[PATCH 5.11 060/120] cifs: warn and fail if trying to use rootfs without the config option

[Greg Kroah-Hartman]

From: Aurelien Aptel <aaptel@xxxxxxxx>

commit af3ef3b1031634724a3763606695ebcd113d782b upstream.

If CONFIG_CIFS_ROOT is not set, rootfs mount option is invalid

Signed-off-by: Aurelien Aptel <aaptel@xxxxxxxx>
CC: <stable@xxxxxxxxxxxxxxx> # v5.11
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 fs/cifs/fs_context.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/fs/cifs/fs_context.c
+++ b/fs/cifs/fs_context.c
@@ -1175,9 +1175,11 @@ static int smb3_fs_context_parse_param(s
 		pr_warn_once("Witness protocol support is experimental\n");
 		break;
 	case Opt_rootfs:
-#ifdef CONFIG_CIFS_ROOT
-		ctx->rootfs = true;
+#ifndef CONFIG_CIFS_ROOT
+		cifs_dbg(VFS, "rootfs support requires CONFIG_CIFS_ROOT config option\n");
+		goto cifs_parse_mount_err;
 #endif
+		ctx->rootfs = true;
 		break;
 	case Opt_posixpaths:
 		if (result.negated)