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 * 87 * @v - signed 64 bit integer 88 * @buf - the (at least 8 byte) buffer to format the result into. 89 * 90 * Returns the number of bytes used by format. 91 */ 92 ssize_t bch_hprint(char *buf, int64_t v) 93 { 94 static const char units[] = "?kMGTPEZY"; 95 int u = 0, t; 96 97 uint64_t q; 98 99 if (v < 0) 100 q = -v; 101 else 102 q = v; 103 104 /* For as long as the number is more than 3 digits, but at least 105 * once, shift right / divide by 1024. Keep the remainder for 106 * a digit after the decimal point. 107 */ 108 do { 109 u++; 110 111 t = q & ~(~0 << 10); 112 q >>= 10; 113 } while (q >= 1000); 114 115 if (v < 0) 116 /* '-', up to 3 digits, '.', 1 digit, 1 character, null; 117 * yields 8 bytes. 118 */ 119 return sprintf(buf, "-%llu.%i%c", q, t * 10 / 1024, units[u]); 120 else 121 return sprintf(buf, "%llu.%i%c", q, t * 10 / 1024, units[u]); 122 } 123 124 ssize_t bch_snprint_string_list(char *buf, size_t size, const char * const list[], 125 size_t selected) 126 { 127 char *out = buf; 128 size_t i; 129 130 for (i = 0; list[i]; i++) 131 out += snprintf(out, buf + size - out, 132 i == selected ? "[%s] " : "%s ", list[i]); 133 134 out[-1] = '\n'; 135 return out - buf; 136 } 137 138 ssize_t bch_read_string_list(const char *buf, const char * const list[]) 139 { 140 size_t i; 141 char *s, *d = kstrndup(buf, PAGE_SIZE - 1, GFP_KERNEL); 142 if (!d) 143 return -ENOMEM; 144 145 s = strim(d); 146 147 for (i = 0; list[i]; i++) 148 if (!strcmp(list[i], s)) 149 break; 150 151 kfree(d); 152 153 if (!list[i]) 154 return -EINVAL; 155 156 return i; 157 } 158 159 bool bch_is_zero(const char *p, size_t n) 160 { 161 size_t i; 162 163 for (i = 0; i < n; i++) 164 if (p[i]) 165 return false; 166 return true; 167 } 168 169 int bch_parse_uuid(const char *s, char *uuid) 170 { 171 size_t i, j, x; 172 memset(uuid, 0, 16); 173 174 for (i = 0, j = 0; 175 i < strspn(s, "-0123456789:ABCDEFabcdef") && j < 32; 176 i++) { 177 x = s[i] | 32; 178 179 switch (x) { 180 case '0'...'9': 181 x -= '0'; 182 break; 183 case 'a'...'f': 184 x -= 'a' - 10; 185 break; 186 default: 187 continue; 188 } 189 190 if (!(j & 1)) 191 x <<= 4; 192 uuid[j++ >> 1] |= x; 193 } 194 return i; 195 } 196 197 void bch_time_stats_update(struct time_stats *stats, uint64_t start_time) 198 { 199 uint64_t now, duration, last; 200 201 spin_lock(&stats->lock); 202 203 now = local_clock(); 204 duration = time_after64(now, start_time) 205 ? now - start_time : 0; 206 last = time_after64(now, stats->last) 207 ? now - stats->last : 0; 208 209 stats->max_duration = max(stats->max_duration, duration); 210 211 if (stats->last) { 212 ewma_add(stats->average_duration, duration, 8, 8); 213 214 if (stats->average_frequency) 215 ewma_add(stats->average_frequency, last, 8, 8); 216 else 217 stats->average_frequency = last << 8; 218 } else { 219 stats->average_duration = duration << 8; 220 } 221 222 stats->last = now ?: 1; 223 224 spin_unlock(&stats->lock); 225 } 226 227 /** 228 * bch_next_delay() - increment @d by the amount of work done, and return how 229 * long to delay until the next time to do some work. 230 * 231 * @d - the struct bch_ratelimit to update 232 * @done - the amount of work done, in arbitrary units 233 * 234 * Returns the amount of time to delay by, in jiffies 235 */ 236 uint64_t bch_next_delay(struct bch_ratelimit *d, uint64_t done) 237 { 238 uint64_t now = local_clock(); 239 240 d->next += div_u64(done * NSEC_PER_SEC, d->rate); 241 242 /* Bound the time. Don't let us fall further than 2 seconds behind 243 * (this prevents unnecessary backlog that would make it impossible 244 * to catch up). If we're ahead of the desired writeback rate, 245 * don't let us sleep more than 2.5 seconds (so we can notice/respond 246 * if the control system tells us to speed up!). 247 */ 248 if (time_before64(now + NSEC_PER_SEC * 5LLU / 2LLU, d->next)) 249 d->next = now + NSEC_PER_SEC * 5LLU / 2LLU; 250 251 if (time_after64(now - NSEC_PER_SEC * 2, d->next)) 252 d->next = now - NSEC_PER_SEC * 2; 253 254 return time_after64(d->next, now) 255 ? div_u64(d->next - now, NSEC_PER_SEC / HZ) 256 : 0; 257 } 258 259 /* 260 * Generally it isn't good to access .bi_io_vec and .bi_vcnt directly, 261 * the preferred way is bio_add_page, but in this case, bch_bio_map() 262 * supposes that the bvec table is empty, so it is safe to access 263 * .bi_vcnt & .bi_io_vec in this way even after multipage bvec is 264 * supported. 265 */ 266 void bch_bio_map(struct bio *bio, void *base) 267 { 268 size_t size = bio->bi_iter.bi_size; 269 struct bio_vec *bv = bio->bi_io_vec; 270 271 BUG_ON(!bio->bi_iter.bi_size); 272 BUG_ON(bio->bi_vcnt); 273 274 bv->bv_offset = base ? offset_in_page(base) : 0; 275 goto start; 276 277 for (; size; bio->bi_vcnt++, bv++) { 278 bv->bv_offset = 0; 279 start: bv->bv_len = min_t(size_t, PAGE_SIZE - bv->bv_offset, 280 size); 281 if (base) { 282 bv->bv_page = is_vmalloc_addr(base) 283 ? vmalloc_to_page(base) 284 : virt_to_page(base); 285 286 base += bv->bv_len; 287 } 288 289 size -= bv->bv_len; 290 } 291 } 292 293 /** 294 * bch_bio_alloc_pages - allocates a single page for each bvec in a bio 295 * @bio: bio to allocate pages for 296 * @gfp_mask: flags for allocation 297 * 298 * Allocates pages up to @bio->bi_vcnt. 299 * 300 * Returns 0 on success, -ENOMEM on failure. On failure, any allocated pages are 301 * freed. 