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