1 /* 2 * random utiility code, for bcache but in theory not specific to bcache 3 * 4 * Copyright 2010, 2011 Kent Overstreet <[email protected]> 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; 136 137 memset(uuid, 0, 16); 138 139 for (i = 0, j = 0; 140 i < strspn(s, "-0123456789:ABCDEFabcdef") && j < 32; 141 i++) { 142 x = s[i] | 32; 143 144 switch (x) { 145 case '0'...'9': 146 x -= '0'; 147 break; 148 case 'a'...'f': 149 x -= 'a' - 10; 150 break; 151 default: 152 continue; 153 } 154 155 if (!(j & 1)) 156 x <<= 4; 157 uuid[j++ >> 1] |= x; 158 } 159 return i; 160 } 161 162 void bch_time_stats_update(struct time_stats *stats, uint64_t start_time) 163 { 164 uint64_t now, duration, last; 165 166 spin_lock(&stats->lock); 167 168 now = local_clock(); 169 duration = time_after64(now, start_time) 170 ? now - start_time : 0; 171 last = time_after64(now, stats->last) 172 ? now - stats->last : 0; 173 174 stats->max_duration = max(stats->max_duration, duration); 175 176 if (stats->last) { 177 ewma_add(stats->average_duration, duration, 8, 8); 178 179 if (stats->average_frequency) 180 ewma_add(stats->average_frequency, last, 8, 8); 181 else 182 stats->average_frequency = last << 8; 183 } else { 184 stats->average_duration = duration << 8; 185 } 186 187 stats->last = now ?: 1; 188 189 spin_unlock(&stats->lock); 190 } 191 192 /** 193 * bch_next_delay() - update ratelimiting statistics and calculate next delay 194 * @d: the struct bch_ratelimit to update 195 * @done: the amount of work done, in arbitrary units 196 * 197 * Increment @d by the amount of work done, and return how long to delay in 198 * jiffies until the next time to do some work. 199 */ 200 uint64_t bch_next_delay(struct bch_ratelimit *d, uint64_t done) 201 { 202 uint64_t now = local_clock(); 203 204 d->next += div_u64(done * NSEC_PER_SEC, atomic_long_read(&d->rate)); 205 206 /* Bound the time. Don't let us fall further than 2 seconds behind 207 * (this prevents unnecessary backlog that would make it impossible 208 * to catch up). If we're ahead of the desired writeback rate, 209 * don't let us sleep more than 2.5 seconds (so we can notice/respond 210 * if the control system tells us to speed up!). 211 */ 212 if (time_before64(now + NSEC_PER_SEC * 5LLU / 2LLU, d->next)) 213 d->next = now + NSEC_PER_SEC * 5LLU / 2LLU; 214 215 if (time_after64(now - NSEC_PER_SEC * 2, d->next)) 216 d->next = now - NSEC_PER_SEC * 2; 217 218 return time_after64(d->next, now) 219 ? div_u64(d->next - now, NSEC_PER_SEC / HZ) 220 : 0; 221 } 222 223 /* 224 * Generally it isn't good to access .bi_io_vec and .bi_vcnt directly, 225 * the preferred way is bio_add_page, but in this case, bch_bio_map() 226 * supposes that the bvec table is empty, so it is safe to access 227 * .bi_vcnt & .bi_io_vec in this way even after multipage bvec is 228 * supported. 