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
  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)                                     \
  22 int 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
  71 STRTO_H(strtoint, int)
  72 STRTO_H(strtouint, unsigned int)
  73 STRTO_H(strtoll, long long)
  74 STRTO_H(strtoull, unsigned long long)
  75
  76 ssize_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
  96 ssize_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
 110 ssize_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
 131 bool 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
 141 int 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
 169 void 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 unsigned bch_next_delay(struct ratelimit *d, uint64_t done)
 194 {
 195         uint64_t now = local_clock();
 196
 197         d->next += div_u64(done, d->rate);
 198
 199         return time_after64(d->next, now)
 200                 ? div_u64(d->next - now, NSEC_PER_SEC / HZ)
 201                 : 0;
 202 }
 203
 204 void bch_bio_map(struct bio *bio, void *base)
 205 {
 206         size_t size = bio->bi_size;
 207         struct bio_vec *bv = bio->bi_io_vec;
 208
 209         BUG_ON(!bio->bi_size);
 210         BUG_ON(bio->bi_vcnt);
 211
 212         bv->bv_offset = base ? ((unsigned long) base) % PAGE_SIZE : 0;
 213         goto start;
 214
 215         for (; size; bio->bi_vcnt++, bv++) {
 216                 bv->bv_offset   = 0;
 217 start:          bv->bv_len      = min_t(size_t, PAGE_SIZE - bv->bv_offset,
 218                                         size);
 219                 if (base) {
 220                         bv->bv_page = is_vmalloc_addr(base)
 221                                 ? vmalloc_to_page(base)
 222                                 : virt_to_page(base);
 223
 224                         base += bv->bv_len;
 225                 }
 226
 227                 size -= bv->bv_len;
 228         }
 229 }
 230
 231 /*
 232  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group (Any
 233  * use permitted, subject to terms of PostgreSQL license; see.)
 234
 235  * If we have a 64-bit integer type, then a 64-bit CRC looks just like the
 236  * usual sort of implementation. (See Ross Williams' excellent introduction
 237  * A PAINLESS GUIDE TO CRC ERROR DETECTION ALGORITHMS, available from
 238  * ftp://ftp.rocksoft.com/papers/crc_v3.txt or several other net sites.)
 239  * If we have no working 64-bit type, then fake it with two 32-bit registers.
 240  *
 241  * The present implementation is a normal (not "reflected", in Williams'
 242  * terms) 64-bit CRC, using initial all-ones register contents and a final
