nfsd: convert to ctime accessor functions

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.
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Message-Id: <20230705190309.579783-56-jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

fs/nfsd/nfsctl.c

@@ -1131,7 +1131,7 @@ static struct inode *nfsd_get_inode(struct super_block *sb, umode_t mode)
 	/* Following advice from simple_fill_super documentation: */
 	inode->i_ino = iunique(sb, NFSD_MaxReserved);
 	inode->i_mode = mode;
-	inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
+	inode->i_atime = inode->i_mtime = inode_set_ctime_current(inode);
 	switch (mode & S_IFMT) {
 	case S_IFDIR:
 		inode->i_fop = &simple_dir_operations;

fs/nfsd/vfs.c

@@ -520,7 +520,7 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp,
 
 	nfsd_sanitize_attrs(inode, iap);
 
-	if (check_guard && guardtime != inode->i_ctime.tv_sec)
+	if (check_guard && guardtime != inode_get_ctime(inode).tv_sec)
 		return nfserr_notsync;
 
 	/*