Merge tag 'icc-6.7-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/djakov/icc...
[linux-2.6-microblaze.git] / fs / bcachefs / movinggc.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Moving/copying garbage collector
4  *
5  * Copyright 2012 Google, Inc.
6  */
7
8 #include "bcachefs.h"
9 #include "alloc_background.h"
10 #include "alloc_foreground.h"
11 #include "btree_iter.h"
12 #include "btree_update.h"
13 #include "btree_write_buffer.h"
14 #include "buckets.h"
15 #include "clock.h"
16 #include "errcode.h"
17 #include "error.h"
18 #include "lru.h"
19 #include "move.h"
20 #include "movinggc.h"
21 #include "trace.h"
22
23 #include <linux/freezer.h>
24 #include <linux/kthread.h>
25 #include <linux/math64.h>
26 #include <linux/sched/task.h>
27 #include <linux/wait.h>
28
29 struct buckets_in_flight {
30         struct rhashtable               table;
31         struct move_bucket_in_flight    *first;
32         struct move_bucket_in_flight    *last;
33         size_t                          nr;
34         size_t                          sectors;
35 };
36
37 static const struct rhashtable_params bch_move_bucket_params = {
38         .head_offset    = offsetof(struct move_bucket_in_flight, hash),
39         .key_offset     = offsetof(struct move_bucket_in_flight, bucket.k),
40         .key_len        = sizeof(struct move_bucket_key),
41 };
42
43 static struct move_bucket_in_flight *
44 move_bucket_in_flight_add(struct buckets_in_flight *list, struct move_bucket b)
45 {
46         struct move_bucket_in_flight *new = kzalloc(sizeof(*new), GFP_KERNEL);
47         int ret;
48
49         if (!new)
50                 return ERR_PTR(-ENOMEM);
51
52         new->bucket = b;
53
54         ret = rhashtable_lookup_insert_fast(&list->table, &new->hash,
55                                             bch_move_bucket_params);
56         if (ret) {
57                 kfree(new);
58                 return ERR_PTR(ret);
59         }
60
61         if (!list->first)
62                 list->first = new;
63         else
64                 list->last->next = new;
65
66         list->last = new;
67         list->nr++;
68         list->sectors += b.sectors;
69         return new;
70 }
71
72 static int bch2_bucket_is_movable(struct btree_trans *trans,
73                                   struct move_bucket *b, u64 time)
74 {
75         struct btree_iter iter;
76         struct bkey_s_c k;
77         struct bch_alloc_v4 _a;
78         const struct bch_alloc_v4 *a;
79         int ret;
80
81         if (bch2_bucket_is_open(trans->c,
82                                 b->k.bucket.inode,
83                                 b->k.bucket.offset))
84                 return 0;
85
86         k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_alloc,
87                                b->k.bucket, BTREE_ITER_CACHED);
88         ret = bkey_err(k);
89         if (ret)
90                 return ret;
91
92         a = bch2_alloc_to_v4(k, &_a);
93         b->k.gen        = a->gen;
94         b->sectors      = a->dirty_sectors;
95
96         ret = data_type_movable(a->data_type) &&
97                 a->fragmentation_lru &&
98                 a->fragmentation_lru <= time;
99
100         bch2_trans_iter_exit(trans, &iter);
101         return ret;
102 }
103
104 static void move_buckets_wait(struct moving_context *ctxt,
105                               struct buckets_in_flight *list,
106                               bool flush)
107 {
108         struct move_bucket_in_flight *i;
109         int ret;
110
111         while ((i = list->first)) {
112                 if (flush)
113                         move_ctxt_wait_event(ctxt, !atomic_read(&i->count));
114
115                 if (atomic_read(&i->count))
116                         break;
117
118                 list->first = i->next;
119                 if (!list->first)
120                         list->last = NULL;
121
122                 list->nr--;
