linux/drivers/md/bcache/util.h
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   1/* SPDX-License-Identifier: GPL-2.0 */
   2
   3#ifndef _BCACHE_UTIL_H
   4#define _BCACHE_UTIL_H
   5
   6#include <linux/blkdev.h>
   7#include <linux/errno.h>
   8#include <linux/kernel.h>
   9#include <linux/sched/clock.h>
  10#include <linux/llist.h>
  11#include <linux/ratelimit.h>
  12#include <linux/vmalloc.h>
  13#include <linux/workqueue.h>
  14#include <linux/crc64.h>
  15
  16#include "closure.h"
  17
  18#define PAGE_SECTORS            (PAGE_SIZE / 512)
  19
  20struct closure;
  21
  22#ifdef CONFIG_BCACHE_DEBUG
  23
  24#define EBUG_ON(cond)                   BUG_ON(cond)
  25#define atomic_dec_bug(v)       BUG_ON(atomic_dec_return(v) < 0)
  26#define atomic_inc_bug(v, i)    BUG_ON(atomic_inc_return(v) <= i)
  27
  28#else /* DEBUG */
  29
  30#define EBUG_ON(cond)           do { if (cond) do {} while (0); } while (0)
  31#define atomic_dec_bug(v)       atomic_dec(v)
  32#define atomic_inc_bug(v, i)    atomic_inc(v)
  33
  34#endif
  35
  36#define DECLARE_HEAP(type, name)                                        \
  37        struct {                                                        \
  38                size_t size, used;                                      \
  39                type *data;                                             \
  40        } name
  41
  42#define init_heap(heap, _size, gfp)                                     \
  43({                                                                      \
  44        size_t _bytes;                                                  \
  45        (heap)->used = 0;                                               \
  46        (heap)->size = (_size);                                         \
  47        _bytes = (heap)->size * sizeof(*(heap)->data);                  \
  48        (heap)->data = kvmalloc(_bytes, (gfp) & GFP_KERNEL);            \
  49        (heap)->data;                                                   \
  50})
  51
  52#define free_heap(heap)                                                 \
  53do {                                                                    \
  54        kvfree((heap)->data);                                           \
  55        (heap)->data = NULL;                                            \
  56} while (0)
  57
  58#define heap_swap(h, i, j)      swap((h)->data[i], (h)->data[j])
  59
  60#define heap_sift(h, i, cmp)                                            \
  61do {                                                                    \
  62        size_t _r, _j = i;                                              \
  63                                                                        \
  64        for (; _j * 2 + 1 < (h)->used; _j = _r) {                       \
  65                _r = _j * 2 + 1;                                        \
  66                if (_r + 1 < (h)->used &&                               \
  67                    cmp((h)->data[_r], (h)->data[_r + 1]))              \
  68                        _r++;                                           \
  69                                                                        \
  70                if (cmp((h)->data[_r], (h)->data[_j]))                  \
  71                        break;                                          \
  72                heap_swap(h, _r, _j);                                   \
  73        }                                                               \
  74} while (0)
  75
  76#define heap_sift_down(h, i, cmp)                                       \
  77do {                                                                    \
  78        while (i) {                                                     \
  79                size_t p = (i - 1) / 2;                                 \
  80                if (cmp((h)->data[i], (h)->data[p]))                    \
  81                        break;                                          \
  82                heap_swap(h, i, p);                                     \
  83                i = p;                                                  \
  84        }                                                               \
  85} while (0)
  86
  87#define heap_add(h, d, cmp)                                             \
  88({                                                                      \
  89        bool _r = !heap_full(h);                                        \
  90        if (_r) {                                                       \
  91                size_t _i = (h)->used++;                                \
  92                (h)->data[_i] = d;                                      \
  93                                                                        \
  94                heap_sift_down(h, _i, cmp);                             \
  95                heap_sift(h, _i, cmp);                                  \
  96        }                                                               \
  97        _r;                                                             \
  98})
  99
 100#define heap_pop(h, d, cmp)                                             \
 101({                                                                      \
 102        bool _r = (h)->used;                                            \
 103        if (_r) {                                                       \
