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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) \
23int 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
79STRTO_H(strtoint, int)
80STRTO_H(strtouint, unsigned int)
81STRTO_H(strtoll, long long)
82STRTO_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 */
91ssize_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
123ssize_t bch_snprint_string_list(char *buf, size_t size, const char * const list[],
124 size_t selected)
125{
126 char *out = buf;
127 size_t i;
128
129 for (i = 0; list[i]; i++)
130 out += snprintf(out, buf + size - out,
131 i == selected ? "[%s] " : "%s ", list[i]);
132
133 out[-1] = '\n';
134 return out - buf;
135}
136
137ssize_t bch_read_string_list(const char *buf, const char * const list[])
138{
139 size_t i;
140 char *s, *d = kstrndup(buf, PAGE_SIZE - 1, GFP_KERNEL);
141 if (!d)
142 return -ENOMEM;
143
144 s = strim(d);
145
146 for (i = 0; list[i]; i++)
147 if (!strcmp(list[i], s))
148 break;
149
150 kfree(d);
151
152 if (!list[i])
153 return -EINVAL;
154
155 return i;
156}
157
158bool bch_is_zero(const char *p, size_t n)
159{
160 size_t i;
161
162 for (i = 0; i < n; i++)
163 if (p[i])
164 return false;
165 return true;
166}
167
168int bch_parse_uuid(const char *s, char *uuid)
169{
170 size_t i, j, x;
171 memset(uuid, 0, 16);
172
173 for (i = 0, j = 0;
174 i < strspn(s, "-0123456789:ABCDEFabcdef") && j < 32;
175 i++) {
176 x = s[i] | 32;
177
178 switch (x) {
179 case '0'...'9':
180 x -= '0';
181 break;
182 case 'a'...'f':
183 x -= 'a' - 10;
184 break;
185 default:
186 continue;
187 }
188
189 if (!(j & 1))
190 x <<= 4;
191 uuid[j++ >> 1] |= x;
192 }
193 return i;
194}
195
196void bch_time_stats_update(struct time_stats *stats, uint64_t start_time)
197{
198 uint64_t now, duration, last;
199
200 spin_lock(&stats->lock);
201
202 now = local_clock();
203 duration = time_after64(now, start_time)
204 ? now - start_time : 0;
205 last = time_after64(now, stats->last)
206 ? now - stats->last : 0;
207
208 stats->max_duration = max(stats->max_duration, duration);
209
210 if (stats->last) {
211 ewma_add(stats->average_duration, duration, 8, 8);
212
213 if (stats->average_frequency)
214 ewma_add(stats->average_frequency, last, 8, 8);
215 else
216 stats->average_frequency = last << 8;
217 } else {
218 stats->average_duration = duration << 8;
219 }
220
221 stats->last = now ?: 1;
222
223 spin_unlock(&stats->lock);
224}
225
226/**
227 * bch_next_delay() - update ratelimiting statistics and calculate next delay
228 * @d: the struct bch_ratelimit to update
229 * @done: the amount of work done, in arbitrary units
230 *
231 * Increment @d by the amount of work done, and return how long to delay in
232 * jiffies until the next time to do some work.
233 */
234uint64_t bch_next_delay(struct bch_ratelimit *d, uint64_t done)
235{
236 uint64_t now = local_clock();
237
238 d->next += div_u64(done * NSEC_PER_SEC, d->rate);
239
240 /* Bound the time. Don't let us fall further than 2 seconds behind
241 * (this prevents unnecessary backlog that would make it impossible
242 * to catch up). If we're ahead of the desired writeback rate,
243 * don't let us sleep more than 2.5 seconds (so we can notice/respond
244 * if the control system tells us to speed up!).