229 */ 230 void bch_bio_map(struct bio *bio, void *base) 231 { 232 size_t size = bio->bi_iter.bi_size; 233 struct bio_vec *bv = bio->bi_io_vec; 234 235 BUG_ON(!bio->bi_iter.bi_size); 236 BUG_ON(bio->bi_vcnt); 237 238 bv->bv_offset = base ? offset_in_page(base) : 0; 239 goto start; 240 241 for (; size; bio->bi_vcnt++, bv++) { 242 bv->bv_offset = 0; 243 start: bv->bv_len = min_t(size_t, PAGE_SIZE - bv->bv_offset, 244 size); 245 if (base) { 246 bv->bv_page = is_vmalloc_addr(base) 247 ? vmalloc_to_page(base) 248 : virt_to_page(base); 249 250 base += bv->bv_len; 251 } 252 253 size -= bv->bv_len; 254 } 255 } 256 257 /** 258 * bch_bio_alloc_pages - allocates a single page for each bvec in a bio 259 * @bio: bio to allocate pages for 260 * @gfp_mask: flags for allocation 261 * 262 * Allocates pages up to @bio->bi_vcnt. 263 * 264 * Returns 0 on success, -ENOMEM on failure. On failure, any allocated pages are 265 * freed. 266 */ 267 int bch_bio_alloc_pages(struct bio *bio, gfp_t gfp_mask) 268 { 269 int i; 270 struct bio_vec *bv; 271 272 bio_for_each_segment_all(bv, bio, i) { 273 bv->bv_page = alloc_page(gfp_mask); 274 if (!bv->bv_page) { 275 while (--bv >= bio->bi_io_vec) 276 __free_page(bv->bv_page); 277 return -ENOMEM; 278 } 279 } 280 281 return 0; 282 } 283 284 /* 285 * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group (Any 286 * use permitted, subject to terms of PostgreSQL license; see.) 287 288 * If we have a 64-bit integer type, then a 64-bit CRC looks just like the 289 * usual sort of implementation. (See Ross Williams' excellent introduction 290 * A PAINLESS GUIDE TO CRC ERROR DETECTION ALGORITHMS, available from 291 * ftp://ftp.rocksoft.com/papers/crc_v3.txt or several other net sites.) 292 * If we have no working 64-bit type, then fake it with two 32-bit registers. 293 * 294 * The present implementation is a normal (not "reflected", in Williams' 295 * terms) 64-bit CRC, using initial all-ones register contents and a final 296 * bit inversion. The chosen polynomial is borrowed from the DLT1 spec 297 * (ECMA-182, available from http://www.ecma.ch/ecma1/STAND/ECMA-182.HTM): 298 * 299 * x^64 + x^62 + x^57 + x^55 + x^54 + x^53 + x^52 + x^47 + x^46 + x^45 + 300 * x^40 + x^39 + x^38 + x^37 + x^35 + x^33 + x^32 + x^31 + x^29 + x^27 + 301 * x^24 + x^23 + x^22 + x^21 + x^19 + x^17 + x^13 + x^12 + x^10 + x^9 + 302 * x^7 + x^4 + x + 1 303 */ 304 305 static const uint64_t crc_table[256] = { 306 0x0000000000000000ULL, 0x42F0E1EBA9EA3693ULL, 0x85E1C3D753D46D26ULL, 307 0xC711223CFA3E5BB5ULL, 0x493366450E42ECDFULL, 0x0BC387AEA7A8DA4CULL, 308 0xCCD2A5925D9681F9ULL, 0x8E224479F47CB76AULL, 0x9266CC8A1C85D9BEULL, 309 0xD0962D61B56FEF2DULL, 0x17870F5D4F51B498ULL, 0x5577EEB6E6BB820BULL, 310 0xDB55AACF12C73561ULL, 0x99A54B24BB2D03F2ULL, 0x5EB4691841135847ULL, 311 0x1C4488F3E8F96ED4ULL, 0x663D78FF90E185EFULL, 0x24CD9914390BB37CULL, 312 0xE3DCBB28C335E8C9ULL, 0xA12C5AC36ADFDE5AULL, 0x2F0E1EBA9EA36930ULL, 313 0x6DFEFF5137495FA3ULL, 0xAAEFDD6DCD770416ULL, 0xE81F3C86649D3285ULL, 314 0xF45BB4758C645C51ULL, 0xB6AB559E258E6AC2ULL, 0x71BA77A2DFB03177ULL, 315 0x334A9649765A07E4ULL, 0xBD68D2308226B08EULL, 0xFF9833DB2BCC861DULL, 