nfs_initialise_sb(sb);
 }
 
+#define NFS_MOUNT_CMP_FLAGMASK ~(NFS_MOUNT_INTR \
+               | NFS_MOUNT_SECURE \
+               | NFS_MOUNT_TCP \
+               | NFS_MOUNT_VER3 \
+               | NFS_MOUNT_KERBEROS \
+               | NFS_MOUNT_NONLM \
+               | NFS_MOUNT_BROKEN_SUID \
+               | NFS_MOUNT_STRICTLOCK \
+               | NFS_MOUNT_UNSHARED \
+               | NFS_MOUNT_NORESVPORT \
+               | NFS_MOUNT_LEGACY_INTERFACE)
+
 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
 {
        const struct nfs_server *a = s->s_fs_info;
                goto Ebusy;
        if (a->nfs_client != b->nfs_client)
                goto Ebusy;
-       if (a->flags != b->flags)
+       if ((a->flags ^ b->flags) & NFS_MOUNT_CMP_FLAGMASK)
                goto Ebusy;
        if (a->wsize != b->wsize)
                goto Ebusy;
                goto Ebusy;
        if (a->acdirmax != b->acdirmax)
                goto Ebusy;
-       if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
+       if (b->flags & NFS_MOUNT_SECFLAVOUR &&
+          clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
                goto Ebusy;
        return 1;
 Ebusy: