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[bcachefs-tools-debian] / libbcachefs / alloc_background.c
1 // SPDX-License-Identifier: GPL-2.0
2 #include "bcachefs.h"
3 #include "alloc_background.h"
4 #include "alloc_foreground.h"
5 #include "btree_cache.h"
6 #include "btree_io.h"
7 #include "btree_key_cache.h"
8 #include "btree_update.h"
9 #include "btree_update_interior.h"
10 #include "btree_gc.h"
11 #include "buckets.h"
12 #include "buckets_waiting_for_journal.h"
13 #include "clock.h"
14 #include "debug.h"
15 #include "ec.h"
16 #include "error.h"
17 #include "lru.h"
18 #include "recovery.h"
19 #include "varint.h"
20
21 #include <linux/kthread.h>
22 #include <linux/math64.h>
23 #include <linux/random.h>
24 #include <linux/rculist.h>
25 #include <linux/rcupdate.h>
26 #include <linux/sched/task.h>
27 #include <linux/sort.h>
28 #include <trace/events/bcachefs.h>
29
30 /* Persistent alloc info: */
31
32 static const unsigned BCH_ALLOC_V1_FIELD_BYTES[] = {
33 #define x(name, bits) [BCH_ALLOC_FIELD_V1_##name] = bits / 8,
34         BCH_ALLOC_FIELDS_V1()
35 #undef x
36 };
37
38 struct bkey_alloc_unpacked {
39         u64             journal_seq;
40         u64             bucket;
41         u8              dev;
42         u8              gen;
43         u8              oldest_gen;
44         u8              data_type;
45         bool            need_discard:1;
46         bool            need_inc_gen:1;
47 #define x(_name, _bits) u##_bits _name;
48         BCH_ALLOC_FIELDS_V2()
49 #undef  x
50 };
51
52 static inline u64 alloc_field_v1_get(const struct bch_alloc *a,
53                                      const void **p, unsigned field)
54 {
55         unsigned bytes = BCH_ALLOC_V1_FIELD_BYTES[field];
56         u64 v;
57
58         if (!(a->fields & (1 << field)))
59                 return 0;
60
61         switch (bytes) {
62         case 1:
63                 v = *((const u8 *) *p);
64                 break;
65         case 2:
66                 v = le16_to_cpup(*p);
67                 break;
68         case 4:
69                 v = le32_to_cpup(*p);
70                 break;
71         case 8:
72                 v = le64_to_cpup(*p);
73                 break;
74         default:
75                 BUG();
76         }
77
78         *p += bytes;
79         return v;
80 }
81
82 static inline void alloc_field_v1_put(struct bkey_i_alloc *a, void **p,
83                                       unsigned field, u64 v)
84 {
85         unsigned bytes = BCH_ALLOC_V1_FIELD_BYTES[field];
86
87         if (!v)
88                 return;
89
90         a->v.fields |= 1 << field;
91
92         switch (bytes) {
93         case 1:
94                 *((u8 *) *p) = v;
95                 break;
96         case 2:
97                 *((__le16 *) *p) = cpu_to_le16(v);
98                 break;
99         case 4:
100                 *((__le32 *) *p) = cpu_to_le32(v);
101                 break;
102         case 8:
103                 *((__le64 *) *p) = cpu_to_le64(v);
104                 break;
105         default:
106                 BUG();
107         }
108
109         *p += bytes;
110 }
111
112 static void bch2_alloc_unpack_v1(struct bkey_alloc_unpacked *out,
113                                  struct bkey_s_c k)
114 {
115         const struct bch_alloc *in = bkey_s_c_to_alloc(k).v;
116         const void *d = in->data;
117         unsigned idx = 0;
118
119         out->gen = in->gen;
120
121 #define x(_name, _bits) out->_name = alloc_field_v1_get(in, &d, idx++);
122         BCH_ALLOC_FIELDS_V1()
123 #undef  x
124 }
125
126 static int bch2_alloc_unpack_v2(struct bkey_alloc_unpacked *out,
127                                 struct bkey_s_c k)
128 {
129         struct bkey_s_c_alloc_v2 a = bkey_s_c_to_alloc_v2(k);
130         const u8 *in = a.v->data;
131         const u8 *end = bkey_val_end(a);
132         unsigned fieldnr = 0;
133         int ret;
134         u64 v;
135
136         out->gen        = a.v->gen;
137         out->oldest_gen = a.v->oldest_gen;
138         out->data_type  = a.v->data_type;
139
140 #define x(_name, _bits)                                                 \
141         if (fieldnr < a.v->nr_fields) {                                 \
142                 ret = bch2_varint_decode_fast(in, end, &v);             \
143                 if (ret < 0)                                            \
144                         return ret;                                     \
145                 in += ret;                                              \
146         } else {                                                        \
147                 v = 0;                                                  \
148         }                                                               \
149         out->_name = v;                                                 \
150         if (v != out->_name)                                            \
151                 return -1;                                              \
152         fieldnr++;
153
154         BCH_ALLOC_FIELDS_V2()
155 #undef  x
156         return 0;
157 }
158
159 static int bch2_alloc_unpack_v3(struct bkey_alloc_unpacked *out,
160                                 struct bkey_s_c k)
161 {
162         struct bkey_s_c_alloc_v3 a = bkey_s_c_to_alloc_v3(k);
163         const u8 *in = a.v->data;
164         const u8 *end = bkey_val_end(a);
165         unsigned fieldnr = 0;
166         int ret;
167         u64 v;
168
169         out->gen        = a.v->gen;
170         out->oldest_gen = a.v->oldest_gen;
171         out->data_type  = a.v->data_type;
172         out->need_discard = BCH_ALLOC_V3_NEED_DISCARD(a.v);
173         out->need_inc_gen = BCH_ALLOC_V3_NEED_INC_GEN(a.v);
174         out->journal_seq = le64_to_cpu(a.v->journal_seq);
175
176 #define x(_name, _bits)                                                 \
177         if (fieldnr < a.v->nr_fields) {                                 \
178                 ret = bch2_varint_decode_fast(in, end, &v);             \
179                 if (ret < 0)                                            \
180                         return ret;                                     \
181                 in += ret;                                              \
182         } else {                                                        \
183                 v = 0;                                                  \
184         }                                                               \
185         out->_name = v;                                                 \
186         if (v != out->_name)                                            \
187                 return -1;                                              \
188         fieldnr++;
189
190         BCH_ALLOC_FIELDS_V2()
191 #undef  x
192         return 0;
193 }
194
195 static struct bkey_alloc_unpacked bch2_alloc_unpack(struct bkey_s_c k)
196 {
197         struct bkey_alloc_unpacked ret = {
198                 .dev    = k.k->p.inode,
199                 .bucket = k.k->p.offset,
200                 .gen    = 0,
