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)                                     \
  23 int 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
  72 STRTO_H(strtoint, int)
  73 STRTO_H(strtouint, unsigned int)
  74 STRTO_H(strtoll, long long)
  75 STRTO_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  */
  85 ssize_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
 117 ssize_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
 131 ssize_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
 152 bool 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
 162 int 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
 190 void 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  */
 229 uint64_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
 252 /*
 253  * Generally it isn't good to access .bi_io_vec and .bi_vcnt directly,
 254  * the preferred way is bio_add_page, but in this case, bch_bio_map()
 255  * supposes that the bvec table is empty, so it is safe to access
 256  * .bi_vcnt & .bi_io_vec in this way even after multipage bvec is
 257  * supported.
 258  */
 259 void bch_bio_map(struct bio *bio, void *base)
 260 {
 261         size_t size = bio->bi_iter.bi_size;
 262         struct bio_vec *bv = bio->bi_io_vec;
 263
 264         BUG_ON(!bio->bi_iter.bi_size);
 265         BUG_ON(bio->bi_vcnt);
 266
 267         bv->bv_offset = base ? offset_in_page(base) : 0;
 268         goto start;
 269
 270         for (; size; bio->bi_vcnt++, bv++) {
 271                 bv->bv_offset   = 0;
 272 start:          bv->bv_len      = min_t(size_t, PAGE_SIZE - bv->bv_offset,
 273                                         size);
 274                 if (base) {
 275                         bv->bv_page = is_vmalloc_addr(base)
 276                                 ? vmalloc_to_page(base)
 277                                 : virt_to_page(base);
 278
 279                         base += bv->bv_len;
 280                 }
 281
 282                 size -= bv->bv_len;
 283         }
 284 }
 285
 286 /**
 287  * bch_bio_alloc_pages - allocates a single page for each bvec in a bio
 288  * @bio: bio to allocate pages for
 289  * @gfp_mask: flags for allocation
 290  *
 291  * Allocates pages up to @bio->bi_vcnt.
 292  *
 293  * Returns 0 on success, -ENOMEM on failure. On failure, any allocated pages are
 294  * freed.
 295  */
 296 int bch_bio_alloc_pages(struct bio *bio, gfp_t gfp_mask)
 297 {
 298         int i;
 299         struct bio_vec *bv;
 300
 301         bio_for_each_segment_all(bv, bio, i) {
 302                 bv->bv_page = alloc_page(gfp_mask);
 303                 if (!bv->bv_page) {
 304                         while (--bv >= bio->bi_io_vec)
 305                                 __free_page(bv->bv_page);
 306                         return -ENOMEM;
 307                 }
 308         }
 309
 310         return 0;
 311 }
 312
 313 /*
 314  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group (Any
 315  * use permitted, subject to terms of PostgreSQL license; see.)
 316
 317  * If we have a 64-bit integer type, then a 64-bit CRC looks just like the
 318  * usual sort of implementation. (See Ross Williams' excellent introduction
 319  * A PAINLESS GUIDE TO CRC ERROR DETECTION ALGORITHMS, available from
 320  * ftp://ftp.rocksoft.com/papers/crc_v3.txt or several other net sites.)
 321  * If we have no working 64-bit type, then fake it with two 32-bit registers.
