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 "free-space-cache.h"
   7
   8 enum btrfs_disk_cache_state {
   9         BTRFS_DC_WRITTEN,
  10         BTRFS_DC_ERROR,
  11         BTRFS_DC_CLEAR,
  12         BTRFS_DC_SETUP,
  13 };
  14
  15 /*
  16  * This describes the state of the block_group for async discard.  This is due
  17  * to the two pass nature of it where extent discarding is prioritized over
  18  * bitmap discarding.  BTRFS_DISCARD_RESET_CURSOR is set when we are resetting
  19  * between lists to prevent contention for discard state variables
  20  * (eg. discard_cursor).
  21  */
  22 enum btrfs_discard_state {
  23         BTRFS_DISCARD_EXTENTS,
  24         BTRFS_DISCARD_BITMAPS,
  25         BTRFS_DISCARD_RESET_CURSOR,
  26 };
  27
  28 /*
  29  * Control flags for do_chunk_alloc's force field CHUNK_ALLOC_NO_FORCE means to
  30  * only allocate a chunk if we really need one.
  31  *
  32  * CHUNK_ALLOC_LIMITED means to only try and allocate one if we have very few
  33  * chunks already allocated.  This is used as part of the clustering code to
  34  * help make sure we have a good pool of storage to cluster in, without filling
  35  * the FS with empty chunks
  36  *
  37  * CHUNK_ALLOC_FORCE means it must try to allocate one
  38  */
  39 enum btrfs_chunk_alloc_enum {
  40         CHUNK_ALLOC_NO_FORCE,
  41         CHUNK_ALLOC_LIMITED,
  42         CHUNK_ALLOC_FORCE,
  43 };
  44
  45 struct btrfs_caching_control {
  46         struct list_head list;
  47         struct mutex mutex;
  48         wait_queue_head_t wait;
  49         struct btrfs_work work;
  50         struct btrfs_block_group *block_group;
  51         u64 progress;
  52         refcount_t count;
  53 };
  54
  55 /* Once caching_thread() finds this much free space, it will wake up waiters. */
  56 #define CACHING_CTL_WAKE_UP SZ_2M
  57
  58 struct btrfs_block_group {
  59         struct btrfs_fs_info *fs_info;
  60         struct inode *inode;
  61         spinlock_t lock;
  62         u64 start;
  63         u64 length;
  64         u64 pinned;
  65         u64 reserved;
  66         u64 used;
  67         u64 delalloc_bytes;
  68         u64 bytes_super;
  69         u64 flags;
  70         u64 cache_generation;
  71
  72         /*
  73          * If the free space extent count exceeds this number, convert the block
  74          * group to bitmaps.
  75          */
  76         u32 bitmap_high_thresh;
  77
  78         /*
  79          * If the free space extent count drops below this number, convert the
  80          * block group back to extents.
  81          */
  82         u32 bitmap_low_thresh;
  83
  84         /*
  85          * It is just used for the delayed data space allocation because
  86          * only the data space allocation and the relative metadata update
  87          * can be done cross the transaction.
  88          */
  89         struct rw_semaphore data_rwsem;
  90
  91         /* For raid56, this is a full stripe, without parity */
  92         unsigned long full_stripe_len;
  93
  94         unsigned int ro;
  95         unsigned int iref:1;
  96         unsigned int has_caching_ctl:1;
  97         unsigned int removed:1;
  98
  99         int disk_cache_state;
 100
 101         /* Cache tracking stuff */
 102         int cached;
 103         struct btrfs_caching_control *caching_ctl;
 104         u64 last_byte_to_unpin;
 105
 106         struct btrfs_space_info *space_info;
 107
 108         /* Free space cache stuff */
 109         struct btrfs_free_space_ctl *free_space_ctl;
 110
 111         /* Block group cache stuff */
 112         struct rb_node cache_node;
 113
 114         /* For block groups in the same raid type */
 115         struct list_head list;
 116
 117         refcount_t refs;
 118
 119         /*
 120          * List of struct btrfs_free_clusters for this block group.
