LXR linux/drivers/md/bcache/util.c

   1/*
   2 * random utiility code, for bcache but in theory not specific to bcache
   3 *
   4 * Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
   5 * Copyright 2012 Google, Inc.
   6 */
   7
   8#include <linux/bio.h>
   9#include <linux/blkdev.h>
  10#include <linux/ctype.h>
  11#include <linux/debugfs.h>
  12#include <linux/module.h>
  13#include <linux/seq_file.h>
  14#include <linux/types.h>
  15#include <linux/sched/clock.h>
  16
  17#include "util.h"
  18
  19#define simple_strtoint(c, end, base)   simple_strtol(c, end, base)
  20#define simple_strtouint(c, end, base)  simple_strtoul(c, end, base)
  21
  22#define STRTO_H(name, type)                                     \
  23int bch_ ## name ## _h(const char *cp, type *res)               \
  24{                                                               \
  25        int u = 0;                                              \
  26        char *e;                                                \
  27        type i = simple_ ## name(cp, &e, 10);                   \
  28                                                                \
  29        switch (tolower(*e)) {                                  \
  30        default:                                                \
  31                return -EINVAL;                                 \
  32        case 'y':                                               \
  33        case 'z':                                               \
  34                u++;                                            \
  35        case 'e':                                               \
  36                u++;                                            \
  37        case 'p':                                               \
  38                u++;                                            \
  39        case 't':                                               \
  40                u++;                                            \
  41        case 'g':                                               \
  42                u++;                                            \
  43        case 'm':                                               \
  44                u++;                                            \
  45        case 'k':                                               \
  46                u++;                                            \
  47                if (e++ == cp)                                  \
  48                        return -EINVAL;                         \
  49        case '\n':                                              \
  50        case '\0':                                              \
  51                if (*e == '\n')                                 \
  52                        e++;                                    \
  53        }                                                       \
  54                                                                \
  55        if (*e)                                                 \
  56                return -EINVAL;                                 \
  57                                                                \
  58        while (u--) {                                           \
  59                if ((type) ~0 > 0 &&                            \
  60                    (type) ~0 / 1024 <= i)                      \
  61                        return -EINVAL;                         \
  62                if ((i > 0 && ANYSINT_MAX(type) / 1024 < i) ||  \
  63                    (i < 0 && -ANYSINT_MAX(type) / 1024 > i))   \
  64                        return -EINVAL;                         \
  65                i *= 1024;                                      \
  66        }                                                       \
  67                                                                \
  68        *res = i;                                               \
  69        return 0;                                               \
  70}                                                               \
  71
  72STRTO_H(strtoint, int)
  73STRTO_H(strtouint, unsigned int)
  74STRTO_H(strtoll, long long)
  75STRTO_H(strtoull, unsigned long long)
  76
  77/**
  78 * bch_hprint() - formats @v to human readable string for sysfs.
  79 *
  80 * @v - signed 64 bit integer
  81 * @buf - the (at least 8 byte) buffer to format the result into.
  82 *
  83 * Returns the number of bytes used by format.
  84 */
  85ssize_t bch_hprint(char *buf, int64_t v)
  86{
  87        static const char units[] = "?kMGTPEZY";
  88        int u = 0, t;
  89
  90        uint64_t q;
  91
  92        if (v < 0)
  93                q = -v;
  94        else
  95                q = v;
  96
  97        /* For as long as the number is more than 3 digits, but at least
  98         * once, shift right / divide by 1024.  Keep the remainder for
  99         * a digit after the decimal point.
 100         */
 101        do {
 102                u++;
 103
 104                t = q & ~(~0 << 10);
 105                q >>= 10;
 106        } while (q >= 1000);
 107
 108        if (v < 0)
 109                /* '-', up to 3 digits, '.', 1 digit, 1 character, null;
 110                 * yields 8 bytes.