 243  * bit inversion. The chosen polynomial is borrowed from the DLT1 spec
 244  * (ECMA-182, available from http://www.ecma.ch/ecma1/STAND/ECMA-182.HTM):
 245  *
 246  * x^64 + x^62 + x^57 + x^55 + x^54 + x^53 + x^52 + x^47 + x^46 + x^45 +
 247  * x^40 + x^39 + x^38 + x^37 + x^35 + x^33 + x^32 + x^31 + x^29 + x^27 +
 248  * x^24 + x^23 + x^22 + x^21 + x^19 + x^17 + x^13 + x^12 + x^10 + x^9 +
 249  * x^7 + x^4 + x + 1
 250 */
 251
 252 static const uint64_t crc_table[256] = {
 253         0x0000000000000000ULL, 0x42F0E1EBA9EA3693ULL, 0x85E1C3D753D46D26ULL,
 254         0xC711223CFA3E5BB5ULL, 0x493366450E42ECDFULL, 0x0BC387AEA7A8DA4CULL,
 255         0xCCD2A5925D9681F9ULL, 0x8E224479F47CB76AULL, 0x9266CC8A1C85D9BEULL,
 256         0xD0962D61B56FEF2DULL, 0x17870F5D4F51B498ULL, 0x5577EEB6E6BB820BULL,
 257         0xDB55AACF12C73561ULL, 0x99A54B24BB2D03F2ULL, 0x5EB4691841135847ULL,
 258         0x1C4488F3E8F96ED4ULL, 0x663D78FF90E185EFULL, 0x24CD9914390BB37CULL,
 259         0xE3DCBB28C335E8C9ULL, 0xA12C5AC36ADFDE5AULL, 0x2F0E1EBA9EA36930ULL,
 260         0x6DFEFF5137495FA3ULL, 0xAAEFDD6DCD770416ULL, 0xE81F3C86649D3285ULL,
 261         0xF45BB4758C645C51ULL, 0xB6AB559E258E6AC2ULL, 0x71BA77A2DFB03177ULL,
 262         0x334A9649765A07E4ULL, 0xBD68D2308226B08EULL, 0xFF9833DB2BCC861DULL,
 263         0x388911E7D1F2DDA8ULL, 0x7A79F00C7818EB3BULL, 0xCC7AF1FF21C30BDEULL,
 264         0x8E8A101488293D4DULL, 0x499B3228721766F8ULL, 0x0B6BD3C3DBFD506BULL,
 265         0x854997BA2F81E701ULL, 0xC7B97651866BD192ULL, 0x00A8546D7C558A27ULL,
 266         0x4258B586D5BFBCB4ULL, 0x5E1C3D753D46D260ULL, 0x1CECDC9E94ACE4F3ULL,
 267         0xDBFDFEA26E92BF46ULL, 0x990D1F49C77889D5ULL, 0x172F5B3033043EBFULL,
 268         0x55DFBADB9AEE082CULL, 0x92CE98E760D05399ULL, 0xD03E790CC93A650AULL,
 269         0xAA478900B1228E31ULL, 0xE8B768EB18C8B8A2ULL, 0x2FA64AD7E2F6E317ULL,
 270         0x6D56AB3C4B1CD584ULL, 0xE374EF45BF6062EEULL, 0xA1840EAE168A547DULL,
 271         0x66952C92ECB40FC8ULL, 0x2465CD79455E395BULL, 0x3821458AADA7578FULL,
 272         0x7AD1A461044D611CULL, 0xBDC0865DFE733AA9ULL, 0xFF3067B657990C3AULL,
 273         0x711223CFA3E5BB50ULL, 0x33E2C2240A0F8DC3ULL, 0xF4F3E018F031D676ULL,
 274         0xB60301F359DBE0E5ULL, 0xDA050215EA6C212FULL, 0x98F5E3FE438617BCULL,
 275         0x5FE4C1C2B9B84C09ULL, 0x1D14202910527A9AULL, 0x93366450E42ECDF0ULL,
 276         0xD1C685BB4DC4FB63ULL, 0x16D7A787B7FAA0D6ULL, 0x5427466C1E109645ULL,
 277         0x4863CE9FF6E9F891ULL, 0x0A932F745F03CE02ULL, 0xCD820D48A53D95B7ULL,
 278         0x8F72ECA30CD7A324ULL, 0x0150A8DAF8AB144EULL, 0x43A04931514122DDULL,
 279         0x84B16B0DAB7F7968ULL, 0xC6418AE602954FFBULL, 0xBC387AEA7A8DA4C0ULL,