123                 list->sectors -= i->bucket.sectors;
124
125                 ret = rhashtable_remove_fast(&list->table, &i->hash,
126                                              bch_move_bucket_params);
127                 BUG_ON(ret);
128                 kfree(i);
129         }
130
131         bch2_trans_unlock_long(ctxt->trans);
132 }
133
134 static bool bucket_in_flight(struct buckets_in_flight *list,
135                              struct move_bucket_key k)
136 {
137         return rhashtable_lookup_fast(&list->table, &k, bch_move_bucket_params);
138 }
139
140 typedef DARRAY(struct move_bucket) move_buckets;
141
142 static int bch2_copygc_get_buckets(struct moving_context *ctxt,
143                         struct buckets_in_flight *buckets_in_flight,
144                         move_buckets *buckets)
145 {
146         struct btree_trans *trans = ctxt->trans;
147         struct bch_fs *c = trans->c;
148         struct btree_iter iter;
149         struct bkey_s_c k;
150         size_t nr_to_get = max_t(size_t, 16U, buckets_in_flight->nr / 4);
151         size_t saw = 0, in_flight = 0, not_movable = 0, sectors = 0;
152         int ret;
153
154         move_buckets_wait(ctxt, buckets_in_flight, false);
155
156         ret = bch2_btree_write_buffer_flush(trans);
157         if (bch2_fs_fatal_err_on(ret, c, "%s: error %s from bch2_btree_write_buffer_flush()",
158                                  __func__, bch2_err_str(ret)))
159                 return ret;
160
161         ret = for_each_btree_key2_upto(trans, iter, BTREE_ID_lru,
162                                   lru_pos(BCH_LRU_FRAGMENTATION_START, 0, 0),
163                                   lru_pos(BCH_LRU_FRAGMENTATION_START, U64_MAX, LRU_TIME_MAX),
164                                   0, k, ({
165                 struct move_bucket b = { .k.bucket = u64_to_bucket(k.k->p.offset) };
166                 int ret2 = 0;
167
168                 saw++;
169
170                 if (!bch2_bucket_is_movable(trans, &b, lru_pos_time(k.k->p)))
171                         not_movable++;
172                 else if (bucket_in_flight(buckets_in_flight, b.k))
173                         in_flight++;
174                 else {
175                         ret2 = darray_push(buckets, b) ?: buckets->nr >= nr_to_get;
176                         if (ret2 >= 0)
177                                 sectors += b.sectors;
178                 }
179                 ret2;
180         }));
181
182         pr_debug("have: %zu (%zu) saw %zu in flight %zu not movable %zu got %zu (%zu)/%zu buckets ret %i",
183                  buckets_in_flight->nr, buckets_in_flight->sectors,
184                  saw, in_flight, not_movable, buckets->nr, sectors, nr_to_get, ret);
185
186         return ret < 0 ? ret : 0;
187 }
188
189 noinline
190 static int bch2_copygc(struct moving_context *ctxt,
191                        struct buckets_in_flight *buckets_in_flight,
192                        bool *did_work)
193 {
194         struct btree_trans *trans = ctxt->trans;
195         struct bch_fs *c = trans->c;
196         struct data_update_opts data_opts = {
197                 .btree_insert_flags = BCH_WATERMARK_copygc,
198         };
199         move_buckets buckets = { 0 };
200         struct move_bucket_in_flight *f;
201         struct move_bucket *i;
202         u64 moved = atomic64_read(&ctxt->stats->sectors_moved);
203         int ret = 0;
204
205         ret = bch2_copygc_get_buckets(ctxt, buckets_in_flight, &buckets);
206         if (ret)
207                 goto err;
208
209         darray_for_each(buckets, i) {
210                 if (kthread_should_stop() || freezing(current))
211                         break;
212
213                 f = move_bucket_in_flight_add(buckets_in_flight, *i);
214                 ret = PTR_ERR_OR_ZERO(f);
215                 if (ret == -EEXIST) { /* rare race: copygc_get_buckets returned same bucket more than once */
216                         ret = 0;
