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, duration, last;
 172
 173         spin_lock(&stats->lock);
 174
 175         now             = local_clock();
 176         duration        = time_after64(now, start_time)
 177                 ? now - start_time : 0;
 178         last            = time_after64(now, stats->last)
 179                 ? now - stats->last : 0;
 180
 181         stats->max_duration = max(stats->max_duration, duration);
 182
 183         if (stats->last) {
 184                 ewma_add(stats->average_duration, duration, 8, 8);
 185
 186                 if (stats->average_frequency)
 187                         ewma_add(stats->average_frequency, last, 8, 8);
 188                 else
 189                         stats->average_frequency  = last << 8;
 190         } else {
 191                 stats->average_duration  = duration << 8;
 192         }
 193
 194         stats->last = now ?: 1;
 195
 196         spin_unlock(&stats->lock);
 197 }
 198
 199 /**
 200  * bch_next_delay() - increment @d by the amount of work done, and return how
 201  * long to delay until the next time to do some work.
 202  *
 203  * @d - the struct bch_ratelimit to update
 204  * @done - the amount of work done, in arbitrary units
 205  *
 206  * Returns the amount of time to delay by, in jiffies
 207  */
 208 uint64_t bch_next_delay(struct bch_ratelimit *d, uint64_t done)
 209 {
 210         uint64_t now = local_clock();
 211
 212         d->next += div_u64(done * NSEC_PER_SEC, d->rate);
 213
 214         if (time_before64(now + NSEC_PER_SEC, d->next))
 215                 d->next = now + NSEC_PER_SEC;
 216
 217         if (time_after64(now - NSEC_PER_SEC * 2, d->next))
 218                 d->next = now - NSEC_PER_SEC * 2;
 219
 220         return time_after64(d->next, now)
 221                 ? div_u64(d->next - now, NSEC_PER_SEC / HZ)
 222                 : 0;
 223 }
 224
 225 void bch_bio_map(struct bio *bio, void *base)
 226 {
 227         size_t size = bio->bi_iter.bi_size;
 228         struct bio_vec *bv = bio->bi_io_vec;
 229
 230         BUG_ON(!bio->bi_iter.bi_size);
 231         BUG_ON(bio->bi_vcnt);
 232
 233         bv->bv_offset = base ? offset_in_page(base) : 0;
 234         goto start;
 235
 236         for (; size; bio->bi_vcnt++, bv++) {
 237                 bv->bv_offset   = 0;
 238 start:          bv->bv_len      = min_t(size_t, PAGE_SIZE - bv->bv_offset,
 239                                         size);
 240                 if (base) {
 241                         bv->bv_page = is_vmalloc_addr(base)
 242                                 ? vmalloc_to_page(base)
 243                                 : virt_to_page(base);
 244
 245                         base += bv->bv_len;
 246                 }
 247
 248                 size -= bv->bv_len;
 249         }
 250 }
 251
 252 /*
 253  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group (Any
 254  * use permitted, subject to terms of PostgreSQL license; see.)
 255
 256  * If we have a 64-bit integer type, then a 64-bit CRC looks just like the
 257  * usual sort of implementation. (See Ross Williams' excellent introduction
 258  * A PAINLESS GUIDE TO CRC ERROR DETECTION ALGORITHMS, available from
 259  * ftp://ftp.rocksoft.com/papers/crc_v3.txt or several other net sites.)
 260  * If we have no working 64-bit type, then fake it with two 32-bit registers.
