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                 /* fall through */                              \
  36         case 'e':                                               \
  37                 u++;                                            \
  38                 /* fall through */                              \
  39         case 'p':                                               \
  40                 u++;                                            \
  41                 /* fall through */                              \
  42         case 't':                                               \
  43                 u++;                                            \
  44                 /* fall through */                              \
  45         case 'g':                                               \
  46                 u++;                                            \
  47                 /* fall through */                              \
  48         case 'm':                                               \
  49                 u++;                                            \
  50                 /* fall through */                              \
  51         case 'k':                                               \
  52                 u++;                                            \
  53                 if (e++ == cp)                                  \
  54                         return -EINVAL;                         \
  55                 /* fall through */                              \
  56         case '\n':                                              \
  57         case '\0':                                              \
  58                 if (*e == '\n')                                 \
  59                         e++;                                    \
  60         }                                                       \
  61                                                                 \
  62         if (*e)                                                 \
  63                 return -EINVAL;                                 \
  64                                                                 \
  65         while (u--) {                                           \
  66                 if ((type) ~0 > 0 &&                            \
  67                     (type) ~0 / 1024 <= i)                      \
  68                         return -EINVAL;                         \
  69                 if ((i > 0 && ANYSINT_MAX(type) / 1024 < i) ||  \
  70                     (i < 0 && -ANYSINT_MAX(type) / 1024 > i))   \
  71                         return -EINVAL;                         \
  72                 i *= 1024;                                      \
  73         }                                                       \
  74                                                                 \
  75         *res = i;                                               \
  76         return 0;                                               \
  77 }                                                               \
  78
  79 STRTO_H(strtoint, int)
  80 STRTO_H(strtouint, unsigned int)
  81 STRTO_H(strtoll, long long)
  82 STRTO_H(strtoull, unsigned long long)
  83
  84 /**
  85  * bch_hprint - formats @v to human readable string for sysfs.
  86  * @buf: the (at least 8 byte) buffer to format the result into.
  87  * @v: signed 64 bit integer
  88  *
  89  * Returns the number of bytes used by format.
  90  */
  91 ssize_t bch_hprint(char *buf, int64_t v)
  92 {
  93         static const char units[] = "?kMGTPEZY";
  94         int u = 0, t;
  95
  96         uint64_t q;
  97
  98         if (v < 0)
  99                 q = -v;
 100         else
 101                 q = v;
 102
 103         /* For as long as the number is more than 3 digits, but at least
 104          * once, shift right / divide by 1024.  Keep the remainder for
 105          * a digit after the decimal point.
 106          */
 107         do {
 108                 u++;
 109
 110                 t = q & ~(~0 << 10);
 111                 q >>= 10;
 112         } while (q >= 1000);
 113
 114         if (v < 0)
 115                 /* '-', up to 3 digits, '.', 1 digit, 1 character, null;
 116                  * yields 8 bytes.