201         };
202
203         switch (k.k->type) {
204         case KEY_TYPE_alloc:
205                 bch2_alloc_unpack_v1(&ret, k);
206                 break;
207         case KEY_TYPE_alloc_v2:
208                 bch2_alloc_unpack_v2(&ret, k);
209                 break;
210         case KEY_TYPE_alloc_v3:
211                 bch2_alloc_unpack_v3(&ret, k);
212                 break;
213         }
214
215         return ret;
216 }
217
218 void bch2_alloc_to_v4(struct bkey_s_c k, struct bch_alloc_v4 *out)
219 {
220         if (k.k->type == KEY_TYPE_alloc_v4) {
221                 *out = *bkey_s_c_to_alloc_v4(k).v;
222         } else {
223                 struct bkey_alloc_unpacked u = bch2_alloc_unpack(k);
224
225                 *out = (struct bch_alloc_v4) {
226                         .journal_seq            = u.journal_seq,
227                         .flags                  = u.need_discard,
228                         .gen                    = u.gen,
229                         .oldest_gen             = u.oldest_gen,
230                         .data_type              = u.data_type,
231                         .stripe_redundancy      = u.stripe_redundancy,
232                         .dirty_sectors          = u.dirty_sectors,
233                         .cached_sectors         = u.cached_sectors,
234                         .io_time[READ]          = u.read_time,
235                         .io_time[WRITE]         = u.write_time,
236                         .stripe                 = u.stripe,
237                 };
238         }
239 }
240
241 struct bkey_i_alloc_v4 *bch2_alloc_to_v4_mut(struct btree_trans *trans, struct bkey_s_c k)
242 {
243         struct bkey_i_alloc_v4 *ret;
244
245         if (k.k->type == KEY_TYPE_alloc_v4) {
246                 ret = bch2_trans_kmalloc(trans, bkey_bytes(k.k));
247                 if (!IS_ERR(ret))
248                         bkey_reassemble(&ret->k_i, k);
249         } else {
250                 ret = bch2_trans_kmalloc(trans, sizeof(*ret));
251                 if (!IS_ERR(ret)) {
252                         bkey_alloc_v4_init(&ret->k_i);
253                         ret->k.p = k.k->p;
254                         bch2_alloc_to_v4(k, &ret->v);
255                 }
256         }
257         return ret;
258 }
259
260 struct bkey_i_alloc_v4 *
261 bch2_trans_start_alloc_update(struct btree_trans *trans, struct btree_iter *iter,
262                               struct bpos pos)
263 {
264         struct bkey_s_c k;
265         struct bkey_i_alloc_v4 *a;
266         int ret;
267
268         bch2_trans_iter_init(trans, iter, BTREE_ID_alloc, pos,
269                              BTREE_ITER_WITH_UPDATES|
270                              BTREE_ITER_CACHED|
271                              BTREE_ITER_INTENT);
272         k = bch2_btree_iter_peek_slot(iter);
273         ret = bkey_err(k);
274         if (ret) {
275                 bch2_trans_iter_exit(trans, iter);
276                 return ERR_PTR(ret);
277         }
278
279         a = bch2_alloc_to_v4_mut(trans, k);
280         if (IS_ERR(a))
281                 bch2_trans_iter_exit(trans, iter);
282         return a;
283 }
284
285 static unsigned bch_alloc_v1_val_u64s(const struct bch_alloc *a)
286 {
287         unsigned i, bytes = offsetof(struct bch_alloc, data);
288
289         for (i = 0; i < ARRAY_SIZE(BCH_ALLOC_V1_FIELD_BYTES); i++)
290                 if (a->fields & (1 << i))
291                         bytes += BCH_ALLOC_V1_FIELD_BYTES[i];
292
293         return DIV_ROUND_UP(bytes, sizeof(u64));
294 }
295
296 int bch2_alloc_v1_invalid(const struct bch_fs *c, struct bkey_s_c k,
297                           int rw, struct printbuf *err)
298 {
299         struct bkey_s_c_alloc a = bkey_s_c_to_alloc(k);
300
301         /* allow for unknown fields */
302         if (bkey_val_u64s(a.k) < bch_alloc_v1_val_u64s(a.v)) {
303                 pr_buf(err, "incorrect value size (%zu < %u)",
304                        bkey_val_u64s(a.k), bch_alloc_v1_val_u64s(a.v));
305                 return -EINVAL;
306         }
307
308         return 0;
309 }
310
311 int bch2_alloc_v2_invalid(const struct bch_fs *c, struct bkey_s_c k,
312                           int rw, struct printbuf *err)
313 {
314         struct bkey_alloc_unpacked u;
315
316         if (bch2_alloc_unpack_v2(&u, k)) {
317                 pr_buf(err, "unpack error");
318                 return -EINVAL;
319         }
320
321         return 0;
322 }
323
324 int bch2_alloc_v3_invalid(const struct bch_fs *c, struct bkey_s_c k,
325                           int rw, struct printbuf *err)
326 {
327         struct bkey_alloc_unpacked u;
328
329         if (bch2_alloc_unpack_v3(&u, k)) {
330                 pr_buf(err, "unpack error");
331                 return -EINVAL;
332         }
333
334         return 0;
335 }
336
337 int bch2_alloc_v4_invalid(const struct bch_fs *c, struct bkey_s_c k,
338                           int rw, struct printbuf *err)
339 {
340         struct bkey_s_c_alloc_v4 a = bkey_s_c_to_alloc_v4(k);
341
342         if (bkey_val_bytes(k.k) != sizeof(struct bch_alloc_v4)) {
343                 pr_buf(err, "bad val size (%zu != %zu)",
344                        bkey_val_bytes(k.k), sizeof(struct bch_alloc_v4));
345                 return -EINVAL;
346         }
347
348         if (rw == WRITE) {
349                 if (alloc_data_type(*a.v, a.v->data_type) != a.v->data_type) {
350                         pr_buf(err, "invalid data type (got %u should be %u)",
351                                a.v->data_type, alloc_data_type(*a.v, a.v->data_type));
352                         return -EINVAL;
353                 }
354
355                 switch (a.v->data_type) {
356                 case BCH_DATA_free:
357                 case BCH_DATA_need_gc_gens:
358                 case BCH_DATA_need_discard:
359                         if (a.v->dirty_sectors ||
360                             a.v->cached_sectors ||
361                             a.v->stripe) {
362                                 pr_buf(err, "empty data type free but have data");
363                                 return -EINVAL;
364                         }
365                         break;
366                 case BCH_DATA_sb:
367                 case BCH_DATA_journal:
368                 case BCH_DATA_btree:
369                 case BCH_DATA_user:
370                 case BCH_DATA_parity:
371                         if (!a.v->dirty_sectors) {
372                                 pr_buf(err, "data_type %s but dirty_sectors==0",
373                                        bch2_data_types[a.v->data_type]);
374                                 return -EINVAL;
375                         }
376                         break;
377                 case BCH_DATA_cached:
378                         if (!a.v->cached_sectors ||
379                             a.v->dirty_sectors ||
380                             a.v->stripe) {
381                                 pr_buf(err, "data type inconsistency");
382                                 return -EINVAL;
