e873b0f7a82a86cba0af47e3be955a5a11ac7261
[sfrench/cifs-2.6.git] / drivers / md / bcache / util.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * random utiility code, for bcache but in theory not specific to bcache
4  *
5  * Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
6  * Copyright 2012 Google, Inc.
7  */
8
9 #include <linux/bio.h>
10 #include <linux/blkdev.h>
11 #include <linux/ctype.h>
12 #include <linux/debugfs.h>
13 #include <linux/module.h>
14 #include <linux/seq_file.h>
15 #include <linux/types.h>
16 #include <linux/sched/clock.h>
17
18 #include "util.h"
19
20 #define simple_strtoint(c, end, base)   simple_strtol(c, end, base)
21 #define simple_strtouint(c, end, base)  simple_strtoul(c, end, base)
22
23 #define STRTO_H(name, type)                                     \
24 int bch_ ## name ## _h(const char *cp, type *res)               \
25 {                                                               \
26         int u = 0;                                              \
27         char *e;                                                \
28         type i = simple_ ## name(cp, &e, 10);                   \
29                                                                 \
30         switch (tolower(*e)) {                                  \
31         default:                                                \
32                 return -EINVAL;                                 \
33         case 'y':                                               \
34         case 'z':                                               \
35                 u++;                                            \
36                 /* fall through */                              \
37         case 'e':                                               \
38                 u++;                                            \
39                 /* fall through */                              \
40         case 'p':                                               \
41                 u++;                                            \
42                 /* fall through */                              \
43         case 't':                                               \
44                 u++;                                            \
45                 /* fall through */                              \
46         case 'g':                                               \
47                 u++;                                            \
48                 /* fall through */                              \
49         case 'm':                                               \
50                 u++;                                            \
51                 /* fall through */                              \
52         case 'k':                                               \
53                 u++;                                            \
54                 if (e++ == cp)                                  \
55                         return -EINVAL;                         \
56                 /* fall through */                              \
57         case '\n':                                              \
58         case '\0':                                              \
59                 if (*e == '\n')                                 \
60                         e++;                                    \
61         }                                                       \
62                                                                 \
63         if (*e)                                                 \
64                 return -EINVAL;                                 \
65                                                                 \
66         while (u--) {                                           \
67                 if ((type) ~0 > 0 &&                            \
68                     (type) ~0 / 1024 <= i)                      \
69                         return -EINVAL;                         \
70                 if ((i > 0 && ANYSINT_MAX(type) / 1024 < i) ||  \
71                     (i < 0 && -ANYSINT_MAX(type) / 1024 > i))   \
72                         return -EINVAL;                         \
73                 i *= 1024;                                      \
74         }                                                       \
75                                                                 \
76         *res = i;                                               \
77         return 0;                                               \
78 }                                                               \
79
80 STRTO_H(strtoint, int)
81 STRTO_H(strtouint, unsigned int)
82 STRTO_H(strtoll, long long)
83 STRTO_H(strtoull, unsigned long long)
84
85 /**
86  * bch_hprint - formats @v to human readable string for sysfs.
87  * @buf: the (at least 8 byte) buffer to format the result into.
88  * @v: signed 64 bit integer
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 bool bch_is_zero(const char *p, size_t n)
125 {
126         size_t i;
127
128         for (i = 0; i < n; i++)
129                 if (p[i])
130                         return false;
131         return true;
132 }
133
134 int bch_parse_uuid(const char *s, char *uuid)
135 {
136         size_t i, j, x;
137
138         memset(uuid, 0, 16);
139
140         for (i = 0, j = 0;
141              i < strspn(s, "-0123456789:ABCDEFabcdef") && j < 32;
142              i++) {
143                 x = s[i] | 32;
144
145                 switch (x) {
146                 case '0'...'9':
147                         x -= '0';
148                         break;
149                 case 'a'...'f':
150                         x -= 'a' - 10;
151                         break;
152                 default:
153                         continue;
154                 }
155
156                 if (!(j & 1))
157                         x <<= 4;
158                 uuid[j++ >> 1] |= x;
159         }
160         return i;
161 }
162
163 void bch_time_stats_update(struct time_stats *stats, uint64_t start_time)
164 {
165         uint64_t now, duration, last;
166
167         spin_lock(&stats->lock);
168
169         now             = local_clock();
170         duration        = time_after64(now, start_time)
171                 ? now - start_time : 0;
172         last            = time_after64(now, stats->last)
173                 ? now - stats->last : 0;
174
175         stats->max_duration = max(stats->max_duration, duration);
176
177         if (stats->last) {
178                 ewma_add(stats->average_duration, duration, 8, 8);
179
180                 if (stats->average_frequency)
181                         ewma_add(stats->average_frequency, last, 8, 8);
182                 else
183                         stats->average_frequency  = last << 8;
184         } else {
185                 stats->average_duration  = duration << 8;
186         }
187
188         stats->last = now ?: 1;
189
190         spin_unlock(&stats->lock);
191 }
192
193 /**
194  * bch_next_delay() - update ratelimiting statistics and calculate next delay
195  * @d: the struct bch_ratelimit to update
196  * @done: the amount of work done, in arbitrary units
197  *
198  * Increment @d by the amount of work done, and return how long to delay in
199  * jiffies until the next time to do some work.
