fs/btrfs/block-group.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2
   3 #ifndef BTRFS_BLOCK_GROUP_H
   4 #define BTRFS_BLOCK_GROUP_H
   5
   6 #include <linux/atomic.h>
   7 #include <linux/mutex.h>
   8 #include <linux/list.h>
   9 #include <linux/spinlock.h>
  10 #include <linux/refcount.h>
  11 #include <linux/wait.h>
  12 #include <linux/sizes.h>
  13 #include <linux/rwsem.h>
  14 #include <linux/rbtree.h>
  15 #include <uapi/linux/btrfs_tree.h>
  16 #include "free-space-cache.h"
  17
  18 struct btrfs_chunk_map;
  19 struct btrfs_fs_info;
  20 struct btrfs_inode;
  21 struct btrfs_trans_handle;
  22
  23 enum btrfs_disk_cache_state {
  24         BTRFS_DC_WRITTEN,
  25         BTRFS_DC_ERROR,
  26         BTRFS_DC_CLEAR,
  27         BTRFS_DC_SETUP,
  28 };
  29
  30 enum btrfs_block_group_size_class {
  31         /* Unset */
  32         BTRFS_BG_SZ_NONE,
  33         /* 0 < size <= 128K */
  34         BTRFS_BG_SZ_SMALL,
  35         /* 128K < size <= 8M */
  36         BTRFS_BG_SZ_MEDIUM,
  37         /* 8M < size < BG_LENGTH */
  38         BTRFS_BG_SZ_LARGE,
  39 };
  40
  41 /*
  42  * This describes the state of the block_group for async discard.  This is due
  43  * to the two pass nature of it where extent discarding is prioritized over
  44  * bitmap discarding.  BTRFS_DISCARD_RESET_CURSOR is set when we are resetting
  45  * between lists to prevent contention for discard state variables
  46  * (eg. discard_cursor).
  47  */
  48 enum btrfs_discard_state {
  49         BTRFS_DISCARD_EXTENTS,
  50         BTRFS_DISCARD_BITMAPS,
  51         BTRFS_DISCARD_RESET_CURSOR,
  52 };
  53
  54 /*
  55  * Control flags for do_chunk_alloc's force field CHUNK_ALLOC_NO_FORCE means to
  56  * only allocate a chunk if we really need one.
  57  *
  58  * CHUNK_ALLOC_LIMITED means to only try and allocate one if we have very few
  59  * chunks already allocated.  This is used as part of the clustering code to
  60  * help make sure we have a good pool of storage to cluster in, without filling
  61  * the FS with empty chunks
  62  *
  63  * CHUNK_ALLOC_FORCE means it must try to allocate one
  64  *
  65  * CHUNK_ALLOC_FORCE_FOR_EXTENT like CHUNK_ALLOC_FORCE but called from
  66  * find_free_extent() that also activaes the zone
  67  */
  68 enum btrfs_chunk_alloc_enum {
  69         CHUNK_ALLOC_NO_FORCE,
  70         CHUNK_ALLOC_LIMITED,
  71         CHUNK_ALLOC_FORCE,
  72         CHUNK_ALLOC_FORCE_FOR_EXTENT,
  73 };
  74
  75 /* Block group flags set at runtime */
  76 enum btrfs_block_group_flags {
  77         BLOCK_GROUP_FLAG_IREF,
  78         BLOCK_GROUP_FLAG_REMOVED,
  79         BLOCK_GROUP_FLAG_TO_COPY,
  80         BLOCK_GROUP_FLAG_RELOCATING_REPAIR,
  81         BLOCK_GROUP_FLAG_CHUNK_ITEM_INSERTED,
  82         BLOCK_GROUP_FLAG_ZONE_IS_ACTIVE,
  83         BLOCK_GROUP_FLAG_ZONED_DATA_RELOC,
  84         /* Does the block group need to be added to the free space tree? */
  85         BLOCK_GROUP_FLAG_NEEDS_FREE_SPACE,
  86         /* Indicate that the block group is placed on a sequential zone */
  87         BLOCK_GROUP_FLAG_SEQUENTIAL_ZONE,
  88         /*
  89          * Indicate that block group is in the list of new block groups of a
  90          * transaction.