 104                (d) = (h)->data[0];                                     \
 105                (h)->used--;                                            \
 106                heap_swap(h, 0, (h)->used);                             \
 107                heap_sift(h, 0, cmp);                                   \
 108        }                                                               \
 109        _r;                                                             \
 110})
 111
 112#define heap_peek(h)    ((h)->used ? (h)->data[0] : NULL)
 113
 114#define heap_full(h)    ((h)->used == (h)->size)
 115
 116#define DECLARE_FIFO(type, name)                                        \
 117        struct {                                                        \
 118                size_t front, back, size, mask;                         \
 119                type *data;                                             \
 120        } name
 121
 122#define fifo_for_each(c, fifo, iter)                                    \
 123        for (iter = (fifo)->front;                                      \
 124             c = (fifo)->data[iter], iter != (fifo)->back;              \
 125             iter = (iter + 1) & (fifo)->mask)
 126
 127#define __init_fifo(fifo, gfp)                                          \
 128({                                                                      \
 129        size_t _allocated_size, _bytes;                                 \
 130        BUG_ON(!(fifo)->size);                                          \
 131                                                                        \
 132        _allocated_size = roundup_pow_of_two((fifo)->size + 1);         \
 133        _bytes = _allocated_size * sizeof(*(fifo)->data);               \
 134                                                                        \
 135        (fifo)->mask = _allocated_size - 1;                             \
 136        (fifo)->front = (fifo)->back = 0;                               \
 137                                                                        \
 138        (fifo)->data = kvmalloc(_bytes, (gfp) & GFP_KERNEL);            \
 139        (fifo)->data;                                                   \
 140})
 141
 142#define init_fifo_exact(fifo, _size, gfp)                               \
 143({                                                                      \
 144        (fifo)->size = (_size);                                         \
 145        __init_fifo(fifo, gfp);                                         \
 146})
 147
 148#define init_fifo(fifo, _size, gfp)                                     \
 149({                                                                      \
 150        (fifo)->size = (_size);                                         \
 151        if ((fifo)->size > 4)                                           \
 152                (fifo)->size = roundup_pow_of_two((fifo)->size) - 1;    \
 153        __init_fifo(fifo, gfp);                                         \
 154})
 155
 156#define free_fifo(fifo)                                                 \
 157do {                                                                    \
 158        kvfree((fifo)->data);                                           \
 159        (fifo)->data = NULL;                                            \
 160} while (0)
 161
 162#define fifo_used(fifo)         (((fifo)->back - (fifo)->front) & (fifo)->mask)
 163#define fifo_free(fifo)         ((fifo)->size - fifo_used(fifo))
 164
 165#define fifo_empty(fifo)        (!fifo_used(fifo))
 166#define fifo_full(fifo)         (!fifo_free(fifo))
 167
 168#define fifo_front(fifo)        ((fifo)->data[(fifo)->front])
 169#define fifo_back(fifo)                                                 \
 170        ((fifo)->data[((fifo)->back - 1) & (fifo)->mask])
 171
 172#define fifo_idx(fifo, p)       (((p) - &fifo_front(fifo)) & (fifo)->mask)
 173
 174#define fifo_push_back(fifo, i)                                         \
 175({                                                                      \
 176        bool _r = !fifo_full((fifo));                                   \
 177        if (_r) {                                                       \
 178                (fifo)->data[(fifo)->back++] = (i);                     \
 179                (fifo)->back &= (fifo)->mask;                           \
 180        }                                                               \
 181        _r;                                                             \
 182})
 183
 184#define fifo_pop_front(fifo, i)                                         \
 185({                                                                      \
 186        bool _r = !fifo_empty((fifo));                                  \
 187        if (_r) {                                                       \
 188                (i) = (fifo)->data[(fifo)->front++];                    \
 189                (fifo)->front &= (fifo)->mask;                          \
 190        }                                                               \
 191        _r;                                                             \
 192})
 193
 194#define fifo_push_front(fifo, i)                                        \
 195({                                                                      \
 196        bool _r = !fifo_full((fifo));                                   \