 322  *
 323  * The present implementation is a normal (not "reflected", in Williams'
 324  * terms) 64-bit CRC, using initial all-ones register contents and a final
 325  * bit inversion. The chosen polynomial is borrowed from the DLT1 spec
 326  * (ECMA-182, available from http://www.ecma.ch/ecma1/STAND/ECMA-182.HTM):
 327  *
 328  * x^64 + x^62 + x^57 + x^55 + x^54 + x^53 + x^52 + x^47 + x^46 + x^45 +
 329  * x^40 + x^39 + x^38 + x^37 + x^35 + x^33 + x^32 + x^31 + x^29 + x^27 +
 330  * x^24 + x^23 + x^22 + x^21 + x^19 + x^17 + x^13 + x^12 + x^10 + x^9 +
 331  * x^7 + x^4 + x + 1
 332 */
 333
 334 static const uint64_t crc_table[256] = {
 335         0x0000000000000000ULL, 0x42F0E1EBA9EA3693ULL, 0x85E1C3D753D46D26ULL,
 336         0xC711223CFA3E5BB5ULL, 0x493366450E42ECDFULL, 0x0BC387AEA7A8DA4CULL,
 337         0xCCD2A5925D9681F9ULL, 0x8E224479F47CB76AULL, 0x9266CC8A1C85D9BEULL,
 338         0xD0962D61B56FEF2DULL, 0x17870F5D4F51B498ULL, 0x5577EEB6E6BB820BULL,
 339         0xDB55AACF12C73561ULL, 0x99A54B24BB2D03F2ULL, 0x5EB4691841135847ULL,
 340         0x1C4488F3E8F96ED4ULL, 0x663D78FF90E185EFULL, 0x24CD9914390BB37CULL,
 341         0xE3DCBB28C335E8C9ULL, 0xA12C5AC36ADFDE5AULL, 0x2F0E1EBA9EA36930ULL,
 342         0x6DFEFF5137495FA3ULL, 0xAAEFDD6DCD770416ULL, 0xE81F3C86649D3285ULL,
 343         0xF45BB4758C645C51ULL, 0xB6AB559E258E6AC2ULL, 0x71BA77A2DFB03177ULL,
 344         0x334A9649765A07E4ULL, 0xBD68D2308226B08EULL, 0xFF9833DB2BCC861DULL,
 345         0x388911E7D1F2DDA8ULL, 0x7A79F00C7818EB3BULL, 0xCC7AF1FF21C30BDEULL,
 346         0x8E8A101488293D4DULL, 0x499B3228721766F8ULL, 0x0B6BD3C3DBFD506BULL,
 347         0x854997BA2F81E701ULL, 0xC7B97651866BD192ULL, 0x00A8546D7C558A27ULL,
 348         0x4258B586D5BFBCB4ULL, 0x5E1C3D753D46D260ULL, 0x1CECDC9E94ACE4F3ULL,
 349         0xDBFDFEA26E92BF46ULL, 0x990D1F49C77889D5ULL, 0x172F5B3033043EBFULL,
 350         0x55DFBADB9AEE082CULL, 0x92CE98E760D05399ULL, 0xD03E790CC93A650AULL,
 351         0xAA478900B1228E31ULL, 0xE8B768EB18C8B8A2ULL, 0x2FA64AD7E2F6E317ULL,
 352         0x6D56AB3C4B1CD584ULL, 0xE374EF45BF6062EEULL, 0xA1840EAE168A547DULL,
 353         0x66952C92ECB40FC8ULL, 0x2465CD79455E395BULL, 0x3821458AADA7578FULL,
 354         0x7AD1A461044D611CULL, 0xBDC0865DFE733AA9ULL, 0xFF3067B657990C3AULL,
 355         0x711223CFA3E5BB50ULL, 0x33E2C2240A0F8DC3ULL, 0xF4F3E018F031D676ULL,
 356         0xB60301F359DBE0E5ULL, 0xDA050215EA6C212FULL, 0x98F5E3FE438617BCULL,
 357         0x5FE4C1C2B9B84C09ULL, 0x1D14202910527A9AULL, 0x93366450E42ECDF0ULL,
 358         0xD1C685BB4DC4FB63ULL, 0x16D7A787B7FAA0D6ULL, 0x5427466C1E109645ULL,
 359         0x4863CE9FF6E9F891ULL, 0x0A932F745F03CE02ULL, 0xCD820D48A53D95B7ULL,
 360         0x8F72ECA30CD7A324ULL, 0x0150A8DAF8AB144EULL, 0x43A04931514122DDULL,