  91          */
  92         BLOCK_GROUP_FLAG_NEW,
  93 };
  94
  95 enum btrfs_caching_type {
  96         BTRFS_CACHE_NO,
  97         BTRFS_CACHE_STARTED,
  98         BTRFS_CACHE_FINISHED,
  99         BTRFS_CACHE_ERROR,
 100 };
 101
 102 struct btrfs_caching_control {
 103         struct list_head list;
 104         struct mutex mutex;
 105         wait_queue_head_t wait;
 106         struct btrfs_work work;
 107         struct btrfs_block_group *block_group;
 108         /* Track progress of caching during allocation. */
 109         atomic_t progress;
 110         refcount_t count;
 111 };
 112
 113 /* Once caching_thread() finds this much free space, it will wake up waiters. */
 114 #define CACHING_CTL_WAKE_UP SZ_2M
 115
 116 struct btrfs_block_group {
 117         struct btrfs_fs_info *fs_info;
 118         struct btrfs_inode *inode;
 119         spinlock_t lock;
 120         u64 start;
 121         u64 length;
 122         u64 pinned;
 123         u64 reserved;
 124         u64 used;
 125         u64 delalloc_bytes;
 126         u64 bytes_super;
 127         u64 flags;
 128         u64 cache_generation;
 129         u64 global_root_id;
 130
 131         /*
 132          * The last committed used bytes of this block group, if the above @used
 133          * is still the same as @commit_used, we don't need to update block
 134          * group item of this block group.
 135          */
 136         u64 commit_used;
 137         /*
 138          * If the free space extent count exceeds this number, convert the block
 139          * group to bitmaps.
 140          */
 141         u32 bitmap_high_thresh;
 142
 143         /*
 144          * If the free space extent count drops below this number, convert the
 145          * block group back to extents.
 146          */
 147         u32 bitmap_low_thresh;
 148
 149         /*
 150          * It is just used for the delayed data space allocation because
 151          * only the data space allocation and the relative metadata update
 152          * can be done cross the transaction.
 153          */
 154         struct rw_semaphore data_rwsem;
 155
 156         /* For raid56, this is a full stripe, without parity */
 157         unsigned long full_stripe_len;
 158         unsigned long runtime_flags;
 159
 160         unsigned int ro;
 161
 162         int disk_cache_state;
 163
 164         /* Cache tracking stuff */
 165         int cached;
 166         struct btrfs_caching_control *caching_ctl;
 167
 168         struct btrfs_space_info *space_info;
 169
 170         /* Free space cache stuff */
 171         struct btrfs_free_space_ctl *free_space_ctl;
 172
 173         /* Block group cache stuff */
 174         struct rb_node cache_node;
 175
 176         /* For block groups in the same raid type */
 177         struct list_head list;
 178
 179         refcount_t refs;
 180
 181         /*
 182          * List of struct btrfs_free_clusters for this block group.
 183          * Today it will only have one thing on it, but that may change
 184          */
 185         struct list_head cluster_list;
 186
 187         /*
 188          * Used for several lists:
 189          *
 190          * 1) struct btrfs_fs_info::unused_bgs
 191          * 2) struct btrfs_fs_info::reclaim_bgs
 192          * 3) struct btrfs_transaction::deleted_bgs
 193          * 4) struct btrfs_trans_handle::new_bgs
 194          */
 195         struct list_head bg_list;
 196
 197         /* For read-only block groups */
 198         struct list_head ro_list;
 199
 200         /*
 201          * When non-zero it means the block group's logical address and its
 202          * device extents can not be reused for future block group allocations
 203          * until the counter goes down to 0. This is to prevent them from being
 204          * reused while some task is still using the block group after it was
 205          * deleted - we want to make sure they can only be reused for new block
 206          * groups after that task is done with the deleted block group.
 207          */
 208         atomic_t frozen;
 209
 210         /* For discard operations */
 211         struct list_head discard_list;
 212         int discard_index;
 213         u64 discard_eligible_time;
 214         u64 discard_cursor;
 215         enum btrfs_discard_state discard_state;
 216
 217         /* For dirty block groups */
 218         struct list_head dirty_list;
 219         struct list_head io_list;
 220
 221         struct btrfs_io_ctl io_ctl;
 222
 223         /*
 224          * Incremented when doing extent allocations and holding a read lock
 225          * on the space_info's groups_sem semaphore.