 197        if (_r) {                                                       \
 198                --(fifo)->front;                                        \
 199                (fifo)->front &= (fifo)->mask;                          \
 200                (fifo)->data[(fifo)->front] = (i);                      \
 201        }                                                               \
 202        _r;                                                             \
 203})
 204
 205#define fifo_pop_back(fifo, i)                                          \
 206({                                                                      \
 207        bool _r = !fifo_empty((fifo));                                  \
 208        if (_r) {                                                       \
 209                --(fifo)->back;                                         \
 210                (fifo)->back &= (fifo)->mask;                           \
 211                (i) = (fifo)->data[(fifo)->back]                        \
 212        }                                                               \
 213        _r;                                                             \
 214})
 215
 216#define fifo_push(fifo, i)      fifo_push_back(fifo, (i))
 217#define fifo_pop(fifo, i)       fifo_pop_front(fifo, (i))
 218
 219#define fifo_swap(l, r)                                                 \
 220do {                                                                    \
 221        swap((l)->front, (r)->front);                                   \
 222        swap((l)->back, (r)->back);                                     \
 223        swap((l)->size, (r)->size);                                     \
 224        swap((l)->mask, (r)->mask);                                     \
 225        swap((l)->data, (r)->data);                                     \
 226} while (0)
 227
 228#define fifo_move(dest, src)                                            \
 229do {                                                                    \
 230        typeof(*((dest)->data)) _t;                                     \
 231        while (!fifo_full(dest) &&                                      \
 232               fifo_pop(src, _t))                                       \
 233                fifo_push(dest, _t);                                    \
 234} while (0)
 235
 236/*
 237 * Simple array based allocator - preallocates a number of elements and you can
 238 * never allocate more than that, also has no locking.
 239 *
 240 * Handy because if you know you only need a fixed number of elements you don't
 241 * have to worry about memory allocation failure, and sometimes a mempool isn't
 242 * what you want.
 243 *
 244 * We treat the free elements as entries in a singly linked list, and the
 245 * freelist as a stack - allocating and freeing push and pop off the freelist.
 246 */
 247
 248#define DECLARE_ARRAY_ALLOCATOR(type, name, size)                       \
 249        struct {                                                        \
 250                type    *freelist;                                      \
 251                type    data[size];                                     \
 252        } name
 253
 254#define array_alloc(array)                                              \
 255({                                                                      \
 256        typeof((array)->freelist) _ret = (array)->freelist;             \
 257                                                                        \
 258        if (_ret)                                                       \
 259                (array)->freelist = *((typeof((array)->freelist) *) _ret);\
 260                                                                        \
 261        _ret;                                                           \
 262})
 263
 264#define array_free(array, ptr)                                          \
 265do {                                                                    \
 266        typeof((array)->freelist) _ptr = ptr;                           \
 267                                                                        \
 268        *((typeof((array)->freelist) *) _ptr) = (array)->freelist;      \
 269        (array)->freelist = _ptr;                                       \
 270} while (0)
 271
 272#define array_allocator_init(array)                                     \
 273do {                                                                    \
 274        typeof((array)->freelist) _i;                                   \
 275                                                                        \
 276        BUILD_BUG_ON(sizeof((array)->data[0]) < sizeof(void *));        \
 277        (array)->freelist = NULL;                                       \
 278                                                                        \
 279        for (_i = (array)->data;                                        \
 280             _i < (array)->data + ARRAY_SIZE((array)->data);            \
 281             _i++)                                                      \
 282                array_free(array, _i);                                  \
 283} while (0)
 284
 285#define array_freelist_empty(array)     ((array)->freelist == NULL)
 286
 287#define ANYSINT_MAX(t)                                                  \