245 */
246 if (time_before64(now + NSEC_PER_SEC * 5LLU / 2LLU, d->next))
247 d->next = now + NSEC_PER_SEC * 5LLU / 2LLU;
248
249 if (time_after64(now - NSEC_PER_SEC * 2, d->next))
250 d->next = now - NSEC_PER_SEC * 2;
251
252 return time_after64(d->next, now)
253 ? div_u64(d->next - now, NSEC_PER_SEC / HZ)
254 : 0;
255}
256
257/*
258 * Generally it isn't good to access .bi_io_vec and .bi_vcnt directly,
259 * the preferred way is bio_add_page, but in this case, bch_bio_map()
260 * supposes that the bvec table is empty, so it is safe to access
261 * .bi_vcnt & .bi_io_vec in this way even after multipage bvec is
262 * supported.
263 */
264void bch_bio_map(struct bio *bio, void *base)
265{
266 size_t size = bio->bi_iter.bi_size;
267 struct bio_vec *bv = bio->bi_io_vec;
268
269 BUG_ON(!bio->bi_iter.bi_size);
270 BUG_ON(bio->bi_vcnt);
271
272 bv->bv_offset = base ? offset_in_page(base) : 0;
273 goto start;
274
275 for (; size; bio->bi_vcnt++, bv++) {
276 bv->bv_offset = 0;
277start: bv->bv_len = min_t(size_t, PAGE_SIZE - bv->bv_offset,
278 size);
279 if (base) {
280 bv->bv_page = is_vmalloc_addr(base)
281 ? vmalloc_to_page(base)
282 : virt_to_page(base);
283
284 base += bv->bv_len;
285 }
286
287 size -= bv->bv_len;
288 }
289}
290
291/**
292 * bch_bio_alloc_pages - allocates a single page for each bvec in a bio
293 * @bio: bio to allocate pages for
294 * @gfp_mask: flags for allocation
295 *
296 * Allocates pages up to @bio->bi_vcnt.
297 *
298 * Returns 0 on success, -ENOMEM on failure. On failure, any allocated pages are
299 * freed.
300 */
301int bch_bio_alloc_pages(struct bio *bio, gfp_t gfp_mask)
302{
303 int i;
304 struct bio_vec *bv;
305
306 bio_for_each_segment_all(bv, bio, i) {
307 bv->bv_page = alloc_page(gfp_mask);
308 if (!bv->bv_page) {
309 while (--bv >= bio->bi_io_vec)
310 __free_page(bv->bv_page);
311 return -ENOMEM;
312 }
313 }
314
315 return 0;
316}
317
318/*
319 * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group (Any
320 * use permitted, subject to terms of PostgreSQL license; see.)
321
322 * If we have a 64-bit integer type, then a 64-bit CRC looks just like the
323 * usual sort of implementation. (See Ross Williams' excellent introduction
324 * A PAINLESS GUIDE TO CRC ERROR DETECTION ALGORITHMS, available from
325 * ftp://ftp.rocksoft.com/papers/crc_v3.txt or several other net sites.)
326 * If we have no working 64-bit type, then fake it with two 32-bit registers.
327 *
