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Date:   Fri, 30 Aug 2019 15:54:43 -0400
From:   "J. Bruce Fields" <bfields@fieldses.org>
To:     Alex Lyakas <alex@zadara.com>
Cc:     chuck.lever@oracle.com, linux-nfs@vger.kernel.org,
        Shyam Kaushik <shyam@zadara.com>
Subject: Re: [RFC-PATCH] nfsd: when unhashing openowners, increment
 openowner's refcount
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On Thu, Aug 29, 2019 at 09:12:49PM +0300, Alex Lyakas wrote:
> Would moving this code into the "unlock_filesystem" infrastructure be
> acceptable? Since the "share_id" approach is very custom for our
> usage, what criteria would you suggest for selecting the openowners to
> be "forgotten"?

Have you looked at what unlock_filesystem()?  It's just translating the
given path to a superblock, then matching that against inodes in
nlmsvc_match_sb().

It's a little more complicated for nfs4_files since they don't have a
pointer to the inode. (Maybe it should.)  You can see how I get around
this in e.g.  fs/nfsd/nfs4state.c:nfs4_show_lock().

A superblock isn't the same thing as an export, thanks to bind mounts
and subdirectory exports.  But if the goal is to be able to unmount,
then a superblock is probably what you want.

--b.