 280         0xFEC89B01D3679253ULL, 0x39D9B93D2959C9E6ULL, 0x7B2958D680B3FF75ULL,
 281         0xF50B1CAF74CF481FULL, 0xB7FBFD44DD257E8CULL, 0x70EADF78271B2539ULL,
 282         0x321A3E938EF113AAULL, 0x2E5EB66066087D7EULL, 0x6CAE578BCFE24BEDULL,
 283         0xABBF75B735DC1058ULL, 0xE94F945C9C3626CBULL, 0x676DD025684A91A1ULL,
 284         0x259D31CEC1A0A732ULL, 0xE28C13F23B9EFC87ULL, 0xA07CF2199274CA14ULL,
 285         0x167FF3EACBAF2AF1ULL, 0x548F120162451C62ULL, 0x939E303D987B47D7ULL,
 286         0xD16ED1D631917144ULL, 0x5F4C95AFC5EDC62EULL, 0x1DBC74446C07F0BDULL,
 287         0xDAAD56789639AB08ULL, 0x985DB7933FD39D9BULL, 0x84193F60D72AF34FULL,
 288         0xC6E9DE8B7EC0C5DCULL, 0x01F8FCB784FE9E69ULL, 0x43081D5C2D14A8FAULL,
 289         0xCD2A5925D9681F90ULL, 0x8FDAB8CE70822903ULL, 0x48CB9AF28ABC72B6ULL,
 290         0x0A3B7B1923564425ULL, 0x70428B155B4EAF1EULL, 0x32B26AFEF2A4998DULL,
 291         0xF5A348C2089AC238ULL, 0xB753A929A170F4ABULL, 0x3971ED50550C43C1ULL,
 292         0x7B810CBBFCE67552ULL, 0xBC902E8706D82EE7ULL, 0xFE60CF6CAF321874ULL,
 293         0xE224479F47CB76A0ULL, 0xA0D4A674EE214033ULL, 0x67C58448141F1B86ULL,
 294         0x253565A3BDF52D15ULL, 0xAB1721DA49899A7FULL, 0xE9E7C031E063ACECULL,
 295         0x2EF6E20D1A5DF759ULL, 0x6C0603E6B3B7C1CAULL, 0xF6FAE5C07D3274CDULL,
 296         0xB40A042BD4D8425EULL, 0x731B26172EE619EBULL, 0x31EBC7FC870C2F78ULL,
 297         0xBFC9838573709812ULL, 0xFD39626EDA9AAE81ULL, 0x3A28405220A4F534ULL,
 298         0x78D8A1B9894EC3A7ULL, 0x649C294A61B7AD73ULL, 0x266CC8A1C85D9BE0ULL,
 299         0xE17DEA9D3263C055ULL, 0xA38D0B769B89F6C6ULL, 0x2DAF4F0F6FF541ACULL,
 300         0x6F5FAEE4C61F773FULL, 0xA84E8CD83C212C8AULL, 0xEABE6D3395CB1A19ULL,
 301         0x90C79D3FEDD3F122ULL, 0xD2377CD44439C7B1ULL, 0x15265EE8BE079C04ULL,
 302         0x57D6BF0317EDAA97ULL, 0xD9F4FB7AE3911DFDULL, 0x9B041A914A7B2B6EULL,
 303         0x5C1538ADB04570DBULL, 0x1EE5D94619AF4648ULL, 0x02A151B5F156289CULL,
 304         0x4051B05E58BC1E0FULL, 0x87409262A28245BAULL, 0xC5B073890B687329ULL,
 305         0x4B9237F0FF14C443ULL, 0x0962D61B56FEF2D0ULL, 0xCE73F427ACC0A965ULL,
 306         0x8C8315CC052A9FF6ULL, 0x3A80143F5CF17F13ULL, 0x7870F5D4F51B4980ULL,
 307         0xBF61D7E80F251235ULL, 0xFD913603A6CF24A6ULL, 0x73B3727A52B393CCULL,
 308         0x31439391FB59A55FULL, 0xF652B1AD0167FEEAULL, 0xB4A25046A88DC879ULL,
 309         0xA8E6D8B54074A6ADULL, 0xEA16395EE99E903EULL, 0x2D071B6213A0CB8BULL,
 310         0x6FF7FA89BA4AFD18ULL, 0xE1D5BEF04E364A72ULL, 0xA3255F1BE7DC7CE1ULL,
 311         0x64347D271DE22754ULL, 0x26C49CCCB40811C7ULL, 0x5CBD6CC0CC10FAFCULL,
 312         0x1E4D8D2B65FACC6FULL, 0xD95CAF179FC497DAULL, 0x9BAC4EFC362EA149ULL,
