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, 15 insertions, 4 deletions

diff --git a/fs/xfs/xfs_inode_item_recover.c b/fs/xfs/xfs_inode_item_recover.c
index 4e895c9ad4d7..cb44f7653f03 100644
--- a/fs/xfs/xfs_inode_item_recover.c
+++ b/fs/xfs/xfs_inode_item_recover.c
@@ -115,15 +115,25 @@ out_free_ip:
 	return error;
 }
 
+static inline bool xfs_log_dinode_has_bigtime(const struct xfs_log_dinode *ld)
+{
+	return ld->di_version >= 3 &&
+	       (ld->di_flags2 & XFS_DIFLAG2_BIGTIME);
+}
+
 /* Convert a log timestamp to an ondisk timestamp. */
 static inline xfs_timestamp_t
 xfs_log_dinode_to_disk_ts(
+	struct xfs_log_dinode		*from,
 	const xfs_ictimestamp_t		its)
 {
 	struct xfs_legacy_timestamp	*lts;
 	struct xfs_legacy_ictimestamp	*lits;
 	xfs_timestamp_t			ts;
 
+	if (xfs_log_dinode_has_bigtime(from))
+		return cpu_to_be64(its);
+
 	lts = (struct xfs_legacy_timestamp *)&ts;
 	lits = (struct xfs_legacy_ictimestamp *)&its;
 	lts->t_sec = cpu_to_be32(lits->t_sec);
@@ -149,9 +159,9 @@ xfs_log_dinode_to_disk(
 	to->di_projid_hi = cpu_to_be16(from->di_projid_hi);
 	memcpy(to->di_pad, from->di_pad, sizeof(to->di_pad));
 
-	to->di_atime = xfs_log_dinode_to_disk_ts(from->di_atime);
-	to->di_mtime = xfs_log_dinode_to_disk_ts(from->di_mtime);
-	to->di_ctime = xfs_log_dinode_to_disk_ts(from->di_ctime);
+	to->di_atime = xfs_log_dinode_to_disk_ts(from, from->di_atime);
+	to->di_mtime = xfs_log_dinode_to_disk_ts(from, from->di_mtime);
+	to->di_ctime = xfs_log_dinode_to_disk_ts(from, from->di_ctime);
 
 	to->di_size = cpu_to_be64(from->di_size);
 	to->di_nblocks = cpu_to_be64(from->di_nblocks);
@@ -167,7 +177,8 @@ xfs_log_dinode_to_disk(
 
 	if (from->di_version == 3) {
 		to->di_changecount = cpu_to_be64(from->di_changecount);
-		to->di_crtime = xfs_log_dinode_to_disk_ts(from->di_crtime);
+		to->di_crtime = xfs_log_dinode_to_disk_ts(from,
+							  from->di_crtime);
 		to->di_flags2 = cpu_to_be64(from->di_flags2);
 		to->di_cowextsize = cpu_to_be32(from->di_cowextsize);
 		to->di_ino = cpu_to_be64(from->di_ino);