fs/bcachefs/util.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * random utility code, for bcache but in theory not specific to bcache
   4  *
   5  * Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
   6  * Copyright 2012 Google, Inc.
   7  */
   8
   9 #include <linux/bio.h>
  10 #include <linux/blkdev.h>
  11 #include <linux/console.h>
  12 #include <linux/ctype.h>
  13 #include <linux/debugfs.h>
  14 #include <linux/freezer.h>
  15 #include <linux/kthread.h>
  16 #include <linux/log2.h>
  17 #include <linux/math64.h>
  18 #include <linux/percpu.h>
  19 #include <linux/preempt.h>
  20 #include <linux/random.h>
  21 #include <linux/seq_file.h>
  22 #include <linux/string.h>
  23 #include <linux/types.h>
  24 #include <linux/sched/clock.h>
  25
  26 #include "eytzinger.h"
  27 #include "mean_and_variance.h"
  28 #include "util.h"
  29
  30 static const char si_units[] = "?kMGTPEZY";
  31
  32 /* string_get_size units: */
  33 static const char *const units_2[] = {
  34         "B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB", "ZiB", "YiB"
  35 };
  36 static const char *const units_10[] = {
  37         "B", "kB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"
  38 };
  39
  40 static int parse_u64(const char *cp, u64 *res)
  41 {
  42         const char *start = cp;
  43         u64 v = 0;
  44
  45         if (!isdigit(*cp))
  46                 return -EINVAL;
  47
  48         do {
  49                 if (v > U64_MAX / 10)
  50                         return -ERANGE;
  51                 v *= 10;
  52                 if (v > U64_MAX - (*cp - '0'))
  53                         return -ERANGE;
  54                 v += *cp - '0';
  55                 cp++;
  56         } while (isdigit(*cp));
  57
  58         *res = v;
  59         return cp - start;
  60 }
  61
  62 static int bch2_pow(u64 n, u64 p, u64 *res)
  63 {
  64         *res = 1;
  65
  66         while (p--) {
  67                 if (*res > div64_u64(U64_MAX, n))
  68                         return -ERANGE;
  69                 *res *= n;
  70         }
  71         return 0;
  72 }
  73
  74 static int parse_unit_suffix(const char *cp, u64 *res)
  75 {
  76         const char *start = cp;
  77         u64 base = 1024;
  78         unsigned u;
  79         int ret;
  80
  81         if (*cp == ' ')
  82                 cp++;
  83
  84         for (u = 1; u < strlen(si_units); u++)
  85                 if (*cp == si_units[u]) {
  86                         cp++;
  87                         goto got_unit;
  88                 }
  89
  90         for (u = 0; u < ARRAY_SIZE(units_2); u++)
  91                 if (!strncmp(cp, units_2[u], strlen(units_2[u]))) {
  92                         cp += strlen(units_2[u]);
  93                         goto got_unit;
  94                 }
  95
  96         for (u = 0; u < ARRAY_SIZE(units_10); u++)
  97                 if (!strncmp(cp, units_10[u], strlen(units_10[u]))) {
  98                         cp += strlen(units_10[u]);
  99                         base = 1000;
 100                         goto got_unit;
 101                 }
 102
 103         *res = 1;
 104         return 0;
 105 got_unit:
 106         ret = bch2_pow(base, u, res);
 107         if (ret)
 108                 return ret;
 109
 110         return cp - start;
 111 }
 112
 113 #define parse_or_ret(cp, _f)                    \
 114 do {                                            \
 115         int _ret = _f;                          \