 226          * Decremented when an ordered extent that represents an IO against this
 227          * block group's range is created (after it's added to its inode's
 228          * root's list of ordered extents) or immediately after the allocation
 229          * if it's a metadata extent or fallocate extent (for these cases we
 230          * don't create ordered extents).
 231          */
 232         atomic_t reservations;
 233
 234         /*
 235          * Incremented while holding the spinlock *lock* by a task checking if
 236          * it can perform a nocow write (incremented if the value for the *ro*
 237          * field is 0). Decremented by such tasks once they create an ordered
 238          * extent or before that if some error happens before reaching that step.
 239          * This is to prevent races between block group relocation and nocow
 240          * writes through direct IO.
 241          */
 242         atomic_t nocow_writers;
 243
 244         /* Lock for free space tree operations. */
 245         struct mutex free_space_lock;
 246
 247         /*
 248          * Number of extents in this block group used for swap files.
 249          * All accesses protected by the spinlock 'lock'.
 250          */
 251         int swap_extents;
 252
 253         /*
 254          * Allocation offset for the block group to implement sequential
 255          * allocation. This is used only on a zoned filesystem.
 256          */
 257         u64 alloc_offset;
 258         u64 zone_unusable;
 259         u64 zone_capacity;
 260         u64 meta_write_pointer;
 261         struct btrfs_chunk_map *physical_map;
 262         struct list_head active_bg_list;
 263         struct work_struct zone_finish_work;
 264         struct extent_buffer *last_eb;
 265         enum btrfs_block_group_size_class size_class;
 266         u64 reclaim_mark;
 267 };
 268
 269 static inline u64 btrfs_block_group_end(const struct btrfs_block_group *block_group)
 270 {
 271         return (block_group->start + block_group->length);
 272 }
 273
 274 static inline bool btrfs_is_block_group_used(const struct btrfs_block_group *bg)
 275 {
 276         lockdep_assert_held(&bg->lock);
 277
 278         return (bg->used > 0 || bg->reserved > 0 || bg->pinned > 0);
 279 }
 280
 281 static inline bool btrfs_is_block_group_data_only(const struct btrfs_block_group *block_group)
 282 {
 283         /*
 284          * In mixed mode the fragmentation is expected to be high, lowering the
 285          * efficiency, so only proper data block groups are considered.
 286          */
 287         return (block_group->flags & BTRFS_BLOCK_GROUP_DATA) &&
 288                !(block_group->flags & BTRFS_BLOCK_GROUP_METADATA);
 289 }
 290
 291 #ifdef CONFIG_BTRFS_DEBUG
 292 int btrfs_should_fragment_free_space(const struct btrfs_block_group *block_group);
 293 #endif
 294
 295 struct btrfs_block_group *btrfs_lookup_first_block_group(
 296                 struct btrfs_fs_info *info, u64 bytenr);
 297 struct btrfs_block_group *btrfs_lookup_block_group(
 298                 struct btrfs_fs_info *info, u64 bytenr);
 299 struct btrfs_block_group *btrfs_next_block_group(
 300                 struct btrfs_block_group *cache);
 301 void btrfs_get_block_group(struct btrfs_block_group *cache);
 302 void btrfs_put_block_group(struct btrfs_block_group *cache);
 303 void btrfs_dec_block_group_reservations(struct btrfs_fs_info *fs_info,
 304                                         const u64 start);
 305 void btrfs_wait_block_group_reservations(struct btrfs_block_group *bg);
 306 struct btrfs_block_group *btrfs_inc_nocow_writers(struct btrfs_fs_info *fs_info,
 307                                                   u64 bytenr);
 308 void btrfs_dec_nocow_writers(struct btrfs_block_group *bg);
 309 void btrfs_wait_nocow_writers(struct btrfs_block_group *bg);
 310 void btrfs_wait_block_group_cache_progress(struct btrfs_block_group *cache,
 311                                            u64 num_bytes);
 312 int btrfs_cache_block_group(struct btrfs_block_group *cache, bool wait);
 313 struct btrfs_caching_control *btrfs_get_caching_control(
 314                 struct btrfs_block_group *cache);
 315 int btrfs_add_new_free_space(struct btrfs_block_group *block_group,