 111                 */
 112                return sprintf(buf, "-%llu.%i%c", q, t * 10 / 1024, units[u]);
 113        else
 114                return sprintf(buf, "%llu.%i%c", q, t * 10 / 1024, units[u]);
 115}
 116
 117ssize_t bch_snprint_string_list(char *buf, size_t size, const char * const list[],
 118                            size_t selected)
 119{
 120        char *out = buf;
 121        size_t i;
 122
 123        for (i = 0; list[i]; i++)
 124                out += snprintf(out, buf + size - out,
 125                                i == selected ? "[%s] " : "%s ", list[i]);
 126
 127        out[-1] = '\n';
 128        return out - buf;
 129}
 130
 131ssize_t bch_read_string_list(const char *buf, const char * const list[])
 132{
 133        size_t i;
 134        char *s, *d = kstrndup(buf, PAGE_SIZE - 1, GFP_KERNEL);
 135        if (!d)
 136                return -ENOMEM;
 137
 138        s = strim(d);
 139
 140        for (i = 0; list[i]; i++)
 141                if (!strcmp(list[i], s))
 142                        break;
 143
 144        kfree(d);
 145
 146        if (!list[i])
 147                return -EINVAL;
 148
 149        return i;
 150}
 151
 152bool bch_is_zero(const char *p, size_t n)
 153{
 154        size_t i;
 155
 156        for (i = 0; i < n; i++)
 157                if (p[i])
 158                        return false;
 159        return true;
 160}
 161
 162int bch_parse_uuid(const char *s, char *uuid)
 163{
 164        size_t i, j, x;
 165        memset(uuid, 0, 16);
 166
 167        for (i = 0, j = 0;
 168             i < strspn(s, "-0123456789:ABCDEFabcdef") && j < 32;
 169             i++) {
 170                x = s[i] | 32;
 171
 172                switch (x) {
 173                case '0'...'9':
 174                        x -= '0';
 175                        break;
 176                case 'a'...'f':
 177                        x -= 'a' - 10;
 178                        break;
 179                default:
 180                        continue;
 181                }
 182
 183                if (!(j & 1))
 184                        x <<= 4;
 185                uuid[j++ >> 1] |= x;
 186        }
 187        return i;
 188}
 189
 190void bch_time_stats_update(struct time_stats *stats, uint64_t start_time)
 191{
 192        uint64_t now, duration, last;
 193
 194        spin_lock(&stats->lock);
 195
 196        now             = local_clock();
 197        duration        = time_after64(now, start_time)
 198                ? now - start_time : 0;
 199        last            = time_after64(now, stats->last)
 200                ? now - stats->last : 0;
 201
 202        stats->max_duration = max(stats->max_duration, duration);
 203
 204        if (stats->last) {
 205                ewma_add(stats->average_duration, duration, 8, 8);
 206
 207                if (stats->average_frequency)
 208                        ewma_add(stats->average_frequency, last, 8, 8);
 209                else
 210                        stats->average_frequency  = last << 8;
 211        } else {
 212                stats->average_duration  = duration << 8;
 213        }
 214
 215        stats->last = now ?: 1;
 216
 217        spin_unlock(&stats->lock);
 218}
 219
 220/**
 221 * bch_next_delay() - increment @d by the amount of work done, and return how
 222 * long to delay until the next time to do some work.
 223 *
 224 * @d - the struct bch_ratelimit to update
 225 * @done - the amount of work done, in arbitrary units
 226 *
 227 * Returns the amount of time to delay by, in jiffies
 228 */
 229uint64_t bch_next_delay(struct bch_ratelimit *d, uint64_t done)
 230{
 231        uint64_t now = local_clock();
 232
 233        d->next += div_u64(done * NSEC_PER_SEC, d->rate);
 234
 235        /* Bound the time.  Don't let us fall further than 2 seconds behind
 236         * (this prevents unnecessary backlog that would make it impossible
 237         * to catch up).  If we're ahead of the desired writeback rate,
 238         * don't let us sleep more than 2.5 seconds (so we can notice/respond
 239         * if the control system tells us to speed up!).