302 */ 303 int bch_bio_alloc_pages(struct bio *bio, gfp_t gfp_mask) 304 { 305 int i; 306 struct bio_vec *bv; 307 308 bio_for_each_segment_all(bv, bio, i) { 309 bv->bv_page = alloc_page(gfp_mask); 310 if (!bv->bv_page) { 311 while (--bv >= bio->bi_io_vec) 312 __free_page(bv->bv_page); 313 return -ENOMEM; 314 } 315 } 316 317 return 0; 318 } 319 320 /* 321 * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group (Any 322 * use permitted, subject to terms of PostgreSQL license; see.) 323 324 * If we have a 64-bit integer type, then a 64-bit CRC looks just like the 325 * usual sort of implementation. (See Ross Williams' excellent introduction 326 * A PAINLESS GUIDE TO CRC ERROR DETECTION ALGORITHMS, available from 327 * ftp://ftp.rocksoft.com/papers/crc_v3.txt or several other net sites.) 328 * If we have no working 64-bit type, then fake it with two 32-bit registers. 329 * 330 * The present implementation is a normal (not "reflected", in Williams' 331 * terms) 64-bit CRC, using initial all-ones register contents and a final 332 * bit inversion. The chosen polynomial is borrowed from the DLT1 spec 333 * (ECMA-182, available from http://www.ecma.ch/ecma1/STAND/ECMA-182.HTM): 334 * 335 * x^64 + x^62 + x^57 + x^55 + x^54 + x^53 + x^52 + x^47 + x^46 + x^45 + 336 * x^40 + x^39 + x^38 + x^37 + x^35 + x^33 + x^32 + x^31 + x^29 + x^27 + 337 * x^24 + x^23 + x^22 + x^21 + x^19 + x^17 + x^13 + x^12 + x^10 + x^9 + 338 * x^7 + x^4 + x + 1 339 */ 340 341 static const uint64_t crc_table[256] = { 342 0x0000000000000000ULL, 0x42F0E1EBA9EA3693ULL, 0x85E1C3D753D46D26ULL, 343 0xC711223CFA3E5BB5ULL, 0x493366450E42ECDFULL, 0x0BC387AEA7A8DA4CULL, 344 0xCCD2A5925D9681F9ULL, 0x8E224479F47CB76AULL, 0x9266CC8A1C85D9BEULL, 345 0xD0962D61B56FEF2DULL, 0x17870F5D4F51B498ULL, 0x5577EEB6E6BB820BULL, 346 0xDB55AACF12C73561ULL, 0x99A54B24BB2D03F2ULL, 0x5EB4691841135847ULL, 347 0x1C4488F3E8F96ED4ULL, 0x663D78FF90E185EFULL, 0x24CD9914390BB37CULL, 348 0xE3DCBB28C335E8C9ULL, 0xA12C5AC36ADFDE5AULL, 0x2F0E1EBA9EA36930ULL, 349 0x6DFEFF5137495FA3ULL, 0xAAEFDD6DCD770416ULL, 0xE81F3C86649D3285ULL, 350 0xF45BB4758C645C51ULL, 0xB6AB559E258E6AC2ULL, 0x71BA77A2DFB03177ULL, 351 0x334A9649765A07E4ULL, 0xBD68D2308226B08EULL, 0xFF9833DB2BCC861DULL, 352 0x388911E7D1F2DDA8ULL, 0x7A79F00C7818EB3BULL, 0xCC7AF1FF21C30BDEULL, 353 0x8E8A101488293D4DULL, 0x499B3228721766F8ULL, 0x0B6BD3C3DBFD506BULL, 354 0x854997BA2F81E701ULL, 0xC7B97651866BD192ULL, 0x00A8546D7C558A27ULL, 355 0x4258B586D5BFBCB4ULL, 0x5E1C3D753D46D260ULL, 0x1CECDC9E94ACE4F3ULL, 356 0xDBFDFEA26E92BF46ULL, 0x990D1F49C77889D5ULL, 0x172F5B3033043EBFULL, 357 0x55DFBADB9AEE082CULL, 0x92CE98E760D05399ULL, 0xD03E790CC93A650AULL, 358 0xAA478900B1228E31ULL, 0xE8B768EB18C8B8A2ULL, 0x2FA64AD7E2F6E317ULL, 359 0x6D56AB3C4B1CD584ULL, 