2 * random utiility code, for bcache but in theory not specific to bcache
4 * Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
5 * Copyright 2012 Google, Inc.
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>
19 #define simple_strtoint(c, end, base) simple_strtol(c, end, base)
20 #define simple_strtouint(c, end, base) simple_strtoul(c, end, base)
22 #define STRTO_H(name, type) \
23 int bch_ ## name ## _h(const char *cp, type *res) \
27 type i = simple_ ## name(cp, &e, 10); \
29 switch (tolower(*e)) { \
59 if ((type) ~0 > 0 && \
60 (type) ~0 / 1024 <= i) \
62 if ((i > 0 && ANYSINT_MAX(type) / 1024 < i) || \
63 (i < 0 && -ANYSINT_MAX(type) / 1024 > i)) \
72 STRTO_H(strtoint, int)
73 STRTO_H(strtouint, unsigned int)
74 STRTO_H(strtoll, long long)
75 STRTO_H(strtoull, unsigned long long)
78 * bch_hprint() - formats @v to human readable string for sysfs.
80 * @v - signed 64 bit integer
81 * @buf - the (at least 8 byte) buffer to format the result into.
83 * Returns the number of bytes used by format.
85 ssize_t bch_hprint(char *buf, int64_t v)
87 static const char units[] = "?kMGTPEZY";
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.
109 /* '-', up to 3 digits, '.', 1 digit, 1 character, null;
112 return sprintf(buf, "-%llu.%i%c", q, t * 10 / 1024, units[u]);
114 return sprintf(buf, "%llu.%i%c", q, t * 10 / 1024, units[u]);
117 ssize_t bch_snprint_string_list(char *buf, size_t size, const char * const list[],
123 for (i = 0; list[i]; i++)
124 out += snprintf(out, buf + size - out,
125 i == selected ? "[%s] " : "%s ", list[i]);
131 ssize_t bch_read_string_list(const char *buf, const char * const list[])
134 char *s, *d = kstrndup(buf, PAGE_SIZE - 1, GFP_KERNEL);
140 for (i = 0; list[i]; i++)
141 if (!strcmp(list[i], s))
152 bool bch_is_zero(const char *p, size_t n)
156 for (i = 0; i < n; i++)
162 int bch_parse_uuid(const char *s, char *uuid)
168 i < strspn(s, "-0123456789:ABCDEFabcdef") && j < 32;
190 void bch_time_stats_update(struct time_stats *stats, uint64_t start_time)
192 uint64_t now, duration, last;
194 spin_lock(&stats->lock);
197 duration = time_after64(now, start_time)
198 ? now - start_time : 0;
199 last = time_after64(now, stats->last)
200 ? now - stats->last : 0;
202 stats->max_duration = max(stats->max_duration, duration);
205 ewma_add(stats->average_duration, duration, 8, 8);
207 if (stats->average_frequency)
208 ewma_add(stats->average_frequency, last, 8, 8);
210 stats->average_frequency = last << 8;
212 stats->average_duration = duration << 8;
215 stats->last = now ?: 1;
217 spin_unlock(&stats->lock);
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.
224 * @d - the struct bch_ratelimit to update
225 * @done - the amount of work done, in arbitrary units
227 * Returns the amount of time to delay by, in jiffies
229 uint64_t bch_next_delay(struct bch_ratelimit *d, uint64_t done)
231 uint64_t now = local_clock();
233 d->next += div_u64(done * NSEC_PER_SEC, d->rate);
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!).
241 if (time_before64(now + NSEC_PER_SEC * 5LLU / 2LLU, d->next))
242 d->next = now + NSEC_PER_SEC * 5LLU / 2LLU;
244 if (time_after64(now - NSEC_PER_SEC * 2, d->next))
245 d->next = now - NSEC_PER_SEC * 2;
247 return time_after64(d->next, now)
248 ? div_u64(d->next - now, NSEC_PER_SEC / HZ)
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
259 void bch_bio_map(struct bio *bio, void *base)
261 size_t size = bio->bi_iter.bi_size;
262 struct bio_vec *bv = bio->bi_io_vec;
264 BUG_ON(!bio->bi_iter.bi_size);
265 BUG_ON(bio->bi_vcnt);
267 bv->bv_offset = base ? offset_in_page(base) : 0;
270 for (; size; bio->bi_vcnt++, bv++) {
272 start: bv->bv_len = min_t(size_t, PAGE_SIZE - bv->bv_offset,
275 bv->bv_page = is_vmalloc_addr(base)
276 ? vmalloc_to_page(base)
277 : virt_to_page(base);
287 * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group (Any
288 * use permitted, subject to terms of PostgreSQL license; see.)
