From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- fs/ntfs/time.h | 89 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 89 insertions(+) create mode 100644 fs/ntfs/time.h (limited to 'fs/ntfs/time.h') diff --git a/fs/ntfs/time.h b/fs/ntfs/time.h new file mode 100644 index 0000000000..6b63261300 --- /dev/null +++ b/fs/ntfs/time.h @@ -0,0 +1,89 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * time.h - NTFS time conversion functions. Part of the Linux-NTFS project. + * + * Copyright (c) 2001-2005 Anton Altaparmakov + */ + +#ifndef _LINUX_NTFS_TIME_H +#define _LINUX_NTFS_TIME_H + +#include /* For current_kernel_time(). */ +#include /* For do_div(). */ + +#include "endian.h" + +#define NTFS_TIME_OFFSET ((s64)(369 * 365 + 89) * 24 * 3600 * 10000000) + +/** + * 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 sle64 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_sle64((s64)ts.tv_sec * 10000000 + ts.tv_nsec / 100 + + NTFS_TIME_OFFSET); +} + +/** + * 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 sle64 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 sle64 time) +{ + struct timespec64 ts; + + /* Subtract the NTFS time offset. */ + u64 t = (u64)(sle64_to_cpu(time) - NTFS_TIME_OFFSET); + /* + * Convert the time to 1-second intervals and the remainder to + * 1-nano-second intervals. + */ + ts.tv_nsec = do_div(t, 10000000) * 100; + ts.tv_sec = t; + return ts; +} + +#endif /* _LINUX_NTFS_TIME_H */ -- cgit v1.2.3