From a252aadfc977473e0851acf0d529c930c6e8e181 Mon Sep 17 00:00:00 2001
From: "Darrick J. Wong" <darrick.wong@oracle.com>
Date: Tue, 10 Nov 2020 16:29:40 -0500
Subject: [PATCH] xfs: redefine xfs_timestamp_t

Source kernel commit: 5a0bb066f60fa02f453d7721844eae59f505c06e

Redefine xfs_timestamp_t as a __be64 typedef in preparation for the
bigtime functionality.  Preserve the legacy structure format so that we
can let the compiler take care of masking and shifting.

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>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
---

diff --git a/db/field.c b/db/field.c
index 66fa37e..4a45c66 100644
--- a/db/field.c
+++ b/db/field.c
@@ -350,7 +350,7 @@ const ftattr_t	ftattrtab[] = {
 	{ FLDT_TIME, "time", fp_time, NULL, SI(bitsz(int32_t)), FTARG_SIGNED,
 	  NULL, NULL },
 	{ FLDT_TIMESTAMP, "timestamp", NULL, (char *)timestamp_flds,
-	  SI(bitsz(xfs_timestamp_t)), 0, NULL, timestamp_flds },
+	  SI(bitsz(struct xfs_legacy_timestamp)), 0, NULL, timestamp_flds },
 	{ FLDT_UINT1, "uint1", fp_num, "%u", SI(1), 0, NULL, NULL },
 	{ FLDT_UINT16D, "uint16d", fp_num, "%u", SI(bitsz(uint16_t)), 0, NULL,
 	  NULL },
diff --git a/db/inode.c b/db/inode.c
index 697f7fe..b308538 100644
--- a/db/inode.c
+++ b/db/inode.c
@@ -176,7 +176,7 @@ const field_t	inode_v3_flds[] = {
 };
 
 
-#define	TOFF(f)	bitize(offsetof(xfs_timestamp_t, t_ ## f))
+#define	TOFF(f)	bitize(offsetof(struct xfs_legacy_timestamp, t_ ## f))
 const field_t	timestamp_flds[] = {
 	{ "sec", FLDT_TIME, OI(TOFF(sec)), C1, 0, TYP_NONE },
 	{ "nsec", FLDT_NSEC, OI(TOFF(nsec)), C1, 0, TYP_NONE },
diff --git a/libxfs/xfs_format.h b/libxfs/xfs_format.h
index 8858341..371f5cd 100644
--- a/libxfs/xfs_format.h
+++ b/libxfs/xfs_format.h
@@ -847,12 +847,16 @@ typedef struct xfs_agfl {
  * seconds and nanoseconds; time zero is the Unix epoch, Jan  1 00:00:00 UTC
  * 1970, which means that the timestamp epoch is the same as the Unix epoch.
  * Therefore, the ondisk min and max defined here can be used directly to
- * constrain the incore timestamps on a Unix system.
+ * constrain the incore timestamps on a Unix system.  Note that we actually
+ * encode a __be64 value on disk.
  */
-typedef struct xfs_timestamp {
+typedef __be64 xfs_timestamp_t;
+
+/* Legacy timestamp encoding format. */
+struct xfs_legacy_timestamp {
 	__be32		t_sec;		/* timestamp seconds */
 	__be32		t_nsec;		/* timestamp nanoseconds */
-} xfs_timestamp_t;
+};
 
 /*
  * Smallest possible ondisk seconds value with traditional timestamps.  This
diff --git a/libxfs/xfs_inode_buf.c b/libxfs/xfs_inode_buf.c
index f80ce10..d8831a1 100644
--- a/libxfs/xfs_inode_buf.c
+++ b/libxfs/xfs_inode_buf.c
@@ -195,6 +195,21 @@ xfs_imap_to_bp(
 	return 0;
 }
 
+/* Convert an ondisk timestamp to an incore timestamp. */
+struct timespec64
+xfs_inode_from_disk_ts(
+	const xfs_timestamp_t		ts)
+{
+	struct timespec64		tv;
+	struct xfs_legacy_timestamp	*lts;
+
+	lts = (struct xfs_legacy_timestamp *)&ts;
+	tv.tv_sec = (int)be32_to_cpu(lts->t_sec);
+	tv.tv_nsec = (int)be32_to_cpu(lts->t_nsec);
+
+	return tv;
+}
+
 void
 xfs_inode_from_disk(
 	struct xfs_inode	*ip,
@@ -231,12 +246,10 @@ xfs_inode_from_disk(
 	 * a time before epoch is converted to a time long after epoch
 	 * on 64 bit systems.
 	 */
-	inode->i_atime.tv_sec = (int)be32_to_cpu(from->di_atime.t_sec);
-	inode->i_atime.tv_nsec = (int)be32_to_cpu(from->di_atime.t_nsec);
-	inode->i_mtime.tv_sec = (int)be32_to_cpu(from->di_mtime.t_sec);
-	inode->i_mtime.tv_nsec = (int)be32_to_cpu(from->di_mtime.t_nsec);
-	inode->i_ctime.tv_sec = (int)be32_to_cpu(from->di_ctime.t_sec);
-	inode->i_ctime.tv_nsec = (int)be32_to_cpu(from->di_ctime.t_nsec);
+	inode->i_atime = xfs_inode_from_disk_ts(from->di_atime);
+	inode->i_mtime = xfs_inode_from_disk_ts(from->di_mtime);
+	inode->i_ctime = xfs_inode_from_disk_ts(from->di_ctime);
+
 	inode->i_generation = be32_to_cpu(from->di_gen);
 	inode->i_mode = be16_to_cpu(from->di_mode);
 
