diff options
Diffstat (limited to 'drivers/md/bcache')
| -rw-r--r-- | drivers/md/bcache/util.c | 50 |
1 files changed, 35 insertions, 15 deletions
diff --git a/drivers/md/bcache/util.c b/drivers/md/bcache/util.c index 8c3a938f4bf0..176d3c2ef5f5 100644 --- a/drivers/md/bcache/util.c +++ b/drivers/md/bcache/util.c @@ -74,24 +74,44 @@ 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. + * + * @v - signed 64 bit integer + * @buf - the (at least 8 byte) buffer to format the result into. + * + * Returns the number of bytes used by format. + */ ssize_t bch_hprint(char *buf, int64_t v) { static const char units[] = "?kMGTPEZY"; - char dec[4] = ""; - int u, t = 0; - - for (u = 0; v >= 1024 || v <= -1024; u++) { - t = v & ~(~0 << 10); - v >>= 10; - } - - if (!u) - return sprintf(buf, "%llu", v); - - if (v < 100 && v > -100) - snprintf(dec, sizeof(dec), ".%i", t / 100); - - return sprintf(buf, "%lli%s%c", v, dec, units[u]); + 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]); } ssize_t bch_snprint_string_list(char *buf, size_t size, const char * const list[], |