 117                  */
 118                 return sprintf(buf, "-%llu.%i%c", q, t * 10 / 1024, units[u]);
 119         else
 120                 return sprintf(buf, "%llu.%i%c", q, t * 10 / 1024, units[u]);
 121 }
 122
 123 ssize_t bch_snprint_string_list(char *buf, size_t size, const char * const list[],
 124                             size_t selected)
 125 {
 126         char *out = buf;
 127         size_t i;
 128
 129         for (i = 0; list[i]; i++)
 130                 out += snprintf(out, buf + size - out,
 131                                 i == selected ? "[%s] " : "%s ", list[i]);
 132
 133         out[-1] = '\n';
 134         return out - buf;
 135 }
 136
 137 ssize_t bch_read_string_list(const char *buf, const char * const list[])
 138 {
 139         size_t i;
 140         char *s, *d = kstrndup(buf, PAGE_SIZE - 1, GFP_KERNEL);
 141         if (!d)
 142                 return -ENOMEM;
 143
 144         s = strim(d);
 145
 146         for (i = 0; list[i]; i++)
 147                 if (!strcmp(list[i], s))
 148                         break;
 149
 150         kfree(d);
 151
 152         if (!list[i])
 153                 return -EINVAL;
 154
 155         return i;
 156 }
 157
 158 bool bch_is_zero(const char *p, size_t n)
 159 {
 160         size_t i;
 161
 162         for (i = 0; i < n; i++)
 163                 if (p[i])
 164                         return false;
 165         return true;
 166 }
 167
 168 int bch_parse_uuid(const char *s, char *uuid)
 169 {
 170         size_t i, j, x;
 171         memset(uuid, 0, 16);
 172
 173         for (i = 0, j = 0;
 174              i < strspn(s, "-0123456789:ABCDEFabcdef") && j < 32;
 175              i++) {
 176                 x = s[i] | 32;
 177
 178                 switch (x) {
 179                 case '0'...'9':
 180                         x -= '0';
 181                         break;
 182                 case 'a'...'f':
 183                         x -= 'a' - 10;
 184                         break;
 185                 default:
 186                         continue;
 187                 }
 188
 189                 if (!(j & 1))
 190                         x <<= 4;
 191                 uuid[j++ >> 1] |= x;
 192         }
 193         return i;
 194 }
 195
 196 void bch_time_stats_update(struct time_stats *stats, uint64_t start_time)
 197 {
 198         uint64_t now, duration, last;
 199
 200         spin_lock(&stats->lock);
 201
 202         now             = local_clock();
 203         duration        = time_after64(now, start_time)
 204                 ? now - start_time : 0;
 205         last            = time_after64(now, stats->last)
 206                 ? now - stats->last : 0;
 207
 208         stats->max_duration = max(stats->max_duration, duration);
 209
 210         if (stats->last) {
 211                 ewma_add(stats->average_duration, duration, 8, 8);
 212
 213                 if (stats->average_frequency)
 214                         ewma_add(stats->average_frequency, last, 8, 8);
 215                 else
 216                         stats->average_frequency  = last << 8;
 217         } else {
 218                 stats->average_duration  = duration << 8;
 219         }
 220
 221         stats->last = now ?: 1;
 222
 223         spin_unlock(&stats->lock);
 224 }
 225
 226 /**
 227  * bch_next_delay() - update ratelimiting statistics and calculate next delay
 228  * @d: the struct bch_ratelimit to update
 229  * @done: the amount of work done, in arbitrary units
 230  *
 231  * Increment @d by the amount of work done, and return how long to delay in
 232  * jiffies until the next time to do some work.
 233  */
 234 uint64_t bch_next_delay(struct bch_ratelimit *d, uint64_t done)
 235 {
 236         uint64_t now = local_clock();
 237
 238         d->next += div_u64(done * NSEC_PER_SEC, d->rate);
 239
 240         /* Bound the time.  Don't let us fall further than 2 seconds behind
 241          * (this prevents unnecessary backlog that would make it impossible
 242          * to catch up).  If we're ahead of the desired writeback rate,
 243          * don't let us sleep more than 2.5 seconds (so we can notice/respond
 244          * if the control system tells us to speed up!).
 245          */
 246         if (time_before64(now + NSEC_PER_SEC * 5LLU / 2LLU, d->next))
 247                 d->next = now + NSEC_PER_SEC * 5LLU / 2LLU;
 248
 249         if (time_after64(now - NSEC_PER_SEC * 2, d->next))
 250                 d->next = now - NSEC_PER_SEC * 2;
 251
 252         return time_after64(d->next, now)
 253                 ? div_u64(d->next - now, NSEC_PER_SEC / HZ)
 254                 : 0;
 255 }
 256
 257 /*
 258  * Generally it isn't good to access .bi_io_vec and .bi_vcnt directly,
 259  * the preferred way is bio_add_page, but in this case, bch_bio_map()
 260  * supposes that the bvec table is empty, so it is safe to access
 261  * .bi_vcnt & .bi_io_vec in this way even after multipage bvec is
 262  * supported.
