cifs: fix missed refcounting of ipc tcon

Fix missed refcounting of IPC tcon used for getting domain-based DFS
root referrals.  We want to keep it alive as long as mount is active
and can be refreshed.  For standalone DFS root referrals it wouldn't
be a problem as the client ends up having an IPC tcon for both mount
and cache.

Fixes: c88f7dcd6d64 ("cifs: support nested dfs links over reconnect")
Signed-off-by: Paulo Alcantara (SUSE) <>
Reviewed-by: Enzo Matsumiya <>
Signed-off-by: Steve French <>
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 6b70502..90f38fb 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -3426,6 +3426,7 @@
+	set_root_ses(mnt_ctx);
 	full_path = build_unc_path_to_root(ctx, cifs_sb, true);
 	if (IS_ERR(full_path))