// SPDX-License-Identifier: GPL-2.0 /* * random utiility code, for bcache but in theory not specific to bcache * * Copyright 2010, 2011 Kent Overstreet * Copyright 2012 Google, Inc. */ #include #include #include #include #include #include #include #include #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++; \ /* fall through */ \ case 'e': \ u++; \ /* fall through */ \ case 'p': \ u++; \ /* fall through */ \ case 't': \ u++; \ /* fall through */ \ case 'g': \ u++; \ /* fall through */ \ case 'm': \ u++; \ /* fall through */ \ case 'k': \ u++; \ if (e++ == cp) \ return -EINVAL; \ /* fall through */ \ 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; }