 313         0x158E0A85C2521623ULL, 0x577EEB6E6BB820B0ULL, 0x906FC95291867B05ULL,
 314         0xD29F28B9386C4D96ULL, 0xCEDBA04AD0952342ULL, 0x8C2B41A1797F15D1ULL,
 315         0x4B3A639D83414E64ULL, 0x09CA82762AAB78F7ULL, 0x87E8C60FDED7CF9DULL,
 316         0xC51827E4773DF90EULL, 0x020905D88D03A2BBULL, 0x40F9E43324E99428ULL,
 317         0x2CFFE7D5975E55E2ULL, 0x6E0F063E3EB46371ULL, 0xA91E2402C48A38C4ULL,
 318         0xEBEEC5E96D600E57ULL, 0x65CC8190991CB93DULL, 0x273C607B30F68FAEULL,
 319         0xE02D4247CAC8D41BULL, 0xA2DDA3AC6322E288ULL, 0xBE992B5F8BDB8C5CULL,
 320         0xFC69CAB42231BACFULL, 0x3B78E888D80FE17AULL, 0x7988096371E5D7E9ULL,
 321         0xF7AA4D1A85996083ULL, 0xB55AACF12C735610ULL, 0x724B8ECDD64D0DA5ULL,
 322         0x30BB6F267FA73B36ULL, 0x4AC29F2A07BFD00DULL, 0x08327EC1AE55E69EULL,
 323         0xCF235CFD546BBD2BULL, 0x8DD3BD16FD818BB8ULL, 0x03F1F96F09FD3CD2ULL,
 324         0x41011884A0170A41ULL, 0x86103AB85A2951F4ULL, 0xC4E0DB53F3C36767ULL,
 325         0xD8A453A01B3A09B3ULL, 0x9A54B24BB2D03F20ULL, 0x5D45907748EE6495ULL,
 326         0x1FB5719CE1045206ULL, 0x919735E51578E56CULL, 0xD367D40EBC92D3FFULL,
 327         0x1476F63246AC884AULL, 0x568617D9EF46BED9ULL, 0xE085162AB69D5E3CULL,
 328         0xA275F7C11F7768AFULL, 0x6564D5FDE549331AULL, 0x279434164CA30589ULL,
 329         0xA9B6706FB8DFB2E3ULL, 0xEB46918411358470ULL, 0x2C57B3B8EB0BDFC5ULL,
 330         0x6EA7525342E1E956ULL, 0x72E3DAA0AA188782ULL, 0x30133B4B03F2B111ULL,
 331         0xF7021977F9CCEAA4ULL, 0xB5F2F89C5026DC37ULL, 0x3BD0BCE5A45A6B5DULL,
 332         0x79205D0E0DB05DCEULL, 0xBE317F32F78E067BULL, 0xFCC19ED95E6430E8ULL,
 333         0x86B86ED5267CDBD3ULL, 0xC4488F3E8F96ED40ULL, 0x0359AD0275A8B6F5ULL,
 334         0x41A94CE9DC428066ULL, 0xCF8B0890283E370CULL, 0x8D7BE97B81D4019FULL,
 335         0x4A6ACB477BEA5A2AULL, 0x089A2AACD2006CB9ULL, 0x14DEA25F3AF9026DULL,
 336         0x562E43B4931334FEULL, 0x913F6188692D6F4BULL, 0xD3CF8063C0C759D8ULL,
 337         0x5DEDC41A34BBEEB2ULL, 0x1F1D25F19D51D821ULL, 0xD80C07CD676F8394ULL,
 338         0x9AFCE626CE85B507ULL,
 339 };
 340
 341 uint64_t bch_crc64_update(uint64_t crc, const void *_data, size_t len)
 342 {
 343         const unsigned char *data = _data;
 344
 345         while (len--) {
 346                 int i = ((int) (crc >> 56) ^ *data++) & 0xFF;
 347                 crc = crc_table[i] ^ (crc << 8);
 348         }
 349
 350         return crc;
 351 }
 352
 353 uint64_t bch_crc64(const void *data, size_t len)
 354 {
 355         uint64_t crc = 0xffffffffffffffffULL;
 356
 357         crc = bch_crc64_update(crc, data, len);
 358
 359         return crc ^ 0xffffffffffffffffULL;
 360 }