 240         */
 241        if (time_before64(now + NSEC_PER_SEC * 5LLU / 2LLU, d->next))
 242                d->next = now + NSEC_PER_SEC * 5LLU / 2LLU;
 243
 244        if (time_after64(now - NSEC_PER_SEC * 2, d->next))
 245                d->next = now - NSEC_PER_SEC * 2;
 246
 247        return time_after64(d->next, now)
 248                ? div_u64(d->next - now, NSEC_PER_SEC / HZ)
 249                : 0;
 250}
 251
 252void bch_bio_map(struct bio *bio, void *base)
 253{
 254        size_t size = bio->bi_iter.bi_size;
 255        struct bio_vec *bv = bio->bi_io_vec;
 256
 257        BUG_ON(!bio->bi_iter.bi_size);
 258        BUG_ON(bio->bi_vcnt);
 259
 260        bv->bv_offset = base ? offset_in_page(base) : 0;
 261        goto start;
 262
 263        for (; size; bio->bi_vcnt++, bv++) {
 264                bv->bv_offset   = 0;
 265start:          bv->bv_len      = min_t(size_t, PAGE_SIZE - bv->bv_offset,
 266                                        size);
 267                if (base) {
 268                        bv->bv_page = is_vmalloc_addr(base)
 269                                ? vmalloc_to_page(base)
 270                                : virt_to_page(base);
 271
 272                        base += bv->bv_len;
 273                }
 274
 275                size -= bv->bv_len;
 276        }
 277}
 278
 279/*
 280 * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group (Any
 281 * use permitted, subject to terms of PostgreSQL license; see.)
 282
 283 * If we have a 64-bit integer type, then a 64-bit CRC looks just like the
 284 * usual sort of implementation. (See Ross Williams' excellent introduction
 285 * A PAINLESS GUIDE TO CRC ERROR DETECTION ALGORITHMS, available from
 286 * ftp://ftp.rocksoft.com/papers/crc_v3.txt or several other net sites.)
 287 * If we have no working 64-bit type, then fake it with two 32-bit registers.
 288 *
 289 * The present implementation is a normal (not "reflected", in Williams'
 290 * terms) 64-bit CRC, using initial all-ones register contents and a final
 291 * bit inversion. The chosen polynomial is borrowed from the DLT1 spec
 292 * (ECMA-182, available from http://www.ecma.ch/ecma1/STAND/ECMA-182.HTM):
 293 *
 294 * x^64 + x^62 + x^57 + x^55 + x^54 + x^53 + x^52 + x^47 + x^46 + x^45 +
 295 * x^40 + x^39 + x^38 + x^37 + x^35 + x^33 + x^32 + x^31 + x^29 + x^27 +
 296 * x^24 + x^23 + x^22 + x^21 + x^19 + x^17 + x^13 + x^12 + x^10 + x^9 +
 297 * x^7 + x^4 + x + 1
 298*/
 299
 300static const uint64_t crc_table[256] = {