 261  *
 262  * The present implementation is a normal (not "reflected", in Williams'
 263  * terms) 64-bit CRC, using initial all-ones register contents and a final
 264  * bit inversion. The chosen polynomial is borrowed from the DLT1 spec
 265  * (ECMA-182, available from http://www.ecma.ch/ecma1/STAND/ECMA-182.HTM):
 266  *
 267  * x^64 + x^62 + x^57 + x^55 + x^54 + x^53 + x^52 + x^47 + x^46 + x^45 +
 268  * x^40 + x^39 + x^38 + x^37 + x^35 + x^33 + x^32 + x^31 + x^29 + x^27 +
 269  * x^24 + x^23 + x^22 + x^21 + x^19 + x^17 + x^13 + x^12 + x^10 + x^9 +
 270  * x^7 + x^4 + x + 1
 271 */
 272
 273 static const uint64_t crc_table[256] = {
 274         0x0000000000000000ULL, 0x42F0E1EBA9EA3693ULL, 0x85E1C3D753D46D26ULL,
 275         0xC711223CFA3E5BB5ULL, 0x493366450E42ECDFULL, 0x0BC387AEA7A8DA4CULL,
 276         0xCCD2A5925D9681F9ULL, 0x8E224479F47CB76AULL, 0x9266CC8A1C85D9BEULL,
 277         0xD0962D61B56FEF2DULL, 0x17870F5D4F51B498ULL, 0x5577EEB6E6BB820BULL,
 278         0xDB55AACF12C73561ULL, 0x99A54B24BB2D03F2ULL, 0x5EB4691841135847ULL,
 279         0x1C4488F3E8F96ED4ULL, 0x663D78FF90E185EFULL, 0x24CD9914390BB37CULL,
 280         0xE3DCBB28C335E8C9ULL, 0xA12C5AC36ADFDE5AULL, 0x2F0E1EBA9EA36930ULL,
 281         0x6DFEFF5137495FA3ULL, 0xAAEFDD6DCD770416ULL, 0xE81F3C86649D3285ULL,
 282         0xF45BB4758C645C51ULL, 0xB6AB559E258E6AC2ULL, 0x71BA77A2DFB03177ULL,
 283         0x334A9649765A07E4ULL, 0xBD68D2308226B08EULL, 0xFF9833DB2BCC861DULL,
 284         0x388911E7D1F2DDA8ULL, 0x7A79F00C7818EB3BULL, 0xCC7AF1FF21C30BDEULL,
 285         0x8E8A101488293D4DULL, 0x499B3228721766F8ULL, 0x0B6BD3C3DBFD506BULL,
 286         0x854997BA2F81E701ULL, 0xC7B97651866BD192ULL, 0x00A8546D7C558A27ULL,
 287         0x4258B586D5BFBCB4ULL, 0x5E1C3D753D46D260ULL, 0x1CECDC9E94ACE4F3ULL,
 288         0xDBFDFEA26E92BF46ULL, 0x990D1F49C77889D5ULL, 0x172F5B3033043EBFULL,
 289         0x55DFBADB9AEE082CULL, 0x92CE98E760D05399ULL, 0xD03E790CC93A650AULL,
 290         0xAA478900B1228E31ULL, 0xE8B768EB18C8B8A2ULL, 0x2FA64AD7E2F6E317ULL,
 291         0x6D56AB3C4B1CD584ULL, 0xE374EF45BF6062EEULL, 0xA1840EAE168A547DULL,
 292         0x66952C92ECB40FC8ULL, 0x2465CD79455E395BULL, 0x3821458AADA7578FULL,
 293         0x7AD1A461044D611CULL, 0xBDC0865DFE733AA9ULL, 0xFF3067B657990C3AULL,
 294         0x711223CFA3E5BB50ULL, 0x33E2C2240A0F8DC3ULL, 0xF4F3E018F031D676ULL,
 295         0xB60301F359DBE0E5ULL, 0xDA050215EA6C212FULL, 0x98F5E3FE438617BCULL,
 296         0x5FE4C1C2B9B84C09ULL, 0x1D14202910527A9AULL, 0x93366450E42ECDF0ULL,
 297         0xD1C685BB4DC4FB63ULL, 0x16D7A787B7FAA0D6ULL, 0x5427466C1E109645ULL,
 298         0x4863CE9FF6E9F891ULL, 0x0A932F745F03CE02ULL, 0xCD820D48A53D95B7ULL,
 299         0x8F72ECA30CD7A324ULL, 0x0150A8DAF8AB144EULL, 0x43A04931514122DDULL,
