xfs: widen ondisk inode timestamps to deal with y2038+

Redesign the ondisk inode timestamps to be a simple unsigned 64-bit
counter of nanoseconds since 14 Dec 1901 (i.e. the minimum time in the
32-bit unix time epoch).  This enables us to handle dates up to 2486,
which solves the y2038 problem.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Gao Xiang <hsiangkao@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

1 files changed, 12 insertions, 1 deletions

diff --git a/fs/xfs/libxfs/xfs_inode_buf.h b/fs/xfs/libxfs/xfs_inode_buf.h
index 3060ecd24a2e..536666143fe7 100644
--- a/fs/xfs/libxfs/xfs_inode_buf.h
+++ b/fs/xfs/libxfs/xfs_inode_buf.h
@@ -32,6 +32,11 @@ struct xfs_icdinode {
 	struct timespec64 di_crtime;	/* time created */
 };
 
+static inline bool xfs_icdinode_has_bigtime(const struct xfs_icdinode *icd)
+{
+	return icd->di_flags2 & XFS_DIFLAG2_BIGTIME;
+}
+
 /*
  * Inode location information.  Stored in the inode and passed to
  * xfs_imap_to_bp() to get a buffer and dinode for a given inode.
@@ -58,6 +63,12 @@ xfs_failaddr_t xfs_inode_validate_cowextsize(struct xfs_mount *mp,
 		uint32_t cowextsize, uint16_t mode, uint16_t flags,
 		uint64_t flags2);
 
-struct timespec64 xfs_inode_from_disk_ts(const xfs_timestamp_t ts);
+static inline uint64_t xfs_inode_encode_bigtime(struct timespec64 tv)
+{
+	return xfs_unix_to_bigtime(tv.tv_sec) * NSEC_PER_SEC + tv.tv_nsec;
+}
+
+struct timespec64 xfs_inode_from_disk_ts(struct xfs_dinode *dip,
+		const xfs_timestamp_t ts);
 
 #endif	/* __XFS_INODE_BUF_H__ */