383                         }
384
385                         if (!a.v->io_time[READ]) {
386                                 pr_buf(err, "cached bucket with read_time == 0");
387                                 return -EINVAL;
388                         }
389                         break;
390                 case BCH_DATA_stripe:
391                         if (!a.v->stripe) {
392                                 pr_buf(err, "data_type %s but stripe==0",
393                                        bch2_data_types[a.v->data_type]);
394                                 return -EINVAL;
395                         }
396                         break;
397                 }
398         }
399
400         return 0;
401 }
402
403 void bch2_alloc_v4_swab(struct bkey_s k)
404 {
405         struct bch_alloc_v4 *a = bkey_s_to_alloc_v4(k).v;
406
407         a->journal_seq          = swab64(a->journal_seq);
408         a->flags                = swab32(a->flags);
409         a->dirty_sectors        = swab32(a->dirty_sectors);
410         a->cached_sectors       = swab32(a->cached_sectors);
411         a->io_time[0]           = swab64(a->io_time[0]);
412         a->io_time[1]           = swab64(a->io_time[1]);
413         a->stripe               = swab32(a->stripe);
414         a->nr_external_backpointers = swab32(a->nr_external_backpointers);
415 }
416
417 void bch2_alloc_to_text(struct printbuf *out, struct bch_fs *c, struct bkey_s_c k)
418 {
419         struct bch_alloc_v4 a;
420
421         bch2_alloc_to_v4(k, &a);
422
423         pr_buf(out, "gen %u oldest_gen %u data_type %s journal_seq %llu need_discard %llu need_inc_gen %llu",
424                a.gen, a.oldest_gen, bch2_data_types[a.data_type],
425                a.journal_seq,
426                BCH_ALLOC_V4_NEED_DISCARD(&a),
427                BCH_ALLOC_V4_NEED_INC_GEN(&a));
428         pr_buf(out, " dirty_sectors %u",        a.dirty_sectors);
429         pr_buf(out, " cached_sectors %u",       a.cached_sectors);
430         pr_buf(out, " stripe %u",               a.stripe);
431         pr_buf(out, " stripe_redundancy %u",    a.stripe_redundancy);
432         pr_buf(out, " read_time %llu",          a.io_time[READ]);
433         pr_buf(out, " write_time %llu",         a.io_time[WRITE]);
434 }
435
436 int bch2_alloc_read(struct bch_fs *c)
437 {
438         struct btree_trans trans;
439         struct btree_iter iter;
440         struct bkey_s_c k;
441         struct bch_alloc_v4 a;
442         struct bch_dev *ca;
443         int ret;
444
445         bch2_trans_init(&trans, c, 0, 0);
446
447         for_each_btree_key(&trans, iter, BTREE_ID_alloc, POS_MIN,
448                            BTREE_ITER_PREFETCH, k, ret) {
449                 /*
450                  * Not a fsck error because this is checked/repaired by
451                  * bch2_check_alloc_key() which runs later:
452                  */
453                 if (!bch2_dev_bucket_exists(c, k.k->p))
454                         continue;
455
456                 ca = bch_dev_bkey_exists(c, k.k->p.inode);
457                 bch2_alloc_to_v4(k, &a);
458
459                 *bucket_gen(ca, k.k->p.offset) = a.gen;
460         }
461         bch2_trans_iter_exit(&trans, &iter);
462
463         bch2_trans_exit(&trans);
464
465         if (ret)
466                 bch_err(c, "error reading alloc info: %i", ret);
467
468         return ret;
469 }
470
471 /* Free space/discard btree: */
472
473 static int bch2_bucket_do_index(struct btree_trans *trans,
474                                 struct bkey_s_c alloc_k,
475                                 const struct bch_alloc_v4 *a,
476                                 bool set)
477 {
478         struct bch_fs *c = trans->c;
479         struct bch_dev *ca = bch_dev_bkey_exists(c, alloc_k.k->p.inode);
480         struct btree_iter iter;
481         struct bkey_s_c old;
482         struct bkey_i *k;
483         enum btree_id btree;
484         enum bch_bkey_type old_type = !set ? KEY_TYPE_set : KEY_TYPE_deleted;
485         enum bch_bkey_type new_type =  set ? KEY_TYPE_set : KEY_TYPE_deleted;
486         struct printbuf buf = PRINTBUF;
487         int ret;
488
489         if (a->data_type != BCH_DATA_free &&
490             a->data_type != BCH_DATA_need_discard)
491                 return 0;
492
493         k = bch2_trans_kmalloc(trans, sizeof(*k));
494         if (IS_ERR(k))
495                 return PTR_ERR(k);
496
497         bkey_init(&k->k);
498         k->k.type = new_type;
499
500         switch (a->data_type) {
501         case BCH_DATA_free:
502                 btree = BTREE_ID_freespace;
503                 k->k.p = alloc_freespace_pos(alloc_k.k->p, *a);
504                 bch2_key_resize(&k->k, 1);
505                 break;
506         case BCH_DATA_need_discard:
507                 btree = BTREE_ID_need_discard;
508                 k->k.p = alloc_k.k->p;
509                 break;
510         default:
511                 return 0;
512         }
513
514         bch2_trans_iter_init(trans, &iter, btree,
515                              bkey_start_pos(&k->k),
516                              BTREE_ITER_INTENT);
517         old = bch2_btree_iter_peek_slot(&iter);
518         ret = bkey_err(old);
519         if (ret)
520                 goto err;
521
522         if (ca->mi.freespace_initialized &&
523             bch2_trans_inconsistent_on(old.k->type != old_type, trans,
524                         "incorrect key when %s %s btree (got %s should be %s)\n"
525                         "  for %s",
526                         set ? "setting" : "clearing",
527                         bch2_btree_ids[btree],
528                         bch2_bkey_types[old.k->type],
529                         bch2_bkey_types[old_type],
530                         (bch2_bkey_val_to_text(&buf, c, alloc_k), buf.buf))) {
531                 ret = -EIO;
532                 goto err;
533         }
534
535         ret = bch2_trans_update(trans, &iter, k, 0);
536 err:
537         bch2_trans_iter_exit(trans, &iter);
538         printbuf_exit(&buf);
539         return ret;
540 }
541
542 int bch2_trans_mark_alloc(struct btree_trans *trans,
543                           struct bkey_s_c old, struct bkey_i *new,
544                           unsigned flags)
545 {
546         struct bch_fs *c = trans->c;
547         struct bch_alloc_v4 old_a, *new_a;
548         int ret = 0;
549
550         /*
551          * Deletion only happens in the device removal path, with
552          * BTREE_TRIGGER_NORUN:
553          */
554         BUG_ON(new->k.type != KEY_TYPE_alloc_v4);
555
556         bch2_alloc_to_v4(old, &old_a);
557         new_a = &bkey_i_to_alloc_v4(new)->v;
558
559         new_a->data_type = alloc_data_type(*new_a, new_a->data_type);
560
561         if (new_a->dirty_sectors > old_a.dirty_sectors ||
562             new_a->cached_sectors > old_a.cached_sectors) {
563                 new_a->io_time[READ] = max_t(u64, 1, atomic64_read(&c->io_clock[READ].now));
564                 new_a->io_time[WRITE]= max_t(u64, 1, atomic64_read(&c->io_clock[WRITE].now));
