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=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 282F7C3A5A1 for ; Sun, 25 Aug 2019 19:40:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EFBD5206E0 for ; Sun, 25 Aug 2019 19:40:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=ziepe.ca header.i=@ziepe.ca header.b="csbaERMJ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729079AbfHYTkv (ORCPT ); Sun, 25 Aug 2019 15:40:51 -0400 Received: from mail-qt1-f195.google.com ([209.85.160.195]:38886 "EHLO mail-qt1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727077AbfHYTkv (ORCPT ); Sun, 25 Aug 2019 15:40:51 -0400 Received: by mail-qt1-f195.google.com with SMTP id q64so4346621qtd.5 for ; Sun, 25 Aug 2019 12:40:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ziepe.ca; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=MbwQAvf1EYum17/LkDk/Jqba2/uydGN6gfIsgEOsYXY=; b=csbaERMJ0Qm3fTZnuLpzIjVz7PuxaBDQQJ/N3o9t1f1/O1EC67YkcNUX1PTDR0QX9F CsiyO4OBG8bzeZJciVsQB91tb6blADeyhKHLyLThI3ARBz75ebkC45wlGR0IkSxBcUD2 2xeTuyMoSBYRe5bqNxCmJQnvuICJPZ9GuLJ4Nml7q/xr5iz9leiEmNUNS3NKBkqV5G3W GoPTz9MQ0GzalUXYG6AV6bPU/WGtGLWX68CCfjNTgPu4NarALIprMgs485MAmtIHW4hf 3vVykhJ+Upyxi5DrpPD1TXlQZLPEEbmUpkTiXOjfd8adN/oepc2B/zAbciY4ewq8xIm/ RYnQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=MbwQAvf1EYum17/LkDk/Jqba2/uydGN6gfIsgEOsYXY=; b=QzhBKUT76WIyYksSDPIQtwi+D48VWtOn85EDgsyxNoCzcQFYND69bZTpB+b6B+z2hz L9RG9xIHL7NbTc9vx7keMNBQ/ap6baWzvP7ehLAbxo35hs3N6rTm5R6FEjXwCUchTLAR PPL2M1SLRCunhEL2RdnBJpPXw+xbY2VKWDbvmEUuifD/6cliKPhYVBfBbZ4nlSgdehBr EF68kAEyFXjVfj5LhMGnss9DGEkLSDDgbymPlzPouXxJzme/wtVJTcpnSVYeqeIjhUri d8HCW4Y+Nht04B3O/i1NZp4Vgm6w4cvFkuJ7TzlnHxbXy6O2D23yfL4DcjjMqwZZOiu+ lTOA== X-Gm-Message-State: APjAAAXkdF6nq2FIeocQfm1EQtxnZTfaYFadPZOvBlvAbNz2kDtEKXye EGfK7LYPn6m2TlmdTY1LR5hDRQ== X-Google-Smtp-Source: APXvYqxk7xnMH5RsCss+5xcOEKbvxQMkTe4ENpEKEAcbqmZYFpESkrWsVxsf7euTTp0g3Hl9/ekeqA== X-Received: by 2002:ac8:42c4:: with SMTP id g4mr14703846qtm.228.1566762050152; Sun, 25 Aug 2019 12:40:50 -0700 (PDT) Received: from ziepe.ca (hlfxns017vw-142-167-216-168.dhcp-dynamic.fibreop.ns.bellaliant.net. [142.167.216.168]) by smtp.gmail.com with ESMTPSA id c5sm5783563qtc.90.2019.08.25.12.40.49 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Sun, 25 Aug 2019 12:40:49 -0700 (PDT) Received: from jgg by mlx.ziepe.ca with local (Exim 4.90_1) (envelope-from ) id 1i1yNd-0005pU-9Z; Sun, 25 Aug 2019 16:40:49 -0300 Date: Sun, 25 Aug 2019 16:40:49 -0300 From: Jason Gunthorpe To: Ira Weiny Cc: Dave Chinner , Jan Kara , Andrew Morton , Dan Williams , Matthew Wilcox , Theodore Ts'o , John Hubbard , Michal Hocko , linux-xfs@vger.kernel.org, linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-nvdimm@lists.01.org, linux-ext4@vger.kernel.org, linux-mm@kvack.org Subject: Re: [RFC PATCH v2 00/19] RDMA/FS DAX truncate proposal V1,000,002 ;-) Message-ID: <20190825194049.GB21239@ziepe.ca> References: <20190819123841.GC5058@ziepe.ca> <20190820011210.GP7777@dread.disaster.area> <20190820115515.GA29246@ziepe.ca> <20190821180200.GA5965@iweiny-DESK2.sc.intel.com> <20190821181343.GH8653@ziepe.ca> <20190821185703.GB5965@iweiny-DESK2.sc.intel.com> <20190821194810.GI8653@ziepe.ca> <20190821204421.GE5965@iweiny-DESK2.sc.intel.com> <20190823032345.GG1119@dread.disaster.area> <20190824044911.GB1092@iweiny-DESK2.sc.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190824044911.GB1092@iweiny-DESK2.sc.intel.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Fri, Aug 23, 2019 at 09:49:12PM -0700, Ira Weiny wrote: > So far, I have not been able to get RDMA to have an issue like Jason suggested > would happen (or used to happen). So from that perspective it may be ok to > hang the close. No, it is not OK to hang the close. You will deadlock on process destruction when the 'lease fd' hangs waiting for the 'uverbs fd' which is later in the single threaded destruction sequence. This is different from the uverbs deadlock I outlined Jason