 263  */
 264 void bch_bio_map(struct bio *bio, void *base)
 265 {
 266         size_t size = bio->bi_iter.bi_size;
 267         struct bio_vec *bv = bio->bi_io_vec;
 268
 269         BUG_ON(!bio->bi_iter.bi_size);
 270         BUG_ON(bio->bi_vcnt);
 271
 272         bv->bv_offset = base ? offset_in_page(base) : 0;
 273         goto start;
 274
 275         for (; size; bio->bi_vcnt++, bv++) {
 276                 bv->bv_offset   = 0;
 277 start:          bv->bv_len      = min_t(size_t, PAGE_SIZE - bv->bv_offset,
 278                                         size);
 279                 if (base) {
 280                         bv->bv_page = is_vmalloc_addr(base)
 281                                 ? vmalloc_to_page(base)
 282                                 : virt_to_page(base);
 283
 284                         base += bv->bv_len;
 285                 }
 286
 287                 size -= bv->bv_len;
 288         }
 289 }
 290
 291 /**
 292  * bch_bio_alloc_pages - allocates a single page for each bvec in a bio
 293  * @bio: bio to allocate pages for
 294  * @gfp_mask: flags for allocation
 295  *
 296  * Allocates pages up to @bio->bi_vcnt.
 297  *
 298  * Returns 0 on success, -ENOMEM on failure. On failure, any allocated pages are
 299  * freed.
 300  */
 301 int bch_bio_alloc_pages(struct bio *bio, gfp_t gfp_mask)
 302 {
 303         int i;
 304         struct bio_vec *bv;
 305
 306         bio_for_each_segment_all(bv, bio, i) {
 307                 bv->bv_page = alloc_page(gfp_mask);
 308                 if (!bv->bv_page) {
 309                         while (--bv >= bio->bi_io_vec)
 310                                 __free_page(bv->bv_page);
 311                         return -ENOMEM;
 312                 }
 313         }
 314
 315         return 0;
 316 }
 317
 318 /*
 319  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group (Any
 320  * use permitted, subject to terms of PostgreSQL license; see.)
 321
 322  * If we have a 64-bit integer type, then a 64-bit CRC looks just like the
 323  * usual sort of implementation. (See Ross Williams' excellent introduction
 324  * A PAINLESS GUIDE TO CRC ERROR DETECTION ALGORITHMS, available from
 325  * ftp://ftp.rocksoft.com/papers/crc_v3.txt or several other net sites.)
 326  * If we have no working 64-bit type, then fake it with two 32-bit registers.
 327  *
 328  * The present implementation is a normal (not "reflected", in Williams'
 329  * terms) 64-bit CRC, using initial all-ones register contents and a final
 330  * bit inversion. The chosen polynomial is borrowed from the DLT1 spec
 331  * (ECMA-182, available from http://www.ecma.ch/ecma1/STAND/ECMA-182.HTM):