 288        ((((t) 1 << (sizeof(t) * 8 - 2)) - (t) 1) * (t) 2 + (t) 1)
 289
 290int bch_strtoint_h(const char *cp, int *res);
 291int bch_strtouint_h(const char *cp, unsigned int *res);
 292int bch_strtoll_h(const char *cp, long long *res);
 293int bch_strtoull_h(const char *cp, unsigned long long *res);
 294
 295static inline int bch_strtol_h(const char *cp, long *res)
 296{
 297#if BITS_PER_LONG == 32
 298        return bch_strtoint_h(cp, (int *) res);
 299#else
 300        return bch_strtoll_h(cp, (long long *) res);
 301#endif
 302}
 303
 304static inline int bch_strtoul_h(const char *cp, long *res)
 305{
 306#if BITS_PER_LONG == 32
 307        return bch_strtouint_h(cp, (unsigned int *) res);
 308#else
 309        return bch_strtoull_h(cp, (unsigned long long *) res);
 310#endif
 311}
 312
 313#define strtoi_h(cp, res)                                               \
 314        (__builtin_types_compatible_p(typeof(*res), int)                \
 315        ? bch_strtoint_h(cp, (void *) res)                              \
 316        : __builtin_types_compatible_p(typeof(*res), long)              \
 317        ? bch_strtol_h(cp, (void *) res)                                \
 318        : __builtin_types_compatible_p(typeof(*res), long long)         \
 319        ? bch_strtoll_h(cp, (void *) res)                               \
 320        : __builtin_types_compatible_p(typeof(*res), unsigned int)      \
 321        ? bch_strtouint_h(cp, (void *) res)                             \
 322        : __builtin_types_compatible_p(typeof(*res), unsigned long)     \
 323        ? bch_strtoul_h(cp, (void *) res)                               \
 324        : __builtin_types_compatible_p(typeof(*res), unsigned long long)\
 325        ? bch_strtoull_h(cp, (void *) res) : -EINVAL)
 326
 327#define strtoul_safe(cp, var)                                           \
 328({                                                                      \
 329        unsigned long _v;                                               \
 330        int _r = kstrtoul(cp, 10, &_v);                                 \
 331        if (!_r)                                                        \
 332                var = _v;                                               \
 333        _r;                                                             \
 334})
 335
 336#define strtoul_safe_clamp(cp, var, min, max)                           \
 337({                                                                      \
 338        unsigned long _v;                                               \
 339        int _r = kstrtoul(cp, 10, &_v);                                 \
 340        if (!_r)                                                        \
 341                var = clamp_t(typeof(var), _v, min, max);               \
 342        _r;                                                             \
 343})
 344
 345#define snprint(buf, size, var)                                         \
 346        snprintf(buf, size,                                             \
 347                __builtin_types_compatible_p(typeof(var), int)          \
 348                     ? "%i\n" :                                         \
 349                __builtin_types_compatible_p(typeof(var), unsigned int) \
 350                     ? "%u\n" :                                         \
 351                __builtin_types_compatible_p(typeof(var), long)         \
 352                     ? "%li\n" :                                        \
 353                __builtin_types_compatible_p(typeof(var), unsigned long)\
 354                     ? "%lu\n" :                                        \
 355                __builtin_types_compatible_p(typeof(var), int64_t)      \
 356                     ? "%lli\n" :                                       \
 357                __builtin_types_compatible_p(typeof(var), uint64_t)     \
 358                     ? "%llu\n" :                                       \
 359                __builtin_types_compatible_p(typeof(var), const char *) \
 360                     ? "%s\n" : "%i\n", var)
 361
 362ssize_t bch_hprint(char *buf, int64_t v);
 363
 364bool bch_is_zero(const char *p, size_t n);
 365int bch_parse_uuid(const char *s, char *uuid);
 366
 367struct time_stats {
 368        spinlock_t      lock;
 369        /*
 370         * all fields are in nanoseconds, averages are ewmas stored left shifted
 371         * by 8
 372         */
 373        uint64_t        max_duration;
 374        uint64_t        average_duration;
 375        uint64_t        average_frequency;
 376        uint64_t        last;
 377};
 378
 379void bch_time_stats_update(struct time_stats *stats, uint64_t time);
 380
 381static inline unsigned int local_clock_us(void)
 382{
 383        return local_clock() >> 10;
 384}
 385
 386#define NSEC_PER_ns                     1L
 387#define NSEC_PER_us                     NSEC_PER_USEC
 388#define NSEC_PER_ms                     NSEC_PER_MSEC
 389#define NSEC_PER_sec                    NSEC_PER_SEC
 390
 391#define __print_time_stat(stats, name, stat, units)                     \
 392        sysfs_print(name ## _ ## stat ## _ ## units,                    \
 393                    div_u64((stats)->stat >> 8, NSEC_PER_ ## units))
 394
 395#define sysfs_print_time_stats(stats, name,                             \
 396                               frequency_units,                         \