290 * If we have a 64-bit integer type, then a 64-bit CRC looks just like the
291 * usual sort of implementation. (See Ross Williams' excellent introduction
292 * A PAINLESS GUIDE TO CRC ERROR DETECTION ALGORITHMS, available from
293 * ftp://ftp.rocksoft.com/papers/crc_v3.txt or several other net sites.)
294 * If we have no working 64-bit type, then fake it with two 32-bit registers.
296 * The present implementation is a normal (not "reflected", in Williams'
297 * terms) 64-bit CRC, using initial all-ones register contents and a final
298 * bit inversion. The chosen polynomial is borrowed from the DLT1 spec
299 * (ECMA-182, available from http://www.ecma.ch/ecma1/STAND/ECMA-182.HTM):
301 * x^64 + x^62 + x^57 + x^55 + x^54 + x^53 + x^52 + x^47 + x^46 + x^45 +
302 * x^40 + x^39 + x^38 + x^37 + x^35 + x^33 + x^32 + x^31 + x^29 + x^27 +
303 * x^24 + x^23 + x^22 + x^21 + x^19 + x^17 + x^13 + x^12 + x^10 + x^9 +
307 static const uint64_t crc_table[256] = {
308 0x0000000000000000ULL, 0x42F0E1EBA9EA3693ULL, 0x85E1C3D753D46D26ULL,
309 0xC711223CFA3E5BB5ULL, 0x493366450E42ECDFULL, 0x0BC387AEA7A8DA4CULL,
310 0xCCD2A5925D9681F9ULL, 0x8E224479F47CB76AULL, 0x9266CC8A1C85D9BEULL,
311 0xD0962D61B56FEF2DULL, 0x17870F5D4F51B498ULL, 0x5577EEB6E6BB820BULL,
312 0xDB55AACF12C73561ULL, 0x99A54B24BB2D03F2ULL, 0x5EB4691841135847ULL,
313 0x1C4488F3E8F96ED4ULL, 0x663D78FF90E185EFULL, 0x24CD9914390BB37CULL,
314 0xE3DCBB28C335E8C9ULL, 0xA12C5AC36ADFDE5AULL, 0x2F0E1EBA9EA36930ULL,
315 0x6DFEFF5137495FA3ULL, 0xAAEFDD6DCD770416ULL, 0xE81F3C86649D3285ULL,
316 0xF45BB4758C645C51ULL, 0xB6AB559E258E6AC2ULL, 0x71BA77A2DFB03177ULL,
317 0x334A9649765A07E4ULL, 0xBD68D2308226B08EULL, 0xFF9833DB2BCC861DULL,
318 0x388911E7D1F2DDA8ULL, 0x7A79F00C7818EB3BULL, 0xCC7AF1FF21C30BDEULL,
319 0x8E8A101488293D4DULL, 0x499B3228721766F8ULL, 0x0B6BD3C3DBFD506BULL,
320 0x854997BA2F81E701ULL, 0xC7B97651866BD192ULL, 0x00A8546D7C558A27ULL,
321 0x4258B586D5BFBCB4ULL, 0x5E1C3D753D46D260ULL, 0x1CECDC9E94ACE4F3ULL,
322 0xDBFDFEA26E92BF46ULL, 0x990D1F49C77889D5ULL, 0x172F5B3033043EBFULL,
323 0x55DFBADB9AEE082CULL, 0x92CE98E760D05399ULL, 0xD03E790CC93A650AULL,
324 0xAA478900B1228E31ULL, 0xE8B768EB18C8B8A2ULL, 0x2FA64AD7E2F6E317ULL,
325 0x6D56AB3C4B1CD584ULL, 0xE374EF45BF6062EEULL, 0xA1840EAE168A547DULL,
326 0x66952C92ECB40FC8ULL, 0x2465CD79455E395BULL, 0x3821458AADA7578FULL,
327 0x7AD1A461044D611CULL, 0xBDC0865DFE733AA9ULL, 0xFF3067B657990C3AULL,
328 0x711223CFA3E5BB50ULL, 0x33E2C2240A0F8DC3ULL, 0xF4F3E018F031D676ULL,
