fs_info);
 433int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset);
 434int find_free_dev_extent_start(struct btrfs_transaction *transaction,
 435                         struct btrfs_device *device, u64 num_bytes,
 436                         u64 search_start, u64 *start, u64 *max_avail);
 437int find_free_dev_extent(struct btrfs_trans_handle *trans,
 438                         struct btrfs_device *device, u64 num_bytes,
 439                         u64 *start, u64 *max_avail);
 440void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index);
 441int btrfs_get_dev_stats(struct btrfs_root *root,
 442                        struct btrfs_ioctl_get_dev_stats *stats);
 443void btrfs_init_devices_late(struct btrfs_fs_info *fs_info);
 444int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info);
 445int btrfs_run_dev_stats(struct btrfs_trans_handle *trans,
 446                        struct btrfs_fs_info *fs_info);
 447void btrfs_rm_dev_replace_remove_srcdev(struct btrfs_fs_info *fs_info,
 448                                        struct btrfs_device *srcdev);
 449void btrfs_rm_dev_replace_free_srcdev(struct btrfs_fs_info *fs_info,
 450                                      struct btrfs_device *srcdev);
 451void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
 452                                      struct btrfs_device *tgtdev);
 453void btrfs_init_dev_replace_tgtdev_for_resume(struct btrfs_fs_info *fs_info,
 454                                              struct btrfs_device *tgtdev);
 455void btrfs_scratch_superblocks(struct block_device *bdev, char *device_path);
 456int btrfs_is_parity_mirror(struct btrfs_mapping_tree *map_tree,
 457                           u64 logical, u64 len, int mirror_num);
 458unsigned long btrfs_full_stripe_len(struct btrfs_root *root,
 459                                    struct btrfs_mapping_tree *map_tree,
 460                                    u64 logical);
 461int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans,
 462                                struct btrfs_root *extent_root,
 463                                u64 chunk_offset, u64 chunk_size);
 464int btrfs_remove_chunk(struct btrfs_trans_handle *trans,
 465                       struct btrfs_root *root, u64 chunk_offset);
 466
 467static inline int btrfs_dev_stats_dirty(struct btrfs_device *dev)
 468{
 469        return atomic_read(&dev->dev_stats_ccnt);
 470}
 471
 472static inline void btrfs_dev_stat_inc(struct btrfs_device *dev,
 473                                      int index)
 474{
 475        atomic_inc(dev->dev_stat_values + index);
 476        smp_mb__before_atomic();
 477        atomic_inc(&dev->dev_stats_ccnt);
 478}
 479
 480static inline int btrfs_dev_stat_read(struct btrfs_device *dev,
 481                                      int index)
 482{
 483        return atomic_read(dev->dev_stat_values + index);
 484}
 485
 486static inline int btrfs_dev_stat_read_and_reset(struct btrfs_device *dev,
 487                                                int index)
 488{
 489        int ret;
 490
 491        ret = atomic_xchg(dev->dev_stat_values + index, 0);
 492        smp_mb__before_atomic();
 493        atomic_inc(&dev->dev_stats_ccnt);
 494        return ret;
 495}
 496
 497static inline void btrfs_dev_stat_set(struct btrfs_device *dev,
 498                                      int index, unsigned long val)
 499{
 500        atomic_set(dev->dev_stat_values + index, val);
 501        smp_mb__before_atomic();
 502        atomic_inc(&dev->dev_stats_ccnt);
 503}
 504
 505static inline void btrfs_dev_stat_reset(struct btrfs_device *dev,
 506                                        int index)
 507{
 508        btrfs_dev_stat_set(dev, index, 0);
 509}
 510
 511void btrfs_update_commit_device_size(struct btrfs_fs_info *fs_info);
 512void btrfs_update_commit_device_bytes_used(struct btrfs_root *root,
 513                                        struct btrfs_transaction *transaction);
 514
 515static inline void lock_chunks(struct btrfs_root *root)
 516{
 517        mutex_lock(&root->fs_info->chunk_mutex);
 518}
 519
 520static inline void unlock_chunks(struct btrfs_root *root)
 521{
 522        mutex_unlock(&root->fs_info->chunk_mutex);
 523}
 524
 525struct list_head *btrfs_get_fs_uuids(void);
 526void btrfs_set_fs_info_ptr(struct btrfs_fs_info *fs_info);
 527void btrfs_reset_fs_info_ptr(struct btrfs_fs_info *fs_info);
 528
 529#endif
 530