 316                              u64 start, u64 end, u64 *total_added_ret);
 317 struct btrfs_trans_handle *btrfs_start_trans_remove_block_group(
 318                                 struct btrfs_fs_info *fs_info,
 319                                 const u64 chunk_offset);
 320 int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
 321                              struct btrfs_chunk_map *map);
 322 void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info);
 323 void btrfs_mark_bg_unused(struct btrfs_block_group *bg);
 324 void btrfs_reclaim_bgs_work(struct work_struct *work);
 325 void btrfs_reclaim_bgs(struct btrfs_fs_info *fs_info);
 326 void btrfs_mark_bg_to_reclaim(struct btrfs_block_group *bg);
 327 int btrfs_read_block_groups(struct btrfs_fs_info *info);
 328 struct btrfs_block_group *btrfs_make_block_group(struct btrfs_trans_handle *trans,
 329                                                  u64 type,
 330                                                  u64 chunk_offset, u64 size);
 331 void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans);
 332 int btrfs_inc_block_group_ro(struct btrfs_block_group *cache,
 333                              bool do_chunk_alloc);
 334 void btrfs_dec_block_group_ro(struct btrfs_block_group *cache);
 335 int btrfs_start_dirty_block_groups(struct btrfs_trans_handle *trans);
 336 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans);
 337 int btrfs_setup_space_cache(struct btrfs_trans_handle *trans);
 338 int btrfs_update_block_group(struct btrfs_trans_handle *trans,
 339                              u64 bytenr, u64 num_bytes, bool alloc);
 340 int btrfs_add_reserved_bytes(struct btrfs_block_group *cache,
 341                              u64 ram_bytes, u64 num_bytes, int delalloc,
 342                              bool force_wrong_size_class);
 343 void btrfs_free_reserved_bytes(struct btrfs_block_group *cache,
 344                                u64 num_bytes, int delalloc);
 345 int btrfs_chunk_alloc(struct btrfs_trans_handle *trans, u64 flags,
 346                       enum btrfs_chunk_alloc_enum force);
 347 int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans, u64 type);
 348 void check_system_chunk(struct btrfs_trans_handle *trans, const u64 type);
 349 void btrfs_reserve_chunk_metadata(struct btrfs_trans_handle *trans,
 350                                   bool is_item_insertion);
 351 u64 btrfs_get_alloc_profile(struct btrfs_fs_info *fs_info, u64 orig_flags);
 352 void btrfs_put_block_group_cache(struct btrfs_fs_info *info);
 353 int btrfs_free_block_groups(struct btrfs_fs_info *info);
 354 int btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start,
 355                      u64 physical, u64 **logical, int *naddrs, int *stripe_len);
 356
 357 static inline u64 btrfs_data_alloc_profile(struct btrfs_fs_info *fs_info)
 358 {
 359         return btrfs_get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_DATA);
 360 }
 361
 362 static inline u64 btrfs_metadata_alloc_profile(struct btrfs_fs_info *fs_info)
 363 {
 364         return btrfs_get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_METADATA);
 365 }
 366
 367 static inline u64 btrfs_system_alloc_profile(struct btrfs_fs_info *fs_info)
 368 {
 369         return btrfs_get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
 370 }
 371
 372 static inline int btrfs_block_group_done(const struct btrfs_block_group *cache)
 373 {
 374         smp_mb();
 375         return cache->cached == BTRFS_CACHE_FINISHED ||
 376                 cache->cached == BTRFS_CACHE_ERROR;
 377 }
 378
 379 void btrfs_freeze_block_group(struct btrfs_block_group *cache);
 380 void btrfs_unfreeze_block_group(struct btrfs_block_group *cache);
 381
 382 bool btrfs_inc_block_group_swap_extents(struct btrfs_block_group *bg);
 383 void btrfs_dec_block_group_swap_extents(struct btrfs_block_group *bg, int amount);
 384
 385 enum btrfs_block_group_size_class btrfs_calc_block_group_size_class(u64 size);
 386 int btrfs_use_block_group_size_class(struct btrfs_block_group *bg,
 387                                      enum btrfs_block_group_size_class size_class,
 388                                      bool force_wrong_size_class);
 389 bool btrfs_block_group_should_use_size_class(const struct btrfs_block_group *bg);
 390
 391 #endif /* BTRFS_BLOCK_GROUP_H */