root/fs/btrfs/block-group.h

INCLUDED FROM

DEFINITIONS

1. btrfs_should_fragment_free_space
2. btrfs_data_alloc_profile
3. btrfs_metadata_alloc_profile
4. btrfs_system_alloc_profile
5. btrfs_block_group_cache_done

   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  * Control flags for do_chunk_alloc's force field CHUNK_ALLOC_NO_FORCE means to
  17  * only allocate a chunk if we really need one.
  18  *
  19  * CHUNK_ALLOC_LIMITED means to only try and allocate one if we have very few
  20  * chunks already allocated.  This is used as part of the clustering code to
  21  * help make sure we have a good pool of storage to cluster in, without filling
  22  * the FS with empty chunks
  23  *
  24  * CHUNK_ALLOC_FORCE means it must try to allocate one
  25  */
  26 enum btrfs_chunk_alloc_enum {
  27         CHUNK_ALLOC_NO_FORCE,
  28         CHUNK_ALLOC_LIMITED,
  29         CHUNK_ALLOC_FORCE,
  30 };
  31 
  32 struct btrfs_caching_control {
  33         struct list_head list;
  34         struct mutex mutex;
  35         wait_queue_head_t wait;
  36         struct btrfs_work work;
  37         struct btrfs_block_group_cache *block_group;
  38         u64 progress;
  39         refcount_t count;
  40 };
  41 
  42 /* Once caching_thread() finds this much free space, it will wake up waiters. */
  43 #define CACHING_CTL_WAKE_UP SZ_2M
  44 
  45 struct btrfs_block_group_cache {
  46         struct btrfs_key key;
  47         struct btrfs_block_group_item item;
  48         struct btrfs_fs_info *fs_info;
  49         struct inode *inode;
  50         spinlock_t lock;
  51         u64 pinned;
  52         u64 reserved;
  53         u64 delalloc_bytes;
  54         u64 bytes_super;
  55         u64 flags;
  56         u64 cache_generation;
  57 
  58         /*
  59          * If the free space extent count exceeds this number, convert the block
  60          * group to bitmaps.
  61          */
  62         u32 bitmap_high_thresh;
  63 
  64         /*
  65          * If the free space extent count drops below this number, convert the
  66          * block group back to extents.
  67          */
  68         u32 bitmap_low_thresh;
  69 
  70         /*
  71          * It is just used for the delayed data space allocation because
  72          * only the data space allocation and the relative metadata update
  73          * can be done cross the transaction.
  74          */
  75         struct rw_semaphore data_rwsem;
  76 
  77         /* For raid56, this is a full stripe, without parity */
  78         unsigned long full_stripe_len;
  79 
  80         unsigned int ro;
  81         unsigned int iref:1;
  82         unsigned int has_caching_ctl:1;
  83         unsigned int removed:1;
  84 
  85         int disk_cache_state;
  86 
  87         /* Cache tracking stuff */
  88         int cached;
  89         struct btrfs_caching_control *caching_ctl;
  90         u64 last_byte_to_unpin;
  91 
  92         struct btrfs_space_info *space_info;
  93 
  94         /* Free space cache stuff */
  95         struct btrfs_free_space_ctl *free_space_ctl;
  96 
  97         /* Block group cache stuff */
  98         struct rb_node cache_node;
  99 
 100         /* For block groups in the same raid type */
 101         struct list_head list;
 102 
 103         /* Usage count */
 104         atomic_t count;
 105 
 106         /*
 107          * List of struct btrfs_free_clusters for this block group.
 108          * Today it will only have one thing on it, but that may change
 109          */
 110         struct list_head cluster_list;
 111 
 112         /* For delayed block group creation or deletion of empty block groups */
 113         struct list_head bg_list;
 114 
 115         /* For read-only block groups */
 116         struct list_head ro_list;
 117 
 118         atomic_t trimming;
 119 
 120         /* For dirty block groups */
 121         struct list_head dirty_list;
 122         struct list_head io_list;
 123 
 124         struct btrfs_io_ctl io_ctl;
 125 
 126         /*
 127          * Incremented when doing extent allocations and holding a read lock
 128          * on the space_info's groups_sem semaphore.
 129          * Decremented when an ordered extent that represents an IO against this
 130          * block group's range is created (after it's added to its inode's
 131          * root's list of ordered extents) or immediately after the allocation
 132          * if it's a metadata extent or fallocate extent (for these cases we
 133          * don't create ordered extents).
 134          */
 135         atomic_t reservations;
 136 
 137         /*
 138          * Incremented while holding the spinlock *lock* by a task checking if
 139          * it can perform a nocow write (incremented if the value for the *ro*
 140          * field is 0). Decremented by such tasks once they create an ordered
 141          * extent or before that if some error happens before reaching that step.
 142          * This is to prevent races between block group relocation and nocow
 143          * writes through direct IO.
 144          */
 145         atomic_t nocow_writers;
 146 
 147         /* Lock for free space tree operations. */
 148         struct mutex free_space_lock;
 149 
 150         /*
 151          * Does the block group need to be added to the free space tree?