217                         continue;
218                 }
219                 if (ret == -ENOMEM) { /* flush IO, continue later */
220                         ret = 0;
221                         break;
222                 }
223
224                 ret = __bch2_evacuate_bucket(ctxt, f, f->bucket.k.bucket,
225                                              f->bucket.k.gen, data_opts);
226                 if (ret)
227                         goto err;
228
229                 *did_work = true;
230         }
231 err:
232         darray_exit(&buckets);
233
234         /* no entries in LRU btree found, or got to end: */
235         if (bch2_err_matches(ret, ENOENT))
236                 ret = 0;
237
238         if (ret < 0 && !bch2_err_matches(ret, EROFS))
239                 bch_err_msg(c, ret, "from bch2_move_data()");
240
241         moved = atomic64_read(&ctxt->stats->sectors_moved) - moved;
242         trace_and_count(c, copygc, c, moved, 0, 0, 0);
243         return ret;
244 }
245
246 /*
247  * Copygc runs when the amount of fragmented data is above some arbitrary
248  * threshold:
249  *
250  * The threshold at the limit - when the device is full - is the amount of space
251  * we reserved in bch2_recalc_capacity; we can't have more than that amount of
252  * disk space stranded due to fragmentation and store everything we have
253  * promised to store.
254  *
255  * But we don't want to be running copygc unnecessarily when the device still
256  * has plenty of free space - rather, we want copygc to smoothly run every so
257  * often and continually reduce the amount of fragmented space as the device
258  * fills up. So, we increase the threshold by half the current free space.
259  */
260 unsigned long bch2_copygc_wait_amount(struct bch_fs *c)
261 {
262         struct bch_dev *ca;
263         unsigned dev_idx;
264         s64 wait = S64_MAX, fragmented_allowed, fragmented;
265         unsigned i;
266
267         for_each_rw_member(ca, c, dev_idx) {
268                 struct bch_dev_usage usage = bch2_dev_usage_read(ca);
269
270                 fragmented_allowed = ((__dev_buckets_available(ca, usage, BCH_WATERMARK_stripe) *
271                                        ca->mi.bucket_size) >> 1);
272                 fragmented = 0;
273
274                 for (i = 0; i < BCH_DATA_NR; i++)
275                         if (data_type_movable(i))
276                                 fragmented += usage.d[i].fragmented;
277
278                 wait = min(wait, max(0LL, fragmented_allowed - fragmented));
279         }
280
281         return wait;
282 }
283
284 void bch2_copygc_wait_to_text(struct printbuf *out, struct bch_fs *c)
285 {
286         prt_printf(out, "Currently waiting for:     ");
287         prt_human_readable_u64(out, max(0LL, c->copygc_wait -
288                                         atomic64_read(&c->io_clock[WRITE].now)) << 9);
289         prt_newline(out);
290
291         prt_printf(out, "Currently waiting since:   ");
292         prt_human_readable_u64(out, max(0LL,
293                                         atomic64_read(&c->io_clock[WRITE].now) -
294                                         c->copygc_wait_at) << 9);
295         prt_newline(out);
296
297         prt_printf(out, "Currently calculated wait: ");
298         prt_human_readable_u64(out, bch2_copygc_wait_amount(c));
299         prt_newline(out);
300 }
301
302 static int bch2_copygc_thread(void *arg)
303 {
304         struct bch_fs *c = arg;
305         struct moving_context ctxt;
306         struct bch_move_stats move_stats;
307         struct io_clock *clock = &c->io_clock[WRITE];
308         struct buckets_in_flight *buckets;
309         u64 last, wait;
310         int ret = 0;
311
312         buckets = kzalloc(sizeof(struct buckets_in_flight), GFP_KERNEL);
313         if (!buckets)
314                 return -ENOMEM;
315         ret = rhashtable_init(&buckets->table, &bch_move_bucket_params);
316         if (ret) {