 116         if (_ret < 0)                           \
 117                 return _ret;                    \
 118         cp += _ret;                             \
 119 } while (0)
 120
 121 static int __bch2_strtou64_h(const char *cp, u64 *res)
 122 {
 123         const char *start = cp;
 124         u64 v = 0, b, f_n = 0, f_d = 1;
 125         int ret;
 126
 127         parse_or_ret(cp, parse_u64(cp, &v));
 128
 129         if (*cp == '.') {
 130                 cp++;
 131                 ret = parse_u64(cp, &f_n);
 132                 if (ret < 0)
 133                         return ret;
 134                 cp += ret;
 135
 136                 ret = bch2_pow(10, ret, &f_d);
 137                 if (ret)
 138                         return ret;
 139         }
 140
 141         parse_or_ret(cp, parse_unit_suffix(cp, &b));
 142
 143         if (v > div64_u64(U64_MAX, b))
 144                 return -ERANGE;
 145         v *= b;
 146
 147         if (f_n > div64_u64(U64_MAX, b))
 148                 return -ERANGE;
 149
 150         f_n = div64_u64(f_n * b, f_d);
 151         if (v + f_n < v)
 152                 return -ERANGE;
 153         v += f_n;
 154
 155         *res = v;
 156         return cp - start;
 157 }
 158
 159 static int __bch2_strtoh(const char *cp, u64 *res,
 160                          u64 t_max, bool t_signed)
 161 {
 162         bool positive = *cp != '-';
 163         u64 v = 0;
 164
 165         if (*cp == '+' || *cp == '-')
 166                 cp++;
 167
 168         parse_or_ret(cp, __bch2_strtou64_h(cp, &v));
 169
 170         if (*cp == '\n')
 171                 cp++;
 172         if (*cp)
 173                 return -EINVAL;
 174
 175         if (positive) {
 176                 if (v > t_max)
 177                         return -ERANGE;
 178         } else {
 179                 if (v && !t_signed)
 180                         return -ERANGE;
 181
 182                 if (v > t_max + 1)
 183                         return -ERANGE;
 184                 v = -v;
 185         }
 186
 187         *res = v;
 188         return 0;
 189 }
 190
 191 #define STRTO_H(name, type)                                     \
 192 int bch2_ ## name ## _h(const char *cp, type *res)              \
 193 {                                                               \
 194         u64 v = 0;                                              \
 195         int ret = __bch2_strtoh(cp, &v, ANYSINT_MAX(type),      \
 196                         ANYSINT_MAX(type) != ((type) ~0ULL));   \
 197         *res = v;                                               \
 198         return ret;                                             \
 199 }
 200
 201 STRTO_H(strtoint, int)
 202 STRTO_H(strtouint, unsigned int)
 203 STRTO_H(strtoll, long long)
 204 STRTO_H(strtoull, unsigned long long)
 205 STRTO_H(strtou64, u64)
 206
 207 u64 bch2_read_flag_list(const char *opt, const char * const list[])
 208 {
 209         u64 ret = 0;
 210         char *p, *s, *d = kstrdup(opt, GFP_KERNEL);
 211
 212         if (!d)
 213                 return -ENOMEM;
 214
 215         s = strim(d);
 216
 217         while ((p = strsep(&s, ",;"))) {
 218                 int flag = match_string(list, -1, p);
 219
 220                 if (flag < 0) {
 221                         ret = -1;
 222                         break;
 223                 }
 224
 225                 ret |= BIT_ULL(flag);
 226         }
 227
 228         kfree(d);
 229
 230         return ret;
 231 }
 232
 233 bool bch2_is_zero(const void *_p, size_t n)
