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         /* Usage count */
 118         atomic_t count;
 119
 120         /*
 121          * List of struct btrfs_free_clusters for this block group.
 122          * Today it will only have one thing on it, but that may change
 123          */
 124         struct list_head cluster_list;
 125
 126         /* For delayed block group creation or deletion of empty block groups */
 127         struct list_head bg_list;
 128
 129         /* For read-only block groups */
 130         struct list_head ro_list;
 131
 132         /* For discard operations */
 133         atomic_t trimming;
 134         struct list_head discard_list;
 135         int discard_index;
 136         u64 discard_eligible_time;
 137         u64 discard_cursor;
 138         enum btrfs_discard_state discard_state;
 139
 140         /* For dirty block groups */
 141         struct list_head dirty_list;
 142         struct list_head io_list;
 143
 144         struct btrfs_io_ctl io_ctl;
 145
 146         /*
 147          * Incremented when doing extent allocations and holding a read lock
 148          * on the space_info's groups_sem semaphore.
 149          * Decremented when an ordered extent that represents an IO against this
 150          * block group's range is created (after it's added to its inode's
 151          * root's list of ordered extents) or immediately after the allocation
 152          * if it's a metadata extent or fallocate extent (for these cases we
 153          * don't create ordered extents).
 154          */
 155         atomic_t reservations;
 156
 157         /*
 158          * Incremented while holding the spinlock *lock* by a task checking if
 159          * it can perform a nocow write (incremented if the value for the *ro*
 160          * field is 0). Decremented by such tasks once they create an ordered
 161          * extent or before that if some error happens before reaching that step.
 162          * This is to prevent races between block group relocation and nocow
 163          * writes through direct IO.
 164          */
 165         atomic_t nocow_writers;
 166
 167         /* Lock for free space tree operations. */
 168         struct mutex free_space_lock;
 169
 170         /*
 171          * Does the block group need to be added to the free space tree?
 172          * Protected by free_space_lock.
 173          */
 174         int needs_free_space;
 175
 176         /* Record locked full stripes for RAID5/6 block group */
 177         struct btrfs_full_stripe_locks_tree full_stripe_locks_root;
 178 };
 179
 180 static inline u64 btrfs_block_group_end(struct btrfs_block_group *block_group)
 181 {
 182         return (block_group->start + block_group->length);
 183 }
 184
 185 static inline bool btrfs_is_block_group_data_only(
 186                                         struct btrfs_block_group *block_group)
 187 {
 188         /*
 189          * In mixed mode the fragmentation is expected to be high, lowering the
 190          * efficiency, so only proper data block groups are considered.
 191          */
 192         return (block_group->flags & BTRFS_BLOCK_GROUP_DATA) &&
 193                !(block_group->flags & BTRFS_BLOCK_GROUP_METADATA);
 194 }
 195
 196 #ifdef CONFIG_BTRFS_DEBUG
 197 static inline int btrfs_should_fragment_free_space(
 198                 struct btrfs_block_group *block_group)
 199 {
 200         struct btrfs_fs_info *fs_info = block_group->fs_info;
 201
 202         return (btrfs_test_opt(fs_info, FRAGMENT_METADATA) &&
 203                 block_group->flags & BTRFS_BLOCK_GROUP_METADATA) ||
 204                (btrfs_test_opt(fs_info, FRAGMENT_DATA) &&
 205                 block_group->flags &  BTRFS_BLOCK_GROUP_DATA);
 206 }
 207 #endif
 208
 209 struct btrfs_block_group *btrfs_lookup_first_block_group(
 210                 struct btrfs_fs_info *info, u64 bytenr);
 211 struct btrfs_block_group *btrfs_lookup_block_group(
 212                 struct btrfs_fs_info *info, u64 bytenr);
 213 struct btrfs_block_group *btrfs_next_block_group(
 214                 struct btrfs_block_group *cache);
 215 void btrfs_get_block_group(struct btrfs_block_group *cache);
 216 void btrfs_put_block_group(struct btrfs_block_group *cache);