 397                               duration_units)                          \
 398do {                                                                    \
 399        __print_time_stat(stats, name,                                  \
 400                          average_frequency,    frequency_units);       \
 401        __print_time_stat(stats, name,                                  \
 402                          average_duration,     duration_units);        \
 403        sysfs_print(name ## _ ##max_duration ## _ ## duration_units,    \
 404                        div_u64((stats)->max_duration,                  \
 405                                NSEC_PER_ ## duration_units));          \
 406                                                                        \
 407        sysfs_print(name ## _last_ ## frequency_units, (stats)->last    \
 408                    ? div_s64(local_clock() - (stats)->last,            \
 409                              NSEC_PER_ ## frequency_units)             \
 410                    : -1LL);                                            \
 411} while (0)
 412
 413#define sysfs_time_stats_attribute(name,                                \
 414                                   frequency_units,                     \
 415                                   duration_units)                      \
 416read_attribute(name ## _average_frequency_ ## frequency_units);         \
 417read_attribute(name ## _average_duration_ ## duration_units);           \
 418read_attribute(name ## _max_duration_ ## duration_units);               \
 419read_attribute(name ## _last_ ## frequency_units)
 420
 421#define sysfs_time_stats_attribute_list(name,                           \
 422                                        frequency_units,                \
 423                                        duration_units)                 \
 424&sysfs_ ## name ## _average_frequency_ ## frequency_units,              \
 425&sysfs_ ## name ## _average_duration_ ## duration_units,                \
 426&sysfs_ ## name ## _max_duration_ ## duration_units,                    \
 427&sysfs_ ## name ## _last_ ## frequency_units,
 428
 429#define ewma_add(ewma, val, weight, factor)                             \
 430({                                                                      \
 431        (ewma) *= (weight) - 1;                                         \
 432        (ewma) += (val) << factor;                                      \
 433        (ewma) /= (weight);                                             \
 434        (ewma) >> factor;                                               \
 435})
 436
 437struct bch_ratelimit {
 438        /* Next time we want to do some work, in nanoseconds */
 439        uint64_t                next;
 440
 441        /*
 442         * Rate at which we want to do work, in units per second
 443         * The units here correspond to the units passed to bch_next_delay()
 444         */
 445        atomic_long_t           rate;
 446};
 447
 448static inline void bch_ratelimit_reset(struct bch_ratelimit *d)
 449{
 450        d->next = local_clock();
 451}
 452
 453uint64_t bch_next_delay(struct bch_ratelimit *d, uint64_t done);
 454
 455#define __DIV_SAFE(n, d, zero)                                          \
 456({                                                                      \
 457        typeof(n) _n = (n);                                             \
 458        typeof(d) _d = (d);                                             \
 459        _d ? _n / _d : zero;                                            \
 460})
 461
 462#define DIV_SAFE(n, d)  __DIV_SAFE(n, d, 0)
 463
 464#define container_of_or_null(ptr, type, member)                         \
 465({                                                                      \
 466        typeof(ptr) _ptr = ptr;                                         \
 467        _ptr ? container_of(_ptr, type, member) : NULL;                 \
 468})
 469
 470#define RB_INSERT(root, new, member, cmp)                               \
 471({                                                                      \
 472        __label__ dup;                                                  \
 473        struct rb_node **n = &(root)->rb_node, *parent = NULL;          \
 474        typeof(new) this;                                               \
 475        int res, ret = -1;                                              \
 476                                                                        \
 477        while (*n) {                                                    \
 478                parent = *n;                                            \
 479                this = container_of(*n, typeof(*(new)), member);        \
 480                res = cmp(new, this);                                   \
 481                if (!res)                                               \
 482                        goto dup;                                       \
 483                n = res < 0                                             \
 484                        ? &(*n)->rb_left                                \
 485                        : &(*n)->rb_right;                              \
 486        }                                                               \
 487                                                                        \
 488        rb_link_node(&(new)->member, parent, n);                        \