 234 {
 235         const char *p = _p;
 236         size_t i;
 237
 238         for (i = 0; i < n; i++)
 239                 if (p[i])
 240                         return false;
 241         return true;
 242 }
 243
 244 void bch2_prt_u64_base2_nbits(struct printbuf *out, u64 v, unsigned nr_bits)
 245 {
 246         while (nr_bits)
 247                 prt_char(out, '0' + ((v >> --nr_bits) & 1));
 248 }
 249
 250 void bch2_prt_u64_base2(struct printbuf *out, u64 v)
 251 {
 252         bch2_prt_u64_base2_nbits(out, v, fls64(v) ?: 1);
 253 }
 254
 255 static void __bch2_print_string_as_lines(const char *prefix, const char *lines,
 256                                          bool nonblocking)
 257 {
 258         bool locked = false;
 259         const char *p;
 260
 261         if (!lines) {
 262                 printk("%s (null)\n", prefix);
 263                 return;
 264         }
 265
 266         if (!nonblocking) {
 267                 console_lock();
 268                 locked = true;
 269         } else {
 270                 locked = console_trylock();
 271         }
 272
 273         while (1) {
 274                 p = strchrnul(lines, '\n');
 275                 printk("%s%.*s\n", prefix, (int) (p - lines), lines);
 276                 if (!*p)
 277                         break;
 278                 lines = p + 1;
 279         }
 280         if (locked)
 281                 console_unlock();
 282 }
 283
 284 void bch2_print_string_as_lines(const char *prefix, const char *lines)
 285 {
 286         return __bch2_print_string_as_lines(prefix, lines, false);
 287 }
 288
 289 void bch2_print_string_as_lines_nonblocking(const char *prefix, const char *lines)
 290 {
 291         return __bch2_print_string_as_lines(prefix, lines, true);
 292 }
 293
 294 int bch2_save_backtrace(bch_stacktrace *stack, struct task_struct *task, unsigned skipnr,
 295                         gfp_t gfp)
 296 {
 297 #ifdef CONFIG_STACKTRACE
 298         unsigned nr_entries = 0;
 299
 300         stack->nr = 0;
 301         int ret = darray_make_room_gfp(stack, 32, gfp);
 302         if (ret)
 303                 return ret;
 304
 305         if (!down_read_trylock(&task->signal->exec_update_lock))
 306                 return -1;
 307
 308         do {
 309                 nr_entries = stack_trace_save_tsk(task, stack->data, stack->size, skipnr + 1);
 310         } while (nr_entries == stack->size &&
 311                  !(ret = darray_make_room_gfp(stack, stack->size * 2, gfp)));
 312
 313         stack->nr = nr_entries;
 314         up_read(&task->signal->exec_update_lock);
 315
 316         return ret;
 317 #else
 318         return 0;
 319 #endif
 320 }
 321
 322 void bch2_prt_backtrace(struct printbuf *out, bch_stacktrace *stack)
 323 {
 324         darray_for_each(*stack, i) {
 325                 prt_printf(out, "[<0>] %pB", (void *) *i);
 326                 prt_newline(out);
 327         }
 328 }
 329
 330 int bch2_prt_task_backtrace(struct printbuf *out, struct task_struct *task, unsigned skipnr, gfp_t gfp)
 331 {
 332         bch_stacktrace stack = { 0 };
 333         int ret = bch2_save_backtrace(&stack, task, skipnr + 1, gfp);
 334
 335         bch2_prt_backtrace(out, &stack);
 336         darray_exit(&stack);
 337         return ret;
 338 }
 339
 340 #ifndef __KERNEL__
 341 #include <time.h>
 342 void bch2_prt_datetime(struct printbuf *out, time64_t sec)
 343 {
 344         time_t t = sec;
 345         char buf[64];
 346         ctime_r(&t, buf);
