namei: introduce struct renamedata

In order to handle idmapped mounts we will extend the vfs rename helper
to take two new arguments in follow up patches. Since this operations
already takes a bunch of arguments add a simple struct renamedata and
make the current helper use it before we extend it.

Link: https://lore.kernel.org/r/20210121131959.646623-14-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 37d8504..f7d83ff2 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1798,7 +1798,13 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
 		close_cached = true;
 		goto out_dput_old;
 	} else {
-		host_err = vfs_rename(fdir, odentry, tdir, ndentry, NULL, 0);
+		struct renamedata rd = {
+			.old_dir	= fdir,
+			.old_dentry	= odentry,
+			.new_dir	= tdir,
+			.new_dentry	= ndentry,
+		};
+		host_err = vfs_rename(&rd);
 		if (!host_err) {
 			host_err = commit_metadata(tfhp);
 			if (!host_err)