 332  *
 333  * x^64 + x^62 + x^57 + x^55 + x^54 + x^53 + x^52 + x^47 + x^46 + x^45 +
 334  * x^40 + x^39 + x^38 + x^37 + x^35 + x^33 + x^32 + x^31 + x^29 + x^27 +
 335  * x^24 + x^23 + x^22 + x^21 + x^19 + x^17 + x^13 + x^12 + x^10 + x^9 +
 336  * x^7 + x^4 + x + 1
 337 */
 338
 339 static const uint64_t crc_table[256] = {
 340         0x0000000000000000ULL, 0x42F0E1EBA9EA3693ULL, 0x85E1C3D753D46D26ULL,
 341         0xC711223CFA3E5BB5ULL, 0x493366450E42ECDFULL, 0x0BC387AEA7A8DA4CULL,
 342         0xCCD2A5925D9681F9ULL, 0x8E224479F47CB76AULL, 0x9266CC8A1C85D9BEULL,
 343         0xD0962D61B56FEF2DULL, 0x17870F5D4F51B498ULL, 0x5577EEB6E6BB820BULL,
 344         0xDB55AACF12C73561ULL, 0x99A54B24BB2D03F2ULL, 0x5EB4691841135847ULL,
 345         0x1C4488F3E8F96ED4ULL, 0x663D78FF90E185EFULL, 0x24CD9914390BB37CULL,
 346         0xE3DCBB28C335E8C9ULL, 0xA12C5AC36ADFDE5AULL, 0x2F0E1EBA9EA36930ULL,
 347         0x6DFEFF5137495FA3ULL, 0xAAEFDD6DCD770416ULL, 0xE81F3C86649D3285ULL,
 348         0xF45BB4758C645C51ULL, 0xB6AB559E258E6AC2ULL, 0x71BA77A2DFB03177ULL,
 349         0x334A9649765A07E4ULL, 0xBD68D2308226B08EULL, 0xFF9833DB2BCC861DULL,
 350         0x388911E7D1F2DDA8ULL, 0x7A79F00C7818EB3BULL, 0xCC7AF1FF21C30BDEULL,
 351         0x8E8A101488293D4DULL, 0x499B3228721766F8ULL, 0x0B6BD3C3DBFD506BULL,
 352         0x854997BA2F81E701ULL, 0xC7B97651866BD192ULL, 0x00A8546D7C558A27ULL,
 353         0x4258B586D5BFBCB4ULL, 0x5E1C3D753D46D260ULL, 0x1CECDC9E94ACE4F3ULL,
 354         0xDBFDFEA26E92BF46ULL, 0x990D1F49C77889D5ULL, 0x172F5B3033043EBFULL,
 355         0x55DFBADB9AEE082CULL, 0x92CE98E760D05399ULL, 0xD03E790CC93A650AULL,
 356         0xAA478900B1228E31ULL, 0xE8B768EB18C8B8A2ULL, 0x2FA64AD7E2F6E317ULL,
 357         0x6D56AB3C4B1CD584ULL, 0xE374EF45BF6062EEULL, 0xA1840EAE168A547DULL,
 358         0x66952C92ECB40FC8ULL, 0x2465CD79455E395BULL, 0x3821458AADA7578FULL,
 359         0x7AD1A461044D611CULL, 0xBDC0865DFE733AA9ULL, 0xFF3067B657990C3AULL,
 360         0x711223CFA3E5BB50ULL, 0x33E2C2240A0F8DC3ULL, 0xF4F3E018F031D676ULL,
 361         0xB60301F359DBE0E5ULL, 0xDA050215EA6C212FULL, 0x98F5E3FE438617BCULL,
 362         0x5FE4C1C2B9B84C09ULL, 0x1D14202910527A9AULL, 0x93366450E42ECDF0ULL,
 363         0xD1C685BB4DC4FB63ULL, 0x16D7A787B7FAA0D6ULL, 0x5427466C1E109645ULL,
 364         0x4863CE9FF6E9F891ULL, 0x0A932F745F03CE02ULL, 0xCD820D48A53D95B7ULL,
 365         0x8F72ECA30CD7A324ULL, 0x0150A8DAF8AB144EULL, 0x43A04931514122DDULL,
 366         0x84B16B0DAB7F7968ULL, 0xC6418AE602954FFBULL, 0xBC387AEA7A8DA4C0ULL,
 367         0xFEC89B01D3679253ULL, 0x39D9B93D2959C9E6ULL, 0x7B2958D680B3FF75ULL,