 347         strim(buf);
 348         prt_str(out, buf);
 349 }
 350 #else
 351 void bch2_prt_datetime(struct printbuf *out, time64_t sec)
 352 {
 353         char buf[64];
 354         snprintf(buf, sizeof(buf), "%ptT", &sec);
 355         prt_u64(out, sec);
 356 }
 357 #endif
 358
 359 void bch2_pr_time_units(struct printbuf *out, u64 ns)
 360 {
 361         const struct time_unit *u = bch2_pick_time_units(ns);
 362
 363         prt_printf(out, "%llu %s", div64_u64(ns, u->nsecs), u->name);
 364 }
 365
 366 static void bch2_pr_time_units_aligned(struct printbuf *out, u64 ns)
 367 {
 368         const struct time_unit *u = bch2_pick_time_units(ns);
 369
 370         prt_printf(out, "%llu \r%s", div64_u64(ns, u->nsecs), u->name);
 371 }
 372
 373 static inline void pr_name_and_units(struct printbuf *out, const char *name, u64 ns)
 374 {
 375         prt_printf(out, "%s\t", name);
 376         bch2_pr_time_units_aligned(out, ns);
 377         prt_newline(out);
 378 }
 379
 380 #define TABSTOP_SIZE 12
 381
 382 void bch2_time_stats_to_text(struct printbuf *out, struct bch2_time_stats *stats)
 383 {
 384         struct quantiles *quantiles = time_stats_to_quantiles(stats);
 385         s64 f_mean = 0, d_mean = 0;
 386         u64 f_stddev = 0, d_stddev = 0;
 387
 388         if (stats->buffer) {
 389                 int cpu;
 390
 391                 spin_lock_irq(&stats->lock);
 392                 for_each_possible_cpu(cpu)
 393                         __bch2_time_stats_clear_buffer(stats, per_cpu_ptr(stats->buffer, cpu));
 394                 spin_unlock_irq(&stats->lock);
 395         }
 396
 397         /*
 398          * avoid divide by zero
 399          */
 400         if (stats->freq_stats.n) {
 401                 f_mean = mean_and_variance_get_mean(stats->freq_stats);
 402                 f_stddev = mean_and_variance_get_stddev(stats->freq_stats);
 403                 d_mean = mean_and_variance_get_mean(stats->duration_stats);
 404                 d_stddev = mean_and_variance_get_stddev(stats->duration_stats);
 405         }
 406
 407         printbuf_tabstop_push(out, out->indent + TABSTOP_SIZE);
 408         prt_printf(out, "count:\t%llu\n", stats->duration_stats.n);
 409         printbuf_tabstop_pop(out);
 410
 411         printbuf_tabstops_reset(out);
 412
 413         printbuf_tabstop_push(out, out->indent + 20);
 414         printbuf_tabstop_push(out, TABSTOP_SIZE + 2);
 415         printbuf_tabstop_push(out, 0);
 416         printbuf_tabstop_push(out, TABSTOP_SIZE + 2);
 417
 418         prt_printf(out, "\tsince mount\r\trecent\r\n");
 419
 420         printbuf_tabstops_reset(out);
 421         printbuf_tabstop_push(out, out->indent + 20);
 422         printbuf_tabstop_push(out, TABSTOP_SIZE);
 423         printbuf_tabstop_push(out, 2);
 424         printbuf_tabstop_push(out, TABSTOP_SIZE);
 425
 426         prt_printf(out, "duration of events\n");
 427         printbuf_indent_add(out, 2);
 428
 429         pr_name_and_units(out, "min:", stats->min_duration);
 430         pr_name_and_units(out, "max:", stats->max_duration);
 431         pr_name_and_units(out, "total:", stats->total_duration);
 432
 433         prt_printf(out, "mean:\t");
 434         bch2_pr_time_units_aligned(out, d_mean);
 435         prt_tab(out);
 436         bch2_pr_time_units_aligned(out, mean_and_variance_weighted_get_mean(stats->duration_stats_weighted, TIME_STATS_MV_WEIGHT));
 437         prt_newline(out);
 438
 439         prt_printf(out, "stddev:\t");
