From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 006C8C00A89 for ; Mon, 2 Nov 2020 14:26:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8423E206F8 for ; Mon, 2 Nov 2020 14:26:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="fdEAAQVJ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726133AbgKBO0P (ORCPT ); Mon, 2 Nov 2020 09:26:15 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:31153 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726104AbgKBO0M (ORCPT ); Mon, 2 Nov 2020 09:26:12 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1604327171; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=l2zRKLgNsnXTGjSSS56WpLlhmJPfrlhiyUVGzUpqBHE=; b=fdEAAQVJoKmcLt0lzRJrptxqXC8yKPyI/UxaQCQYAQ69G0lNT46Xg7p55eIF3JuSAOwWEI dbgrm5VcuiGzJ48pXmPuIfktqLAJNYEBt2Vr/uf+Cnv5bb3PU+Apw7qouJIO56VMnmlBx0 n5J6rvm51eBlVEWygo0toXPyBAW+yuc= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-270-L8aQTOltN0aPgeK5VZD5WQ-1; Mon, 02 Nov 2020 09:26:10 -0500 X-MC-Unique: L8aQTOltN0aPgeK5VZD5WQ-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A83FA18BA283; Mon, 2 Nov 2020 14:26:08 +0000 (UTC) Received: from ovpn-112-12.rdu2.redhat.com (ovpn-112-12.rdu2.redhat.com [10.10.112.12]) by smtp.corp.redhat.com (Postfix) with ESMTP id A5EB05DA6B; Mon, 2 Nov 2020 14:25:57 +0000 (UTC) Message-ID: <77529e99ca9c2d228a67dd8d789d83afdcd1ace3.camel@redhat.com> Subject: Re: WARN_ON(fuse_insert_writeback(root, wpa)) in tree_insert() From: Qian Cai To: Miklos Szeredi Cc: Vivek Goyal , Stefan Hajnoczi , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, virtio-fs-list Date: Mon, 02 Nov 2020 09:25:57 -0500 In-Reply-To: References: <89f0dbf6713ebd44ec519425e3a947e71f7aed55.camel@redhat.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2020-10-29 at 16:20 +0100, Miklos Szeredi wrote: > On Thu, Oct 29, 2020 at 4:02 PM Qian Cai wrote: > > On Wed, 2020-10-07 at 16:08 -0400, Qian Cai wrote: > > > Running some fuzzing by a unprivileged user on virtiofs could trigger the > > > warning below. The warning was introduced not long ago by the commit > > > c146024ec44c ("fuse: fix warning in tree_insert() and clean up writepage > > > insertion"). > > > > > > From the logs, the last piece of the fuzzing code is: > > > > > > fgetxattr(fd=426, name=0x7f39a69af000, value=0x7f39a8abf000, size=1) > > > > I can still reproduce it on today's linux-next. Any idea on how to debug it > > further? > > Can you please try the attached patch? It has survived the testing over the weekend. There is a issue that virtiofsd hung, but it looks like a separate issue.