 368         0xF50B1CAF74CF481FULL, 0xB7FBFD44DD257E8CULL, 0x70EADF78271B2539ULL,
 369         0x321A3E938EF113AAULL, 0x2E5EB66066087D7EULL, 0x6CAE578BCFE24BEDULL,
 370         0xABBF75B735DC1058ULL, 0xE94F945C9C3626CBULL, 0x676DD025684A91A1ULL,
 371         0x259D31CEC1A0A732ULL, 0xE28C13F23B9EFC87ULL, 0xA07CF2199274CA14ULL,
 372         0x167FF3EACBAF2AF1ULL, 0x548F120162451C62ULL, 0x939E303D987B47D7ULL,
 373         0xD16ED1D631917144ULL, 0x5F4C95AFC5EDC62EULL, 0x1DBC74446C07F0BDULL,
 374         0xDAAD56789639AB08ULL, 0x985DB7933FD39D9BULL, 0x84193F60D72AF34FULL,
 375         0xC6E9DE8B7EC0C5DCULL, 0x01F8FCB784FE9E69ULL, 0x43081D5C2D14A8FAULL,
 376         0xCD2A5925D9681F90ULL, 0x8FDAB8CE70822903ULL, 0x48CB9AF28ABC72B6ULL,
 377         0x0A3B7B1923564425ULL, 0x70428B155B4EAF1EULL, 0x32B26AFEF2A4998DULL,
 378         0xF5A348C2089AC238ULL, 0xB753A929A170F4ABULL, 0x3971ED50550C43C1ULL,
 379         0x7B810CBBFCE67552ULL, 0xBC902E8706D82EE7ULL, 0xFE60CF6CAF321874ULL,
 380         0xE224479F47CB76A0ULL, 0xA0D4A674EE214033ULL, 0x67C58448141F1B86ULL,
 381         0x253565A3BDF52D15ULL, 0xAB1721DA49899A7FULL, 0xE9E7C031E063ACECULL,
 382         0x2EF6E20D1A5DF759ULL, 0x6C0603E6B3B7C1CAULL, 0xF6FAE5C07D3274CDULL,
 383         0xB40A042BD4D8425EULL, 0x731B26172EE619EBULL, 0x31EBC7FC870C2F78ULL,
 384         0xBFC9838573709812ULL, 0xFD39626EDA9AAE81ULL, 0x3A28405220A4F534ULL,
 385         0x78D8A1B9894EC3A7ULL, 0x649C294A61B7AD73ULL, 0x266CC8A1C85D9BE0ULL,
 386         0xE17DEA9D3263C055ULL, 0xA38D0B769B89F6C6ULL, 0x2DAF4F0F6FF541ACULL,
 387         0x6F5FAEE4C61F773FULL, 0xA84E8CD83C212C8AULL, 0xEABE6D3395CB1A19ULL,
 388         0x90C79D3FEDD3F122ULL, 0xD2377CD44439C7B1ULL, 0x15265EE8BE079C04ULL,
 389         0x57D6BF0317EDAA97ULL, 0xD9F4FB7AE3911DFDULL, 0x9B041A914A7B2B6EULL,
 390         0x5C1538ADB04570DBULL, 0x1EE5D94619AF4648ULL, 0x02A151B5F156289CULL,
 391         0x4051B05E58BC1E0FULL, 0x87409262A28245BAULL, 0xC5B073890B687329ULL,
 392         0x4B9237F0FF14C443ULL, 0x0962D61B56FEF2D0ULL, 0xCE73F427ACC0A965ULL,
 393         0x8C8315CC052A9FF6ULL, 0x3A80143F5CF17F13ULL, 0x7870F5D4F51B4980ULL,
 394         0xBF61D7E80F251235ULL, 0xFD913603A6CF24A6ULL, 0x73B3727A52B393CCULL,
 395         0x31439391FB59A55FULL, 0xF652B1AD0167FEEAULL, 0xB4A25046A88DC879ULL,
 396         0xA8E6D8B54074A6ADULL, 0xEA16395EE99E903EULL, 0x2D071B6213A0CB8BULL,
 397         0x6FF7FA89BA4AFD18ULL, 0xE1D5BEF04E364A72ULL, 0xA3255F1BE7DC7CE1ULL,
 398         0x64347D271DE22754ULL, 0x26C49CCCB40811C7ULL, 0x5CBD6CC0CC10FAFCULL,
 399         0x1E4D8D2B65FACC6FULL, 0xD95CAF179FC497DAULL, 0x9BAC4EFC362EA149ULL,
