From: "Frank Filz" <ffilzlnx@mindspring.com>
To: "'J. Bruce Fields'" <bfields@fieldses.org>,
"'Kenneth Johansson'" <ken@kenjo.org>
Cc: "'Patrick Goetz'" <pgoetz@math.utexas.edu>, <linux-nfs@vger.kernel.org>
Subject: RE: nfs home directory and google chrome.
Date: Wed, 7 Oct 2020 07:34:27 -0700 [thread overview]
Message-ID: <031501d69cb6$f6843a10$e38cae30$@mindspring.com> (raw)
In-Reply-To: <20201007131037.GA23452@fieldses.org>
> -----Original Message-----
> From: J. Bruce Fields [mailto:bfields@fieldses.org]
> Maybe I overlooked the obvious: if Chrome holds a lock on that file when you
> suspend, and if you stay in suspend for longer than the NFSv4 lease time (default
> 90 seconds), then the client will lose its lease, hence any file locks. I think these
> days the client then returns EIO on any further IO to that file descriptor.
>
> Maybe there's some way to turn off that locking as a workaround.
>
> The simplest thing we can do to help might be implementing "courteous server"
> behavior: instead of automatically removing locks after a client's lease expires,
> it can wait until there's an actual lock conflict. That might be enough for your
> case.
>
> There's been a little planning done and it's not a big project, but I don't think it's
> actually at the top of anyone's todo list right now, so I'm not sure when that will
> get done.
I've had courtesy locks on my back burner for Ganesha though I hadn't thought about that there might actually be an important practical issue. Does any other server implement them? If we suggest this as a solution to the Chrome suspend issue, it might be good to assure that the major server vendors implement this.
There is a problem with the courtesy locks for this solution though... The clientid is still going to be expired, and the locks are associated with the clientid, so unless we allow courtesy re-instatement of expired clientids, courtesy locks don't actually solve the problem...
Option - use NFSv3 instead :-) The lack of lock expiry due to AWOL client would work in a suspended client's favor... Note also that a suspended client could be a VM, for example, VirtualBox allows saving and suspending a VM in running state.
Interesting problem...
Frank
next prev parent reply other threads:[~2020-10-07 15:27 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-04 11:53 nfs home directory and google chrome Kenneth Johansson
2020-10-05 16:46 ` Patrick Goetz
2020-10-05 20:07 ` Kenneth Johansson
2020-10-06 18:14 ` J. Bruce Fields
2020-10-07 10:54 ` Kenneth Johansson
2020-10-07 13:10 ` J. Bruce Fields
2020-10-07 14:34 ` Frank Filz [this message]
2020-10-07 15:17 ` 'J. Bruce Fields'
2020-10-07 15:39 ` Chuck Lever
2020-10-07 18:11 ` Frank Filz
2020-10-07 18:36 ` Chuck Lever
2020-10-07 23:58 ` Rick Macklem
2020-10-07 21:10 ` Kenneth Johansson
2020-10-27 23:01 ` Kenneth Johansson
2020-10-29 17:36 ` J. Bruce Fields
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