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 } 443