200  */
201 uint64_t bch_next_delay(struct bch_ratelimit *d, uint64_t done)
202 {
203         uint64_t now = local_clock();
204
205         d->next += div_u64(done * NSEC_PER_SEC, atomic_long_read(&d->rate));
206
207         /* Bound the time.  Don't let us fall further than 2 seconds behind
208          * (this prevents unnecessary backlog that would make it impossible
209          * to catch up).  If we're ahead of the desired writeback rate,
210          * don't let us sleep more than 2.5 seconds (so we can notice/respond
211          * if the control system tells us to speed up!).
212          */
213         if (time_before64(now + NSEC_PER_SEC * 5LLU / 2LLU, d->next))
214                 d->next = now + NSEC_PER_SEC * 5LLU / 2LLU;
215
216         if (time_after64(now - NSEC_PER_SEC * 2, d->next))
217                 d->next = now - NSEC_PER_SEC * 2;
218
219         return time_after64(d->next, now)
220                 ? div_u64(d->next - now, NSEC_PER_SEC / HZ)
221                 : 0;
222 }
223
224 /*
225  * Generally it isn't good to access .bi_io_vec and .bi_vcnt directly,
226  * the preferred way is bio_add_page, but in this case, bch_bio_map()
227  * supposes that the bvec table is empty, so it is safe to access
228  * .bi_vcnt & .bi_io_vec in this way even after multipage bvec is
229  * supported.
230  */
231 void bch_bio_map(struct bio *bio, void *base)
232 {
233         size_t size = bio->bi_iter.bi_size;
234         struct bio_vec *bv = bio->bi_io_vec;
235
236         BUG_ON(!bio->bi_iter.bi_size);
237         BUG_ON(bio->bi_vcnt);
238
239         bv->bv_offset = base ? offset_in_page(base) : 0;
240         goto start;
241
242         for (; size; bio->bi_vcnt++, bv++) {
243                 bv->bv_offset   = 0;
244 start:          bv->bv_len      = min_t(size_t, PAGE_SIZE - bv->bv_offset,
245                                         size);
246                 if (base) {
247                         bv->bv_page = is_vmalloc_addr(base)
248                                 ? vmalloc_to_page(base)
249                                 : virt_to_page(base);
250
251                         base += bv->bv_len;
252                 }
253
254                 size -= bv->bv_len;
255         }
256 }
257
258 /**
259  * bch_bio_alloc_pages - allocates a single page for each bvec in a bio
260  * @bio: bio to allocate pages for
261  * @gfp_mask: flags for allocation
262  *
263  * Allocates pages up to @bio->bi_vcnt.
264  *
265  * Returns 0 on success, -ENOMEM on failure. On failure, any allocated pages are
266  * freed.
267  */
268 int bch_bio_alloc_pages(struct bio *bio, gfp_t gfp_mask)
269 {
270         int i;
271         struct bio_vec *bv;
272
273         bio_for_each_segment_all(bv, bio, i) {
274                 bv->bv_page = alloc_page(gfp_mask);
275                 if (!bv->bv_page) {
276                         while (--bv >= bio->bi_io_vec)
277                                 __free_page(bv->bv_page);
278                         return -ENOMEM;
279                 }
280         }
281
282         return 0;
283 }
284
285 /*
286  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group (Any
287  * use permitted, subject to terms of PostgreSQL license; see.)
288
289  * If we have a 64-bit integer type, then a 64-bit CRC looks just like the
290  * usual sort of implementation. (See Ross Williams' excellent introduction
291  * A PAINLESS GUIDE TO CRC ERROR DETECTION ALGORITHMS, available from
292  * ftp://ftp.rocksoft.com/papers/crc_v3.txt or several other net sites.)
