ubifs: journal: Make sure to not dirty twice for auth nodes

When removing the last reference of an inode the size of an auth node
is already part of write_len. So we must not call ubifs_add_auth_dirt().
Call it only when needed.

Cc: <stable@vger.kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Kristof Havasi <havasiefr@gmail.com>
Fixes: 6a98bc4614 ("ubifs: Add authentication nodes to journal")
Reported-and-tested-by: Kristof Havasi <havasiefr@gmail.com>
Reviewed-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Richard Weinberger <richard@nod.at>

fs/ubifs/journal.c

@@ -938,8 +938,6 @@ int ubifs_jnl_write_inode(struct ubifs_info *c, const struct inode *inode)
 					  inode->i_ino);
 	release_head(c, BASEHD);
 
-	ubifs_add_auth_dirt(c, lnum);
-
 	if (last_reference) {
 		err = ubifs_tnc_remove_ino(c, inode->i_ino);
 		if (err)
@@ -949,6 +947,8 @@ int ubifs_jnl_write_inode(struct ubifs_info *c, const struct inode *inode)
 	} else {
 		union ubifs_key key;
 
+		ubifs_add_auth_dirt(c, lnum);
+
 		ino_key_init(c, &key, inode->i_ino);
 		err = ubifs_tnc_add(c, &key, lnum, offs, ilen, hash);
 	}