 152          * Protected by free_space_lock.
 153          */
 154         int needs_free_space;
 155 
 156         /* Record locked full stripes for RAID5/6 block group */
 157         struct btrfs_full_stripe_locks_tree full_stripe_locks_root;
 158 };
 159 
 160 #ifdef CONFIG_BTRFS_DEBUG
 161 static inline int btrfs_should_fragment_free_space(
 162                 struct btrfs_block_group_cache *block_group)
 163 {
 164         struct btrfs_fs_info *fs_info = block_group->fs_info;
 165 
 166         return (btrfs_test_opt(fs_info, FRAGMENT_METADATA) &&
 167                 block_group->flags & BTRFS_BLOCK_GROUP_METADATA) ||
 168                (btrfs_test_opt(fs_info, FRAGMENT_DATA) &&
 169                 block_group->flags &  BTRFS_BLOCK_GROUP_DATA);
 170 }
 171 #endif
 172 
 173 struct btrfs_block_group_cache *btrfs_lookup_first_block_group(
 174                 struct btrfs_fs_info *info, u64 bytenr);
 175 struct btrfs_block_group_cache *btrfs_lookup_block_group(
 176                 struct btrfs_fs_info *info, u64 bytenr);
 177 struct btrfs_block_group_cache *btrfs_next_block_group(
 178                 struct btrfs_block_group_cache *cache);
 179 void btrfs_get_block_group(struct btrfs_block_group_cache *cache);
 180 void btrfs_put_block_group(struct btrfs_block_group_cache *cache);
 181 void btrfs_dec_block_group_reservations(struct btrfs_fs_info *fs_info,
 182                                         const u64 start);
 183 void btrfs_wait_block_group_reservations(struct btrfs_block_group_cache *bg);
 184 bool btrfs_inc_nocow_writers(struct btrfs_fs_info *fs_info, u64 bytenr);
 185 void btrfs_dec_nocow_writers(struct btrfs_fs_info *fs_info, u64 bytenr);
 186 void btrfs_wait_nocow_writers(struct btrfs_block_group_cache *bg);
 187 void btrfs_wait_block_group_cache_progress(struct btrfs_block_group_cache *cache,
 188                                            u64 num_bytes);
 189 int btrfs_wait_block_group_cache_done(struct btrfs_block_group_cache *cache);
 190 int btrfs_cache_block_group(struct btrfs_block_group_cache *cache,
 191                             int load_cache_only);
 192 void btrfs_put_caching_control(struct btrfs_caching_control *ctl);
 193 struct btrfs_caching_control *btrfs_get_caching_control(
 194                 struct btrfs_block_group_cache *cache);
 195 u64 add_new_free_space(struct btrfs_block_group_cache *block_group,
 196                        u64 start, u64 end);
 197 struct btrfs_trans_handle *btrfs_start_trans_remove_block_group(
 198                                 struct btrfs_fs_info *fs_info,
 199                                 const u64 chunk_offset);
 200 int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
 201                              u64 group_start, struct extent_map *em);
 202 void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info);
 203 void btrfs_mark_bg_unused(struct btrfs_block_group_cache *bg);
 204 int btrfs_read_block_groups(struct btrfs_fs_info *info);
 205 int btrfs_make_block_group(struct btrfs_trans_handle *trans, u64 bytes_used,
 206                            u64 type, u64 chunk_offset, u64 size);
 207 void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans);
 208 int btrfs_inc_block_group_ro(struct btrfs_block_group_cache *cache);
 209 void btrfs_dec_block_group_ro(struct btrfs_block_group_cache *cache);
 210 int btrfs_start_dirty_block_groups(struct btrfs_trans_handle *trans);
 211 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans);
 212 int btrfs_setup_space_cache(struct btrfs_trans_handle *trans);
 213 int btrfs_update_block_group(struct btrfs_trans_handle *trans,
 214                              u64 bytenr, u64 num_bytes, int alloc);
 215 int btrfs_add_reserved_bytes(struct btrfs_block_group_cache *cache,
 216                              u64 ram_bytes, u64 num_bytes, int delalloc);
 217 void btrfs_free_reserved_bytes(struct btrfs_block_group_cache *cache,
 218                                u64 num_bytes, int delalloc);
 219 int btrfs_chunk_alloc(struct btrfs_trans_handle *trans, u64 flags,
 220                       enum btrfs_chunk_alloc_enum force);
 221 int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans, u64 type);
 222 void check_system_chunk(struct btrfs_trans_handle *trans, const u64 type);
 223 u64 btrfs_get_alloc_profile(struct btrfs_fs_info *fs_info, u64 orig_flags);
 224 void btrfs_put_block_group_cache(struct btrfs_fs_info *info);
 225 int btrfs_free_block_groups(struct btrfs_fs_info *info);
 226 
 227 static inline u64 btrfs_data_alloc_profile(struct btrfs_fs_info *fs_info)
 228 {
 229         return btrfs_get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_DATA);
 230 }
 231 
 232 static inline u64 btrfs_metadata_alloc_profile(struct btrfs_fs_info *fs_info)
 233 {
 234         return btrfs_get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_METADATA);
 235 }
 236 
 237 static inline u64 btrfs_system_alloc_profile(struct btrfs_fs_info *fs_info)
 238 {
 239         return btrfs_get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
 240 }
 241 
 242 static inline int btrfs_block_group_cache_done(
 243                 struct btrfs_block_group_cache *cache)
 244 {
 245         smp_mb();
 246         return cache->cached == BTRFS_CACHE_FINISHED ||
 247                 cache->cached == BTRFS_CACHE_ERROR;
 248 }
 249 
 250 #endif /* BTRFS_BLOCK_GROUP_H */