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1// SPDX-License-Identifier: GPL-2.0
2
3#include "misc.h"
4#include "ctree.h"
5#include "block-rsv.h"
6#include "space-info.h"
7#include "transaction.h"
8
9static u64 block_rsv_release_bytes(struct btrfs_fs_info *fs_info,
10 struct btrfs_block_rsv *block_rsv,
11 struct btrfs_block_rsv *dest, u64 num_bytes,
12 u64 *qgroup_to_release_ret)
13{
14 struct btrfs_space_info *space_info = block_rsv->space_info;
15 u64 qgroup_to_release = 0;
16 u64 ret;
17
18 spin_lock(&block_rsv->lock);
19 if (num_bytes == (u64)-1) {
20 num_bytes = block_rsv->size;
21 qgroup_to_release = block_rsv->qgroup_rsv_size;
22 }
23 block_rsv->size -= num_bytes;
24 if (block_rsv->reserved >= block_rsv->size) {
25 num_bytes = block_rsv->reserved - block_rsv->size;
26 block_rsv->reserved = block_rsv->size;
27 block_rsv->full = 1;
28 } else {
29 num_bytes = 0;
30 }
31 if (block_rsv->qgroup_rsv_reserved >= block_rsv->qgroup_rsv_size) {
32 qgroup_to_release = block_rsv->qgroup_rsv_reserved -
33 block_rsv->qgroup_rsv_size;
34 block_rsv->qgroup_rsv_reserved = block_rsv->qgroup_rsv_size;
35 } else {
36 qgroup_to_release = 0;
37 }
38 spin_unlock(&block_rsv->lock);
39
40 ret = num_bytes;
41 if (num_bytes > 0) {
42 if (dest) {
43 spin_lock(&dest->lock);
44 if (!dest->full) {
45 u64 bytes_to_add;
46
47 bytes_to_add = dest->size - dest->reserved;
48 bytes_to_add = min(num_bytes, bytes_to_add);
49 dest->reserved += bytes_to_add;
50 if (dest->reserved >= dest->size)
51 dest->full = 1;
52 num_bytes -= bytes_to_add;
53 }
54 spin_unlock(&dest->lock);
55 }
56 if (num_bytes)
57 btrfs_space_info_free_bytes_may_use(fs_info,
58 space_info,
59 num_bytes);
60 }
61 if (qgroup_to_release_ret)
62 *qgroup_to_release_ret = qgroup_to_release;
63 return ret;
64}
65
66int btrfs_block_rsv_migrate(struct btrfs_block_rsv *src,
67 struct btrfs_block_rsv *dst, u64 num_bytes,
68 bool update_size)
69{
70 int ret;
71
72 ret = btrfs_block_rsv_use_bytes(src, num_bytes);
73 if (ret)
74 return ret;
75
76 btrfs_block_rsv_add_bytes(dst, num_bytes, update_size);
77 return 0;
78}
79
80void btrfs_init_block_rsv(struct btrfs_block_rsv *rsv, unsigned short type)
81{
82 memset(rsv, 0, sizeof(*rsv));
83 spin_lock_init(&rsv->lock);
84 rsv->type = type;
85}
86
87void btrfs_init_metadata_block_rsv(struct btrfs_fs_info *fs_info,
88 struct btrfs_block_rsv *rsv,
89 unsigned short type)
90{
91 btrfs_init_block_rsv(rsv, type);
92 rsv->space_info = btrfs_find_space_info(fs_info,
93 BTRFS_BLOCK_GROUP_METADATA);
94}
95
96struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_fs_info *fs_info,
97 unsigned short type)
98{
99 struct btrfs_block_rsv *block_rsv;
100
101 block_rsv = kmalloc(sizeof(*block_rsv), GFP_NOFS);
102 if (!block_rsv)
103 return NULL;
104
105 btrfs_init_metadata_block_rsv(fs_info, block_rsv, type);
106 return block_rsv;
107}
108
109void btrfs_free_block_rsv(struct btrfs_fs_info *fs_info,
110 struct btrfs_block_rsv *rsv)
111{
112 if (!rsv)
113 return;
114 btrfs_block_rsv_release(fs_info, rsv, (u64)-1);
115 kfree(rsv);
116}
117
118int btrfs_block_rsv_add(struct btrfs_root *root,
119 struct btrfs_block_rsv *block_rsv, u64 num_bytes,
120 enum btrfs_reserve_flush_enum flush)
121{
122 int ret;
123
124 if (num_bytes == 0)
125 return 0;
126
127 ret = btrfs_reserve_metadata_bytes(root, block_rsv, num_bytes, flush);
128 if (!ret)
129 btrfs_block_rsv_add_bytes(block_rsv, num_bytes, true);
130
131 return ret;
132}
133
134int btrfs_block_rsv_check(struct btrfs_block_rsv *block_rsv, int min_factor)
135{
136 u64 num_bytes = 0;
137 int ret = -ENOSPC;
138
139 if (!block_rsv)
140 return 0;