 121          * Today it will only have one thing on it, but that may change
 122          */
 123         struct list_head cluster_list;
 124
 125         /* For delayed block group creation or deletion of empty block groups */
 126         struct list_head bg_list;
 127
 128         /* For read-only block groups */
 129         struct list_head ro_list;
 130
 131         /*
 132          * When non-zero it means the block group's logical address and its
 133          * device extents can not be reused for future block group allocations
 134          * until the counter goes down to 0. This is to prevent them from being
 135          * reused while some task is still using the block group after it was
 136          * deleted - we want to make sure they can only be reused for new block
 137          * groups after that task is done with the deleted block group.
 138          */
 139         atomic_t frozen;
 140
 141         /* For discard operations */
 142         struct list_head discard_list;
 143         int discard_index;
 144         u64 discard_eligible_time;
 145         u64 discard_cursor;
 146         enum btrfs_discard_state discard_state;
 147
 148         /* For dirty block groups */
 149         struct list_head dirty_list;
 150         struct list_head io_list;
 151
 152         struct btrfs_io_ctl io_ctl;
 153
 154         /*
 155          * Incremented when doing extent allocations and holding a read lock
 156          * on the space_info's groups_sem semaphore.
 157          * Decremented when an ordered extent that represents an IO against this
 158          * block group's range is created (after it's added to its inode's
 159          * root's list of ordered extents) or immediately after the allocation
 160          * if it's a metadata extent or fallocate extent (for these cases we
 161          * don't create ordered extents).
 162          */
 163         atomic_t reservations;
 164
 165         /*
 166          * Incremented while holding the spinlock *lock* by a task checking if
 167          * it can perform a nocow write (incremented if the value for the *ro*
 168          * field is 0). Decremented by such tasks once they create an ordered
 169          * extent or before that if some error happens before reaching that step.
 170          * This is to prevent races between block group relocation and nocow
 171          * writes through direct IO.
 172          */
 173         atomic_t nocow_writers;
 174
 175         /* Lock for free space tree operations. */
 176         struct mutex free_space_lock;
 177
 178         /*
 179          * Does the block group need to be added to the free space tree?
 180          * Protected by free_space_lock.
 181          */
 182         int needs_free_space;
 183
 184         /* Record locked full stripes for RAID5/6 block group */
 185         struct btrfs_full_stripe_locks_tree full_stripe_locks_root;
 186 };
 187
 188 static inline u64 btrfs_block_group_end(struct btrfs_block_group *block_group)
 189 {
 190         return (block_group->start + block_group->length);
 191 }
 192
 193 static inline bool btrfs_is_block_group_data_only(
 194                                         struct btrfs_block_group *block_group)
 195 {
 196         /*
 197          * In mixed mode the fragmentation is expected to be high, lowering the
 198          * efficiency, so only proper data block groups are considered.
 199          */
 200         return (block_group->flags & BTRFS_BLOCK_GROUP_DATA) &&
 201                !(block_group->flags & BTRFS_BLOCK_GROUP_METADATA);
 202 }
 203
 204 #ifdef CONFIG_BTRFS_DEBUG
 205 static inline int btrfs_should_fragment_free_space(
 206                 struct btrfs_block_group *block_group)
 207 {
 208         struct btrfs_fs_info *fs_info = block_group->fs_info;
 209
 210         return (btrfs_test_opt(fs_info, FRAGMENT_METADATA) &&
 211                 block_group->flags & BTRFS_BLOCK_GROUP_METADATA) ||
 212                (btrfs_test_opt(fs_info, FRAGMENT_DATA) &&
 213                 block_group->flags &  BTRFS_BLOCK_GROUP_DATA);
 214 }
 215 #endif
 216
 217 struct btrfs_block_group *btrfs_lookup_first_block_group(
 218                 struct btrfs_fs_info *info, u64 bytenr);
 219 struct btrfs_block_group *btrfs_lookup_block_group(
 220                 struct btrfs_fs_info *info, u64 bytenr);
 221 struct btrfs_block_group *btrfs_next_block_group(
 222                 struct btrfs_block_group *cache);
 223 void btrfs_get_block_group(struct btrfs_block_group *cache);
 224 void btrfs_put_block_group(struct btrfs_block_group *cache);