317                 kfree(buckets);
318                 bch_err_msg(c, ret, "allocating copygc buckets in flight");
319                 return ret;
320         }
321
322         set_freezable();
323
324         bch2_move_stats_init(&move_stats, "copygc");
325         bch2_moving_ctxt_init(&ctxt, c, NULL, &move_stats,
326                               writepoint_ptr(&c->copygc_write_point),
327                               false);
328
329         while (!ret && !kthread_should_stop()) {
330                 bool did_work = false;
331
332                 bch2_trans_unlock_long(ctxt.trans);
333                 cond_resched();
334
335                 if (!c->copy_gc_enabled) {
336                         move_buckets_wait(&ctxt, buckets, true);
337                         kthread_wait_freezable(c->copy_gc_enabled);
338                 }
339
340                 if (unlikely(freezing(current))) {
341                         move_buckets_wait(&ctxt, buckets, true);
342                         __refrigerator(false);
343                         continue;
344                 }
345
346                 last = atomic64_read(&clock->now);
347                 wait = bch2_copygc_wait_amount(c);
348
349                 if (wait > clock->max_slop) {
350                         c->copygc_wait_at = last;
351                         c->copygc_wait = last + wait;
352                         move_buckets_wait(&ctxt, buckets, true);
353                         trace_and_count(c, copygc_wait, c, wait, last + wait);
354                         bch2_kthread_io_clock_wait(clock, last + wait,
355                                         MAX_SCHEDULE_TIMEOUT);
356                         continue;
357                 }
358
359                 c->copygc_wait = 0;
360
361                 c->copygc_running = true;
362                 ret = bch2_copygc(&ctxt, buckets, &did_work);
363                 c->copygc_running = false;
364
365                 wake_up(&c->copygc_running_wq);
366
367                 if (!wait && !did_work) {
368                         u64 min_member_capacity = bch2_min_rw_member_capacity(c);
369
370                         if (min_member_capacity == U64_MAX)
371                                 min_member_capacity = 128 * 2048;
372
373                         bch2_trans_unlock_long(ctxt.trans);
374                         bch2_kthread_io_clock_wait(clock, last + (min_member_capacity >> 6),
375                                         MAX_SCHEDULE_TIMEOUT);
376                 }
377         }
378
379         move_buckets_wait(&ctxt, buckets, true);
380
381         rhashtable_destroy(&buckets->table);
382         kfree(buckets);
383         bch2_moving_ctxt_exit(&ctxt);
384         bch2_move_stats_exit(&move_stats, c);
385
386         return 0;
387 }
388
389 void bch2_copygc_stop(struct bch_fs *c)
390 {
391         if (c->copygc_thread) {
392                 kthread_stop(c->copygc_thread);
393                 put_task_struct(c->copygc_thread);
394         }
395         c->copygc_thread = NULL;
396 }
397
398 int bch2_copygc_start(struct bch_fs *c)
399 {
400         struct task_struct *t;
401         int ret;
402
403         if (c->copygc_thread)
404                 return 0;
405
406         if (c->opts.nochanges)
407                 return 0;
408
409         if (bch2_fs_init_fault("copygc_start"))
410                 return -ENOMEM;
411
412         t = kthread_create(bch2_copygc_thread, c, "bch-copygc/%s", c->name);
413         ret = PTR_ERR_OR_ZERO(t);
414         if (ret) {
415                 bch_err_msg(c, ret, "creating copygc thread");
416                 return ret;
417         }
418
419         get_task_struct(t);
420
421         c->copygc_thread = t;
422         wake_up_process(c->copygc_thread);
423
424         return 0;
425 }
426
427 void bch2_fs_copygc_init(struct bch_fs *c)
428 {
429         init_waitqueue_head(&c->copygc_running_wq);
430         c->copygc_running = false;
431 }