0xE374EF45BF6062EEULL, 0xA1840EAE168A547DULL, 360 0x66952C92ECB40FC8ULL, 0x2465CD79455E395BULL, 0x3821458AADA7578FULL, 361 0x7AD1A461044D611CULL, 0xBDC0865DFE733AA9ULL, 0xFF3067B657990C3AULL, 362 0x711223CFA3E5BB50ULL, 0x33E2C2240A0F8DC3ULL, 0xF4F3E018F031D676ULL, 363 0xB60301F359DBE0E5ULL, 0xDA050215EA6C212FULL, 0x98F5E3FE438617BCULL, 364 0x5FE4C1C2B9B84C09ULL, 0x1D14202910527A9AULL, 0x93366450E42ECDF0ULL, 365 0xD1C685BB4DC4FB63ULL, 0x16D7A787B7FAA0D6ULL, 0x5427466C1E109645ULL, 366 0x4863CE9FF6E9F891ULL, 0x0A932F745F03CE02ULL, 0xCD820D48A53D95B7ULL, 367 0x8F72ECA30CD7A324ULL, 0x0150A8DAF8AB144EULL, 0x43A04931514122DDULL, 368 0x84B16B0DAB7F7968ULL, 0xC6418AE602954FFBULL, 0xBC387AEA7A8DA4C0ULL, 369 0xFEC89B01D3679253ULL, 0x39D9B93D2959C9E6ULL, 0x7B2958D680B3FF75ULL, 370 0xF50B1CAF74CF481FULL, 0xB7FBFD44DD257E8CULL, 0x70EADF78271B2539ULL, 371 0x321A3E938EF113AAULL, 0x2E5EB66066087D7EULL, 0x6CAE578BCFE24BEDULL, 372 0xABBF75B735DC1058ULL, 0xE94F945C9C3626CBULL, 0x676DD025684A91A1ULL, 373 0x259D31CEC1A0A732ULL, 0xE28C13F23B9EFC87ULL, 0xA07CF2199274CA14ULL, 374 0x167FF3EACBAF2AF1ULL, 0x548F120162451C62ULL, 0x939E303D987B47D7ULL, 375 0xD16ED1D631917144ULL, 0x5F4C95AFC5EDC62EULL, 0x1DBC74446C07F0BDULL, 376 0xDAAD56789639AB08ULL, 0x985DB7933FD39D9BULL, 0x84193F60D72AF34FULL, 377 0xC6E9DE8B7EC0C5DCULL, 0x01F8FCB784FE9E69ULL, 0x43081D5C2D14A8FAULL, 378 0xCD2A5925D9681F90ULL, 0x8FDAB8CE70822903ULL, 0x48CB9AF28ABC72B6ULL, 379 0x0A3B7B1923564425ULL, 0x70428B155B4EAF1EULL, 0x32B26AFEF2A4998DULL, 380 0xF5A348C2089AC238ULL, 0xB753A929A170F4ABULL, 0x3971ED50550C43C1ULL, 381 0x7B810CBBFCE67552ULL, 0xBC902E8706D82EE7ULL, 0xFE60CF6CAF321874ULL, 382 0xE224479F47CB76A0ULL, 0xA0D4A674EE214033ULL, 0x67C58448141F1B86ULL, 383 0x253565A3BDF52D15ULL, 0xAB1721DA49899A7FULL, 0xE9E7C031E063ACECULL, 384 0x2EF6E20D1A5DF759ULL, 0x6C0603E6B3B7C1CAULL, 0xF6FAE5C07D3274CDULL, 385 0xB40A042BD4D8425EULL, 0x731B26172EE619EBULL, 0x31EBC7FC870C2F78ULL, 386 0xBFC9838573709812ULL, 0xFD39626EDA9AAE81ULL, 0x3A28405220A4F534ULL, 387 0x78D8A1B9894EC3A7ULL, 0x649C294A61B7AD73ULL, 0x266CC8A1C85D9BE0ULL, 388 0xE17DEA9D3263C055ULL, 0xA38D0B769B89F6C6ULL, 0x2DAF4F0F6FF541ACULL, 389 0x6F5FAEE4C61F773FULL, 0xA84E8CD83C212C8AULL, 0xEABE6D3395CB1A19ULL, 390 0x90C79D3FEDD3F122ULL, 0xD2377CD44439C7B1ULL, 0x15265EE8BE079C04ULL, 391 0x57D6BF0317EDAA97ULL, 0xD9F4FB7AE3911DFDULL, 0x9B041A914A7B2B6EULL, 392 0x5C1538ADB04570DBULL, 0x1EE5D94619AF4648ULL, 0x02A151B5F156289CULL, 393 0x4051B05E58BC1E0FULL, 0x87409262A28245BAULL, 0xC5B073890B687329ULL, 394 0x4B9237F0FF14C443ULL, 0x0962D61B56FEF2D0ULL, 0xCE73F427ACC0A965ULL, 395 0x8C8315CC052A9FF6ULL, 0x3A80143F5CF17F13ULL, 0x7870F5D4F51B4980ULL, 396 0xBF61D7E80F251235ULL, 0xFD913603A6CF24A6ULL, 