141
142 spin_lock(&block_rsv->lock);
143 num_bytes = div_factor(block_rsv->size, min_factor);
144 if (block_rsv->reserved >= num_bytes)
145 ret = 0;
146 spin_unlock(&block_rsv->lock);
147
148 return ret;
149}
150
151int btrfs_block_rsv_refill(struct btrfs_root *root,
152 struct btrfs_block_rsv *block_rsv, u64 min_reserved,
153 enum btrfs_reserve_flush_enum flush)
154{
155 u64 num_bytes = 0;
156 int ret = -ENOSPC;
157
158 if (!block_rsv)
159 return 0;
160
161 spin_lock(&block_rsv->lock);
162 num_bytes = min_reserved;
163 if (block_rsv->reserved >= num_bytes)
164 ret = 0;
165 else
166 num_bytes -= block_rsv->reserved;
167 spin_unlock(&block_rsv->lock);
168
169 if (!ret)
170 return 0;
171
172 ret = btrfs_reserve_metadata_bytes(root, block_rsv, num_bytes, flush);
173 if (!ret) {
174 btrfs_block_rsv_add_bytes(block_rsv, num_bytes, false);
175 return 0;
176 }
177
178 return ret;
179}
180
181u64 __btrfs_block_rsv_release(struct btrfs_fs_info *fs_info,
182 struct btrfs_block_rsv *block_rsv,
183 u64 num_bytes, u64 *qgroup_to_release)
184{
185 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
186 struct btrfs_block_rsv *delayed_rsv = &fs_info->delayed_refs_rsv;
187 struct btrfs_block_rsv *target = NULL;
188
189 /*
190 * If we are the delayed_rsv then push to the global rsv, otherwise dump
191 * into the delayed rsv if it is not full.
192 */
193 if (block_rsv == delayed_rsv)
194 target = global_rsv;
195 else if (block_rsv != global_rsv && !delayed_rsv->full)
196 target = delayed_rsv;
197
198 if (target && block_rsv->space_info != target->space_info)
199 target = NULL;
200
201 return block_rsv_release_bytes(fs_info, block_rsv, target, num_bytes,
202 qgroup_to_release);
203}
204
205int btrfs_block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv, u64 num_bytes)
206{
207 int ret = -ENOSPC;
208
209 spin_lock(&block_rsv->lock);
210 if (block_rsv->reserved >= num_bytes) {
211 block_rsv->reserved -= num_bytes;
212 if (block_rsv->reserved < block_rsv->size)
213 block_rsv->full = 0;
214 ret = 0;
215 }
216 spin_unlock(&block_rsv->lock);
217 return ret;
218}
219
220void btrfs_block_rsv_add_bytes(struct btrfs_block_rsv *block_rsv,
221 u64 num_bytes, bool update_size)
222{
223 spin_lock(&block_rsv->lock);
224 block_rsv->reserved += num_bytes;
225 if (update_size)
226 block_rsv->size += num_bytes;
227 else if (block_rsv->reserved >= block_rsv->size)
228 block_rsv->full = 1;
229 spin_unlock(&block_rsv->lock);
230}
231
232int btrfs_cond_migrate_bytes(struct btrfs_fs_info *fs_info,
233 struct btrfs_block_rsv *dest, u64 num_bytes,
234 int min_factor)
235{
236 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
237 u64 min_bytes;
238
239 if (global_rsv->space_info != dest->space_info)
240 return -ENOSPC;
241
242 spin_lock(&global_rsv->lock);
243 min_bytes = div_factor(global_rsv->size, min_factor);
244 if (global_rsv->reserved < min_bytes + num_bytes) {
245 spin_unlock(&global_rsv->lock);
246 return -ENOSPC;
247 }
248 global_rsv->reserved -= num_bytes;
249 if (global_rsv->reserved < global_rsv->size)
250 global_rsv->full = 0;
251 spin_unlock(&global_rsv->lock);
252
253 btrfs_block_rsv_add_bytes(dest, num_bytes, true);
254 return 0;
255}
256
257void btrfs_update_global_block_rsv(struct btrfs_fs_info *fs_info)
258{
259 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
260 struct btrfs_space_info *sinfo = block_rsv->space_info;
261 u64 num_bytes;
262 unsigned min_items;
263
264 /*
265 * The global block rsv is based on the size of the extent tree, the
266 * checksum tree and the root tree. If the fs is empty we want to set
267 * it to a minimal amount for safety.