316 0x388911E7D1F2DDA8ULL, 0x7A79F00C7818EB3BULL, 0xCC7AF1FF21C30BDEULL, 317 0x8E8A101488293D4DULL, 0x499B3228721766F8ULL, 0x0B6BD3C3DBFD506BULL, 318 0x854997BA2F81E701ULL, 0xC7B97651866BD192ULL, 0x00A8546D7C558A27ULL, 319 0x4258B586D5BFBCB4ULL, 0x5E1C3D753D46D260ULL, 0x1CECDC9E94ACE4F3ULL, 320 0xDBFDFEA26E92BF46ULL, 0x990D1F49C77889D5ULL, 0x172F5B3033043EBFULL, 321 0x55DFBADB9AEE082CULL, 0x92CE98E760D05399ULL, 0xD03E790CC93A650AULL, 322 0xAA478900B1228E31ULL, 0xE8B768EB18C8B8A2ULL, 0x2FA64AD7E2F6E317ULL, 323 0x6D56AB3C4B1CD584ULL, 0xE374EF45BF6062EEULL, 0xA1840EAE168A547DULL, 324 0x66952C92ECB40FC8ULL, 0x2465CD79455E395BULL, 0x3821458AADA7578FULL, 325 0x7AD1A461044D611CULL, 0xBDC0865DFE733AA9ULL, 0xFF3067B657990C3AULL, 326 0x711223CFA3E5BB50ULL, 0x33E2C2240A0F8DC3ULL, 0xF4F3E018F031D676ULL, 327 0xB60301F359DBE0E5ULL, 0xDA050215EA6C212FULL, 0x98F5E3FE438617BCULL, 328 0x5FE4C1C2B9B84C09ULL, 0x1D14202910527A9AULL, 0x93366450E42ECDF0ULL, 329 0xD1C685BB4DC4FB63ULL, 0x16D7A787B7FAA0D6ULL, 0x5427466C1E109645ULL, 330 0x4863CE9FF6E9F891ULL, 0x0A932F745F03CE02ULL, 0xCD820D48A53D95B7ULL, 331 0x8F72ECA30CD7A324ULL, 0x0150A8DAF8AB144EULL, 0x43A04931514122DDULL, 332 0x84B16B0DAB7F7968ULL, 0xC6418AE602954FFBULL, 0xBC387AEA7A8DA4C0ULL, 333 0xFEC89B01D3679253ULL, 0x39D9B93D2959C9E6ULL, 0x7B2958D680B3FF75ULL, 334 0xF50B1CAF74CF481FULL, 0xB7FBFD44DD257E8CULL, 0x70EADF78271B2539ULL, 335 0x321A3E938EF113AAULL, 0x2E5EB66066087D7EULL, 0x6CAE578BCFE24BEDULL, 336 0xABBF75B735DC1058ULL, 0xE94F945C9C3626CBULL, 0x676DD025684A91A1ULL, 337 0x259D31CEC1A0A732ULL, 0xE28C13F23B9EFC87ULL, 0xA07CF2199274CA14ULL, 338 0x167FF3EACBAF2AF1ULL, 0x548F120162451C62ULL, 0x939E303D987B47D7ULL, 339 0xD16ED1D631917144ULL, 0x5F4C95AFC5EDC62EULL, 0x1DBC74446C07F0BDULL, 340 0xDAAD56789639AB08ULL, 0x985DB7933FD39D9BULL, 0x84193F60D72AF34FULL, 341 0xC6E9DE8B7EC0C5DCULL, 0x01F8FCB784FE9E69ULL, 0x43081D5C2D14A8FAULL, 342 0xCD2A5925D9681F90ULL, 0x8FDAB8CE70822903ULL, 0x48CB9AF28ABC72B6ULL, 343 0x0A3B7B1923564425ULL, 0x70428B155B4EAF1EULL, 0x32B26AFEF2A4998DULL, 344 0xF5A348C2089AC238ULL, 0xB753A929A170F4ABULL, 0x3971ED50550C43C1ULL, 345 0x7B810CBBFCE67552ULL, 0xBC902E8706D82EE7ULL, 0xFE60CF6CAF321874ULL, 346 0xE224479F47CB76A0ULL, 0xA0D4A674EE214033ULL, 0x67C58448141F1B86ULL, 347 0x253565A3BDF52D15ULL, 0xAB1721DA49899A7FULL, 0xE9E7C031E063ACECULL, 348 0x2EF6E20D1A5DF759ULL, 0x6C0603E6B3B7C1CAULL, 0xF6FAE5C07D3274CDULL, 349 0xB40A042BD4D8425EULL, 0x731B26172EE619EBULL, 0x31EBC7FC870C2F78ULL, 350 0xBFC9838573709812ULL, 0xFD39626EDA9AAE81ULL, 0x3A28405220A4F534ULL, 351 0x78D8A1B9894EC3A7ULL, 0x649C294A61B7AD73ULL, 0x266CC8A1C85D9BE0ULL, 352 0xE17DEA9D3263C055ULL, 0xA38D0B769B89F6C6ULL, 0x2DAF4F0F6FF541ACULL, 353 0x6F5FAEE4C61F773FULL, 0xA84E8CD83C212C8AULL, 0xEABE6D3395CB1A19ULL, 354 0x90C79D3FEDD3F122ULL, 0xD2377CD44439C7B1ULL, 0x15265EE8BE079C04ULL, 355 0x57D6BF0317EDAA97ULL, 0xD9F4FB7AE3911DFDULL, 0x9B041A914A7B2B6EULL, 356 0x5C1538ADB04570DBULL, 0x1EE5D94619AF4648ULL, 0x02A151B5F156289CULL, 