1 /* SPDX-License-Identifier: GPL-2.0 */
3 #ifndef BTRFS_BLOCK_GROUP_H
4 #define BTRFS_BLOCK_GROUP_H
6 #include "free-space-cache.h"
8 enum btrfs_disk_cache_state {
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).
22 enum btrfs_discard_state {
23 BTRFS_DISCARD_EXTENTS,
24 BTRFS_DISCARD_BITMAPS,
25 BTRFS_DISCARD_RESET_CURSOR,
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.
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
37 * CHUNK_ALLOC_FORCE means it must try to allocate one
39 enum btrfs_chunk_alloc_enum {
45 struct btrfs_caching_control {
46 struct list_head list;
48 wait_queue_head_t wait;
49 struct btrfs_work work;
50 struct btrfs_block_group *block_group;
55 /* Once caching_thread() finds this much free space, it will wake up waiters. */
56 #define CACHING_CTL_WAKE_UP SZ_2M
58 struct btrfs_block_group {
59 struct btrfs_fs_info *fs_info;
73 * If the free space extent count exceeds this number, convert the block
76 u32 bitmap_high_thresh;
79 * If the free space extent count drops below this number, convert the
80 * block group back to extents.
82 u32 bitmap_low_thresh;
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.
89 struct rw_semaphore data_rwsem;
91 /* For raid56, this is a full stripe, without parity */
92 unsigned long full_stripe_len;
96 unsigned int has_caching_ctl:1;
97 unsigned int removed:1;
101 /* Cache tracking stuff */
103 struct btrfs_caching_control *caching_ctl;
104 u64 last_byte_to_unpin;
106 struct btrfs_space_info *space_info;
108 /* Free space cache stuff */
109 struct btrfs_free_space_ctl *free_space_ctl;
111 /* Block group cache stuff */
112 struct rb_node cache_node;
114 /* For block groups in the same raid type */
115 struct list_head list;
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
124 struct list_head cluster_list;
126 /* For delayed block group creation or deletion of empty block groups */
127 struct list_head bg_list;
129 /* For read-only block groups */
130 struct list_head ro_list;
132 /* For discard operations */
134 struct list_head discard_list;
136 u64 discard_eligible_time;
138 enum btrfs_discard_state discard_state;
140 /* For dirty block groups */
141 struct list_head dirty_list;
142 struct list_head io_list;
144 struct btrfs_io_ctl io_ctl;
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).
155 atomic_t reservations;
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.
165 atomic_t nocow_writers;
167 /* Lock for free space tree operations. */
168 struct mutex free_space_lock;
171 * Does the block group need to be added to the free space tree?
172 * Protected by free_space_lock.
174 int needs_free_space;
176 /* Record locked full stripes for RAID5/6 block group */
177 struct btrfs_full_stripe_locks_tree full_stripe_locks_root;
180 static inline u64 btrfs_block_group_end(struct btrfs_block_group *block_group)
182 return (block_group->start + block_group->length);
185 #ifdef CONFIG_BTRFS_DEBUG
186 static inline int btrfs_should_fragment_free_space(
187 struct btrfs_block_group *block_group)
189 struct btrfs_fs_info *fs_info = block_group->fs_info;
191 return (btrfs_test_opt(fs_info, FRAGMENT_METADATA) &&
192 block_group->flags & BTRFS_BLOCK_GROUP_METADATA) ||
193 (btrfs_test_opt(fs_info, FRAGMENT_DATA) &&
194 block_group->flags & BTRFS_BLOCK_GROUP_DATA);
198 struct btrfs_block_group *btrfs_lookup_first_block_group(
199 struct btrfs_fs_info *info, u64 bytenr);
200 struct btrfs_block_group *btrfs_lookup_block_group(
201 struct btrfs_fs_info *info, u64 bytenr);
202 struct btrfs_block_group *btrfs_next_block_group(
203 struct btrfs_block_group *cache);
204 void btrfs_get_block_group(struct btrfs_block_group *cache);
205 void btrfs_put_block_group(struct btrfs_block_group *cache);
206 void btrfs_dec_block_group_reservations(struct btrfs_fs_info *fs_info,
208 void btrfs_wait_block_group_reservations(struct btrfs_block_group *bg);
209 bool btrfs_inc_nocow_writers(struct btrfs_fs_info *fs_info, u64 bytenr);
210 void btrfs_dec_nocow_writers(struct btrfs_fs_info *fs_info, u64 bytenr);
211 void btrfs_wait_nocow_writers(struct btrfs_block_group *bg);
212 void btrfs_wait_block_group_cache_progress(struct btrfs_block_group *cache,
214 int btrfs_wait_block_group_cache_done(struct btrfs_block_group *cache);
215 int btrfs_cache_block_group(struct btrfs_block_group *cache,
216 int load_cache_only);
217 void btrfs_put_caching_control(struct btrfs_caching_control *ctl);
218 struct btrfs_caching_control *btrfs_get_caching_control(
219 struct btrfs_block_group *cache);
220 u64 add_new_free_space(struct btrfs_block_group *block_group,
222 struct btrfs_trans_handle *btrfs_start_trans_remove_block_group(
223 struct btrfs_fs_info *fs_info,
224 const u64 chunk_offset);
225 int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
226 u64 group_start, struct extent_map *em);
227 void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info);
228 void btrfs_mark_bg_unused(struct btrfs_block_group *bg);
229 int btrfs_read_block_groups(struct btrfs_fs_info *info);
230 int btrfs_make_block_group(struct btrfs_trans_handle *trans, u64 bytes_used,
231 u64 type, u64 chunk_offset, u64 size);
232 void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans);
233 int btrfs_inc_block_group_ro(struct btrfs_block_group *cache,
234 bool do_chunk_alloc);
235 void btrfs_dec_block_group_ro(struct btrfs_block_group *cache);
236 int btrfs_start_dirty_block_groups(struct btrfs_trans_handle *trans);
237 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans);
238 int btrfs_setup_space_cache(struct btrfs_trans_handle *trans);
239 int btrfs_update_block_group(struct btrfs_trans_handle *trans,
240 u64 bytenr, u64 num_bytes, int alloc);
241 int btrfs_add_reserved_bytes(struct btrfs_block_group *cache,
242 u64 ram_bytes, u64 num_bytes, int delalloc);
243 void btrfs_free_reserved_bytes(struct btrfs_block_group *cache,
244 u64 num_bytes, int delalloc);
245 int btrfs_chunk_alloc(struct btrfs_trans_handle *trans, u64 flags,
246 enum btrfs_chunk_alloc_enum force);
247 int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans, u64 type);
248 void check_system_chunk(struct btrfs_trans_handle *trans, const u64 type);
249 u64 btrfs_get_alloc_profile(struct btrfs_fs_info *fs_info, u64 orig_flags);
250 void btrfs_put_block_group_cache(struct btrfs_fs_info *info);
251 int btrfs_free_block_groups(struct btrfs_fs_info *info);
253 static inline u64 btrfs_data_alloc_profile(struct btrfs_fs_info *fs_info)
255 return btrfs_get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_DATA);
258 static inline u64 btrfs_metadata_alloc_profile(struct btrfs_fs_info *fs_info)
260 return btrfs_get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_METADATA);
263 static inline u64 btrfs_system_alloc_profile(struct btrfs_fs_info *fs_info)
265 return btrfs_get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
268 static inline int btrfs_block_group_done(struct btrfs_block_group *cache)
271 return cache->cached == BTRFS_CACHE_FINISHED ||
272 cache->cached == BTRFS_CACHE_ERROR;
275 #endif /* BTRFS_BLOCK_GROUP_H */