 440         bch2_pr_time_units_aligned(out, d_stddev);
 441         prt_tab(out);
 442         bch2_pr_time_units_aligned(out, mean_and_variance_weighted_get_stddev(stats->duration_stats_weighted, TIME_STATS_MV_WEIGHT));
 443
 444         printbuf_indent_sub(out, 2);
 445         prt_newline(out);
 446
 447         prt_printf(out, "time between events\n");
 448         printbuf_indent_add(out, 2);
 449
 450         pr_name_and_units(out, "min:", stats->min_freq);
 451         pr_name_and_units(out, "max:", stats->max_freq);
 452
 453         prt_printf(out, "mean:\t");
 454         bch2_pr_time_units_aligned(out, f_mean);
 455         prt_tab(out);
 456         bch2_pr_time_units_aligned(out, mean_and_variance_weighted_get_mean(stats->freq_stats_weighted, TIME_STATS_MV_WEIGHT));
 457         prt_newline(out);
 458
 459         prt_printf(out, "stddev:\t");
 460         bch2_pr_time_units_aligned(out, f_stddev);
 461         prt_tab(out);
 462         bch2_pr_time_units_aligned(out, mean_and_variance_weighted_get_stddev(stats->freq_stats_weighted, TIME_STATS_MV_WEIGHT));
 463
 464         printbuf_indent_sub(out, 2);
 465         prt_newline(out);
 466
 467         printbuf_tabstops_reset(out);
 468
 469         if (quantiles) {
 470                 int i = eytzinger0_first(NR_QUANTILES);
 471                 const struct time_unit *u =
 472                         bch2_pick_time_units(quantiles->entries[i].m);
 473                 u64 last_q = 0;
 474
 475                 prt_printf(out, "quantiles (%s):\t", u->name);
 476                 eytzinger0_for_each(i, NR_QUANTILES) {
 477                         bool is_last = eytzinger0_next(i, NR_QUANTILES) == -1;
 478
 479                         u64 q = max(quantiles->entries[i].m, last_q);
 480                         prt_printf(out, "%llu ", div64_u64(q, u->nsecs));
 481                         if (is_last)
 482                                 prt_newline(out);
 483                         last_q = q;
 484                 }
 485         }
 486 }
 487
 488 /* ratelimit: */
 489
 490 /**
 491  * bch2_ratelimit_delay() - return how long to delay until the next time to do
 492  *              some work
 493  * @d:          the struct bch_ratelimit to update
 494  * Returns:     the amount of time to delay by, in jiffies
 495  */
 496 u64 bch2_ratelimit_delay(struct bch_ratelimit *d)
 497 {
 498         u64 now = local_clock();
 499
 500         return time_after64(d->next, now)
 501                 ? nsecs_to_jiffies(d->next - now)
 502                 : 0;
 503 }
 504
 505 /**
 506  * bch2_ratelimit_increment() - increment @d by the amount of work done
 507  * @d:          the struct bch_ratelimit to update
 508  * @done:       the amount of work done, in arbitrary units
 509  */
 510 void bch2_ratelimit_increment(struct bch_ratelimit *d, u64 done)
 511 {
 512         u64 now = local_clock();
 513
 514         d->next += div_u64(done * NSEC_PER_SEC, d->rate);
 515
 516         if (time_before64(now + NSEC_PER_SEC, d->next))
 517                 d->next = now + NSEC_PER_SEC;
 518
 519         if (time_after64(now - NSEC_PER_SEC * 2, d->next))
 520                 d->next = now - NSEC_PER_SEC * 2;
 521 }
 522
 523 /* pd controller: */
 524
 525 /*
 526  * Updates pd_controller. Attempts to scale inputed values to units per second.
 527  * @target: desired value
 528  * @actual: current value
 529  *
 530  * @sign: 1 or -1; 1 if increasing the rate makes actual go up, -1 if increasing
 531  * it makes actual go down.