 225 void btrfs_dec_block_group_reservations(struct btrfs_fs_info *fs_info,
 226                                         const u64 start);
 227 void btrfs_wait_block_group_reservations(struct btrfs_block_group *bg);
 228 bool btrfs_inc_nocow_writers(struct btrfs_fs_info *fs_info, u64 bytenr);
 229 void btrfs_dec_nocow_writers(struct btrfs_fs_info *fs_info, u64 bytenr);
 230 void btrfs_wait_nocow_writers(struct btrfs_block_group *bg);
 231 void btrfs_wait_block_group_cache_progress(struct btrfs_block_group *cache,
 232                                            u64 num_bytes);
 233 int btrfs_wait_block_group_cache_done(struct btrfs_block_group *cache);
 234 int btrfs_cache_block_group(struct btrfs_block_group *cache,
 235                             int load_cache_only);
 236 void btrfs_put_caching_control(struct btrfs_caching_control *ctl);
 237 struct btrfs_caching_control *btrfs_get_caching_control(
 238                 struct btrfs_block_group *cache);
 239 u64 add_new_free_space(struct btrfs_block_group *block_group,
 240                        u64 start, u64 end);
 241 struct btrfs_trans_handle *btrfs_start_trans_remove_block_group(
 242                                 struct btrfs_fs_info *fs_info,
 243                                 const u64 chunk_offset);
 244 int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
 245                              u64 group_start, struct extent_map *em);
 246 void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info);
 247 void btrfs_mark_bg_unused(struct btrfs_block_group *bg);
 248 int btrfs_read_block_groups(struct btrfs_fs_info *info);
 249 int btrfs_make_block_group(struct btrfs_trans_handle *trans, u64 bytes_used,
 250                            u64 type, u64 chunk_offset, u64 size);
 251 void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans);
 252 int btrfs_inc_block_group_ro(struct btrfs_block_group *cache,
 253                              bool do_chunk_alloc);
 254 void btrfs_dec_block_group_ro(struct btrfs_block_group *cache);
 255 int btrfs_start_dirty_block_groups(struct btrfs_trans_handle *trans);
 256 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans);
 257 int btrfs_setup_space_cache(struct btrfs_trans_handle *trans);
 258 int btrfs_update_block_group(struct btrfs_trans_handle *trans,
 259                              u64 bytenr, u64 num_bytes, int alloc);
 260 int btrfs_add_reserved_bytes(struct btrfs_block_group *cache,
 261                              u64 ram_bytes, u64 num_bytes, int delalloc);
 262 void btrfs_free_reserved_bytes(struct btrfs_block_group *cache,
 263                                u64 num_bytes, int delalloc);
 264 int btrfs_chunk_alloc(struct btrfs_trans_handle *trans, u64 flags,
 265                       enum btrfs_chunk_alloc_enum force);
 266 int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans, u64 type);
 267 void check_system_chunk(struct btrfs_trans_handle *trans, const u64 type);
 268 u64 btrfs_get_alloc_profile(struct btrfs_fs_info *fs_info, u64 orig_flags);
 269 void btrfs_put_block_group_cache(struct btrfs_fs_info *info);
 270 int btrfs_free_block_groups(struct btrfs_fs_info *info);
 271 void btrfs_wait_space_cache_v1_finished(struct btrfs_block_group *cache,
 272                                 struct btrfs_caching_control *caching_ctl);
 273
 274 static inline u64 btrfs_data_alloc_profile(struct btrfs_fs_info *fs_info)
 275 {
 276         return btrfs_get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_DATA);
 277 }
 278
 279 static inline u64 btrfs_metadata_alloc_profile(struct btrfs_fs_info *fs_info)
 280 {
 281         return btrfs_get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_METADATA);
 282 }
 283
 284 static inline u64 btrfs_system_alloc_profile(struct btrfs_fs_info *fs_info)
 285 {
 286         return btrfs_get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
 287 }
 288
 289 static inline int btrfs_block_group_done(struct btrfs_block_group *cache)
 290 {
 291         smp_mb();
 292         return cache->cached == BTRFS_CACHE_FINISHED ||
 293                 cache->cached == BTRFS_CACHE_ERROR;
 294 }
 295
 296 void btrfs_freeze_block_group(struct btrfs_block_group *cache);
 297 void btrfs_unfreeze_block_group(struct btrfs_block_group *cache);
 298
 299 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
 300 int btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start,
 301                      u64 physical, u64 **logical, int *naddrs, int *stripe_len);
 302 #endif
 303
 304 #endif /* BTRFS_BLOCK_GROUP_H */