summaryrefslogtreecommitdiffstats
path: root/kernel/fs/ntfs/time.h
diff options
context:
space:
mode:
authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/fs/ntfs/time.h
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/fs/ntfs/time.h')
-rw-r--r--kernel/fs/ntfs/time.h100
1 files changed, 100 insertions, 0 deletions
diff --git a/kernel/fs/ntfs/time.h b/kernel/fs/ntfs/time.h
new file mode 100644
index 000000000..01233989d
--- /dev/null
+++ b/kernel/fs/ntfs/time.h
@@ -0,0 +1,100 @@
+/*
+ * time.h - NTFS time conversion functions. Part of the Linux-NTFS project.
+ *
+ * Copyright (c) 2001-2005 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. */
+ 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 */