328 * The present implementation is a normal (not "reflected", in Williams'
329 * terms) 64-bit CRC, using initial all-ones register contents and a final
330 * bit inversion. The chosen polynomial is borrowed from the DLT1 spec
331 * (ECMA-182, available from http://www.ecma.ch/ecma1/STAND/ECMA-182.HTM):
332 *
333 * x^64 + x^62 + x^57 + x^55 + x^54 + x^53 + x^52 + x^47 + x^46 + x^45 +
334 * x^40 + x^39 + x^38 + x^37 + x^35 + x^33 + x^32 + x^31 + x^29 + x^27 +
335 * x^24 + x^23 + x^22 + x^21 + x^19 + x^17 + x^13 + x^12 + x^10 + x^9 +
336 * x^7 + x^4 + x + 1
337*/
338
339static const uint64_t crc_table[256] = {
340 0x0000000000000000ULL, 0x42F0E1EBA9EA3693ULL, 0x85E1C3D753D46D26ULL,
341 0xC711223CFA3E5BB5ULL, 0x493366450E42ECDFULL, 0x0BC387AEA7A8DA4CULL,
342 0xCCD2A5925D9681F9ULL, 0x8E224479F47CB76AULL, 0x9266CC8A1C85D9BEULL,
343 0xD0962D61B56FEF2DULL, 0x17870F5D4F51B498ULL, 0x5577EEB6E6BB820BULL,
344 0xDB55AACF12C73561ULL, 0x99A54B24BB2D03F2ULL, 0x5EB4691841135847ULL,
345 0x1C4488F3E8F96ED4ULL, 0x663D78FF90E185EFULL, 0x24CD9914390BB37CULL,
346 0xE3DCBB28C335E8C9ULL, 0xA12C5AC36ADFDE5AULL, 0x2F0E1EBA9EA36930ULL,
347 0x6DFEFF5137495FA3ULL, 0xAAEFDD6DCD770416ULL, 0xE81F3C86649D3285ULL,
348 0xF45BB4758C645C51ULL, 0xB6AB559E258E6AC2ULL, 0x71BA77A2DFB03177ULL,
349 0x334A9649765A07E4ULL, 0xBD68D2308226B08EULL, 0xFF9833DB2BCC861DULL,
350 0x388911E7D1F2DDA8ULL, 0x7A79F00C7818EB3BULL, 0xCC7AF1FF21C30BDEULL,
351 0x8E8A101488293D4DULL, 0x499B3228721766F8ULL, 0x0B6BD3C3DBFD506BULL,
352 0x854997BA2F81E701ULL, 0xC7B97651866BD192ULL, 0x00A8546D7C558A27ULL,
353 0x4258B586D5BFBCB4ULL, 0x5E1C3D753D46D260ULL, 0x1CECDC9E94ACE4F3ULL,
354 0xDBFDFEA26E92BF46ULL, 0x990D1F49C77889D5ULL, 0x172F5B3033043EBFULL,
355 0x55DFBADB9AEE082CULL, 0x92CE98E760D05399ULL, 0xD03E790CC93A650AULL,
356 0xAA478900B1228E31ULL, 0xE8B768EB18C8B8A2ULL, 0x2FA64AD7E2F6E317ULL,
357 0x6D56AB3C4B1CD584ULL, 0xE374EF45BF6062EEULL, 0xA1840EAE168A547DULL,
358 0x66952C92ECB40FC8ULL, 0x2465CD79455E395BULL, 0x3821458AADA7578FULL,
359 0x7AD1A461044D611CULL, 0xBDC0865DFE733AA9ULL, 0xFF3067B657990C3AULL,
360 0x711223CFA3E5BB50ULL, 0x33E2C2240A0F8DC3ULL, 0xF4F3E018F031D676ULL,
361 0xB60301F359DBE0E5ULL, 0xDA050215EA6C212FULL, 0x98F5E3FE438617BCULL,
362 0x5FE4C1C2B9B84C09ULL, 0x1D14202910527A9AULL, 0x93366450E42ECDF0ULL,
363 0xD1C685BB4DC4FB63ULL, 0x16D7A787B7FAA0D6ULL, 0x5427466C1E109645ULL,
364 0x4863CE9FF6E9F891ULL, 0x0A932F745F03CE02ULL, 0xCD820D48A53D95B7ULL,
