cifs: do d_move in rename

See commit 349457cc
"Allow file systems to manually d_move() inside of ->rename()"

Lessens possibility of race conditions in rename
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/cifs/cifsfs.c

@@ -1018,7 +1018,7 @@ struct file_system_type cifs_fs_type = {
 	.name = "cifs",
 	.mount = cifs_do_mount,
 	.kill_sb = cifs_kill_sb,
-	/*  .fs_flags */
+	.fs_flags = FS_RENAME_DOES_D_MOVE,
 };
 MODULE_ALIAS_FS("cifs");
 
@@ -1027,7 +1027,7 @@ static struct file_system_type smb3_fs_type = {
 	.name = "smb3",
 	.mount = smb3_do_mount,
 	.kill_sb = cifs_kill_sb,
-	/*  .fs_flags */
+	.fs_flags = FS_RENAME_DOES_D_MOVE,
 };
 MODULE_ALIAS_FS("smb3");
 MODULE_ALIAS("smb3");

fs/cifs/inode.c

@@ -1835,6 +1835,8 @@ cifs_do_rename(const unsigned int xid, struct dentry *from_dentry,
 		CIFSSMBClose(xid, tcon, fid.netfid);
 	}
 do_rename_exit:
+	if (rc == 0)
+		d_move(from_dentry, to_dentry);
 	cifs_put_tlink(tlink);
 	return rc;
 }