 400         0x158E0A85C2521623ULL, 0x577EEB6E6BB820B0ULL, 0x906FC95291867B05ULL,
 401         0xD29F28B9386C4D96ULL, 0xCEDBA04AD0952342ULL, 0x8C2B41A1797F15D1ULL,
 402         0x4B3A639D83414E64ULL, 0x09CA82762AAB78F7ULL, 0x87E8C60FDED7CF9DULL,
 403         0xC51827E4773DF90EULL, 0x020905D88D03A2BBULL, 0x40F9E43324E99428ULL,
 404         0x2CFFE7D5975E55E2ULL, 0x6E0F063E3EB46371ULL, 0xA91E2402C48A38C4ULL,
 405         0xEBEEC5E96D600E57ULL, 0x65CC8190991CB93DULL, 0x273C607B30F68FAEULL,
 406         0xE02D4247CAC8D41BULL, 0xA2DDA3AC6322E288ULL, 0xBE992B5F8BDB8C5CULL,
 407         0xFC69CAB42231BACFULL, 0x3B78E888D80FE17AULL, 0x7988096371E5D7E9ULL,
 408         0xF7AA4D1A85996083ULL, 0xB55AACF12C735610ULL, 0x724B8ECDD64D0DA5ULL,
 409         0x30BB6F267FA73B36ULL, 0x4AC29F2A07BFD00DULL, 0x08327EC1AE55E69EULL,
 410         0xCF235CFD546BBD2BULL, 0x8DD3BD16FD818BB8ULL, 0x03F1F96F09FD3CD2ULL,
 411         0x41011884A0170A41ULL, 0x86103AB85A2951F4ULL, 0xC4E0DB53F3C36767ULL,
 412         0xD8A453A01B3A09B3ULL, 0x9A54B24BB2D03F20ULL, 0x5D45907748EE6495ULL,
 413         0x1FB5719CE1045206ULL, 0x919735E51578E56CULL, 0xD367D40EBC92D3FFULL,
 414         0x1476F63246AC884AULL, 0x568617D9EF46BED9ULL, 0xE085162AB69D5E3CULL,
 415         0xA275F7C11F7768AFULL, 0x6564D5FDE549331AULL, 0x279434164CA30589ULL,
 416         0xA9B6706FB8DFB2E3ULL, 0xEB46918411358470ULL, 0x2C57B3B8EB0BDFC5ULL,
 417         0x6EA7525342E1E956ULL, 0x72E3DAA0AA188782ULL, 0x30133B4B03F2B111ULL,
 418         0xF7021977F9CCEAA4ULL, 0xB5F2F89C5026DC37ULL, 0x3BD0BCE5A45A6B5DULL,
 419         0x79205D0E0DB05DCEULL, 0xBE317F32F78E067BULL, 0xFCC19ED95E6430E8ULL,
 420         0x86B86ED5267CDBD3ULL, 0xC4488F3E8F96ED40ULL, 0x0359AD0275A8B6F5ULL,
 421         0x41A94CE9DC428066ULL, 0xCF8B0890283E370CULL, 0x8D7BE97B81D4019FULL,
 422         0x4A6ACB477BEA5A2AULL, 0x089A2AACD2006CB9ULL, 0x14DEA25F3AF9026DULL,
 423         0x562E43B4931334FEULL, 0x913F6188692D6F4BULL, 0xD3CF8063C0C759D8ULL,
 424         0x5DEDC41A34BBEEB2ULL, 0x1F1D25F19D51D821ULL, 0xD80C07CD676F8394ULL,
 425         0x9AFCE626CE85B507ULL,
 426 };
 427
 428 uint64_t bch_crc64_update(uint64_t crc, const void *_data, size_t len)
 429 {
 430         const unsigned char *data = _data;
 431
 432         while (len--) {
 433                 int i = ((int) (crc >> 56) ^ *data++) & 0xFF;
 434                 crc = crc_table[i] ^ (crc << 8);
 435         }
 436
 437         return crc;
 438 }
 439
 440 uint64_t bch_crc64(const void *data, size_t len)
 441 {
 442         uint64_t crc = 0xffffffffffffffffULL;
 443
 444         crc = bch_crc64_update(crc, data, len);
 445
 446         return crc ^ 0xffffffffffffffffULL;
 447 }