365 0x8F72ECA30CD7A324ULL, 0x0150A8DAF8AB144EULL, 0x43A04931514122DDULL,
366 0x84B16B0DAB7F7968ULL, 0xC6418AE602954FFBULL, 0xBC387AEA7A8DA4C0ULL,
367 0xFEC89B01D3679253ULL, 0x39D9B93D2959C9E6ULL, 0x7B2958D680B3FF75ULL,
368 0xF50B1CAF74CF481FULL, 0xB7FBFD44DD257E8CULL, 0x70EADF78271B2539ULL,
369 0x321A3E938EF113AAULL, 0x2E5EB66066087D7EULL, 0x6CAE578BCFE24BEDULL,
370 0xABBF75B735DC1058ULL, 0xE94F945C9C3626CBULL, 0x676DD025684A91A1ULL,
371 0x259D31CEC1A0A732ULL, 0xE28C13F23B9EFC87ULL, 0xA07CF2199274CA14ULL,
372 0x167FF3EACBAF2AF1ULL, 0x548F120162451C62ULL, 0x939E303D987B47D7ULL,
373 0xD16ED1D631917144ULL, 0x5F4C95AFC5EDC62EULL, 0x1DBC74446C07F0BDULL,
374 0xDAAD56789639AB08ULL, 0x985DB7933FD39D9BULL, 0x84193F60D72AF34FULL,
375 0xC6E9DE8B7EC0C5DCULL, 0x01F8FCB784FE9E69ULL, 0x43081D5C2D14A8FAULL,
376 0xCD2A5925D9681F90ULL, 0x8FDAB8CE70822903ULL, 0x48CB9AF28ABC72B6ULL,
377 0x0A3B7B1923564425ULL, 0x70428B155B4EAF1EULL, 0x32B26AFEF2A4998DULL,
378 0xF5A348C2089AC238ULL, 0xB753A929A170F4ABULL, 0x3971ED50550C43C1ULL,
379 0x7B810CBBFCE67552ULL, 0xBC902E8706D82EE7ULL, 0xFE60CF6CAF321874ULL,
380 0xE224479F47CB76A0ULL, 0xA0D4A674EE214033ULL, 0x67C58448141F1B86ULL,
381 0x253565A3BDF52D15ULL, 0xAB1721DA49899A7FULL, 0xE9E7C031E063ACECULL,
382 0x2EF6E20D1A5DF759ULL, 0x6C0603E6B3B7C1CAULL, 0xF6FAE5C07D3274CDULL,
383 0xB40A042BD4D8425EULL, 0x731B26172EE619EBULL, 0x31EBC7FC870C2F78ULL,
384 0xBFC9838573709812ULL, 0xFD39626EDA9AAE81ULL, 0x3A28405220A4F534ULL,
385 0x78D8A1B9894EC3A7ULL, 0x649C294A61B7AD73ULL, 0x266CC8A1C85D9BE0ULL,
386 0xE17DEA9D3263C055ULL, 0xA38D0B769B89F6C6ULL, 0x2DAF4F0F6FF541ACULL,
387 0x6F5FAEE4C61F773FULL, 0xA84E8CD83C212C8AULL, 0xEABE6D3395CB1A19ULL,
388 0x90C79D3FEDD3F122ULL, 0xD2377CD44439C7B1ULL, 0x15265EE8BE079C04ULL,
389 0x57D6BF0317EDAA97ULL, 0xD9F4FB7AE3911DFDULL, 0x9B041A914A7B2B6EULL,
390 0x5C1538ADB04570DBULL, 0x1EE5D94619AF4648ULL, 0x02A151B5F156289CULL,
391 0x4051B05E58BC1E0FULL, 0x87409262A28245BAULL, 0xC5B073890B687329ULL,
392 0x4B9237F0FF14C443ULL, 0x0962D61B56FEF2D0ULL, 0xCE73F427ACC0A965ULL,
393 0x8C8315CC052A9FF6ULL, 0x3A80143F5CF17F13ULL, 0x7870F5D4F51B4980ULL,
394 0xBF61D7E80F251235ULL, 0xFD913603A6CF24A6ULL, 0x73B3727A52B393CCULL,
395 0x31439391FB59A55FULL, 0xF652B1AD0167FEEAULL, 0xB4A25046A88DC879ULL,
396 0xA8E6D8B54074A6ADULL, 0xEA16395EE99E903EULL, 0x2D071B6213A0CB8BULL,
397 0x6FF7FA89BA4AFD18ULL, 0xE1D5BEF04E364A72ULL, 0xA3255F1BE7DC7CE1ULL,