565                 SET_BCH_ALLOC_V4_NEED_INC_GEN(new_a, true);
566                 SET_BCH_ALLOC_V4_NEED_DISCARD(new_a, true);
567         }
568
569         if (data_type_is_empty(new_a->data_type) &&
570             BCH_ALLOC_V4_NEED_INC_GEN(new_a) &&
571             !bch2_bucket_is_open_safe(c, new->k.p.inode, new->k.p.offset)) {
572                 new_a->gen++;
573                 SET_BCH_ALLOC_V4_NEED_INC_GEN(new_a, false);
574         }
575
576         if (old_a.data_type != new_a->data_type ||
577             (new_a->data_type == BCH_DATA_free &&
578              alloc_freespace_genbits(old_a) != alloc_freespace_genbits(*new_a))) {
579                 ret =   bch2_bucket_do_index(trans, old, &old_a, false) ?:
580                         bch2_bucket_do_index(trans, bkey_i_to_s_c(new), new_a, true);
581                 if (ret)
582                         return ret;
583         }
584
585         if (new_a->data_type == BCH_DATA_cached &&
586             !new_a->io_time[READ])
587                 new_a->io_time[READ] = max_t(u64, 1, atomic64_read(&c->io_clock[READ].now));
588
589         if ((old_a.data_type == BCH_DATA_cached) !=
590             (new_a->data_type == BCH_DATA_cached)) {
591                 u64 old_lru = alloc_lru_idx(old_a);
592                 u64 new_lru = alloc_lru_idx(*new_a);
593
594                 ret = bch2_lru_change(trans, new->k.p.inode, new->k.p.offset,
595                                       old_lru, &new_lru);
596                 if (ret)
597                         return ret;
598
599                 if (new_a->data_type == BCH_DATA_cached)
600                         new_a->io_time[READ] = new_lru;
601         }
602
603         return 0;
604 }
605
606 static int bch2_check_alloc_key(struct btree_trans *trans,
607                                 struct btree_iter *alloc_iter)
608 {
609         struct bch_fs *c = trans->c;
610         struct bch_dev *ca;
611         struct btree_iter discard_iter, freespace_iter;
612         struct bch_alloc_v4 a;
613         unsigned discard_key_type, freespace_key_type;
614         struct bkey_s_c alloc_k, k;
615         struct printbuf buf = PRINTBUF;
616         struct printbuf buf2 = PRINTBUF;
617         int ret;
618
619         alloc_k = bch2_btree_iter_peek(alloc_iter);
620         if (!alloc_k.k)
621                 return 0;
622
623         ret = bkey_err(alloc_k);
624         if (ret)
625                 return ret;
626
627         if (fsck_err_on(!bch2_dev_bucket_exists(c, alloc_k.k->p), c,
628                         "alloc key for invalid device:bucket %llu:%llu",
629                         alloc_k.k->p.inode, alloc_k.k->p.offset))
630                 return bch2_btree_delete_at(trans, alloc_iter, 0);
631
632         ca = bch_dev_bkey_exists(c, alloc_k.k->p.inode);
633         if (!ca->mi.freespace_initialized)
634                 return 0;
635
636         bch2_alloc_to_v4(alloc_k, &a);
637
638         discard_key_type = a.data_type == BCH_DATA_need_discard
639                 ? KEY_TYPE_set : 0;
640         freespace_key_type = a.data_type == BCH_DATA_free
641                 ? KEY_TYPE_set : 0;
642
643         bch2_trans_iter_init(trans, &discard_iter, BTREE_ID_need_discard,
644                              alloc_k.k->p, 0);
645         bch2_trans_iter_init(trans, &freespace_iter, BTREE_ID_freespace,
646                              alloc_freespace_pos(alloc_k.k->p, a), 0);
647
648         k = bch2_btree_iter_peek_slot(&discard_iter);
649         ret = bkey_err(k);
650         if (ret)
651                 goto err;
652
653         if (fsck_err_on(k.k->type != discard_key_type, c,
654                         "incorrect key in need_discard btree (got %s should be %s)\n"
655                         "  %s",
656                         bch2_bkey_types[k.k->type],
657                         bch2_bkey_types[discard_key_type],
658                         (bch2_bkey_val_to_text(&buf, c, alloc_k), buf.buf))) {
659                 struct bkey_i *update =
660                         bch2_trans_kmalloc(trans, sizeof(*update));
661
662                 ret = PTR_ERR_OR_ZERO(update);
663                 if (ret)
664                         goto err;
665
666                 bkey_init(&update->k);
667                 update->k.type  = discard_key_type;
668                 update->k.p     = discard_iter.pos;
669
670                 ret = bch2_trans_update(trans, &discard_iter, update, 0);
671                 if (ret)
672                         goto err;
673         }
674
675         k = bch2_btree_iter_peek_slot(&freespace_iter);
676         ret = bkey_err(k);
677         if (ret)
678                 goto err;
679
680         if (fsck_err_on(k.k->type != freespace_key_type, c,
681                         "incorrect key in freespace btree (got %s should be %s)\n"
682                         "  %s",
683                         bch2_bkey_types[k.k->type],
684                         bch2_bkey_types[freespace_key_type],
685                         (printbuf_reset(&buf),
686                          bch2_bkey_val_to_text(&buf, c, alloc_k), buf.buf))) {
687                 struct bkey_i *update =
688                         bch2_trans_kmalloc(trans, sizeof(*update));
689
690                 ret = PTR_ERR_OR_ZERO(update);
691                 if (ret)
692                         goto err;
693
694                 bkey_init(&update->k);
695                 update->k.type  = freespace_key_type;
696                 update->k.p     = freespace_iter.pos;
697                 bch2_key_resize(&update->k, 1);
698
699                 ret = bch2_trans_update(trans, &freespace_iter, update, 0);
700                 if (ret)
701                         goto err;
702         }
703 err:
704 fsck_err:
705         bch2_trans_iter_exit(trans, &freespace_iter);
706         bch2_trans_iter_exit(trans, &discard_iter);
707         printbuf_exit(&buf2);
708         printbuf_exit(&buf);
709         return ret;
710 }
711
712 static int bch2_check_discard_freespace_key(struct btree_trans *trans,
713                                             struct btree_iter *iter)
714 {
715         struct bch_fs *c = trans->c;
716         struct btree_iter alloc_iter;
717         struct bkey_s_c k, freespace_k;
718         struct bch_alloc_v4 a;
719         u64 genbits;
720         struct bpos pos;
721         enum bch_data_type state = iter->btree_id == BTREE_ID_need_discard
722                 ? BCH_DATA_need_discard
723                 : BCH_DATA_free;
724         struct printbuf buf = PRINTBUF;
725         int ret;
726
727         freespace_k = bch2_btree_iter_peek(iter);
728         if (!freespace_k.k)
729                 return 1;
730
731         ret = bkey_err(freespace_k);
732         if (ret)
733                 return ret;
734
735         pos = iter->pos;
736         pos.offset &= ~(~0ULL << 56);
737         genbits = iter->pos.offset & (~0ULL << 56);
738
739         bch2_trans_iter_init(trans, &alloc_iter, BTREE_ID_alloc, pos, 0);
740
741         if (fsck_err_on(!bch2_dev_bucket_exists(c, pos), c,
