cifs: Properly handle auto disabling of serverino option

Fix mount options comparison when serverino option is turned off later
in cifs_autodisable_serverino() and thus avoiding mismatch of new cifs
mounts.

Cc: stable@vger.kernel.org
Signed-off-by: Paulo Alcantara (SUSE) <paulo@paulo.ac>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilove@microsoft.com>
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 51f2723..b8a6006 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -3467,12 +3467,16 @@ compare_mount_options(struct super_block *sb, struct cifs_mnt_data *mnt_data)
 {
 	struct cifs_sb_info *old = CIFS_SB(sb);
 	struct cifs_sb_info *new = mnt_data->cifs_sb;
+	unsigned int oldflags = old->mnt_cifs_flags & CIFS_MOUNT_MASK;
+	unsigned int newflags = new->mnt_cifs_flags & CIFS_MOUNT_MASK;
 
 	if ((sb->s_flags & CIFS_MS_MASK) != (mnt_data->flags & CIFS_MS_MASK))
 		return 0;
 
-	if ((old->mnt_cifs_flags & CIFS_MOUNT_MASK) !=
-	    (new->mnt_cifs_flags & CIFS_MOUNT_MASK))
+	if (old->mnt_cifs_serverino_autodisabled)
+		newflags &= ~CIFS_MOUNT_SERVER_INUM;
+
+	if (oldflags != newflags)
 		return 0;
 
 	/*