268 */
269 num_bytes = btrfs_root_used(&fs_info->extent_root->root_item) +
270 btrfs_root_used(&fs_info->csum_root->root_item) +
271 btrfs_root_used(&fs_info->tree_root->root_item);
272
273 /*
274 * We at a minimum are going to modify the csum root, the tree root, and
275 * the extent root.
276 */
277 min_items = 3;
278
279 /*
280 * But we also want to reserve enough space so we can do the fallback
281 * global reserve for an unlink, which is an additional 5 items (see the
282 * comment in __unlink_start_trans for what we're modifying.)
283 *
284 * But we also need space for the delayed ref updates from the unlink,
285 * so its 10, 5 for the actual operation, and 5 for the delayed ref
286 * updates.
287 */
288 min_items += 10;
289
290 num_bytes = max_t(u64, num_bytes,
291 btrfs_calc_insert_metadata_size(fs_info, min_items));
292
293 spin_lock(&sinfo->lock);
294 spin_lock(&block_rsv->lock);
295
296 block_rsv->size = min_t(u64, num_bytes, SZ_512M);
297
298 if (block_rsv->reserved < block_rsv->size) {
299 num_bytes = block_rsv->size - block_rsv->reserved;
300 block_rsv->reserved += num_bytes;
301 btrfs_space_info_update_bytes_may_use(fs_info, sinfo,
302 num_bytes);
303 } else if (block_rsv->reserved > block_rsv->size) {
304 num_bytes = block_rsv->reserved - block_rsv->size;
305 btrfs_space_info_update_bytes_may_use(fs_info, sinfo,
306 -num_bytes);
307 block_rsv->reserved = block_rsv->size;
308 btrfs_try_granting_tickets(fs_info, sinfo);
309 }
310
311 if (block_rsv->reserved == block_rsv->size)
312 block_rsv->full = 1;
313 else
314 block_rsv->full = 0;
315
316 spin_unlock(&block_rsv->lock);
317 spin_unlock(&sinfo->lock);
318}
319
320void btrfs_init_global_block_rsv(struct btrfs_fs_info *fs_info)
321{
322 struct btrfs_space_info *space_info;
323
324 space_info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
325 fs_info->chunk_block_rsv.space_info = space_info;
326
327 space_info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
328 fs_info->global_block_rsv.space_info = space_info;
329 fs_info->trans_block_rsv.space_info = space_info;
330 fs_info->empty_block_rsv.space_info = space_info;
331 fs_info->delayed_block_rsv.space_info = space_info;
332 fs_info->delayed_refs_rsv.space_info = space_info;
333
334 fs_info->extent_root->block_rsv = &fs_info->delayed_refs_rsv;
335 fs_info->csum_root->block_rsv = &fs_info->delayed_refs_rsv;
336 fs_info->dev_root->block_rsv = &fs_info->global_block_rsv;
337 fs_info->tree_root->block_rsv = &fs_info->global_block_rsv;
338 if (fs_info->quota_root)
339 fs_info->quota_root->block_rsv = &fs_info->global_block_rsv;
340 fs_info->chunk_root->block_rsv = &fs_info->chunk_block_rsv;
341
342 btrfs_update_global_block_rsv(fs_info);
343}
344
345void btrfs_release_global_block_rsv(struct btrfs_fs_info *fs_info)
346{