 532  */
 533 void bch2_pd_controller_update(struct bch_pd_controller *pd,
 534                               s64 target, s64 actual, int sign)
 535 {
 536         s64 proportional, derivative, change;
 537
 538         unsigned long seconds_since_update = (jiffies - pd->last_update) / HZ;
 539
 540         if (seconds_since_update == 0)
 541                 return;
 542
 543         pd->last_update = jiffies;
 544
 545         proportional = actual - target;
 546         proportional *= seconds_since_update;
 547         proportional = div_s64(proportional, pd->p_term_inverse);
 548
 549         derivative = actual - pd->last_actual;
 550         derivative = div_s64(derivative, seconds_since_update);
 551         derivative = ewma_add(pd->smoothed_derivative, derivative,
 552                               (pd->d_term / seconds_since_update) ?: 1);
 553         derivative = derivative * pd->d_term;
 554         derivative = div_s64(derivative, pd->p_term_inverse);
 555
 556         change = proportional + derivative;
 557
 558         /* Don't increase rate if not keeping up */
 559         if (change > 0 &&
 560             pd->backpressure &&
 561             time_after64(local_clock(),
 562                          pd->rate.next + NSEC_PER_MSEC))
 563                 change = 0;
 564
 565         change *= (sign * -1);
 566
 567         pd->rate.rate = clamp_t(s64, (s64) pd->rate.rate + change,
 568                                 1, UINT_MAX);
 569
 570         pd->last_actual         = actual;
 571         pd->last_derivative     = derivative;
 572         pd->last_proportional   = proportional;
 573         pd->last_change         = change;
 574         pd->last_target         = target;
 575 }
 576
 577 void bch2_pd_controller_init(struct bch_pd_controller *pd)
 578 {
 579         pd->rate.rate           = 1024;
 580         pd->last_update         = jiffies;
 581         pd->p_term_inverse      = 6000;
 582         pd->d_term              = 30;
 583         pd->d_smooth            = pd->d_term;
 584         pd->backpressure        = 1;
 585 }
 586
 587 void bch2_pd_controller_debug_to_text(struct printbuf *out, struct bch_pd_controller *pd)
 588 {
 589         if (!out->nr_tabstops)
 590                 printbuf_tabstop_push(out, 20);
 591
 592         prt_printf(out, "rate:\t");
 593         prt_human_readable_s64(out, pd->rate.rate);
 594         prt_newline(out);
 595
 596         prt_printf(out, "target:\t");
 597         prt_human_readable_u64(out, pd->last_target);
 598         prt_newline(out);
 599
 600         prt_printf(out, "actual:\t");
 601         prt_human_readable_u64(out, pd->last_actual);
 602         prt_newline(out);
 603
 604         prt_printf(out, "proportional:\t");
 605         prt_human_readable_s64(out, pd->last_proportional);
 606         prt_newline(out);
 607
 608         prt_printf(out, "derivative:\t");
 609         prt_human_readable_s64(out, pd->last_derivative);
 610         prt_newline(out);
 611
 612         prt_printf(out, "change:\t");
 613         prt_human_readable_s64(out, pd->last_change);
 614         prt_newline(out);
 615
 616         prt_printf(out, "next io:\t%llims\n", div64_s64(pd->rate.next - local_clock(), NSEC_PER_MSEC));
 617 }
 618
 619 /* misc: */
 620
 621 void bch2_bio_map(struct bio *bio, void *base, size_t size)
 622 {
 623         while (size) {
 624                 struct page *page = is_vmalloc_addr(base)
 625                                 ? vmalloc_to_page(base)
 626                                 : virt_to_page(base);
 627                 unsigned offset = offset_in_page(base);
 628                 unsigned len = min_t(size_t, PAGE_SIZE - offset, size);
 629
 630                 BUG_ON(!bio_add_page(bio, page, len, offset));
 631                 size -= len;
 632                 base += len;
 633         }
 634 }
 635
 636 int bch2_bio_alloc_pages(struct bio *bio, size_t size, gfp_t gfp_mask)
 637 {
 638         while (size) {
 639                 struct page *page = alloc_pages(gfp_mask, 0);
 640                 unsigned len = min_t(size_t, PAGE_SIZE, size);
 641