 217 void btrfs_dec_block_group_reservations(struct btrfs_fs_info *fs_info,
 218                                         const u64 start);
 219 void btrfs_wait_block_group_reservations(struct btrfs_block_group *bg);
 220 bool btrfs_inc_nocow_writers(struct btrfs_fs_info *fs_info, u64 bytenr);
 221 void btrfs_dec_nocow_writers(struct btrfs_fs_info *fs_info, u64 bytenr);
 222 void btrfs_wait_nocow_writers(struct btrfs_block_group *bg);
 223 void btrfs_wait_block_group_cache_progress(struct btrfs_block_group *cache,
 224                                            u64 num_bytes);
 225 int btrfs_wait_block_group_cache_done(struct btrfs_block_group *cache);
 226 int btrfs_cache_block_group(struct btrfs_block_group *cache,
 227                             int load_cache_only);
 228 void btrfs_put_caching_control(struct btrfs_caching_control *ctl);
 229 struct btrfs_caching_control *btrfs_get_caching_control(
 230                 struct btrfs_block_group *cache);
 231 u64 add_new_free_space(struct btrfs_block_group *block_group,
 232                        u64 start, u64 end);
 233 struct btrfs_trans_handle *btrfs_start_trans_remove_block_group(
 234                                 struct btrfs_fs_info *fs_info,
 235                                 const u64 chunk_offset);
 236 int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
 237                              u64 group_start, struct extent_map *em);
 238 void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info);
 239 void btrfs_mark_bg_unused(struct btrfs_block_group *bg);
 240 int btrfs_read_block_groups(struct btrfs_fs_info *info);
 241 int btrfs_make_block_group(struct btrfs_trans_handle *trans, u64 bytes_used,
 242                            u64 type, u64 chunk_offset, u64 size);
 243 void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans);
 244 int btrfs_inc_block_group_ro(struct btrfs_block_group *cache,
 245                              bool do_chunk_alloc);
 246 void btrfs_dec_block_group_ro(struct btrfs_block_group *cache);
 247 int btrfs_start_dirty_block_groups(struct btrfs_trans_handle *trans);
 248 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans);
 249 int btrfs_setup_space_cache(struct btrfs_trans_handle *trans);
 250 int btrfs_update_block_group(struct btrfs_trans_handle *trans,
 251                              u64 bytenr, u64 num_bytes, int alloc);
 252 int btrfs_add_reserved_bytes(struct btrfs_block_group *cache,
 253                              u64 ram_bytes, u64 num_bytes, int delalloc);
 254 void btrfs_free_reserved_bytes(struct btrfs_block_group *cache,
 255                                u64 num_bytes, int delalloc);
 256 int btrfs_chunk_alloc(struct btrfs_trans_handle *trans, u64 flags,
 257                       enum btrfs_chunk_alloc_enum force);
 258 int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans, u64 type);
 259 void check_system_chunk(struct btrfs_trans_handle *trans, const u64 type);
 260 u64 btrfs_get_alloc_profile(struct btrfs_fs_info *fs_info, u64 orig_flags);
 261 void btrfs_put_block_group_cache(struct btrfs_fs_info *info);
 262 int btrfs_free_block_groups(struct btrfs_fs_info *info);
 263
 264 static inline u64 btrfs_data_alloc_profile(struct btrfs_fs_info *fs_info)
 265 {
 266         return btrfs_get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_DATA);
 267 }
 268
 269 static inline u64 btrfs_metadata_alloc_profile(struct btrfs_fs_info *fs_info)
 270 {
 271         return btrfs_get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_METADATA);
 272 }
 273
 274 static inline u64 btrfs_system_alloc_profile(struct btrfs_fs_info *fs_info)
 275 {
 276         return btrfs_get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
 277 }
 278
 279 static inline int btrfs_block_group_done(struct btrfs_block_group *cache)
 280 {
 281         smp_mb();
 282         return cache->cached == BTRFS_CACHE_FINISHED ||
 283                 cache->cached == BTRFS_CACHE_ERROR;
 284 }
 285
 286 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
 287 int btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start,
 288                      u64 physical, u64 **logical, int *naddrs, int *stripe_len);
 289 #endif
 290
 291 #endif /* BTRFS_BLOCK_GROUP_H */