293  * If we have no working 64-bit type, then fake it with two 32-bit registers.
294  *
295  * The present implementation is a normal (not "reflected", in Williams'
296  * terms) 64-bit CRC, using initial all-ones register contents and a final
297  * bit inversion. The chosen polynomial is borrowed from the DLT1 spec
298  * (ECMA-182, available from http://www.ecma.ch/ecma1/STAND/ECMA-182.HTM):
299  *
300  * x^64 + x^62 + x^57 + x^55 + x^54 + x^53 + x^52 + x^47 + x^46 + x^45 +
301  * x^40 + x^39 + x^38 + x^37 + x^35 + x^33 + x^32 + x^31 + x^29 + x^27 +
302  * x^24 + x^23 + x^22 + x^21 + x^19 + x^17 + x^13 + x^12 + x^10 + x^9 +
303  * x^7 + x^4 + x + 1
304 */
305
306 static const uint64_t crc_table[256] = {
307         0x0000000000000000ULL, 0x42F0E1EBA9EA3693ULL, 0x85E1C3D753D46D26ULL,
308         0xC711223CFA3E5BB5ULL, 0x493366450E42ECDFULL, 0x0BC387AEA7A8DA4CULL,
309         0xCCD2A5925D9681F9ULL, 0x8E224479F47CB76AULL, 0x9266CC8A1C85D9BEULL,
310         0xD0962D61B56FEF2DULL, 0x17870F5D4F51B498ULL, 0x5577EEB6E6BB820BULL,
311         0xDB55AACF12C73561ULL, 0x99A54B24BB2D03F2ULL, 0x5EB4691841135847ULL,
312         0x1C4488F3E8F96ED4ULL, 0x663D78FF90E185EFULL, 0x24CD9914390BB37CULL,
313         0xE3DCBB28C335E8C9ULL, 0xA12C5AC36ADFDE5AULL, 0x2F0E1EBA9EA36930ULL,
314         0x6DFEFF5137495FA3ULL, 0xAAEFDD6DCD770416ULL, 0xE81F3C86649D3285ULL,
315         0xF45BB4758C645C51ULL, 0xB6AB559E258E6AC2ULL, 0x71BA77A2DFB03177ULL,
316         0x334A9649765A07E4ULL, 0xBD68D2308226B08EULL, 0xFF9833DB2BCC861DULL,
317         0x388911E7D1F2DDA8ULL, 0x7A79F00C7818EB3BULL, 0xCC7AF1FF21C30BDEULL,
318         0x8E8A101488293D4DULL, 0x499B3228721766F8ULL, 0x0B6BD3C3DBFD506BULL,
319         0x854997BA2F81E701ULL, 0xC7B97651866BD192ULL, 0x00A8546D7C558A27ULL,
320         0x4258B586D5BFBCB4ULL, 0x5E1C3D753D46D260ULL, 0x1CECDC9E94ACE4F3ULL,
321         0xDBFDFEA26E92BF46ULL, 0x990D1F49C77889D5ULL, 0x172F5B3033043EBFULL,
322         0x55DFBADB9AEE082CULL, 0x92CE98E760D05399ULL, 0xD03E790CC93A650AULL,
323         0xAA478900B1228E31ULL, 0xE8B768EB18C8B8A2ULL, 0x2FA64AD7E2F6E317ULL,
324         0x6D56AB3C4B1CD584ULL, 0xE374EF45BF6062EEULL, 0xA1840EAE168A547DULL,
325         0x66952C92ECB40FC8ULL, 0x2465CD79455E395BULL, 0x3821458AADA7578FULL,
326         0x7AD1A461044D611CULL, 0xBDC0865DFE733AA9ULL, 0xFF3067B657990C3AULL,
327         0x711223CFA3E5BB50ULL, 0x33E2C2240A0F8DC3ULL, 0xF4F3E018F031D676ULL,
328         0xB60301F359DBE0E5ULL, 0xDA050215EA6C212FULL, 0x98F5E3FE438617BCULL,
329         0x5FE4C1C2B9B84C09ULL, 0x1D14202910527A9AULL, 0x93366450E42ECDF0ULL,
330         0xD1C685BB4DC4FB63ULL, 0x16D7A787B7FAA0D6ULL, 0x5427466C1E109645ULL,
331         0x4863CE9FF6E9F891ULL, 0x0A932F745F03CE02ULL, 0xCD820D48A53D95B7ULL,
