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