 642                 if (!page)
 643                         return -ENOMEM;
 644
 645                 if (unlikely(!bio_add_page(bio, page, len, 0))) {
 646                         __free_page(page);
 647                         break;
 648                 }
 649
 650                 size -= len;
 651         }
 652
 653         return 0;
 654 }
 655
 656 size_t bch2_rand_range(size_t max)
 657 {
 658         size_t rand;
 659
 660         if (!max)
 661                 return 0;
 662
 663         do {
 664                 rand = get_random_long();
 665                 rand &= roundup_pow_of_two(max) - 1;
 666         } while (rand >= max);
 667
 668         return rand;
 669 }
 670
 671 void memcpy_to_bio(struct bio *dst, struct bvec_iter dst_iter, const void *src)
 672 {
 673         struct bio_vec bv;
 674         struct bvec_iter iter;
 675
 676         __bio_for_each_segment(bv, dst, iter, dst_iter) {
 677                 void *dstp = kmap_local_page(bv.bv_page);
 678
 679                 memcpy(dstp + bv.bv_offset, src, bv.bv_len);
 680                 kunmap_local(dstp);
 681
 682                 src += bv.bv_len;
 683         }
 684 }
 685
 686 void memcpy_from_bio(void *dst, struct bio *src, struct bvec_iter src_iter)
 687 {
 688         struct bio_vec bv;
 689         struct bvec_iter iter;
 690
 691         __bio_for_each_segment(bv, src, iter, src_iter) {
 692                 void *srcp = kmap_local_page(bv.bv_page);
 693
 694                 memcpy(dst, srcp + bv.bv_offset, bv.bv_len);
 695                 kunmap_local(srcp);
 696
 697                 dst += bv.bv_len;
 698         }
 699 }
 700
 701 #if 0
 702 void eytzinger1_test(void)
 703 {
 704         unsigned inorder, eytz, size;
 705
 706         pr_info("1 based eytzinger test:");
 707
 708         for (size = 2;
 709              size < 65536;
 710              size++) {
 711                 unsigned extra = eytzinger1_extra(size);
 712
 713                 if (!(size % 4096))
 714                         pr_info("tree size %u", size);
 715
 716                 BUG_ON(eytzinger1_prev(0, size) != eytzinger1_last(size));
 717                 BUG_ON(eytzinger1_next(0, size) != eytzinger1_first(size));
 718
 719                 BUG_ON(eytzinger1_prev(eytzinger1_first(size), size)    != 0);
 720                 BUG_ON(eytzinger1_next(eytzinger1_last(size), size)     != 0);
 721
 722                 inorder = 1;
 723                 eytzinger1_for_each(eytz, size) {
 724                         BUG_ON(__inorder_to_eytzinger1(inorder, size, extra) != eytz);
 725                         BUG_ON(__eytzinger1_to_inorder(eytz, size, extra) != inorder);
 726                         BUG_ON(eytz != eytzinger1_last(size) &&
 727                                eytzinger1_prev(eytzinger1_next(eytz, size), size) != eytz);
 728
 729                         inorder++;
 730                 }
 731         }
 732 }
 733
 734 void eytzinger0_test(void)
 735 {
 736
 737         unsigned inorder, eytz, size;
 738
 739         pr_info("0 based eytzinger test:");
 740
 741         for (size = 1;
 742              size < 65536;
 743              size++) {
 744                 unsigned extra = eytzinger0_extra(size);
 745
 746                 if (!(size % 4096))
 747                         pr_info("tree size %u", size);
 748
 749                 BUG_ON(eytzinger0_prev(-1, size) != eytzinger0_last(size));
 750                 BUG_ON(eytzinger0_next(-1, size) != eytzinger0_first(size));
 751
 752                 BUG_ON(eytzinger0_prev(eytzinger0_first(size), size)    != -1);
 753                 BUG_ON(eytzinger0_next(eytzinger0_last(size), size)     != -1);
 754
 755                 inorder = 0;
 756                 eytzinger0_for_each(eytz, size) {
 757                         BUG_ON(__inorder_to_eytzinger0(inorder, size, extra) != eytz);
 758                         BUG_ON(__eytzinger0_to_inorder(eytz, size, extra) != inorder);
 759                         BUG_ON(eytz != eytzinger0_last(size) &&
 760                                eytzinger0_prev(eytzinger0_next(eytz, size), size) != eytz);
 761
 762                         inorder++;