332         0x8F72ECA30CD7A324ULL, 0x0150A8DAF8AB144EULL, 0x43A04931514122DDULL,
333         0x84B16B0DAB7F7968ULL, 0xC6418AE602954FFBULL, 0xBC387AEA7A8DA4C0ULL,
334         0xFEC89B01D3679253ULL, 0x39D9B93D2959C9E6ULL, 0x7B2958D680B3FF75ULL,
335         0xF50B1CAF74CF481FULL, 0xB7FBFD44DD257E8CULL, 0x70EADF78271B2539ULL,
336         0x321A3E938EF113AAULL, 0x2E5EB66066087D7EULL, 0x6CAE578BCFE24BEDULL,
337         0xABBF75B735DC1058ULL, 0xE94F945C9C3626CBULL, 0x676DD025684A91A1ULL,
338         0x259D31CEC1A0A732ULL, 0xE28C13F23B9EFC87ULL, 0xA07CF2199274CA14ULL,
339         0x167FF3EACBAF2AF1ULL, 0x548F120162451C62ULL, 0x939E303D987B47D7ULL,
340         0xD16ED1D631917144ULL, 0x5F4C95AFC5EDC62EULL, 0x1DBC74446C07F0BDULL,
341         0xDAAD56789639AB08ULL, 0x985DB7933FD39D9BULL, 0x84193F60D72AF34FULL,
342         0xC6E9DE8B7EC0C5DCULL, 0x01F8FCB784FE9E69ULL, 0x43081D5C2D14A8FAULL,
343         0xCD2A5925D9681F90ULL, 0x8FDAB8CE70822903ULL, 0x48CB9AF28ABC72B6ULL,
344         0x0A3B7B1923564425ULL, 0x70428B155B4EAF1EULL, 0x32B26AFEF2A4998DULL,
345         0xF5A348C2089AC238ULL, 0xB753A929A170F4ABULL, 0x3971ED50550C43C1ULL,
346         0x7B810CBBFCE67552ULL, 0xBC902E8706D82EE7ULL, 0xFE60CF6CAF321874ULL,
347         0xE224479F47CB76A0ULL, 0xA0D4A674EE214033ULL, 0x67C58448141F1B86ULL,
348         0x253565A3BDF52D15ULL, 0xAB1721DA49899A7FULL, 0xE9E7C031E063ACECULL,
349         0x2EF6E20D1A5DF759ULL, 0x6C0603E6B3B7C1CAULL, 0xF6FAE5C07D3274CDULL,
350         0xB40A042BD4D8425EULL, 0x731B26172EE619EBULL, 0x31EBC7FC870C2F78ULL,
351         0xBFC9838573709812ULL, 0xFD39626EDA9AAE81ULL, 0x3A28405220A4F534ULL,
352         0x78D8A1B9894EC3A7ULL, 0x649C294A61B7AD73ULL, 0x266CC8A1C85D9BE0ULL,
353         0xE17DEA9D3263C055ULL, 0xA38D0B769B89F6C6ULL, 0x2DAF4F0F6FF541ACULL,
354         0x6F5FAEE4C61F773FULL, 0xA84E8CD83C212C8AULL, 0xEABE6D3395CB1A19ULL,
355         0x90C79D3FEDD3F122ULL, 0xD2377CD44439C7B1ULL, 0x15265EE8BE079C04ULL,
356         0x57D6BF0317EDAA97ULL, 0xD9F4FB7AE3911DFDULL, 0x9B041A914A7B2B6EULL,
357         0x5C1538ADB04570DBULL, 0x1EE5D94619AF4648ULL, 0x02A151B5F156289CULL,
358         0x4051B05E58BC1E0FULL, 0x87409262A28245BAULL, 0xC5B073890B687329ULL,
359         0x4B9237F0FF14C443ULL, 0x0962D61B56FEF2D0ULL, 0xCE73F427ACC0A965ULL,
360         0x8C8315CC052A9FF6ULL, 0x3A80143F5CF17F13ULL, 0x7870F5D4F51B4980ULL,
361         0xBF61D7E80F251235ULL, 0xFD913603A6CF24A6ULL, 0x73B3727A52B393CCULL,
362         0x31439391FB59A55FULL, 0xF652B1AD0167FEEAULL, 0xB4A25046A88DC879ULL,
363         0xA8E6D8B54074A6ADULL, 0xEA16395EE99E903EULL, 0x2D071B6213A0CB8BULL,
364         0x6FF7FA89BA4AFD18ULL, 0xE1D5BEF04E364A72ULL, 0xA3255F1BE7DC7CE1ULL,
365         0x64347D271DE22754ULL, 0x26C49CCCB40811C7ULL, 0x5CBD6CC0CC10FAFCULL,
