Files
linux/fs/ntfs/time.h
Namjae Jeon 4079605199 ntfs: update in-memory, on-disk structures and headers
Update the NTFS filesystem driver's in-memory and on-disk structures:

  - Introduce the  infrastructure and initial support for reparse
    points and EA attribute.
  - Refactor the core ntfs_inode and ntfs_volume structures to support
    new features such as iomap.
  - Remove the unnecessary types.h and endian.h headers.
  - Reorganize the comments in headers for better readability, including
    fixing warnings from checkpatch.pl.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-02-19 21:48:06 +09:00

88 lines
2.7 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* NTFS time conversion functions.
*
* Copyright (c) 2001-2005 Anton Altaparmakov
*/
#ifndef _LINUX_NTFS_TIME_H
#define _LINUX_NTFS_TIME_H
#include <linux/time.h>
#include <asm/div64.h> /* For do_div(). */
#define NTFS_TIME_OFFSET ((s64)(369 * 365 + 89) * 24 * 3600)
/*
* utc2ntfs - convert Linux UTC time to NTFS time
* @ts: Linux UTC time to convert to NTFS time
*
* Convert the Linux UTC time @ts to its corresponding NTFS time and return
* that in little endian format.
*
* Linux stores time in a struct timespec64 consisting of a time64_t tv_sec
* and a long tv_nsec where tv_sec is the number of 1-second intervals since
* 1st January 1970, 00:00:00 UTC and tv_nsec is the number of 1-nano-second
* intervals since the value of tv_sec.
*
* NTFS uses Microsoft's standard time format which is stored in a s64 and is
* measured as the number of 100-nano-second intervals since 1st January 1601,
* 00:00:00 UTC.
*/
static inline __le64 utc2ntfs(const struct timespec64 ts)
{
/*
* Convert the seconds to 100ns intervals, add the nano-seconds
* converted to 100ns intervals, and then add the NTFS time offset.
*/
return cpu_to_le64((u64)(ts.tv_sec + NTFS_TIME_OFFSET) * 10000000 +
ts.tv_nsec / 100);
}
/*
* get_current_ntfs_time - get the current time in little endian NTFS format
*
* Get the current time from the Linux kernel, convert it to its corresponding
* NTFS time and return that in little endian format.
*/
static inline __le64 get_current_ntfs_time(void)
{
struct timespec64 ts;
ktime_get_coarse_real_ts64(&ts);
return utc2ntfs(ts);
}
/*
* ntfs2utc - convert NTFS time to Linux time
* @time: NTFS time (little endian) to convert to Linux UTC
*
* Convert the little endian NTFS time @time to its corresponding Linux UTC
* time and return that in cpu format.
*
* Linux stores time in a struct timespec64 consisting of a time64_t tv_sec
* and a long tv_nsec where tv_sec is the number of 1-second intervals since
* 1st January 1970, 00:00:00 UTC and tv_nsec is the number of 1-nano-second
* intervals since the value of tv_sec.
*
* NTFS uses Microsoft's standard time format which is stored in a s64 and is
* measured as the number of 100 nano-second intervals since 1st January 1601,
* 00:00:00 UTC.
*/
static inline struct timespec64 ntfs2utc(const __le64 time)
{
struct timespec64 ts;
s32 t32;
/* Subtract the NTFS time offset. */
s64 t = le64_to_cpu(time) - NTFS_TIME_OFFSET * 10000000;
/*
* Convert the time to 1-second intervals and the remainder to
* 1-nano-second intervals.
*/
ts.tv_sec = div_s64_rem(t, 10000000, &t32);
ts.tv_nsec = t32 * 100;
return ts;
}
#endif /* _LINUX_NTFS_TIME_H */