 361         0x84B16B0DAB7F7968ULL, 0xC6418AE602954FFBULL, 0xBC387AEA7A8DA4C0ULL,
 362         0xFEC89B01D3679253ULL, 0x39D9B93D2959C9E6ULL, 0x7B2958D680B3FF75ULL,
 363         0xF50B1CAF74CF481FULL, 0xB7FBFD44DD257E8CULL, 0x70EADF78271B2539ULL,
 364         0x321A3E938EF113AAULL, 0x2E5EB66066087D7EULL, 0x6CAE578BCFE24BEDULL,
 365         0xABBF75B735DC1058ULL, 0xE94F945C9C3626CBULL, 0x676DD025684A91A1ULL,
 366         0x259D31CEC1A0A732ULL, 0xE28C13F23B9EFC87ULL, 0xA07CF2199274CA14ULL,
 367         0x167FF3EACBAF2AF1ULL, 0x548F120162451C62ULL, 0x939E303D987B47D7ULL,
 368         0xD16ED1D631917144ULL, 0x5F4C95AFC5EDC62EULL, 0x1DBC74446C07F0BDULL,
 369         0xDAAD56789639AB08ULL, 0x985DB7933FD39D9BULL, 0x84193F60D72AF34FULL,
 370         0xC6E9DE8B7EC0C5DCULL, 0x01F8FCB784FE9E69ULL, 0x43081D5C2D14A8FAULL,
 371         0xCD2A5925D9681F90ULL, 0x8FDAB8CE70822903ULL, 0x48CB9AF28ABC72B6ULL,
 372         0x0A3B7B1923564425ULL, 0x70428B155B4EAF1EULL, 0x32B26AFEF2A4998DULL,
 373         0xF5A348C2089AC238ULL, 0xB753A929A170F4ABULL, 0x3971ED50550C43C1ULL,
 374         0x7B810CBBFCE67552ULL, 0xBC902E8706D82EE7ULL, 0xFE60CF6CAF321874ULL,
 375         0xE224479F47CB76A0ULL, 0xA0D4A674EE214033ULL, 0x67C58448141F1B86ULL,
 376         0x253565A3BDF52D15ULL, 0xAB1721DA49899A7FULL, 0xE9E7C031E063ACECULL,
 377         0x2EF6E20D1A5DF759ULL, 0x6C0603E6B3B7C1CAULL, 0xF6FAE5C07D3274CDULL,
 378         0xB40A042BD4D8425EULL, 0x731B26172EE619EBULL, 0x31EBC7FC870C2F78ULL,
 379         0xBFC9838573709812ULL, 0xFD39626EDA9AAE81ULL, 0x3A28405220A4F534ULL,
 380         0x78D8A1B9894EC3A7ULL, 0x649C294A61B7AD73ULL, 0x266CC8A1C85D9BE0ULL,
 381         0xE17DEA9D3263C055ULL, 0xA38D0B769B89F6C6ULL, 0x2DAF4F0F6FF541ACULL,
 382         0x6F5FAEE4C61F773FULL, 0xA84E8CD83C212C8AULL, 0xEABE6D3395CB1A19ULL,
 383         0x90C79D3FEDD3F122ULL, 0xD2377CD44439C7B1ULL, 0x15265EE8BE079C04ULL,
 384         0x57D6BF0317EDAA97ULL, 0xD9F4FB7AE3911DFDULL, 0x9B041A914A7B2B6EULL,
 385         0x5C1538ADB04570DBULL, 0x1EE5D94619AF4648ULL, 0x02A151B5F156289CULL,
 386         0x4051B05E58BC1E0FULL, 0x87409262A28245BAULL, 0xC5B073890B687329ULL,
 387         0x4B9237F0FF14C443ULL, 0x0962D61B56FEF2D0ULL, 0xCE73F427ACC0A965ULL,
 388         0x8C8315CC052A9FF6ULL, 0x3A80143F5CF17F13ULL, 0x7870F5D4F51B4980ULL,
 389         0xBF61D7E80F251235ULL, 0xFD913603A6CF24A6ULL, 0x73B3727A52B393CCULL,
 390         0x31439391FB59A55FULL, 0xF652B1AD0167FEEAULL, 0xB4A25046A88DC879ULL,
 391         0xA8E6D8B54074A6ADULL, 0xEA16395EE99E903EULL, 0x2D071B6213A0CB8BULL,
 392         0x6FF7FA89BA4AFD18ULL, 0xE1D5BEF04E364A72ULL, 0xA3255F1BE7DC7CE1ULL,
 393         0x64347D271DE22754ULL, 0x26C49CCCB40811C7ULL, 0x5CBD6CC0CC10FAFCULL,
