[RFC v2a 01/12] vfs: Add vfs_time abstractions

[Deepa Dinamani]

Add vfs_time aliases to help convert vfs timestamps to use
64 bit times. These create an abstraction layer so that
vfs inode times can be switched to use struct timespec64
instead of struct timespec.

Use uapi exposed data types, timespec and timespec64 here to keep
minimal timestamp data type conversions in API's interfacing with
vfs.

Signed-off-by: Deepa Dinamani <deepa.kernel@xxxxxxxxx>
---
 include/linux/fs.h | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 4af612f..ec25603 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1412,6 +1412,25 @@ static inline struct timespec current_fs_time_sec(struct super_block *sb)
 	return (struct timespec) { get_seconds(), 0 };
 }
 
+/* Place holder defines until it is safe to use timespec64
+ * in the vfs layer.
+ * timespec64 data type and functions will be used at that
+ * time directly by all filesystems and these defines will be deleted.
+ */
+#define vfs_time timespec
+
+#define vfs_time_compare timespec_compare
+#define vfs_time_equal   timespec_equal
+#define vfs_time_add     timespec_add
+
+/* This returns current time in a timespec/seconds format to match vfs
+ * timestamp data type.
+ * This is for timestamps that use the same functions
+ * as vfs_time but have nothing to do with inode timestamps.
+ */
+#define vfs_get_real_ts       ktime_get_real_ts
+#define vfs_get_real_seconds  get_seconds
+
 /*
  * Snapshotting support.
  */
-- 
1.9.1