@@ -254,13 +267,27 @@ xfs_inode_from_disk(
 	if (to->di_version == 3) {
 		inode_set_iversion_queried(inode,
 					   be64_to_cpu(from->di_changecount));
-		to->di_crtime.tv_sec = be32_to_cpu(from->di_crtime.t_sec);
-		to->di_crtime.tv_nsec = be32_to_cpu(from->di_crtime.t_nsec);
+		to->di_crtime = xfs_inode_from_disk_ts(from->di_crtime);
 		to->di_flags2 = be64_to_cpu(from->di_flags2);
 		to->di_cowextsize = be32_to_cpu(from->di_cowextsize);
 	}
 }
 
+/* Convert an incore timestamp to an ondisk timestamp. */
+static inline xfs_timestamp_t
+xfs_inode_to_disk_ts(
+	const struct timespec64		tv)
+{
+	struct xfs_legacy_timestamp	*lts;
+	xfs_timestamp_t			ts;
+
+	lts = (struct xfs_legacy_timestamp *)&ts;
+	lts->t_sec = cpu_to_be32(tv.tv_sec);
+	lts->t_nsec = cpu_to_be32(tv.tv_nsec);
+
+	return ts;
+}
+
 void
 xfs_inode_to_disk(
 	struct xfs_inode	*ip,
@@ -281,12 +308,9 @@ xfs_inode_to_disk(
 	to->di_projid_hi = cpu_to_be16(from->di_projid_hi);
 
 	memset(to->di_pad, 0, sizeof(to->di_pad));
-	to->di_atime.t_sec = cpu_to_be32(inode->i_atime.tv_sec);
-	to->di_atime.t_nsec = cpu_to_be32(inode->i_atime.tv_nsec);
-	to->di_mtime.t_sec = cpu_to_be32(inode->i_mtime.tv_sec);
-	to->di_mtime.t_nsec = cpu_to_be32(inode->i_mtime.tv_nsec);
-	to->di_ctime.t_sec = cpu_to_be32(inode->i_ctime.tv_sec);
-	to->di_ctime.t_nsec = cpu_to_be32(inode->i_ctime.tv_nsec);
+	to->di_atime = xfs_inode_to_disk_ts(inode->i_atime);
+	to->di_mtime = xfs_inode_to_disk_ts(inode->i_mtime);
+	to->di_ctime = xfs_inode_to_disk_ts(inode->i_ctime);
 	to->di_nlink = cpu_to_be32(inode->i_nlink);
 	to->di_gen = cpu_to_be32(inode->i_generation);
 	to->di_mode = cpu_to_be16(inode->i_mode);
@@ -304,8 +328,7 @@ xfs_inode_to_disk(
 
 	if (from->di_version == 3) {
 		to->di_changecount = cpu_to_be64(inode_peek_iversion(inode));
-		to->di_crtime.t_sec = cpu_to_be32(from->di_crtime.tv_sec);
-		to->di_crtime.t_nsec = cpu_to_be32(from->di_crtime.tv_nsec);
+		to->di_crtime = xfs_inode_to_disk_ts(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(ip->i_ino);
diff --git a/libxfs/xfs_inode_buf.h b/libxfs/xfs_inode_buf.h
index 0343368..6147f42 100644
--- a/libxfs/xfs_inode_buf.h
+++ b/libxfs/xfs_inode_buf.h
@@ -76,4 +76,6 @@ 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);
+
 #endif	/* __XFS_INODE_BUF_H__ */
diff --git a/repair/dinode.c b/repair/dinode.c
index 8fa5f88..0c40f2a 100644
--- a/repair/dinode.c
+++ b/repair/dinode.c
@@ -2213,9 +2213,12 @@ static void
 check_nsec(
 	const char		*name,
 	xfs_ino_t		lino,
-	struct xfs_timestamp	*t,
+	xfs_timestamp_t		*ts,
 	int			*dirty)
 {
+	struct xfs_legacy_timestamp *t;
+
+	t = (struct xfs_legacy_timestamp *)ts;
 	if (be32_to_cpu(t->t_nsec) < NSEC_PER_SEC)
 		return;