 394         0x1E4D8D2B65FACC6FULL, 0xD95CAF179FC497DAULL, 0x9BAC4EFC362EA149ULL,
 395         0x158E0A85C2521623ULL, 0x577EEB6E6BB820B0ULL, 0x906FC95291867B05ULL,
 396         0xD29F28B9386C4D96ULL, 0xCEDBA04AD0952342ULL, 0x8C2B41A1797F15D1ULL,
 397         0x4B3A639D83414E64ULL, 0x09CA82762AAB78F7ULL, 0x87E8C60FDED7CF9DULL,
 398         0xC51827E4773DF90EULL, 0x020905D88D03A2BBULL, 0x40F9E43324E99428ULL,
 399         0x2CFFE7D5975E55E2ULL, 0x6E0F063E3EB46371ULL, 0xA91E2402C48A38C4ULL,
 400         0xEBEEC5E96D600E57ULL, 0x65CC8190991CB93DULL, 0x273C607B30F68FAEULL,
 401         0xE02D4247CAC8D41BULL, 0xA2DDA3AC6322E288ULL, 0xBE992B5F8BDB8C5CULL,
 402         0xFC69CAB42231BACFULL, 0x3B78E888D80FE17AULL, 0x7988096371E5D7E9ULL,
 403         0xF7AA4D1A85996083ULL, 0xB55AACF12C735610ULL, 0x724B8ECDD64D0DA5ULL,
 404         0x30BB6F267FA73B36ULL, 0x4AC29F2A07BFD00DULL, 0x08327EC1AE55E69EULL,
 405         0xCF235CFD546BBD2BULL, 0x8DD3BD16FD818BB8ULL, 0x03F1F96F09FD3CD2ULL,
 406         0x41011884A0170A41ULL, 0x86103AB85A2951F4ULL, 0xC4E0DB53F3C36767ULL,
 407         0xD8A453A01B3A09B3ULL, 0x9A54B24BB2D03F20ULL, 0x5D45907748EE6495ULL,
 408         0x1FB5719CE1045206ULL, 0x919735E51578E56CULL, 0xD367D40EBC92D3FFULL,
 409         0x1476F63246AC884AULL, 0x568617D9EF46BED9ULL, 0xE085162AB69D5E3CULL,
 410         0xA275F7C11F7768AFULL, 0x6564D5FDE549331AULL, 0x279434164CA30589ULL,
 411         0xA9B6706FB8DFB2E3ULL, 0xEB46918411358470ULL, 0x2C57B3B8EB0BDFC5ULL,
 412         0x6EA7525342E1E956ULL, 0x72E3DAA0AA188782ULL, 0x30133B4B03F2B111ULL,
 413         0xF7021977F9CCEAA4ULL, 0xB5F2F89C5026DC37ULL, 0x3BD0BCE5A45A6B5DULL,
 414         0x79205D0E0DB05DCEULL, 0xBE317F32F78E067BULL, 0xFCC19ED95E6430E8ULL,
 415         0x86B86ED5267CDBD3ULL, 0xC4488F3E8F96ED40ULL, 0x0359AD0275A8B6F5ULL,
 416         0x41A94CE9DC428066ULL, 0xCF8B0890283E370CULL, 0x8D7BE97B81D4019FULL,
 417         0x4A6ACB477BEA5A2AULL, 0x089A2AACD2006CB9ULL, 0x14DEA25F3AF9026DULL,
 418         0x562E43B4931334FEULL, 0x913F6188692D6F4BULL, 0xD3CF8063C0C759D8ULL,
 419         0x5DEDC41A34BBEEB2ULL, 0x1F1D25F19D51D821ULL, 0xD80C07CD676F8394ULL,
 420         0x9AFCE626CE85B507ULL,
 421 };
 422
 423 uint64_t bch_crc64_update(uint64_t crc, const void *_data, size_t len)
 424 {
 425         const unsigned char *data = _data;
 426
 427         while (len--) {
 428                 int i = ((int) (crc >> 56) ^ *data++) & 0xFF;
 429                 crc = crc_table[i] ^ (crc << 8);
 430         }
 431
 432         return crc;
 433 }
 434
 435 uint64_t bch_crc64(const void *data, size_t len)
 436 {
 437         uint64_t crc = 0xffffffffffffffffULL;
 438
 439         crc = bch_crc64_update(crc, data, len);
 440
 441         return crc ^ 0xffffffffffffffffULL;
 442 }