0x73B3727A52B393CCULL, 397 0x31439391FB59A55FULL, 0xF652B1AD0167FEEAULL, 0xB4A25046A88DC879ULL, 398 0xA8E6D8B54074A6ADULL, 0xEA16395EE99E903EULL, 0x2D071B6213A0CB8BULL, 399 0x6FF7FA89BA4AFD18ULL, 0xE1D5BEF04E364A72ULL, 0xA3255F1BE7DC7CE1ULL, 400 0x64347D271DE22754ULL, 0x26C49CCCB40811C7ULL, 0x5CBD6CC0CC10FAFCULL, 401 0x1E4D8D2B65FACC6FULL, 0xD95CAF179FC497DAULL, 0x9BAC4EFC362EA149ULL, 402 0x158E0A85C2521623ULL, 0x577EEB6E6BB820B0ULL, 0x906FC95291867B05ULL, 403 0xD29F28B9386C4D96ULL, 0xCEDBA04AD0952342ULL, 0x8C2B41A1797F15D1ULL, 404 0x4B3A639D83414E64ULL, 0x09CA82762AAB78F7ULL, 0x87E8C60FDED7CF9DULL, 405 0xC51827E4773DF90EULL, 0x020905D88D03A2BBULL, 0x40F9E43324E99428ULL, 406 0x2CFFE7D5975E55E2ULL, 0x6E0F063E3EB46371ULL, 0xA91E2402C48A38C4ULL, 407 0xEBEEC5E96D600E57ULL, 0x65CC8190991CB93DULL, 0x273C607B30F68FAEULL, 408 0xE02D4247CAC8D41BULL, 0xA2DDA3AC6322E288ULL, 0xBE992B5F8BDB8C5CULL, 409 0xFC69CAB42231BACFULL, 0x3B78E888D80FE17AULL, 0x7988096371E5D7E9ULL, 410 0xF7AA4D1A85996083ULL, 0xB55AACF12C735610ULL, 0x724B8ECDD64D0DA5ULL, 411 0x30BB6F267FA73B36ULL, 0x4AC29F2A07BFD00DULL, 0x08327EC1AE55E69EULL, 412 0xCF235CFD546BBD2BULL, 0x8DD3BD16FD818BB8ULL, 0x03F1F96F09FD3CD2ULL, 413 0x41011884A0170A41ULL, 0x86103AB85A2951F4ULL, 0xC4E0DB53F3C36767ULL, 414 0xD8A453A01B3A09B3ULL, 0x9A54B24BB2D03F20ULL, 0x5D45907748EE6495ULL, 415 0x1FB5719CE1045206ULL, 0x919735E51578E56CULL, 0xD367D40EBC92D3FFULL, 416 0x1476F63246AC884AULL, 0x568617D9EF46BED9ULL, 0xE085162AB69D5E3CULL, 417 0xA275F7C11F7768AFULL, 0x6564D5FDE549331AULL, 0x279434164CA30589ULL, 418 0xA9B6706FB8DFB2E3ULL, 0xEB46918411358470ULL, 0x2C57B3B8EB0BDFC5ULL, 419 0x6EA7525342E1E956ULL, 0x72E3DAA0AA188782ULL, 0x30133B4B03F2B111ULL, 420 0xF7021977F9CCEAA4ULL, 0xB5F2F89C5026DC37ULL, 0x3BD0BCE5A45A6B5DULL, 421 0x79205D0E0DB05DCEULL, 0xBE317F32F78E067BULL, 0xFCC19ED95E6430E8ULL, 422 0x86B86ED5267CDBD3ULL, 0xC4488F3E8F96ED40ULL, 0x0359AD0275A8B6F5ULL, 423 0x41A94CE9DC428066ULL, 0xCF8B0890283E370CULL, 0x8D7BE97B81D4019FULL, 424 0x4A6ACB477BEA5A2AULL, 0x089A2AACD2006CB9ULL, 0x14DEA25F3AF9026DULL, 425 0x562E43B4931334FEULL, 0x913F6188692D6F4BULL, 0xD3CF8063C0C759D8ULL, 426 0x5DEDC41A34BBEEB2ULL, 0x1F1D25F19D51D821ULL, 0xD80C07CD676F8394ULL, 427 0x9AFCE626CE85B507ULL, 428 }; 429 430 uint64_t bch_crc64_update(uint64_t crc, const void *_data, size_t len) 431 { 432 const unsigned char *data = _data; 433 434 while (len--) { 435 int i = ((int) (crc >> 56) ^ *data++) & 0xFF; 436 crc = crc_table[i] ^ (crc << 8); 437 } 438 439 return crc; 440 } 441 442 uint64_t bch_crc64(const void *data, size_t len) 443 { 444 uint64_t crc = 0xffffffffffffffffULL; 445 446 crc = bch_crc64_update(crc, data, len); 447 448 return crc ^ 0xffffffffffffffffULL; 449 } 450