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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/ntfs/time.h | |
download | linux-3.10-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz linux-3.10-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.bz2 linux-3.10-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'fs/ntfs/time.h')
-rw-r--r-- | fs/ntfs/time.h | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/fs/ntfs/time.h b/fs/ntfs/time.h new file mode 100644 index 00000000000..a09a51dabe4 --- /dev/null +++ b/fs/ntfs/time.h @@ -0,0 +1,100 @@ +/* + * time.h - NTFS time conversion functions. Part of the Linux-NTFS project. + * + * Copyright (c) 2001-2004 Anton Altaparmakov + * + * This program/include file is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as published + * by the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program/include file is distributed in the hope that it will be + * useful, but WITHOUT ANY WARRANTY; without even the implied warranty + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program (in the main directory of the Linux-NTFS + * distribution in the file COPYING); if not, write to the Free Software + * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#ifndef _LINUX_NTFS_TIME_H +#define _LINUX_NTFS_TIME_H + +#include <linux/time.h> /* For current_kernel_time(). */ +#include <asm/div64.h> /* 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 timespec consisting of a time_t (long at + * present) 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 timespec 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) +{ + return utc2ntfs(current_kernel_time()); +} + +/** + * 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 timespec consisting of a time_t (long at + * present) 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 timespec ntfs2utc(const sle64 time) +{ + struct timespec ts; + + /* Subtract the NTFS time offset. */ + s64 t = 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 */ |