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udf: Convert udf_disk_stamp_to_time() to use mktime64()

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Convert udf_disk_stamp_to_time() to use mktime64() to simplify the code.
As a bonus we get working timestamp conversion for dates before epoch
and after 2038 (both of which are allowed by UDF standard).

Signed-off-by: Jan Kara <jack@suse.cz>
This commit is contained in:
Jan Kara 2017-06-14 10:42:48 +02:00
parent 3c399fa40f
commit fd3cfad374
1 changed files with 2 additions and 51 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

53
fs/udf/udftime.c
View file

@ -40,52 +40,9 @@
#include <linux/kernel.h>
#include <linux/time.h>
#define EPOCH_YEAR 1970
#ifndef __isleap
/* Nonzero if YEAR is a leap year (every 4 years,
except every 100th isn't, and every 400th is). */
#define __isleap(year) \
((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0))
#endif
/* How many days come before each month (0-12). */
static const unsigned short int __mon_yday[2][13] = {
/* Normal years. */
{0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365},
/* Leap years. */
{0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366}
};
#define MAX_YEAR_SECONDS 69
#define SPD 0x15180 /*3600*24 */
#define SPY(y, l, s) (SPD * (365 * y + l) + s)
static time_t year_seconds[MAX_YEAR_SECONDS] = {
/*1970*/ SPY(0, 0, 0), SPY(1, 0, 0), SPY(2, 0, 0), SPY(3, 1, 0),
/*1974*/ SPY(4, 1, 0), SPY(5, 1, 0), SPY(6, 1, 0), SPY(7, 2, 0),
/*1978*/ SPY(8, 2, 0), SPY(9, 2, 0), SPY(10, 2, 0), SPY(11, 3, 0),
/*1982*/ SPY(12, 3, 0), SPY(13, 3, 0), SPY(14, 3, 0), SPY(15, 4, 0),
/*1986*/ SPY(16, 4, 0), SPY(17, 4, 0), SPY(18, 4, 0), SPY(19, 5, 0),
/*1990*/ SPY(20, 5, 0), SPY(21, 5, 0), SPY(22, 5, 0), SPY(23, 6, 0),
/*1994*/ SPY(24, 6, 0), SPY(25, 6, 0), SPY(26, 6, 0), SPY(27, 7, 0),
/*1998*/ SPY(28, 7, 0), SPY(29, 7, 0), SPY(30, 7, 0), SPY(31, 8, 0),
/*2002*/ SPY(32, 8, 0), SPY(33, 8, 0), SPY(34, 8, 0), SPY(35, 9, 0),
/*2006*/ SPY(36, 9, 0), SPY(37, 9, 0), SPY(38, 9, 0), SPY(39, 10, 0),
/*2010*/ SPY(40, 10, 0), SPY(41, 10, 0), SPY(42, 10, 0), SPY(43, 11, 0),
/*2014*/ SPY(44, 11, 0), SPY(45, 11, 0), SPY(46, 11, 0), SPY(47, 12, 0),
/*2018*/ SPY(48, 12, 0), SPY(49, 12, 0), SPY(50, 12, 0), SPY(51, 13, 0),
/*2022*/ SPY(52, 13, 0), SPY(53, 13, 0), SPY(54, 13, 0), SPY(55, 14, 0),
/*2026*/ SPY(56, 14, 0), SPY(57, 14, 0), SPY(58, 14, 0), SPY(59, 15, 0),
/*2030*/ SPY(60, 15, 0), SPY(61, 15, 0), SPY(62, 15, 0), SPY(63, 16, 0),
/*2034*/ SPY(64, 16, 0), SPY(65, 16, 0), SPY(66, 16, 0), SPY(67, 17, 0),
/*2038*/ SPY(68, 17, 0)
};
struct timespec *
udf_disk_stamp_to_time(struct timespec *dest, struct timestamp src)
{
int yday;
u16 typeAndTimezone = le16_to_cpu(src.typeAndTimezone);
u16 year = le16_to_cpu(src.year);
uint8_t type = typeAndTimezone >> 12;
@ -100,15 +57,9 @@ udf_disk_stamp_to_time(struct timespec *dest, struct timestamp src)
} else
offset = 0;
if ((year < EPOCH_YEAR) ||
(year >= EPOCH_YEAR + MAX_YEAR_SECONDS)) {
return NULL;
}
dest->tv_sec = year_seconds[year - EPOCH_YEAR];
dest->tv_sec = mktime64(year, src.month, src.day, src.hour, src.minute,
src.second);
dest->tv_sec -= offset * 60;
yday = ((__mon_yday[__isleap(year)][src.month - 1]) + src.day - 1);
dest->tv_sec += (((yday * 24) + src.hour) * 60 + src.minute) * 60 + src.second;
dest->tv_nsec = 1000 * (src.centiseconds * 10000 +
src.hundredsOfMicroseconds * 100 + src.microseconds);
return dest;