398 0x64347D271DE22754ULL, 0x26C49CCCB40811C7ULL, 0x5CBD6CC0CC10FAFCULL,
399 0x1E4D8D2B65FACC6FULL, 0xD95CAF179FC497DAULL, 0x9BAC4EFC362EA149ULL,
400 0x158E0A85C2521623ULL, 0x577EEB6E6BB820B0ULL, 0x906FC95291867B05ULL,
401 0xD29F28B9386C4D96ULL, 0xCEDBA04AD0952342ULL, 0x8C2B41A1797F15D1ULL,
402 0x4B3A639D83414E64ULL, 0x09CA82762AAB78F7ULL, 0x87E8C60FDED7CF9DULL,
403 0xC51827E4773DF90EULL, 0x020905D88D03A2BBULL, 0x40F9E43324E99428ULL,
404 0x2CFFE7D5975E55E2ULL, 0x6E0F063E3EB46371ULL, 0xA91E2402C48A38C4ULL,
405 0xEBEEC5E96D600E57ULL, 0x65CC8190991CB93DULL, 0x273C607B30F68FAEULL,
406 0xE02D4247CAC8D41BULL, 0xA2DDA3AC6322E288ULL, 0xBE992B5F8BDB8C5CULL,
407 0xFC69CAB42231BACFULL, 0x3B78E888D80FE17AULL, 0x7988096371E5D7E9ULL,
408 0xF7AA4D1A85996083ULL, 0xB55AACF12C735610ULL, 0x724B8ECDD64D0DA5ULL,
409 0x30BB6F267FA73B36ULL, 0x4AC29F2A07BFD00DULL, 0x08327EC1AE55E69EULL,
410 0xCF235CFD546BBD2BULL, 0x8DD3BD16FD818BB8ULL, 0x03F1F96F09FD3CD2ULL,
411 0x41011884A0170A41ULL, 0x86103AB85A2951F4ULL, 0xC4E0DB53F3C36767ULL,
412 0xD8A453A01B3A09B3ULL, 0x9A54B24BB2D03F20ULL, 0x5D45907748EE6495ULL,
413 0x1FB5719CE1045206ULL, 0x919735E51578E56CULL, 0xD367D40EBC92D3FFULL,
414 0x1476F63246AC884AULL, 0x568617D9EF46BED9ULL, 0xE085162AB69D5E3CULL,
415 0xA275F7C11F7768AFULL, 0x6564D5FDE549331AULL, 0x279434164CA30589ULL,
416 0xA9B6706FB8DFB2E3ULL, 0xEB46918411358470ULL, 0x2C57B3B8EB0BDFC5ULL,
417 0x6EA7525342E1E956ULL, 0x72E3DAA0AA188782ULL, 0x30133B4B03F2B111ULL,
418 0xF7021977F9CCEAA4ULL, 0xB5F2F89C5026DC37ULL, 0x3BD0BCE5A45A6B5DULL,
419 0x79205D0E0DB05DCEULL, 0xBE317F32F78E067BULL, 0xFCC19ED95E6430E8ULL,
420 0x86B86ED5267CDBD3ULL, 0xC4488F3E8F96ED40ULL, 0x0359AD0275A8B6F5ULL,
421 0x41A94CE9DC428066ULL, 0xCF8B0890283E370CULL, 0x8D7BE97B81D4019FULL,
422 0x4A6ACB477BEA5A2AULL, 0x089A2AACD2006CB9ULL, 0x14DEA25F3AF9026DULL,
423 0x562E43B4931334FEULL, 0x913F6188692D6F4BULL, 0xD3CF8063C0C759D8ULL,
424 0x5DEDC41A34BBEEB2ULL, 0x1F1D25F19D51D821ULL, 0xD80C07CD676F8394ULL,
425 0x9AFCE626CE85B507ULL,
426};
427
428uint64_t bch_crc64_update(uint64_t crc, const void *_data, size_t len)
429{
430 const unsigned char *data = _data;
431
432 while (len--) {
433 int i = ((int) (crc >> 56) ^ *data++) & 0xFF;
434 crc = crc_table[i] ^ (crc << 8);
435 }
436
437 return crc;
438}
439
440uint64_t bch_crc64(const void *data, size_t len)
441{
442 uint64_t crc = 0xffffffffffffffffULL;
443
444 crc = bch_crc64_update(crc, data, len);
445
446 return crc ^ 0xffffffffffffffffULL;
447}