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