From: "J. Bruce Fields" <bfields@fieldses.org>
To: Jeff Layton <jlayton@kernel.org>
Cc: Scott Mayhew <smayhew@redhat.com>, linux-nfs@vger.kernel.org
Subject: Re: [PATCH v2 3/3] nfsd: keep a tally of RECLAIM_COMPLETE operations when using nfsdcld
Date: Thu, 20 Dec 2018 13:05:36 -0500 [thread overview]
Message-ID: <20181220180536.GE6063@fieldses.org> (raw)
In-Reply-To: <901adec26f1fd20259bd3e50d963f304b903d312.camel@kernel.org>
On Thu, Dec 20, 2018 at 12:29:43PM -0500, Jeff Layton wrote:
> That wasn't my thinking here.
>
> Suppose we have a client that holds some locks. Server reboots and we do
> EXCHANGE_ID and start reclaiming, and eventually send a
> RECLAIM_COMPLETE.
>
> Now, there is a network partition and we lose contact with the server
> for more than a lease period. The client record gets tossed out. Client
> eventually reestablishes the connection before the grace period ends and
> attempts to reclaim.
>
> That reclaim should succeed, IMO, as there is no reason that it
> shouldn't. Nothing can have claimed competing state since we're still in
> the grace period.
That scenario requires a grace period longer than the lease period,
which isn't impossible but sounds rare? I guess you're thinking in the
cluster case about the possibility of a second node failure extending
the grace period.
Still, that's different from the case where the client explicitly
destroys its own state. That could happen in less than a lease period
and in that case there won't be a reclaim. I think that case could
happen if a client rebooted quickly or maybe just unmounted.
Hm.
--b.
next prev parent reply other threads:[~2018-12-20 18:05 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-18 14:29 [PATCH v2 0/3] un-deprecate nfsdcld Scott Mayhew
2018-12-18 14:29 ` [PATCH v2 1/3] nfsd: make nfs4_client_reclaim use an xdr_netobj instead of a fixed char array Scott Mayhew
2018-12-18 14:29 ` [PATCH v2 2/3] nfsd: un-deprecate nfsdcld Scott Mayhew
2018-12-19 21:23 ` Jeff Layton
2018-12-19 22:11 ` Scott Mayhew
2018-12-20 0:19 ` Jeff Layton
2018-12-20 1:59 ` J. Bruce Fields
2018-12-20 15:24 ` Jeff Layton
2018-12-18 14:29 ` [PATCH v2 3/3] nfsd: keep a tally of RECLAIM_COMPLETE operations when using nfsdcld Scott Mayhew
2018-12-19 17:46 ` J. Bruce Fields
2018-12-19 21:57 ` Scott Mayhew
2018-12-19 18:28 ` J. Bruce Fields
2018-12-19 22:01 ` Scott Mayhew
2018-12-19 18:36 ` J. Bruce Fields
2018-12-19 22:05 ` Scott Mayhew
2018-12-19 22:21 ` J. Bruce Fields
2018-12-19 22:43 ` J. Bruce Fields
2018-12-20 16:36 ` Scott Mayhew
2018-12-20 17:32 ` Jeff Layton
2018-12-20 17:29 ` Jeff Layton
2018-12-20 18:05 ` J. Bruce Fields [this message]
2018-12-20 18:26 ` Jeff Layton
2018-12-20 19:02 ` J. Bruce Fields
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