742                         "entry in %s btree for nonexistant dev:bucket %llu:%llu",
743                         bch2_btree_ids[iter->btree_id], pos.inode, pos.offset))
744                 goto delete;
745
746         k = bch2_btree_iter_peek_slot(&alloc_iter);
747         ret = bkey_err(k);
748         if (ret)
749                 goto err;
750
751         bch2_alloc_to_v4(k, &a);
752
753         if (fsck_err_on(a.data_type != state ||
754                         (state == BCH_DATA_free &&
755                          genbits != alloc_freespace_genbits(a)), c,
756                         "%s\n  incorrectly set in %s index (free %u, genbits %llu should be %llu)",
757                         (bch2_bkey_val_to_text(&buf, c, k), buf.buf),
758                         bch2_btree_ids[iter->btree_id],
759                         a.data_type == state,
760                         genbits >> 56, alloc_freespace_genbits(a) >> 56))
761                 goto delete;
762 out:
763 err:
764 fsck_err:
765         bch2_trans_iter_exit(trans, &alloc_iter);
766         printbuf_exit(&buf);
767         return ret;
768 delete:
769         ret = bch2_btree_delete_extent_at(trans, iter,
770                         iter->btree_id == BTREE_ID_freespace ? 1 : 0, 0);
771         goto out;
772 }
773
774 int bch2_check_alloc_info(struct bch_fs *c)
775 {
776         struct btree_trans trans;
777         struct btree_iter iter;
778         struct bkey_s_c k;
779         int ret = 0;
780
781         bch2_trans_init(&trans, c, 0, 0);
782
783         for_each_btree_key(&trans, iter, BTREE_ID_alloc, POS_MIN,
784                            BTREE_ITER_PREFETCH, k, ret) {
785                 ret = __bch2_trans_do(&trans, NULL, NULL, 0,
786                         bch2_check_alloc_key(&trans, &iter));
787                 if (ret)
788                         break;
789         }
790         bch2_trans_iter_exit(&trans, &iter);
791
792         if (ret)
793                 goto err;
794
795         bch2_trans_iter_init(&trans, &iter, BTREE_ID_need_discard, POS_MIN,
796                              BTREE_ITER_PREFETCH);
797         while (1) {
798                 ret = __bch2_trans_do(&trans, NULL, NULL, 0,
799                         bch2_check_discard_freespace_key(&trans, &iter));
800                 if (ret)
801                         break;
802
803                 bch2_btree_iter_set_pos(&iter, bpos_nosnap_successor(iter.pos));
804         }
805         bch2_trans_iter_exit(&trans, &iter);
806
807         if (ret)
808                 goto err;
809
810         bch2_trans_iter_init(&trans, &iter, BTREE_ID_freespace, POS_MIN,
811                              BTREE_ITER_PREFETCH);
812         while (1) {
813                 ret = __bch2_trans_do(&trans, NULL, NULL, 0,
814                         bch2_check_discard_freespace_key(&trans, &iter));
815                 if (ret)
816                         break;
817
818                 bch2_btree_iter_set_pos(&iter, bpos_nosnap_successor(iter.pos));
819         }
820         bch2_trans_iter_exit(&trans, &iter);
821 err:
822         bch2_trans_exit(&trans);
823         return ret < 0 ? ret : 0;
824 }
825
826 static int bch2_check_alloc_to_lru_ref(struct btree_trans *trans,
827                                        struct btree_iter *alloc_iter)
828 {
829         struct bch_fs *c = trans->c;
830         struct btree_iter lru_iter;
831         struct bch_alloc_v4 a;
832         struct bkey_s_c alloc_k, k;
833         struct printbuf buf = PRINTBUF;
834         struct printbuf buf2 = PRINTBUF;
835         int ret;
836
837         alloc_k = bch2_btree_iter_peek(alloc_iter);
838         if (!alloc_k.k)
839                 return 0;
840
841         ret = bkey_err(alloc_k);
842         if (ret)
843                 return ret;
844
845         bch2_alloc_to_v4(alloc_k, &a);
846
847         if (a.data_type != BCH_DATA_cached)
848                 return 0;
849
850         bch2_trans_iter_init(trans, &lru_iter, BTREE_ID_lru,
851                              POS(alloc_k.k->p.inode, a.io_time[READ]), 0);
852
853         k = bch2_btree_iter_peek_slot(&lru_iter);
854         ret = bkey_err(k);
855         if (ret)
856                 goto err;
857
858         if (fsck_err_on(!a.io_time[READ], c,
859                         "cached bucket with read_time 0\n"
860                         "  %s",
861                 (printbuf_reset(&buf),
862                  bch2_bkey_val_to_text(&buf, c, alloc_k), buf.buf)) ||
863             fsck_err_on(k.k->type != KEY_TYPE_lru ||
864                         le64_to_cpu(bkey_s_c_to_lru(k).v->idx) != alloc_k.k->p.offset, c,
865                         "incorrect/missing lru entry\n"
866                         "  %s\n"
867                         "  %s",
868                         (printbuf_reset(&buf),
869                          bch2_bkey_val_to_text(&buf, c, alloc_k), buf.buf),
870                         (bch2_bkey_val_to_text(&buf2, c, k), buf2.buf))) {
871                 u64 read_time = a.io_time[READ];
872
873                 if (!a.io_time[READ])
874                         a.io_time[READ] = atomic64_read(&c->io_clock[READ].now);
875
876                 ret = bch2_lru_set(trans,
877                                    alloc_k.k->p.inode,
878                                    alloc_k.k->p.offset,
879                                    &a.io_time[READ]);
880                 if (ret)
881                         goto err;
882
883                 if (a.io_time[READ] != read_time) {
884                         struct bkey_i_alloc_v4 *a_mut =
885                                 bch2_alloc_to_v4_mut(trans, alloc_k);
886                         ret = PTR_ERR_OR_ZERO(a_mut);
887                         if (ret)
888                                 goto err;
889
890                         a_mut->v.io_time[READ] = a.io_time[READ];
891                         ret = bch2_trans_update(trans, alloc_iter,
892                                                 &a_mut->k_i, BTREE_TRIGGER_NORUN);
893                         if (ret)
894                                 goto err;
895                 }
896         }
897 err:
898 fsck_err:
899         bch2_trans_iter_exit(trans, &lru_iter);
900         printbuf_exit(&buf2);
901         printbuf_exit(&buf);
902         return ret;
903 }
904
905 int bch2_check_alloc_to_lru_refs(struct bch_fs *c)
906 {
907         struct btree_trans trans;
908         struct btree_iter iter;
909         struct bkey_s_c k;
910         int ret = 0;
911
912         bch2_trans_init(&trans, c, 0, 0);
913
914         for_each_btree_key(&trans, iter, BTREE_ID_alloc, POS_MIN,
915                            BTREE_ITER_PREFETCH, k, ret) {
916                 ret = __bch2_trans_do(&trans, NULL, NULL,
917                                       BTREE_INSERT_NOFAIL|
918                                       BTREE_INSERT_LAZY_RW,
919                         bch2_check_alloc_to_lru_ref(&trans, &iter));
920                 if (ret)
921                         break;
922         }
923         bch2_trans_iter_exit(&trans, &iter);
924
925         bch2_trans_exit(&trans);