 763                 }
 764         }
 765 }
 766
 767 static inline int cmp_u16(const void *_l, const void *_r, size_t size)
 768 {
 769         const u16 *l = _l, *r = _r;
 770
 771         return (*l > *r) - (*r - *l);
 772 }
 773
 774 static void eytzinger0_find_test_val(u16 *test_array, unsigned nr, u16 search)
 775 {
 776         int i, c1 = -1, c2 = -1;
 777         ssize_t r;
 778
 779         r = eytzinger0_find_le(test_array, nr,
 780                                sizeof(test_array[0]),
 781                                cmp_u16, &search);
 782         if (r >= 0)
 783                 c1 = test_array[r];
 784
 785         for (i = 0; i < nr; i++)
 786                 if (test_array[i] <= search && test_array[i] > c2)
 787                         c2 = test_array[i];
 788
 789         if (c1 != c2) {
 790                 eytzinger0_for_each(i, nr)
 791                         pr_info("[%3u] = %12u", i, test_array[i]);
 792                 pr_info("find_le(%2u) -> [%2zi] = %2i should be %2i",
 793                         i, r, c1, c2);
 794         }
 795 }
 796
 797 void eytzinger0_find_test(void)
 798 {
 799         unsigned i, nr, allocated = 1 << 12;
 800         u16 *test_array = kmalloc_array(allocated, sizeof(test_array[0]), GFP_KERNEL);
 801
 802         for (nr = 1; nr < allocated; nr++) {
 803                 pr_info("testing %u elems", nr);
 804
 805                 get_random_bytes(test_array, nr * sizeof(test_array[0]));
 806                 eytzinger0_sort(test_array, nr, sizeof(test_array[0]), cmp_u16, NULL);
 807
 808                 /* verify array is sorted correctly: */
 809                 eytzinger0_for_each(i, nr)
 810                         BUG_ON(i != eytzinger0_last(nr) &&
 811                                test_array[i] > test_array[eytzinger0_next(i, nr)]);
 812
 813                 for (i = 0; i < U16_MAX; i += 1 << 12)
 814                         eytzinger0_find_test_val(test_array, nr, i);
 815
 816                 for (i = 0; i < nr; i++) {
 817                         eytzinger0_find_test_val(test_array, nr, test_array[i] - 1);
 818                         eytzinger0_find_test_val(test_array, nr, test_array[i]);
 819                         eytzinger0_find_test_val(test_array, nr, test_array[i] + 1);
 820                 }
 821         }
 822
 823         kfree(test_array);
 824 }
 825 #endif
 826
 827 /*
 828  * Accumulate percpu counters onto one cpu's copy - only valid when access
 829  * against any percpu counter is guarded against
 830  */
 831 u64 *bch2_acc_percpu_u64s(u64 __percpu *p, unsigned nr)
 832 {
 833         u64 *ret;
 834         int cpu;
 835
 836         /* access to pcpu vars has to be blocked by other locking */
 837         preempt_disable();
 838         ret = this_cpu_ptr(p);
 839         preempt_enable();
 840
 841         for_each_possible_cpu(cpu) {
 842                 u64 *i = per_cpu_ptr(p, cpu);
 843
 844                 if (i != ret) {
 845                         acc_u64s(ret, i, nr);
 846                         memset(i, 0, nr * sizeof(u64));
 847                 }
 848         }
 849
 850         return ret;
 851 }
 852
 853 void bch2_darray_str_exit(darray_str *d)
 854 {
 855         darray_for_each(*d, i)
 856                 kfree(*i);
 857         darray_exit(d);
 858 }
 859
 860 int bch2_split_devs(const char *_dev_name, darray_str *ret)
 861 {
 862         darray_init(ret);
 863
 864         char *dev_name, *s, *orig;
 865
 866         dev_name = orig = kstrdup(_dev_name, GFP_KERNEL);
 867         if (!dev_name)
 868                 return -ENOMEM;
 869
 870         while ((s = strsep(&dev_name, ":"))) {
 871                 char *p = kstrdup(s, GFP_KERNEL);
 872                 if (!p)
 873                         goto err;
 874
 875                 if (darray_push(ret, p)) {
 876                         kfree(p);
 877                         goto err;
 878                 }
 879         }
 880
 881         kfree(orig);
 882         return 0;
 883 err:
 884         bch2_darray_str_exit(ret);
 885         kfree(orig);
 886         return -ENOMEM;
 887 }