[PATCH 01/14] xfs: explicitly define inode timestamp range

["Darrick J. Wong" <darrick.wong@xxxxxxxxxx>]

From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>

Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
 fs/xfs/libxfs/xfs_format.h |   19 +++++++++++++++++++
 fs/xfs/xfs_ondisk.h        |    8 ++++++++
 fs/xfs/xfs_super.c         |    4 ++--
 3 files changed, 29 insertions(+), 2 deletions(-)


diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h
index 9ff373962d10..82b15832ba32 100644
--- a/fs/xfs/libxfs/xfs_format.h
+++ b/fs/xfs/libxfs/xfs_format.h
@@ -841,11 +841,30 @@ typedef struct xfs_agfl {
 	    ASSERT(xfs_daddr_to_agno(mp, d) == \
 		   xfs_daddr_to_agno(mp, (d) + (len) - 1)))
 
+/*
+ * XFS Timestamps
+ * ==============
+ *
+ * Inode timestamps consist of signed 32-bit counters for seconds and
+ * nanoseconds; time zero is the Unix epoch, Jan  1 00:00:00 UTC 1970.
+ */
 typedef struct xfs_timestamp {
 	__be32		t_sec;		/* timestamp seconds */
 	__be32		t_nsec;		/* timestamp nanoseconds */
 } xfs_timestamp_t;
 
+/*
+ * Smallest possible timestamp with traditional timestamps, which is
+ * Dec 13 20:45:52 UTC 1901.
+ */
+#define XFS_INO_TIME_MIN	((int64_t)S32_MIN)
+
+/*
+ * Largest possible timestamp with traditional timestamps, which is
+ * Jan 19 03:14:07 UTC 2038.
+ */
+#define XFS_INO_TIME_MAX	((int64_t)S32_MAX)
+
 /*
  * On-disk inode structure.
  *
diff --git a/fs/xfs/xfs_ondisk.h b/fs/xfs/xfs_ondisk.h
index fa0ec2fae14a..f67f3645efcd 100644
--- a/fs/xfs/xfs_ondisk.h
+++ b/fs/xfs/xfs_ondisk.h
@@ -15,9 +15,17 @@
 		"XFS: offsetof(" #structname ", " #member ") is wrong, " \
 		"expected " #off)
 
+#define XFS_CHECK_VALUE(value, expected) \
+	BUILD_BUG_ON_MSG((value) != (expected), \
+		"XFS: value of " #value " is wrong, expected " #expected)
+
 static inline void __init
 xfs_check_ondisk_structs(void)
 {
+	/* make sure timestamp limits are correct */
+	XFS_CHECK_VALUE(XFS_INO_TIME_MIN, 			-2147483648LL);
+	XFS_CHECK_VALUE(XFS_INO_TIME_MAX,			2147483647LL);
+
 	/* ag/file structures */
 	XFS_CHECK_STRUCT_SIZE(struct xfs_acl,			4);
 	XFS_CHECK_STRUCT_SIZE(struct xfs_acl_entry,		12);
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index f687181a2720..3bddf13cd8ea 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -1582,8 +1582,8 @@ xfs_fc_fill_super(
 	sb->s_maxbytes = xfs_max_file_offset(sb->s_blocksize_bits);
 	sb->s_max_links = XFS_MAXLINK;
 	sb->s_time_gran = 1;
-	sb->s_time_min = S32_MIN;
-	sb->s_time_max = S32_MAX;
+	sb->s_time_min = XFS_INO_TIME_MIN;
+	sb->s_time_max = XFS_INO_TIME_MAX;
 	sb->s_iflags |= SB_I_CGROUPWB;
 
 	set_posix_acl_flag(sb);