 301        0x0000000000000000ULL, 0x42F0E1EBA9EA3693ULL, 0x85E1C3D753D46D26ULL,
 302        0xC711223CFA3E5BB5ULL, 0x493366450E42ECDFULL, 0x0BC387AEA7A8DA4CULL,
 303        0xCCD2A5925D9681F9ULL, 0x8E224479F47CB76AULL, 0x9266CC8A1C85D9BEULL,
 304        0xD0962D61B56FEF2DULL, 0x17870F5D4F51B498ULL, 0x5577EEB6E6BB820BULL,
 305        0xDB55AACF12C73561ULL, 0x99A54B24BB2D03F2ULL, 0x5EB4691841135847ULL,
 306        0x1C4488F3E8F96ED4ULL, 0x663D78FF90E185EFULL, 0x24CD9914390BB37CULL,
 307        0xE3DCBB28C335E8C9ULL, 0xA12C5AC36ADFDE5AULL, 0x2F0E1EBA9EA36930ULL,
 308        0x6DFEFF5137495FA3ULL, 0xAAEFDD6DCD770416ULL, 0xE81F3C86649D3285ULL,
 309        0xF45BB4758C645C51ULL, 0xB6AB559E258E6AC2ULL, 0x71BA77A2DFB03177ULL,
 310        0x334A9649765A07E4ULL, 0xBD68D2308226B08EULL, 0xFF9833DB2BCC861DULL,
 311        0x388911E7D1F2DDA8ULL, 0x7A79F00C7818EB3BULL, 0xCC7AF1FF21C30BDEULL,
 312        0x8E8A101488293D4DULL, 0x499B3228721766F8ULL, 0x0B6BD3C3DBFD506BULL,
 313        0x854997BA2F81E701ULL, 0xC7B97651866BD192ULL, 0x00A8546D7C558A27ULL,
 314        0x4258B586D5BFBCB4ULL, 0x5E1C3D753D46D260ULL, 0x1CECDC9E94ACE4F3ULL,
 315        0xDBFDFEA26E92BF46ULL, 0x990D1F49C77889D5ULL, 0x172F5B3033043EBFULL,
 316        0x55DFBADB9AEE082CULL, 0x92CE98E760D05399ULL, 0xD03E790CC93A650AULL,
 317        0xAA478900B1228E31ULL, 0xE8B768EB18C8B8A2ULL, 0x2FA64AD7E2F6E317ULL,
 318        0x6D56AB3C4B1CD584ULL, 0xE374EF45BF6062EEULL, 0xA1840EAE168A547DULL,
 319        0x66952C92ECB40FC8ULL, 0x2465CD79455E395BULL, 0x3821458AADA7578FULL,
 320        0x7AD1A461044D611CULL, 0xBDC0865DFE733AA9ULL, 0xFF3067B657990C3AULL,
 321        0x711223CFA3E5BB50ULL, 0x33E2C2240A0F8DC3ULL, 0xF4F3E018F031D676ULL,
 322        0xB60301F359DBE0E5ULL, 0xDA050215EA6C212FULL, 0x98F5E3FE438617BCULL,
 323        0x5FE4C1C2B9B84C09ULL, 0x1D14202910527A9AULL, 0x93366450E42ECDF0ULL,
 324        0xD1C685BB4DC4FB63ULL, 0x16D7A787B7FAA0D6ULL, 0x5427466C1E109645ULL,
 325        0x4863CE9FF6E9F891ULL, 0x0A932F745F03CE02ULL, 0xCD820D48A53D95B7ULL,
 326        0x8F72ECA30CD7A324ULL, 0x0150A8DAF8AB144EULL, 0x43A04931514122DDULL,
 327        0x84B16B0DAB7F7968ULL, 0xC6418AE602954FFBULL, 0xBC387AEA7A8DA4C0ULL,
 328        0xFEC89B01D3679253ULL, 0x39D9B93D2959C9E6ULL, 0x7B2958D680B3FF75ULL,
 329        0xF50B1CAF74CF481FULL, 0xB7FBFD44DD257E8CULL, 0x70EADF78271B2539ULL,
 330        0x321A3E938EF113AAULL, 0x2E5EB66066087D7EULL, 0x6CAE578BCFE24BEDULL,
 331        0xABBF75B735DC1058ULL, 0xE94F945C9C3626CBULL, 0x676DD025684A91A1ULL,