 300         0x84B16B0DAB7F7968ULL, 0xC6418AE602954FFBULL, 0xBC387AEA7A8DA4C0ULL,
 301         0xFEC89B01D3679253ULL, 0x39D9B93D2959C9E6ULL, 0x7B2958D680B3FF75ULL,
 302         0xF50B1CAF74CF481FULL, 0xB7FBFD44DD257E8CULL, 0x70EADF78271B2539ULL,
 303         0x321A3E938EF113AAULL, 0x2E5EB66066087D7EULL, 0x6CAE578BCFE24BEDULL,
 304         0xABBF75B735DC1058ULL, 0xE94F945C9C3626CBULL, 0x676DD025684A91A1ULL,
 305         0x259D31CEC1A0A732ULL, 0xE28C13F23B9EFC87ULL, 0xA07CF2199274CA14ULL,
 306         0x167FF3EACBAF2AF1ULL, 0x548F120162451C62ULL, 0x939E303D987B47D7ULL,
 307         0xD16ED1D631917144ULL, 0x5F4C95AFC5EDC62EULL, 0x1DBC74446C07F0BDULL,
 308         0xDAAD56789639AB08ULL, 0x985DB7933FD39D9BULL, 0x84193F60D72AF34FULL,
 309         0xC6E9DE8B7EC0C5DCULL, 0x01F8FCB784FE9E69ULL, 0x43081D5C2D14A8FAULL,
 310         0xCD2A5925D9681F90ULL, 0x8FDAB8CE70822903ULL, 0x48CB9AF28ABC72B6ULL,
 311         0x0A3B7B1923564425ULL, 0x70428B155B4EAF1EULL, 0x32B26AFEF2A4998DULL,
 312         0xF5A348C2089AC238ULL, 0xB753A929A170F4ABULL, 0x3971ED50550C43C1ULL,
 313         0x7B810CBBFCE67552ULL, 0xBC902E8706D82EE7ULL, 0xFE60CF6CAF321874ULL,
 314         0xE224479F47CB76A0ULL, 0xA0D4A674EE214033ULL, 0x67C58448141F1B86ULL,
 315         0x253565A3BDF52D15ULL, 0xAB1721DA49899A7FULL, 0xE9E7C031E063ACECULL,
 316         0x2EF6E20D1A5DF759ULL, 0x6C0603E6B3B7C1CAULL, 0xF6FAE5C07D3274CDULL,
 317         0xB40A042BD4D8425EULL, 0x731B26172EE619EBULL, 0x31EBC7FC870C2F78ULL,
 318         0xBFC9838573709812ULL, 0xFD39626EDA9AAE81ULL, 0x3A28405220A4F534ULL,
 319         0x78D8A1B9894EC3A7ULL, 0x649C294A61B7AD73ULL, 0x266CC8A1C85D9BE0ULL,
 320         0xE17DEA9D3263C055ULL, 0xA38D0B769B89F6C6ULL, 0x2DAF4F0F6FF541ACULL,
 321         0x6F5FAEE4C61F773FULL, 0xA84E8CD83C212C8AULL, 0xEABE6D3395CB1A19ULL,
 322         0x90C79D3FEDD3F122ULL, 0xD2377CD44439C7B1ULL, 0x15265EE8BE079C04ULL,
 323         0x57D6BF0317EDAA97ULL, 0xD9F4FB7AE3911DFDULL, 0x9B041A914A7B2B6EULL,
 324         0x5C1538ADB04570DBULL, 0x1EE5D94619AF4648ULL, 0x02A151B5F156289CULL,
 325         0x4051B05E58BC1E0FULL, 0x87409262A28245BAULL, 0xC5B073890B687329ULL,
 326         0x4B9237F0FF14C443ULL, 0x0962D61B56FEF2D0ULL, 0xCE73F427ACC0A965ULL,
 327         0x8C8315CC052A9FF6ULL, 0x3A80143F5CF17F13ULL, 0x7870F5D4F51B4980ULL,
 328         0xBF61D7E80F251235ULL, 0xFD913603A6CF24A6ULL, 0x73B3727A52B393CCULL,
 329         0x31439391FB59A55FULL, 0xF652B1AD0167FEEAULL, 0xB4A25046A88DC879ULL,
 330         0xA8E6D8B54074A6ADULL, 0xEA16395EE99E903EULL, 0x2D071B6213A0CB8BULL,
 331         0x6FF7FA89BA4AFD18ULL, 0xE1D5BEF04E364A72ULL, 0xA3255F1BE7DC7CE1ULL,
 332         0x64347D271DE22754ULL, 0x26C49CCCB40811C7ULL, 0x5CBD6CC0CC10FAFCULL,
