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
btrfs_block_group_end(struct btrfs_block_group * block_group)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
btrfs_is_block_group_data_only(struct btrfs_block_group * block_group)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
btrfs_should_fragment_free_space(struct btrfs_block_group * block_group)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
btrfs_data_alloc_profile(struct btrfs_fs_info * fs_info)272 static inline u64 btrfs_data_alloc_profile(struct btrfs_fs_info *fs_info)
273 {
274 return btrfs_get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_DATA);
275 }
276
btrfs_metadata_alloc_profile(struct btrfs_fs_info * fs_info)277 static inline u64 btrfs_metadata_alloc_profile(struct btrfs_fs_info *fs_info)
278 {
279 return btrfs_get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_METADATA);
280 }
281
btrfs_system_alloc_profile(struct btrfs_fs_info * fs_info)282 static inline u64 btrfs_system_alloc_profile(struct btrfs_fs_info *fs_info)
283 {
284 return btrfs_get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
285 }
286
btrfs_block_group_done(struct btrfs_block_group * cache)287 static inline int btrfs_block_group_done(struct btrfs_block_group *cache)
288 {
289 smp_mb();
290 return cache->cached == BTRFS_CACHE_FINISHED ||
291 cache->cached == BTRFS_CACHE_ERROR;
292 }
293
294 void btrfs_freeze_block_group(struct btrfs_block_group *cache);
295 void btrfs_unfreeze_block_group(struct btrfs_block_group *cache);
296
297 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
298 int btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start,
299 u64 physical, u64 **logical, int *naddrs, int *stripe_len);
300 #endif
301
302 #endif /* BTRFS_BLOCK_GROUP_H */
303