926         return ret < 0 ? ret : 0;
927 }
928
929 static int bch2_clear_need_discard(struct btree_trans *trans, struct bpos pos,
930                                    struct bch_dev *ca, bool *discard_done)
931 {
932         struct bch_fs *c = trans->c;
933         struct btree_iter iter;
934         struct bkey_s_c k;
935         struct bkey_i_alloc_v4 *a;
936         struct printbuf buf = PRINTBUF;
937         int ret;
938
939         bch2_trans_iter_init(trans, &iter, BTREE_ID_alloc, pos,
940                              BTREE_ITER_CACHED);
941         k = bch2_btree_iter_peek_slot(&iter);
942         ret = bkey_err(k);
943         if (ret)
944                 goto out;
945
946         a = bch2_alloc_to_v4_mut(trans, k);
947         ret = PTR_ERR_OR_ZERO(a);
948         if (ret)
949                 goto out;
950
951         if (BCH_ALLOC_V4_NEED_INC_GEN(&a->v)) {
952                 a->v.gen++;
953                 SET_BCH_ALLOC_V4_NEED_INC_GEN(&a->v, false);
954                 goto write;
955         }
956
957         if (bch2_trans_inconsistent_on(a->v.journal_seq > c->journal.flushed_seq_ondisk, trans,
958                         "clearing need_discard but journal_seq %llu > flushed_seq %llu\n"
959                         "%s",
960                         a->v.journal_seq,
961                         c->journal.flushed_seq_ondisk,
962                         (bch2_bkey_val_to_text(&buf, c, k), buf.buf))) {
963                 ret = -EIO;
964                 goto out;
965         }
966
967         if (bch2_trans_inconsistent_on(a->v.data_type != BCH_DATA_need_discard, trans,
968                         "bucket incorrectly set in need_discard btree\n"
969                         "%s",
970                         (bch2_bkey_val_to_text(&buf, c, k), buf.buf))) {
971                 ret = -EIO;
972                 goto out;
973         }
974
975         if (!*discard_done && ca->mi.discard && !c->opts.nochanges) {
976                 /*
977                  * This works without any other locks because this is the only
978                  * thread that removes items from the need_discard tree
979                  */
980                 bch2_trans_unlock(trans);
981                 blkdev_issue_discard(ca->disk_sb.bdev,
982                                      k.k->p.offset * ca->mi.bucket_size,
983                                      ca->mi.bucket_size,
984                                      GFP_KERNEL, 0);
985                 *discard_done = true;
986
987                 ret = bch2_trans_relock(trans) ? 0 : -EINTR;
988                 if (ret)
989                         goto out;
990         }
991
992         SET_BCH_ALLOC_V4_NEED_DISCARD(&a->v, false);
993         a->v.data_type = alloc_data_type(a->v, a->v.data_type);
994 write:
995         ret = bch2_trans_update(trans, &iter, &a->k_i, 0);
996 out:
997         bch2_trans_iter_exit(trans, &iter);
998         printbuf_exit(&buf);
999         return ret;
1000 }
1001
1002 static void bch2_do_discards_work(struct work_struct *work)
1003 {
1004         struct bch_fs *c = container_of(work, struct bch_fs, discard_work);
1005         struct bch_dev *ca = NULL;
1006         struct btree_trans trans;
1007         struct btree_iter iter;
1008         struct bkey_s_c k;
1009         u64 seen = 0, open = 0, need_journal_commit = 0, discarded = 0;
1010         int ret;
1011
1012         bch2_trans_init(&trans, c, 0, 0);
1013
1014         for_each_btree_key(&trans, iter, BTREE_ID_need_discard,
1015                            POS_MIN, 0, k, ret) {
1016                 bool discard_done = false;
1017
1018                 if (ca && k.k->p.inode != ca->dev_idx) {
1019                         percpu_ref_put(&ca->io_ref);
1020                         ca = NULL;
1021                 }
1022
1023                 if (!ca) {
1024                         ca = bch_dev_bkey_exists(c, k.k->p.inode);
1025                         if (!percpu_ref_tryget(&ca->io_ref)) {
1026                                 ca = NULL;
1027                                 bch2_btree_iter_set_pos(&iter, POS(k.k->p.inode + 1, 0));
1028                                 continue;
1029                         }
1030                 }
1031
1032                 seen++;
1033
1034                 if (bch2_bucket_is_open_safe(c, k.k->p.inode, k.k->p.offset)) {
1035                         open++;
1036                         continue;
1037                 }
1038
1039                 if (bch2_bucket_needs_journal_commit(&c->buckets_waiting_for_journal,
1040                                 c->journal.flushed_seq_ondisk,
1041                                 k.k->p.inode, k.k->p.offset)) {
1042                         need_journal_commit++;
1043                         continue;
1044                 }
1045
1046                 ret = __bch2_trans_do(&trans, NULL, NULL,
1047                                       BTREE_INSERT_USE_RESERVE|
1048                                       BTREE_INSERT_NOFAIL,
1049                                 bch2_clear_need_discard(&trans, k.k->p, ca, &discard_done));
1050                 if (ret)
1051                         break;
1052
1053                 discarded++;
1054         }
1055         bch2_trans_iter_exit(&trans, &iter);
1056
1057         if (ca)
1058                 percpu_ref_put(&ca->io_ref);
1059
1060         bch2_trans_exit(&trans);
1061
1062         if (need_journal_commit * 2 > seen)
1063                 bch2_journal_flush_async(&c->journal, NULL);
1064
1065         percpu_ref_put(&c->writes);
1066
1067         trace_do_discards(c, seen, open, need_journal_commit, discarded, ret);
1068 }
1069
1070 void bch2_do_discards(struct bch_fs *c)
1071 {
1072         if (percpu_ref_tryget(&c->writes) &&
1073             !queue_work(system_long_wq, &c->discard_work))
1074                 percpu_ref_put(&c->writes);
1075 }
1076
1077 static int invalidate_one_bucket(struct btree_trans *trans, struct bch_dev *ca)
1078 {
1079         struct bch_fs *c = trans->c;
1080         struct btree_iter lru_iter, alloc_iter = { NULL };
1081         struct bkey_s_c k;
1082         struct bkey_i_alloc_v4 *a;
1083         u64 bucket, idx;
1084         struct printbuf buf = PRINTBUF;
1085         int ret;
1086
1087         bch2_trans_iter_init(trans, &lru_iter, BTREE_ID_lru,
1088                              POS(ca->dev_idx, 0), 0);
1089         k = bch2_btree_iter_peek(&lru_iter);
1090         ret = bkey_err(k);
1091         if (ret)
1092                 goto out;
1093
1094         if (!k.k || k.k->p.inode != ca->dev_idx)
1095                 goto out;
1096
1097         if (bch2_trans_inconsistent_on(k.k->type != KEY_TYPE_lru, trans,
1098                                        "non lru key in lru btree"))
1099                 goto out;
1100
1101         idx     = k.k->p.offset;
1102         bucket  = le64_to_cpu(bkey_s_c_to_lru(k).v->idx);
1103
1104         a = bch2_trans_start_alloc_update(trans, &alloc_iter,
1105                                           POS(ca->dev_idx, bucket));
1106         ret = PTR_ERR_OR_ZERO(a);
