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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288// SPDX-License-Identifier: GPL-2.0/* * random utility code, for bcache but in theory not specific to bcache * * Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com> * Copyright 2012 Google, Inc. */
#include <linux/bio.h>#include <linux/blkdev.h>#include <linux/ctype.h>#include <linux/debugfs.h>#include <linux/module.h>#include <linux/seq_file.h>#include <linux/types.h>#include <linux/sched/clock.h>
#include "util.h"
#define simple_strtoint(c, end, base) simple_strtol(c, end, base)#define simple_strtouint(c, end, base) simple_strtoul(c, end, base)
#define STRTO_H(name, type) \int bch_ ## name ## _h(const char *cp, type *res) \{ \ int u = 0; \ char *e; \ type i = simple_ ## name(cp, &e, 10); \ \ switch (tolower(*e)) { \ default: \ return -EINVAL; \ case 'y': \ case 'z': \ u++; \ fallthrough; \ case 'e': \ u++; \ fallthrough; \ case 'p': \ u++; \ fallthrough; \ case 't': \ u++; \ fallthrough; \ case 'g': \ u++; \ fallthrough; \ case 'm': \ u++; \ fallthrough; \ case 'k': \ u++; \ if (e++ == cp) \ return -EINVAL; \ fallthrough; \ case '\n': \ case '\0': \ if (*e == '\n') \ e++; \ } \ \ if (*e) \ return -EINVAL; \ \ while (u--) { \ if ((type) ~0 > 0 && \ (type) ~0 / 1024 <= i) \ return -EINVAL; \ if ((i > 0 && ANYSINT_MAX(type) / 1024 < i) || \ (i < 0 && -ANYSINT_MAX(type) / 1024 > i)) \ return -EINVAL; \ i *= 1024; \ } \ \ *res = i; \ return 0; \} \
STRTO_H(strtoint, int)STRTO_H(strtouint, unsigned int)STRTO_H(strtoll, long long)STRTO_H(strtoull, unsigned long long)
/** * bch_hprint - formats @v to human readable string for sysfs. * @buf: the (at least 8 byte) buffer to format the result into. * @v: signed 64 bit integer * * Returns the number of bytes used by format. */ssize_t bch_hprint(char *buf, int64_t v){ static const char units[] = "?kMGTPEZY"; int u = 0, t;
uint64_t q;
if (v < 0) q = -v; else q = v;
/* For as long as the number is more than 3 digits, but at least * once, shift right / divide by 1024. Keep the remainder for * a digit after the decimal point. */ do { u++;
t = q & ~(~0 << 10); q >>= 10; } while (q >= 1000);
if (v < 0) /* '-', up to 3 digits, '.', 1 digit, 1 character, null; * yields 8 bytes. */ return sprintf(buf, "-%llu.%i%c", q, t * 10 / 1024, units[u]); else return sprintf(buf, "%llu.%i%c", q, t * 10 / 1024, units[u]);}
bool bch_is_zero(const char *p, size_t n){ size_t i;
for (i = 0; i < n; i++) if (p[i]) return false; return true;}
int bch_parse_uuid(const char *s, char *uuid){ size_t i, j, x;
memset(uuid, 0, 16);
for (i = 0, j = 0; i < strspn(s, "-0123456789:ABCDEFabcdef") && j < 32; i++) { x = s[i] | 32;
switch (x) { case '0'...'9': x -= '0'; break; case 'a'...'f': x -= 'a' - 10; break; default: continue; }
if (!(j & 1)) x <<= 4; uuid[j++ >> 1] |= x; } return i;}
void bch_time_stats_update(struct time_stats *stats, uint64_t start_time){ uint64_t now, duration, last;
spin_lock(&stats->lock);
now = local_clock(); duration = time_after64(now, start_time) ? now - start_time : 0; last = time_after64(now, stats->last) ? now - stats->last : 0;
stats->max_duration = max(stats->max_duration, duration);
if (stats->last) { ewma_add(stats->average_duration, duration, 8, 8);
if (stats->average_frequency) ewma_add(stats->average_frequency, last, 8, 8); else stats->average_frequency = last << 8; } else { stats->average_duration = duration << 8; }
stats->last = now ?: 1;
spin_unlock(&stats->lock);}
/** * bch_next_delay() - update ratelimiting statistics and calculate next delay * @d: the struct bch_ratelimit to update * @done: the amount of work done, in arbitrary units * * Increment @d by the amount of work done, and return how long to delay in * jiffies until the next time to do some work. */uint64_t bch_next_delay(struct bch_ratelimit *d, uint64_t done){ uint64_t now = local_clock();
d->next += div_u64(done * NSEC_PER_SEC, atomic_long_read(&d->rate));
/* Bound the time. Don't let us fall further than 2 seconds behind * (this prevents unnecessary backlog that would make it impossible * to catch up). If we're ahead of the desired writeback rate, * don't let us sleep more than 2.5 seconds (so we can notice/respond * if the control system tells us to speed up!). */ if (time_before64(now + NSEC_PER_SEC * 5LLU / 2LLU, d->next)) d->next = now + NSEC_PER_SEC * 5LLU / 2LLU;
if (time_after64(now - NSEC_PER_SEC * 2, d->next)) d->next = now - NSEC_PER_SEC * 2;
return time_after64(d->next, now) ? div_u64(d->next - now, NSEC_PER_SEC / HZ) : 0;}
/* * Generally it isn't good to access .bi_io_vec and .bi_vcnt directly, * the preferred way is bio_add_page, but in this case, bch_bio_map() * supposes that the bvec table is empty, so it is safe to access * .bi_vcnt & .bi_io_vec in this way even after multipage bvec is * supported. */void bch_bio_map(struct bio *bio, void *base){ size_t size = bio->bi_iter.bi_size; struct bio_vec *bv = bio->bi_io_vec;
BUG_ON(!bio->bi_iter.bi_size); BUG_ON(bio->bi_vcnt);
bv->bv_offset = base ? offset_in_page(base) : 0; goto start;
for (; size; bio->bi_vcnt++, bv++) { bv->bv_offset = 0;start: bv->bv_len = min_t(size_t, PAGE_SIZE - bv->bv_offset, size); if (base) { bv->bv_page = is_vmalloc_addr(base) ? vmalloc_to_page(base) : virt_to_page(base);
base += bv->bv_len; }
size -= bv->bv_len; }}
/** * bch_bio_alloc_pages - allocates a single page for each bvec in a bio * @bio: bio to allocate pages for * @gfp_mask: flags for allocation * * Allocates pages up to @bio->bi_vcnt. * * Returns 0 on success, -ENOMEM on failure. On failure, any allocated pages are * freed. */int bch_bio_alloc_pages(struct bio *bio, gfp_t gfp_mask){ int i; struct bio_vec *bv;
/* * This is called on freshly new bio, so it is safe to access the * bvec table directly. */ for (i = 0, bv = bio->bi_io_vec; i < bio->bi_vcnt; bv++, i++) { bv->bv_page = alloc_page(gfp_mask); if (!bv->bv_page) { while (--bv >= bio->bi_io_vec) __free_page(bv->bv_page); return -ENOMEM; } }
return 0;}