329 0xB60301F359DBE0E5ULL, 0xDA050215EA6C212FULL, 0x98F5E3FE438617BCULL,
330 0x5FE4C1C2B9B84C09ULL, 0x1D14202910527A9AULL, 0x93366450E42ECDF0ULL,
331 0xD1C685BB4DC4FB63ULL, 0x16D7A787B7FAA0D6ULL, 0x5427466C1E109645ULL,
332 0x4863CE9FF6E9F891ULL, 0x0A932F745F03CE02ULL, 0xCD820D48A53D95B7ULL,
333 0x8F72ECA30CD7A324ULL, 0x0150A8DAF8AB144EULL, 0x43A04931514122DDULL,
334 0x84B16B0DAB7F7968ULL, 0xC6418AE602954FFBULL, 0xBC387AEA7A8DA4C0ULL,
335 0xFEC89B01D3679253ULL, 0x39D9B93D2959C9E6ULL, 0x7B2958D680B3FF75ULL,
336 0xF50B1CAF74CF481FULL, 0xB7FBFD44DD257E8CULL, 0x70EADF78271B2539ULL,
337 0x321A3E938EF113AAULL, 0x2E5EB66066087D7EULL, 0x6CAE578BCFE24BEDULL,
338 0xABBF75B735DC1058ULL, 0xE94F945C9C3626CBULL, 0x676DD025684A91A1ULL,
339 0x259D31CEC1A0A732ULL, 0xE28C13F23B9EFC87ULL, 0xA07CF2199274CA14ULL,
340 0x167FF3EACBAF2AF1ULL, 0x548F120162451C62ULL, 0x939E303D987B47D7ULL,
341 0xD16ED1D631917144ULL, 0x5F4C95AFC5EDC62EULL, 0x1DBC74446C07F0BDULL,
342 0xDAAD56789639AB08ULL, 0x985DB7933FD39D9BULL, 0x84193F60D72AF34FULL,
343 0xC6E9DE8B7EC0C5DCULL, 0x01F8FCB784FE9E69ULL, 0x43081D5C2D14A8FAULL,
344 0xCD2A5925D9681F90ULL, 0x8FDAB8CE70822903ULL, 0x48CB9AF28ABC72B6ULL,
345 0x0A3B7B1923564425ULL, 0x70428B155B4EAF1EULL, 0x32B26AFEF2A4998DULL,
346 0xF5A348C2089AC238ULL, 0xB753A929A170F4ABULL, 0x3971ED50550C43C1ULL,
347 0x7B810CBBFCE67552ULL, 0xBC902E8706D82EE7ULL, 0xFE60CF6CAF321874ULL,
348 0xE224479F47CB76A0ULL, 0xA0D4A674EE214033ULL, 0x67C58448141F1B86ULL,
349 0x253565A3BDF52D15ULL, 0xAB1721DA49899A7FULL, 0xE9E7C031E063ACECULL,
350 0x2EF6E20D1A5DF759ULL, 0x6C0603E6B3B7C1CAULL, 0xF6FAE5C07D3274CDULL,
351 0xB40A042BD4D8425EULL, 0x731B26172EE619EBULL, 0x31EBC7FC870C2F78ULL,
352 0xBFC9838573709812ULL, 0xFD39626EDA9AAE81ULL, 0x3A28405220A4F534ULL,
353 0x78D8A1B9894EC3A7ULL, 0x649C294A61B7AD73ULL, 0x266CC8A1C85D9BE0ULL,
354 0xE17DEA9D3263C055ULL, 0xA38D0B769B89F6C6ULL, 0x2DAF4F0F6FF541ACULL,
355 0x6F5FAEE4C61F773FULL, 0xA84E8CD83C212C8AULL, 0xEABE6D3395CB1A19ULL,
356 0x90C79D3FEDD3F122ULL, 0xD2377CD44439C7B1ULL, 0x15265EE8BE079C04ULL,
357 0x57D6BF0317EDAA97ULL, 0xD9F4FB7AE3911DFDULL, 0x9B041A914A7B2B6EULL,
358 0x5C1538ADB04570DBULL, 0x1EE5D94619AF4648ULL, 0x02A151B5F156289CULL,
359 0x4051B05E58BC1E0FULL, 0x87409262A28245BAULL, 0xC5B073890B687329ULL,
360 0x4B9237F0FF14C443ULL, 0x0962D61B56FEF2D0ULL, 0xCE73F427ACC0A965ULL,
361 0x8C8315CC052A9FF6ULL, 0x3A80143F5CF17F13ULL, 0x7870F5D4F51B4980ULL,
362 0xBF61D7E80F251235ULL, 0xFD913603A6CF24A6ULL, 0x73B3727A52B393CCULL,
363 0x31439391FB59A55FULL, 0xF652B1AD0167FEEAULL, 0xB4A25046A88DC879ULL,