347 btrfs_block_rsv_release(fs_info, &fs_info->global_block_rsv, (u64)-1);
348 WARN_ON(fs_info->trans_block_rsv.size > 0);
349 WARN_ON(fs_info->trans_block_rsv.reserved > 0);
350 WARN_ON(fs_info->chunk_block_rsv.size > 0);
351 WARN_ON(fs_info->chunk_block_rsv.reserved > 0);
352 WARN_ON(fs_info->delayed_block_rsv.size > 0);
353 WARN_ON(fs_info->delayed_block_rsv.reserved > 0);
354 WARN_ON(fs_info->delayed_refs_rsv.reserved > 0);
355 WARN_ON(fs_info->delayed_refs_rsv.size > 0);
356}
357
358static struct btrfs_block_rsv *get_block_rsv(
359 const struct btrfs_trans_handle *trans,
360 const struct btrfs_root *root)
361{
362 struct btrfs_fs_info *fs_info = root->fs_info;
363 struct btrfs_block_rsv *block_rsv = NULL;
364
365 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
366 (root == fs_info->csum_root && trans->adding_csums) ||
367 (root == fs_info->uuid_root))
368 block_rsv = trans->block_rsv;
369
370 if (!block_rsv)
371 block_rsv = root->block_rsv;
372
373 if (!block_rsv)
374 block_rsv = &fs_info->empty_block_rsv;
375
376 return block_rsv;
377}
378
379struct btrfs_block_rsv *btrfs_use_block_rsv(struct btrfs_trans_handle *trans,
380 struct btrfs_root *root,
381 u32 blocksize)
382{
383 struct btrfs_fs_info *fs_info = root->fs_info;
384 struct btrfs_block_rsv *block_rsv;
385 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
386 int ret;
387 bool global_updated = false;
388
389 block_rsv = get_block_rsv(trans, root);
390
391 if (unlikely(block_rsv->size == 0))
392 goto try_reserve;
393again:
394 ret = btrfs_block_rsv_use_bytes(block_rsv, blocksize);
395 if (!ret)
396 return block_rsv;
397
398 if (block_rsv->failfast)
399 return ERR_PTR(ret);
400
401 if (block_rsv->type == BTRFS_BLOCK_RSV_GLOBAL && !global_updated) {
402 global_updated = true;
403 btrfs_update_global_block_rsv(fs_info);
404 goto again;
405 }
406
407 /*
408 * The global reserve still exists to save us from ourselves, so don't
409 * warn_on if we are short on our delayed refs reserve.
410 */
411 if (block_rsv->type != BTRFS_BLOCK_RSV_DELREFS &&
412 btrfs_test_opt(fs_info, ENOSPC_DEBUG)) {
413 static DEFINE_RATELIMIT_STATE(_rs,
414 DEFAULT_RATELIMIT_INTERVAL * 10,
415 /*DEFAULT_RATELIMIT_BURST*/ 1);
416 if (__ratelimit(&_rs))
417 WARN(1, KERN_DEBUG
418 "BTRFS: block rsv returned %d\n", ret);
419 }
420try_reserve:
421 ret = btrfs_reserve_metadata_bytes(root, block_rsv, blocksize,
422 BTRFS_RESERVE_NO_FLUSH);
423 if (!ret)
424 return block_rsv;
425 /*
426 * If we couldn't reserve metadata bytes try and use some from
427 * the global reserve if its space type is the same as the global
428 * reservation.
429 */
430 if (block_rsv->type != BTRFS_BLOCK_RSV_GLOBAL &&
431 block_rsv->space_info == global_rsv->space_info) {
432 ret = btrfs_block_rsv_use_bytes(global_rsv, blocksize);
433 if (!ret)
434 return global_rsv;
435 }
436 return ERR_PTR(ret);
437}