 332        0x259D31CEC1A0A732ULL, 0xE28C13F23B9EFC87ULL, 0xA07CF2199274CA14ULL,
 333        0x167FF3EACBAF2AF1ULL, 0x548F120162451C62ULL, 0x939E303D987B47D7ULL,
 334        0xD16ED1D631917144ULL, 0x5F4C95AFC5EDC62EULL, 0x1DBC74446C07F0BDULL,
 335        0xDAAD56789639AB08ULL, 0x985DB7933FD39D9BULL, 0x84193F60D72AF34FULL,
 336        0xC6E9DE8B7EC0C5DCULL, 0x01F8FCB784FE9E69ULL, 0x43081D5C2D14A8FAULL,
 337        0xCD2A5925D9681F90ULL, 0x8FDAB8CE70822903ULL, 0x48CB9AF28ABC72B6ULL,
 338        0x0A3B7B1923564425ULL, 0x70428B155B4EAF1EULL, 0x32B26AFEF2A4998DULL,
 339        0xF5A348C2089AC238ULL, 0xB753A929A170F4ABULL, 0x3971ED50550C43C1ULL,
 340        0x7B810CBBFCE67552ULL, 0xBC902E8706D82EE7ULL, 0xFE60CF6CAF321874ULL,
 341        0xE224479F47CB76A0ULL, 0xA0D4A674EE214033ULL, 0x67C58448141F1B86ULL,
 342        0x253565A3BDF52D15ULL, 0xAB1721DA49899A7FULL, 0xE9E7C031E063ACECULL,
 343        0x2EF6E20D1A5DF759ULL, 0x6C0603E6B3B7C1CAULL, 0xF6FAE5C07D3274CDULL,
 344        0xB40A042BD4D8425EULL, 0x731B26172EE619EBULL, 0x31EBC7FC870C2F78ULL,
 345        0xBFC9838573709812ULL, 0xFD39626EDA9AAE81ULL, 0x3A28405220A4F534ULL,
 346        0x78D8A1B9894EC3A7ULL, 0x649C294A61B7AD73ULL, 0x266CC8A1C85D9BE0ULL,
 347        0xE17DEA9D3263C055ULL, 0xA38D0B769B89F6C6ULL, 0x2DAF4F0F6FF541ACULL,
 348        0x6F5FAEE4C61F773FULL, 0xA84E8CD83C212C8AULL, 0xEABE6D3395CB1A19ULL,
 349        0x90C79D3FEDD3F122ULL, 0xD2377CD44439C7B1ULL, 0x15265EE8BE079C04ULL,
 350        0x57D6BF0317EDAA97ULL, 0xD9F4FB7AE3911DFDULL, 0x9B041A914A7B2B6EULL,
 351        0x5C1538ADB04570DBULL, 0x1EE5D94619AF4648ULL, 0x02A151B5F156289CULL,
 352        0x4051B05E58BC1E0FULL, 0x87409262A28245BAULL, 0xC5B073890B687329ULL,
 353        0x4B9237F0FF14C443ULL, 0x0962D61B56FEF2D0ULL, 0xCE73F427ACC0A965ULL,
 354        0x8C8315CC052A9FF6ULL, 0x3A80143F5CF17F13ULL, 0x7870F5D4F51B4980ULL,
 355        0xBF61D7E80F251235ULL, 0xFD913603A6CF24A6ULL, 0x73B3727A52B393CCULL,
 356        0x31439391FB59A55FULL, 0xF652B1AD0167FEEAULL, 0xB4A25046A88DC879ULL,
 357        0xA8E6D8B54074A6ADULL, 0xEA16395EE99E903EULL, 0x2D071B6213A0CB8BULL,
 358        0x6FF7FA89BA4AFD18ULL, 0xE1D5BEF04E364A72ULL, 0xA3255F1BE7DC7CE1ULL,
 359        0x64347D271DE22754ULL, 0x26C49CCCB40811C7ULL, 0x5CBD6CC0CC10FAFCULL,
 360        0x1E4D8D2B65FACC6FULL, 0xD95CAF179FC497DAULL, 0x9BAC4EFC362EA149ULL,
 361        0x158E0A85C2521623ULL, 0x577EEB6E6BB820B0ULL, 0x906FC95291867B05ULL,
 362        0xD29F28B9386C4D96ULL, 0xCEDBA04AD0952342ULL, 0x8C2B41A1797F15D1ULL,