364 0xA8E6D8B54074A6ADULL, 0xEA16395EE99E903EULL, 0x2D071B6213A0CB8BULL,
365 0x6FF7FA89BA4AFD18ULL, 0xE1D5BEF04E364A72ULL, 0xA3255F1BE7DC7CE1ULL,
366 0x64347D271DE22754ULL, 0x26C49CCCB40811C7ULL, 0x5CBD6CC0CC10FAFCULL,
367 0x1E4D8D2B65FACC6FULL, 0xD95CAF179FC497DAULL, 0x9BAC4EFC362EA149ULL,
368 0x158E0A85C2521623ULL, 0x577EEB6E6BB820B0ULL, 0x906FC95291867B05ULL,
369 0xD29F28B9386C4D96ULL, 0xCEDBA04AD0952342ULL, 0x8C2B41A1797F15D1ULL,
370 0x4B3A639D83414E64ULL, 0x09CA82762AAB78F7ULL, 0x87E8C60FDED7CF9DULL,
371 0xC51827E4773DF90EULL, 0x020905D88D03A2BBULL, 0x40F9E43324E99428ULL,
372 0x2CFFE7D5975E55E2ULL, 0x6E0F063E3EB46371ULL, 0xA91E2402C48A38C4ULL,
373 0xEBEEC5E96D600E57ULL, 0x65CC8190991CB93DULL, 0x273C607B30F68FAEULL,
374 0xE02D4247CAC8D41BULL, 0xA2DDA3AC6322E288ULL, 0xBE992B5F8BDB8C5CULL,
375 0xFC69CAB42231BACFULL, 0x3B78E888D80FE17AULL, 0x7988096371E5D7E9ULL,
376 0xF7AA4D1A85996083ULL, 0xB55AACF12C735610ULL, 0x724B8ECDD64D0DA5ULL,
377 0x30BB6F267FA73B36ULL, 0x4AC29F2A07BFD00DULL, 0x08327EC1AE55E69EULL,
378 0xCF235CFD546BBD2BULL, 0x8DD3BD16FD818BB8ULL, 0x03F1F96F09FD3CD2ULL,
379 0x41011884A0170A41ULL, 0x86103AB85A2951F4ULL, 0xC4E0DB53F3C36767ULL,
380 0xD8A453A01B3A09B3ULL, 0x9A54B24BB2D03F20ULL, 0x5D45907748EE6495ULL,
381 0x1FB5719CE1045206ULL, 0x919735E51578E56CULL, 0xD367D40EBC92D3FFULL,
382 0x1476F63246AC884AULL, 0x568617D9EF46BED9ULL, 0xE085162AB69D5E3CULL,
383 0xA275F7C11F7768AFULL, 0x6564D5FDE549331AULL, 0x279434164CA30589ULL,
384 0xA9B6706FB8DFB2E3ULL, 0xEB46918411358470ULL, 0x2C57B3B8EB0BDFC5ULL,
385 0x6EA7525342E1E956ULL, 0x72E3DAA0AA188782ULL, 0x30133B4B03F2B111ULL,
386 0xF7021977F9CCEAA4ULL, 0xB5F2F89C5026DC37ULL, 0x3BD0BCE5A45A6B5DULL,
387 0x79205D0E0DB05DCEULL, 0xBE317F32F78E067BULL, 0xFCC19ED95E6430E8ULL,
388 0x86B86ED5267CDBD3ULL, 0xC4488F3E8F96ED40ULL, 0x0359AD0275A8B6F5ULL,
389 0x41A94CE9DC428066ULL, 0xCF8B0890283E370CULL, 0x8D7BE97B81D4019FULL,
390 0x4A6ACB477BEA5A2AULL, 0x089A2AACD2006CB9ULL, 0x14DEA25F3AF9026DULL,
391 0x562E43B4931334FEULL, 0x913F6188692D6F4BULL, 0xD3CF8063C0C759D8ULL,
392 0x5DEDC41A34BBEEB2ULL, 0x1F1D25F19D51D821ULL, 0xD80C07CD676F8394ULL,
393 0x9AFCE626CE85B507ULL,
396 uint64_t bch_crc64_update(uint64_t crc, const void *_data, size_t len)
398 const unsigned char *data = _data;
401 int i = ((int) (crc >> 56) ^ *data++) & 0xFF;
402 crc = crc_table[i] ^ (crc << 8);
408 uint64_t bch_crc64(const void *data, size_t len)
410 uint64_t crc = 0xffffffffffffffffULL;
412 crc = bch_crc64_update(crc, data, len);
414 return crc ^ 0xffffffffffffffffULL;