1107         if (ret)
1108                 goto out;
1109
1110         if (idx != alloc_lru_idx(a->v)) {
1111                 pr_buf(&buf, "alloc key does not point back to lru entry when invalidating bucket:\n  ");
1112
1113                 bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(&a->k_i));
1114                 pr_buf(&buf, "\n  ");
1115                 bch2_bkey_val_to_text(&buf, c, k);
1116                 bch2_trans_inconsistent(trans, "%s", buf.buf);
1117                 ret = -EINVAL;
1118                 goto out;
1119         }
1120
1121         SET_BCH_ALLOC_V4_NEED_INC_GEN(&a->v, false);
1122         a->v.gen++;
1123         a->v.data_type          = 0;
1124         a->v.dirty_sectors      = 0;
1125         a->v.cached_sectors     = 0;
1126         a->v.io_time[READ]      = atomic64_read(&c->io_clock[READ].now);
1127         a->v.io_time[WRITE]     = atomic64_read(&c->io_clock[WRITE].now);
1128
1129         ret = bch2_trans_update(trans, &alloc_iter, &a->k_i,
1130                                 BTREE_TRIGGER_BUCKET_INVALIDATE);
1131 out:
1132         bch2_trans_iter_exit(trans, &alloc_iter);
1133         bch2_trans_iter_exit(trans, &lru_iter);
1134         printbuf_exit(&buf);
1135         return ret;
1136 }
1137
1138 static void bch2_do_invalidates_work(struct work_struct *work)
1139 {
1140         struct bch_fs *c = container_of(work, struct bch_fs, invalidate_work);
1141         struct bch_dev *ca;
1142         struct btree_trans trans;
1143         unsigned i;
1144         int ret = 0;
1145
1146         bch2_trans_init(&trans, c, 0, 0);
1147
1148         for_each_member_device(ca, c, i) {
1149                 s64 nr_to_invalidate =
1150                         should_invalidate_buckets(ca, bch2_dev_usage_read(ca));
1151
1152                 while (!ret && nr_to_invalidate-- >= 0)
1153                         ret = __bch2_trans_do(&trans, NULL, NULL,
1154                                               BTREE_INSERT_USE_RESERVE|
1155                                               BTREE_INSERT_NOFAIL,
1156                                         invalidate_one_bucket(&trans, ca));
1157         }
1158
1159         bch2_trans_exit(&trans);
1160         percpu_ref_put(&c->writes);
1161 }
1162
1163 void bch2_do_invalidates(struct bch_fs *c)
1164 {
1165         if (percpu_ref_tryget(&c->writes))
1166                 queue_work(system_long_wq, &c->invalidate_work);
1167 }
1168
1169 static int bch2_dev_freespace_init(struct bch_fs *c, struct bch_dev *ca)
1170 {
1171         struct btree_trans trans;
1172         struct btree_iter iter;
1173         struct bkey_s_c k;
1174         struct bch_alloc_v4 a;
1175         struct bch_member *m;
1176         int ret;
1177
1178         bch2_trans_init(&trans, c, 0, 0);
1179
1180         for_each_btree_key(&trans, iter, BTREE_ID_alloc,
1181                            POS(ca->dev_idx, ca->mi.first_bucket),
1182                            BTREE_ITER_SLOTS|
1183                            BTREE_ITER_PREFETCH, k, ret) {
1184                 if (iter.pos.offset >= ca->mi.nbuckets)
1185                         break;
1186
1187                 bch2_alloc_to_v4(k, &a);
1188                 ret = __bch2_trans_do(&trans, NULL, NULL,
1189                                       BTREE_INSERT_LAZY_RW,
1190                                  bch2_bucket_do_index(&trans, k, &a, true));
1191                 if (ret)
1192                         break;
1193         }
1194         bch2_trans_iter_exit(&trans, &iter);
1195
1196         bch2_trans_exit(&trans);
1197
1198         if (ret) {
1199                 bch_err(ca, "error initializing free space: %i", ret);
1200                 return ret;
1201         }
1202
1203         mutex_lock(&c->sb_lock);
1204         m = bch2_sb_get_members(c->disk_sb.sb)->members + ca->dev_idx;
1205         SET_BCH_MEMBER_FREESPACE_INITIALIZED(m, true);
1206         mutex_unlock(&c->sb_lock);
1207
1208         return ret;
1209 }
1210
1211 int bch2_fs_freespace_init(struct bch_fs *c)
1212 {
1213         struct bch_dev *ca;
1214         unsigned i;
1215         int ret = 0;
1216         bool doing_init = false;
1217
1218         /*
1219          * We can crash during the device add path, so we need to check this on
1220          * every mount:
1221          */
1222
1223         for_each_member_device(ca, c, i) {
1224                 if (ca->mi.freespace_initialized)
1225                         continue;
1226
1227                 if (!doing_init) {
1228                         bch_info(c, "initializing freespace");
1229                         doing_init = true;
1230                 }
1231
1232                 ret = bch2_dev_freespace_init(c, ca);
1233                 if (ret) {
1234                         percpu_ref_put(&ca->ref);
1235                         return ret;
1236                 }
1237         }
1238
1239         if (doing_init) {
1240                 mutex_lock(&c->sb_lock);
1241                 bch2_write_super(c);
1242                 mutex_unlock(&c->sb_lock);
1243
1244                 bch_verbose(c, "done initializing freespace");
1245         }
1246
1247         return ret;
1248 }
1249
1250 /* Bucket IO clocks: */
1251
1252 int bch2_bucket_io_time_reset(struct btree_trans *trans, unsigned dev,
1253                               size_t bucket_nr, int rw)
1254 {
1255         struct bch_fs *c = trans->c;
1256         struct btree_iter iter;
1257         struct bkey_i_alloc_v4 *a;
1258         u64 now;
1259         int ret = 0;
1260
1261         a = bch2_trans_start_alloc_update(trans, &iter,  POS(dev, bucket_nr));
1262         ret = PTR_ERR_OR_ZERO(a);
1263         if (ret)
1264                 return ret;
1265
1266         now = atomic64_read(&c->io_clock[rw].now);
1267         if (a->v.io_time[rw] == now)
1268                 goto out;
1269
1270         a->v.io_time[rw] = now;
1271
1272         ret   = bch2_trans_update(trans, &iter, &a->k_i, 0) ?:
1273                 bch2_trans_commit(trans, NULL, NULL, 0);
1274 out:
1275         bch2_trans_iter_exit(trans, &iter);
1276         return ret;
1277 }
1278
1279 /* Startup/shutdown (ro/rw): */
1280
1281 void bch2_recalc_capacity(struct bch_fs *c)
1282 {
1283         struct bch_dev *ca;
1284         u64 capacity = 0, reserved_sectors = 0, gc_reserve;
1285         unsigned bucket_size_max = 0;
1286         unsigned long ra_pages = 0;
1287         unsigned i;
1288
1289         lockdep_assert_held(&c->state_lock);
1290
1291         for_each_online_member(ca, c, i) {
1292                 struct backing_dev_info *bdi = ca->disk_sb.bdev->bd_disk->bdi;
1293
1294                 ra_pages += bdi->ra_pages;
1295         }
1296
1297         bch2_set_ra_pages(c, ra_pages);
1298
1299         for_each_rw_member(ca, c, i) {
1300                 u64 dev_reserve = 0;
1301
1302                 /*
1303                  * We need to reserve buckets (from the number
1304                  * of currently available buckets) against
1305                  * foreground writes so that mainly copygc can
1306                  * make forward progress.
