There were a number of updates to protocol version 4, take account of
that when setting the super block info sub version field.

Signed-off-by: Ian Kent <raven@themaw.net>
---
 fs/autofs/inode.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/fs/autofs/inode.c b/fs/autofs/inode.c
index 3f2dfed428f9..53c0df354206 100644
--- a/fs/autofs/inode.c
+++ b/fs/autofs/inode.c
@@ -279,7 +279,17 @@ static int autofs_validate_protocol(struct fs_context *fc)
 		sbi->version = AUTOFS_MAX_PROTO_VERSION;
 	else
 		sbi->version = sbi->max_proto;
-	sbi->sub_version = AUTOFS_PROTO_SUBVERSION;
+
+	switch (sbi->version) {
+	case 4:
+		sbi->sub_version = 7;
+		break;
+	case 5:
+		sbi->sub_version = AUTOFS_PROTO_SUBVERSION;
+		break;
+	default:
+		sbi->sub_version = 0;
+	}
 
 	return 0;
 }
-- 
2.41.0