 333         0x1E4D8D2B65FACC6FULL, 0xD95CAF179FC497DAULL, 0x9BAC4EFC362EA149ULL,
 334         0x158E0A85C2521623ULL, 0x577EEB6E6BB820B0ULL, 0x906FC95291867B05ULL,
 335         0xD29F28B9386C4D96ULL, 0xCEDBA04AD0952342ULL, 0x8C2B41A1797F15D1ULL,
 336         0x4B3A639D83414E64ULL, 0x09CA82762AAB78F7ULL, 0x87E8C60FDED7CF9DULL,
 337         0xC51827E4773DF90EULL, 0x020905D88D03A2BBULL, 0x40F9E43324E99428ULL,
 338         0x2CFFE7D5975E55E2ULL, 0x6E0F063E3EB46371ULL, 0xA91E2402C48A38C4ULL,
 339         0xEBEEC5E96D600E57ULL, 0x65CC8190991CB93DULL, 0x273C607B30F68FAEULL,
 340         0xE02D4247CAC8D41BULL, 0xA2DDA3AC6322E288ULL, 0xBE992B5F8BDB8C5CULL,
 341         0xFC69CAB42231BACFULL, 0x3B78E888D80FE17AULL, 0x7988096371E5D7E9ULL,
 342         0xF7AA4D1A85996083ULL, 0xB55AACF12C735610ULL, 0x724B8ECDD64D0DA5ULL,
 343         0x30BB6F267FA73B36ULL, 0x4AC29F2A07BFD00DULL, 0x08327EC1AE55E69EULL,
 344         0xCF235CFD546BBD2BULL, 0x8DD3BD16FD818BB8ULL, 0x03F1F96F09FD3CD2ULL,
 345         0x41011884A0170A41ULL, 0x86103AB85A2951F4ULL, 0xC4E0DB53F3C36767ULL,
 346         0xD8A453A01B3A09B3ULL, 0x9A54B24BB2D03F20ULL, 0x5D45907748EE6495ULL,
 347         0x1FB5719CE1045206ULL, 0x919735E51578E56CULL, 0xD367D40EBC92D3FFULL,
 348         0x1476F63246AC884AULL, 0x568617D9EF46BED9ULL, 0xE085162AB69D5E3CULL,
 349         0xA275F7C11F7768AFULL, 0x6564D5FDE549331AULL, 0x279434164CA30589ULL,
 350         0xA9B6706FB8DFB2E3ULL, 0xEB46918411358470ULL, 0x2C57B3B8EB0BDFC5ULL,
 351         0x6EA7525342E1E956ULL, 0x72E3DAA0AA188782ULL, 0x30133B4B03F2B111ULL,
 352         0xF7021977F9CCEAA4ULL, 0xB5F2F89C5026DC37ULL, 0x3BD0BCE5A45A6B5DULL,
 353         0x79205D0E0DB05DCEULL, 0xBE317F32F78E067BULL, 0xFCC19ED95E6430E8ULL,
 354         0x86B86ED5267CDBD3ULL, 0xC4488F3E8F96ED40ULL, 0x0359AD0275A8B6F5ULL,
 355         0x41A94CE9DC428066ULL, 0xCF8B0890283E370CULL, 0x8D7BE97B81D4019FULL,
 356         0x4A6ACB477BEA5A2AULL, 0x089A2AACD2006CB9ULL, 0x14DEA25F3AF9026DULL,
 357         0x562E43B4931334FEULL, 0x913F6188692D6F4BULL, 0xD3CF8063C0C759D8ULL,
 358         0x5DEDC41A34BBEEB2ULL, 0x1F1D25F19D51D821ULL, 0xD80C07CD676F8394ULL,
 359         0x9AFCE626CE85B507ULL,
 360 };
 361
 362 uint64_t bch_crc64_update(uint64_t crc, const void *_data, size_t len)
 363 {
 364         const unsigned char *data = _data;
 365
 366         while (len--) {
 367                 int i = ((int) (crc >> 56) ^ *data++) & 0xFF;
 368                 crc = crc_table[i] ^ (crc << 8);
 369         }
 370
 371         return crc;
 372 }
 373
 374 uint64_t bch_crc64(const void *data, size_t len)
 375 {
 376         uint64_t crc = 0xffffffffffffffffULL;
 377
 378         crc = bch_crc64_update(crc, data, len);
 379
 380         return crc ^ 0xffffffffffffffffULL;
 381 }