[PATCH 1/5] xfs: convert to ctime accessor functions

["Darrick J. Wong" <djwong@xxxxxxxxxx>]

From: Jeff Layton <jlayton@xxxxxxxxxx>

Source kernel commit: a0a415e34b57368acd262e1172720252c028b936

In later patches, we're going to change how the inode's ctime field is
used. Switch to using accessor functions instead of raw accesses of
inode->i_ctime.

Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
Reviewed-by: Jan Kara <jack@xxxxxxx>
Message-Id: <20230705190309.579783-80-jlayton@xxxxxxxxxx>
Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx>
---
 include/xfs_inode.h      |   22 +++++++++++++++++++++-
 libxfs/xfs_inode_buf.c   |    5 +++--
 libxfs/xfs_trans_inode.c |    2 +-
 3 files changed, 25 insertions(+), 4 deletions(-)


diff --git a/include/xfs_inode.h b/include/xfs_inode.h
index 069fcf362ec..39b1bee8444 100644
--- a/include/xfs_inode.h
+++ b/include/xfs_inode.h
@@ -43,7 +43,7 @@ struct inode {
 	uint64_t		i_version;
 	struct timespec64	i_atime;
 	struct timespec64	i_mtime;
-	struct timespec64	i_ctime;
+	struct timespec64	__i_ctime; /* use inode_*_ctime accessors! */
 	spinlock_t		i_lock;
 };
 
@@ -69,6 +69,26 @@ static inline void ihold(struct inode *inode)
 	inode->i_count++;
 }
 
+/* Userspace does not support multigrain timestamps incore. */
+#define I_CTIME_QUERIED		(0)
+
+static inline struct timespec64 inode_get_ctime(const struct inode *inode)
+{
+	struct timespec64 ctime;
+
+	ctime.tv_sec = inode->__i_ctime.tv_sec;
+	ctime.tv_nsec = inode->__i_ctime.tv_nsec & ~I_CTIME_QUERIED;
+
+	return ctime;
+}
+
+static inline struct timespec64 inode_set_ctime_to_ts(struct inode *inode,
+						      struct timespec64 ts)
+{
+	inode->__i_ctime = ts;
+	return ts;
+}
+
 typedef struct xfs_inode {
 	struct cache_node	i_node;
 	struct xfs_mount	*i_mount;	/* fs mount struct ptr */
diff --git a/libxfs/xfs_inode_buf.c b/libxfs/xfs_inode_buf.c
index cbcaadbcf69..fccab419354 100644
--- a/libxfs/xfs_inode_buf.c
+++ b/libxfs/xfs_inode_buf.c
@@ -219,7 +219,8 @@ xfs_inode_from_disk(
 	 */
 	inode->i_atime = xfs_inode_from_disk_ts(from, from->di_atime);
 	inode->i_mtime = xfs_inode_from_disk_ts(from, from->di_mtime);
-	inode->i_ctime = xfs_inode_from_disk_ts(from, from->di_ctime);
+	inode_set_ctime_to_ts(inode,
+			      xfs_inode_from_disk_ts(from, from->di_ctime));
 
 	ip->i_disk_size = be64_to_cpu(from->di_size);
 	ip->i_nblocks = be64_to_cpu(from->di_nblocks);
@@ -313,7 +314,7 @@ xfs_inode_to_disk(
 
 	to->di_atime = xfs_inode_to_disk_ts(ip, inode->i_atime);
 	to->di_mtime = xfs_inode_to_disk_ts(ip, inode->i_mtime);
-	to->di_ctime = xfs_inode_to_disk_ts(ip, inode->i_ctime);
+	to->di_ctime = xfs_inode_to_disk_ts(ip, inode_get_ctime(inode));
 	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);
diff --git a/libxfs/xfs_trans_inode.c b/libxfs/xfs_trans_inode.c
index c4f81e5d12a..ca8e823762c 100644
--- a/libxfs/xfs_trans_inode.c
+++ b/libxfs/xfs_trans_inode.c
@@ -64,7 +64,7 @@ xfs_trans_ichgtime(
 	if (flags & XFS_ICHGTIME_MOD)
 		inode->i_mtime = tv;
 	if (flags & XFS_ICHGTIME_CHG)
-		inode->i_ctime = tv;
+		inode_set_ctime_to_ts(inode, tv);
 	if (flags & XFS_ICHGTIME_CREATE)
 		ip->i_crtime = tv;
 }