 489        rb_insert_color(&(new)->member, root);                          \
 490        ret = 0;                                                        \
 491dup:                                                                    \
 492        ret;                                                            \
 493})
 494
 495#define RB_SEARCH(root, search, member, cmp)                            \
 496({                                                                      \
 497        struct rb_node *n = (root)->rb_node;                            \
 498        typeof(&(search)) this, ret = NULL;                             \
 499        int res;                                                        \
 500                                                                        \
 501        while (n) {                                                     \
 502                this = container_of(n, typeof(search), member);         \
 503                res = cmp(&(search), this);                             \
 504                if (!res) {                                             \
 505                        ret = this;                                     \
 506                        break;                                          \
 507                }                                                       \
 508                n = res < 0                                             \
 509                        ? n->rb_left                                    \
 510                        : n->rb_right;                                  \
 511        }                                                               \
 512        ret;                                                            \
 513})
 514
 515#define RB_GREATER(root, search, member, cmp)                           \
 516({                                                                      \
 517        struct rb_node *n = (root)->rb_node;                            \
 518        typeof(&(search)) this, ret = NULL;                             \
 519        int res;                                                        \
 520                                                                        \
 521        while (n) {                                                     \
 522                this = container_of(n, typeof(search), member);         \
 523                res = cmp(&(search), this);                             \
 524                if (res < 0) {                                          \
 525                        ret = this;                                     \
 526                        n = n->rb_left;                                 \
 527                } else                                                  \
 528                        n = n->rb_right;                                \
 529        }                                                               \
 530        ret;                                                            \
 531})
 532
 533#define RB_FIRST(root, type, member)                                    \
 534        container_of_or_null(rb_first(root), type, member)
 535
 536#define RB_LAST(root, type, member)                                     \
 537        container_of_or_null(rb_last(root), type, member)
 538
 539#define RB_NEXT(ptr, member)                                            \
 540        container_of_or_null(rb_next(&(ptr)->member), typeof(*ptr), member)
 541
 542#define RB_PREV(ptr, member)                                            \
 543        container_of_or_null(rb_prev(&(ptr)->member), typeof(*ptr), member)
 544
 545static inline uint64_t bch_crc64(const void *p, size_t len)
 546{
 547        uint64_t crc = 0xffffffffffffffffULL;
 548
 549        crc = crc64_be(crc, p, len);
 550        return crc ^ 0xffffffffffffffffULL;
 551}
 552
 553static inline uint64_t bch_crc64_update(uint64_t crc,
 554                                        const void *p,
 555                                        size_t len)
 556{
 557        crc = crc64_be(crc, p, len);
 558        return crc;
 559}
 560
 561/*
 562 * A stepwise-linear pseudo-exponential.  This returns 1 << (x >>
 563 * frac_bits), with the less-significant bits filled in by linear
 564 * interpolation.
 565 *
 566 * This can also be interpreted as a floating-point number format,
 567 * where the low frac_bits are the mantissa (with implicit leading
 568 * 1 bit), and the more significant bits are the exponent.
 569 * The return value is 1.mantissa * 2^exponent.
 570 *
 571 * The way this is used, fract_bits is 6 and the largest possible
 572 * input is CONGESTED_MAX-1 = 1023 (exponent 16, mantissa 0x1.fc),
 573 * so the maximum output is 0x1fc00.
 574 */
 575static inline unsigned int fract_exp_two(unsigned int x,
 576                                         unsigned int fract_bits)
 577{
 578        unsigned int mantissa = 1 << fract_bits;        /* Implicit bit */
 579
 580        mantissa += x & (mantissa - 1);
 581        x >>= fract_bits;       /* The exponent */
 582        /* Largest intermediate value 0x7f0000 */
 583        return mantissa << x >> fract_bits;
 584}
 585
 586void bch_bio_map(struct bio *bio, void *base);
 587int bch_bio_alloc_pages(struct bio *bio, gfp_t gfp_mask);
 588
 589static inline sector_t bdev_sectors(struct block_device *bdev)
 590{
 591        return bdev->bd_inode->i_size >> 9;
 592}
 593#endif /* _BCACHE_UTIL_H */
 594