366         0x1E4D8D2B65FACC6FULL, 0xD95CAF179FC497DAULL, 0x9BAC4EFC362EA149ULL,
367         0x158E0A85C2521623ULL, 0x577EEB6E6BB820B0ULL, 0x906FC95291867B05ULL,
368         0xD29F28B9386C4D96ULL, 0xCEDBA04AD0952342ULL, 0x8C2B41A1797F15D1ULL,
369         0x4B3A639D83414E64ULL, 0x09CA82762AAB78F7ULL, 0x87E8C60FDED7CF9DULL,
370         0xC51827E4773DF90EULL, 0x020905D88D03A2BBULL, 0x40F9E43324E99428ULL,
371         0x2CFFE7D5975E55E2ULL, 0x6E0F063E3EB46371ULL, 0xA91E2402C48A38C4ULL,
372         0xEBEEC5E96D600E57ULL, 0x65CC8190991CB93DULL, 0x273C607B30F68FAEULL,
373         0xE02D4247CAC8D41BULL, 0xA2DDA3AC6322E288ULL, 0xBE992B5F8BDB8C5CULL,
374         0xFC69CAB42231BACFULL, 0x3B78E888D80FE17AULL, 0x7988096371E5D7E9ULL,
375         0xF7AA4D1A85996083ULL, 0xB55AACF12C735610ULL, 0x724B8ECDD64D0DA5ULL,
376         0x30BB6F267FA73B36ULL, 0x4AC29F2A07BFD00DULL, 0x08327EC1AE55E69EULL,
377         0xCF235CFD546BBD2BULL, 0x8DD3BD16FD818BB8ULL, 0x03F1F96F09FD3CD2ULL,
378         0x41011884A0170A41ULL, 0x86103AB85A2951F4ULL, 0xC4E0DB53F3C36767ULL,
379         0xD8A453A01B3A09B3ULL, 0x9A54B24BB2D03F20ULL, 0x5D45907748EE6495ULL,
380         0x1FB5719CE1045206ULL, 0x919735E51578E56CULL, 0xD367D40EBC92D3FFULL,
381         0x1476F63246AC884AULL, 0x568617D9EF46BED9ULL, 0xE085162AB69D5E3CULL,
382         0xA275F7C11F7768AFULL, 0x6564D5FDE549331AULL, 0x279434164CA30589ULL,
383         0xA9B6706FB8DFB2E3ULL, 0xEB46918411358470ULL, 0x2C57B3B8EB0BDFC5ULL,
384         0x6EA7525342E1E956ULL, 0x72E3DAA0AA188782ULL, 0x30133B4B03F2B111ULL,
385         0xF7021977F9CCEAA4ULL, 0xB5F2F89C5026DC37ULL, 0x3BD0BCE5A45A6B5DULL,
386         0x79205D0E0DB05DCEULL, 0xBE317F32F78E067BULL, 0xFCC19ED95E6430E8ULL,
387         0x86B86ED5267CDBD3ULL, 0xC4488F3E8F96ED40ULL, 0x0359AD0275A8B6F5ULL,
388         0x41A94CE9DC428066ULL, 0xCF8B0890283E370CULL, 0x8D7BE97B81D4019FULL,
389         0x4A6ACB477BEA5A2AULL, 0x089A2AACD2006CB9ULL, 0x14DEA25F3AF9026DULL,
390         0x562E43B4931334FEULL, 0x913F6188692D6F4BULL, 0xD3CF8063C0C759D8ULL,
391         0x5DEDC41A34BBEEB2ULL, 0x1F1D25F19D51D821ULL, 0xD80C07CD676F8394ULL,
392         0x9AFCE626CE85B507ULL,
393 };
394
395 uint64_t bch_crc64_update(uint64_t crc, const void *_data, size_t len)
396 {
397         const unsigned char *data = _data;
398
399         while (len--) {
400                 int i = ((int) (crc >> 56) ^ *data++) & 0xFF;
401                 crc = crc_table[i] ^ (crc << 8);
402         }
403
404         return crc;
405 }
406
407 uint64_t bch_crc64(const void *data, size_t len)
408 {
409         uint64_t crc = 0xffffffffffffffffULL;
410
411         crc = bch_crc64_update(crc, data, len);
412
413         return crc ^ 0xffffffffffffffffULL;
414 }