 363        0x4B3A639D83414E64ULL, 0x09CA82762AAB78F7ULL, 0x87E8C60FDED7CF9DULL,
 364        0xC51827E4773DF90EULL, 0x020905D88D03A2BBULL, 0x40F9E43324E99428ULL,
 365        0x2CFFE7D5975E55E2ULL, 0x6E0F063E3EB46371ULL, 0xA91E2402C48A38C4ULL,
 366        0xEBEEC5E96D600E57ULL, 0x65CC8190991CB93DULL, 0x273C607B30F68FAEULL,
 367        0xE02D4247CAC8D41BULL, 0xA2DDA3AC6322E288ULL, 0xBE992B5F8BDB8C5CULL,
 368        0xFC69CAB42231BACFULL, 0x3B78E888D80FE17AULL, 0x7988096371E5D7E9ULL,
 369        0xF7AA4D1A85996083ULL, 0xB55AACF12C735610ULL, 0x724B8ECDD64D0DA5ULL,
 370        0x30BB6F267FA73B36ULL, 0x4AC29F2A07BFD00DULL, 0x08327EC1AE55E69EULL,
 371        0xCF235CFD546BBD2BULL, 0x8DD3BD16FD818BB8ULL, 0x03F1F96F09FD3CD2ULL,
 372        0x41011884A0170A41ULL, 0x86103AB85A2951F4ULL, 0xC4E0DB53F3C36767ULL,
 373        0xD8A453A01B3A09B3ULL, 0x9A54B24BB2D03F20ULL, 0x5D45907748EE6495ULL,
 374        0x1FB5719CE1045206ULL, 0x919735E51578E56CULL, 0xD367D40EBC92D3FFULL,
 375        0x1476F63246AC884AULL, 0x568617D9EF46BED9ULL, 0xE085162AB69D5E3CULL,
 376        0xA275F7C11F7768AFULL, 0x6564D5FDE549331AULL, 0x279434164CA30589ULL,
 377        0xA9B6706FB8DFB2E3ULL, 0xEB46918411358470ULL, 0x2C57B3B8EB0BDFC5ULL,
 378        0x6EA7525342E1E956ULL, 0x72E3DAA0AA188782ULL, 0x30133B4B03F2B111ULL,
 379        0xF7021977F9CCEAA4ULL, 0xB5F2F89C5026DC37ULL, 0x3BD0BCE5A45A6B5DULL,
 380        0x79205D0E0DB05DCEULL, 0xBE317F32F78E067BULL, 0xFCC19ED95E6430E8ULL,
 381        0x86B86ED5267CDBD3ULL, 0xC4488F3E8F96ED40ULL, 0x0359AD0275A8B6F5ULL,
 382        0x41A94CE9DC428066ULL, 0xCF8B0890283E370CULL, 0x8D7BE97B81D4019FULL,
 383        0x4A6ACB477BEA5A2AULL, 0x089A2AACD2006CB9ULL, 0x14DEA25F3AF9026DULL,
 384        0x562E43B4931334FEULL, 0x913F6188692D6F4BULL, 0xD3CF8063C0C759D8ULL,
 385        0x5DEDC41A34BBEEB2ULL, 0x1F1D25F19D51D821ULL, 0xD80C07CD676F8394ULL,
 386        0x9AFCE626CE85B507ULL,
 387};
 388
 389uint64_t bch_crc64_update(uint64_t crc, const void *_data, size_t len)
 390{
 391        const unsigned char *data = _data;
 392
 393        while (len--) {
 394                int i = ((int) (crc >> 56) ^ *data++) & 0xFF;
 395                crc = crc_table[i] ^ (crc << 8);
 396        }
 397
 398        return crc;
 399}
 400
 401uint64_t bch_crc64(const void *data, size_t len)
 402{
 403        uint64_t crc = 0xffffffffffffffffULL;
 404
 405        crc = bch_crc64_update(crc, data, len);
 406
 407        return crc ^ 0xffffffffffffffffULL;
 408}
 409