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Date:   Sun, 25 Aug 2019 16:40:49 -0300
From:   Jason Gunthorpe <jgg@ziepe.ca>
To:     Ira Weiny <ira.weiny@intel.com>
Cc:     Dave Chinner <david@fromorbit.com>, Jan Kara <jack@suse.cz>,
        Andrew Morton <akpm@linux-foundation.org>,
        Dan Williams <dan.j.williams@intel.com>,
        Matthew Wilcox <willy@infradead.org>,
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        John Hubbard <jhubbard@nvidia.com>,
        Michal Hocko <mhocko@suse.com>, 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 ;-)
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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