357 0x4051B05E58BC1E0FULL, 0x87409262A28245BAULL, 0xC5B073890B687329ULL, 358 0x4B9237F0FF14C443ULL, 0x0962D61B56FEF2D0ULL, 0xCE73F427ACC0A965ULL, 359 0x8C8315CC052A9FF6ULL, 0x3A80143F5CF17F13ULL, 0x7870F5D4F51B4980ULL, 360 0xBF61D7E80F251235ULL, 0xFD913603A6CF24A6ULL, 0x73B3727A52B393CCULL, 361 0x31439391FB59A55FULL, 0xF652B1AD0167FEEAULL, 0xB4A25046A88DC879ULL, 362 0xA8E6D8B54074A6ADULL, 0xEA16395EE99E903EULL, 0x2D071B6213A0CB8BULL, 363 0x6FF7FA89BA4AFD18ULL, 0xE1D5BEF04E364A72ULL, 0xA3255F1BE7DC7CE1ULL, 364 0x64347D271DE22754ULL, 0x26C49CCCB40811C7ULL, 0x5CBD6CC0CC10FAFCULL, 365 0x1E4D8D2B65FACC6FULL, 0xD95CAF179FC497DAULL, 0x9BAC4EFC362EA149ULL, 366 0x158E0A85C2521623ULL, 0x577EEB6E6BB820B0ULL, 0x906FC95291867B05ULL, 367 0xD29F28B9386C4D96ULL, 0xCEDBA04AD0952342ULL, 0x8C2B41A1797F15D1ULL, 368 0x4B3A639D83414E64ULL, 0x09CA82762AAB78F7ULL, 0x87E8C60FDED7CF9DULL, 369 0xC51827E4773DF90EULL, 0x020905D88D03A2BBULL, 0x40F9E43324E99428ULL, 370 0x2CFFE7D5975E55E2ULL, 0x6E0F063E3EB46371ULL, 0xA91E2402C48A38C4ULL, 371 0xEBEEC5E96D600E57ULL, 0x65CC8190991CB93DULL, 0x273C607B30F68FAEULL, 372 0xE02D4247CAC8D41BULL, 0xA2DDA3AC6322E288ULL, 0xBE992B5F8BDB8C5CULL, 373 0xFC69CAB42231BACFULL, 0x3B78E888D80FE17AULL, 0x7988096371E5D7E9ULL, 374 0xF7AA4D1A85996083ULL, 0xB55AACF12C735610ULL, 0x724B8ECDD64D0DA5ULL, 375 0x30BB6F267FA73B36ULL, 0x4AC29F2A07BFD00DULL, 0x08327EC1AE55E69EULL, 376 0xCF235CFD546BBD2BULL, 0x8DD3BD16FD818BB8ULL, 0x03F1F96F09FD3CD2ULL, 377 0x41011884A0170A41ULL, 0x86103AB85A2951F4ULL, 0xC4E0DB53F3C36767ULL, 378 0xD8A453A01B3A09B3ULL, 0x9A54B24BB2D03F20ULL, 0x5D45907748EE6495ULL, 379 0x1FB5719CE1045206ULL, 0x919735E51578E56CULL, 0xD367D40EBC92D3FFULL, 380 0x1476F63246AC884AULL, 0x568617D9EF46BED9ULL, 0xE085162AB69D5E3CULL, 381 0xA275F7C11F7768AFULL, 0x6564D5FDE549331AULL, 0x279434164CA30589ULL, 382 0xA9B6706FB8DFB2E3ULL, 0xEB46918411358470ULL, 0x2C57B3B8EB0BDFC5ULL, 383 0x6EA7525342E1E956ULL, 0x72E3DAA0AA188782ULL, 0x30133B4B03F2B111ULL, 384 0xF7021977F9CCEAA4ULL, 0xB5F2F89C5026DC37ULL, 0x3BD0BCE5A45A6B5DULL, 385 0x79205D0E0DB05DCEULL, 0xBE317F32F78E067BULL, 0xFCC19ED95E6430E8ULL, 386 0x86B86ED5267CDBD3ULL, 0xC4488F3E8F96ED40ULL, 0x0359AD0275A8B6F5ULL, 387 0x41A94CE9DC428066ULL, 0xCF8B0890283E370CULL, 0x8D7BE97B81D4019FULL, 388 0x4A6ACB477BEA5A2AULL, 0x089A2AACD2006CB9ULL, 0x14DEA25F3AF9026DULL, 389 0x562E43B4931334FEULL, 0x913F6188692D6F4BULL, 0xD3CF8063C0C759D8ULL, 390 0x5DEDC41A34BBEEB2ULL, 0x1F1D25F19D51D821ULL, 0xD80C07CD676F8394ULL, 391 0x9AFCE626CE85B507ULL, 392 }; 393 394 uint64_t bch_crc64_update(uint64_t crc, const void *_data, size_t len) 395 { 396 const unsigned char *data = _data; 397 398 while (len--) { 399 int i = ((int) (crc >> 56) ^ *data++) & 0xFF; 400 crc = crc_table[i] ^ (crc << 8); 401 } 402 403 return crc; 404 } 405 406 uint64_t bch_crc64(const void *data, size_t len) 407 { 408 uint64_t crc = 0xffffffffffffffffULL; 409 410 crc = bch_crc64_update(crc, data, len); 411 412 return crc ^ 0xffffffffffffffffULL; 413 } 414