1307                  *
1308                  * We need enough to refill the various reserves
1309                  * from scratch - copygc will use its entire
1310                  * reserve all at once, then run against when
1311                  * its reserve is refilled (from the formerly
1312                  * available buckets).
1313                  *
1314                  * This reserve is just used when considering if
1315                  * allocations for foreground writes must wait -
1316                  * not -ENOSPC calculations.
1317                  */
1318
1319                 dev_reserve += ca->nr_btree_reserve * 2;
1320                 dev_reserve += ca->mi.nbuckets >> 6; /* copygc reserve */
1321
1322                 dev_reserve += 1;       /* btree write point */
1323                 dev_reserve += 1;       /* copygc write point */
1324                 dev_reserve += 1;       /* rebalance write point */
1325
1326                 dev_reserve *= ca->mi.bucket_size;
1327
1328                 capacity += bucket_to_sector(ca, ca->mi.nbuckets -
1329                                              ca->mi.first_bucket);
1330
1331                 reserved_sectors += dev_reserve * 2;
1332
1333                 bucket_size_max = max_t(unsigned, bucket_size_max,
1334                                         ca->mi.bucket_size);
1335         }
1336
1337         gc_reserve = c->opts.gc_reserve_bytes
1338                 ? c->opts.gc_reserve_bytes >> 9
1339                 : div64_u64(capacity * c->opts.gc_reserve_percent, 100);
1340
1341         reserved_sectors = max(gc_reserve, reserved_sectors);
1342
1343         reserved_sectors = min(reserved_sectors, capacity);
1344
1345         c->capacity = capacity - reserved_sectors;
1346
1347         c->bucket_size_max = bucket_size_max;
1348
1349         /* Wake up case someone was waiting for buckets */
1350         closure_wake_up(&c->freelist_wait);
1351 }
1352
1353 static bool bch2_dev_has_open_write_point(struct bch_fs *c, struct bch_dev *ca)
1354 {
1355         struct open_bucket *ob;
1356         bool ret = false;
1357
1358         for (ob = c->open_buckets;
1359              ob < c->open_buckets + ARRAY_SIZE(c->open_buckets);
1360              ob++) {
1361                 spin_lock(&ob->lock);
1362                 if (ob->valid && !ob->on_partial_list &&
1363                     ob->dev == ca->dev_idx)
1364                         ret = true;
1365                 spin_unlock(&ob->lock);
1366         }
1367
1368         return ret;
1369 }
1370
1371 /* device goes ro: */
1372 void bch2_dev_allocator_remove(struct bch_fs *c, struct bch_dev *ca)
1373 {
1374         unsigned i;
1375
1376         /* First, remove device from allocation groups: */
1377
1378         for (i = 0; i < ARRAY_SIZE(c->rw_devs); i++)
1379                 clear_bit(ca->dev_idx, c->rw_devs[i].d);
1380
1381         /*
1382          * Capacity is calculated based off of devices in allocation groups:
1383          */
1384         bch2_recalc_capacity(c);
1385
1386         /* Next, close write points that point to this device... */
1387         for (i = 0; i < ARRAY_SIZE(c->write_points); i++)
1388                 bch2_writepoint_stop(c, ca, &c->write_points[i]);
1389
1390         bch2_writepoint_stop(c, ca, &c->copygc_write_point);
1391         bch2_writepoint_stop(c, ca, &c->rebalance_write_point);
1392         bch2_writepoint_stop(c, ca, &c->btree_write_point);
1393
1394         mutex_lock(&c->btree_reserve_cache_lock);
1395         while (c->btree_reserve_cache_nr) {
1396                 struct btree_alloc *a =
1397                         &c->btree_reserve_cache[--c->btree_reserve_cache_nr];
1398
1399                 bch2_open_buckets_put(c, &a->ob);
1400         }
1401         mutex_unlock(&c->btree_reserve_cache_lock);
1402
1403         while (1) {
1404                 struct open_bucket *ob;
1405
1406                 spin_lock(&c->freelist_lock);
1407                 if (!ca->open_buckets_partial_nr) {
1408                         spin_unlock(&c->freelist_lock);
1409                         break;
1410                 }
1411                 ob = c->open_buckets +
1412                         ca->open_buckets_partial[--ca->open_buckets_partial_nr];
1413                 ob->on_partial_list = false;
1414                 spin_unlock(&c->freelist_lock);
1415
1416                 bch2_open_bucket_put(c, ob);
1417         }
1418
1419         bch2_ec_stop_dev(c, ca);
1420
1421         /*
1422          * Wake up threads that were blocked on allocation, so they can notice
1423          * the device can no longer be removed and the capacity has changed:
1424          */
1425         closure_wake_up(&c->freelist_wait);
1426
1427         /*
1428          * journal_res_get() can block waiting for free space in the journal -
1429          * it needs to notice there may not be devices to allocate from anymore:
1430          */
1431         wake_up(&c->journal.wait);
1432
1433         /* Now wait for any in flight writes: */
1434
1435         closure_wait_event(&c->open_buckets_wait,
1436                            !bch2_dev_has_open_write_point(c, ca));
1437 }
1438
1439 /* device goes rw: */
1440 void bch2_dev_allocator_add(struct bch_fs *c, struct bch_dev *ca)
1441 {
1442         unsigned i;
1443
1444         for (i = 0; i < ARRAY_SIZE(c->rw_devs); i++)
1445                 if (ca->mi.data_allowed & (1 << i))
1446                         set_bit(ca->dev_idx, c->rw_devs[i].d);
1447 }
1448
1449 void bch2_fs_allocator_background_init(struct bch_fs *c)
1450 {
1451         spin_lock_init(&c->freelist_lock);
1452         INIT_WORK(&c->discard_work, bch2_do_discards_work);
1453         INIT_WORK(&c->invalidate_work, bch2_do_invalidates_work);
1454 }