Re: [PATCH] nfs.man: document incompatibility between "bg" option and systemd.

From: NeilBrown <neilb@suse.com>
To: Steve Dickson <SteveD@RedHat.com>
Cc: systemd-devel@freedesktop.org, linux-nfs@vger.kernel.org,
	Lennart Poettering <lennart@poettering.net>
Subject: Re: [PATCH] nfs.man: document incompatibility between "bg" option and systemd.
Date: Tue, 11 Jul 2017 08:56:44 +1000	[thread overview]
Message-ID: <877ezf6gur.fsf@notabene.neil.brown.name> (raw)
In-Reply-To: <8403677d-cb85-41b2-3c9c-179b82928b80@RedHat.com>

[-- Attachment #1: Type: text/plain, Size: 1578 bytes --]

On Mon, Jul 10 2017, Steve Dickson wrote:

> Hey Neil,
>
> On 07/04/2017 06:20 PM, NeilBrown wrote:
>> On Tue, May 30 2017, NeilBrown wrote:
>> 
>>> Systemd does not, and will not, support "bg" correctly.
>>> It has other, better, ways to handle "background" mounting.
>> 
>> For those who aren't closely watching systemd development, a
>> patch was recently accepted which causes systemd to work correctly with
>> NFS bg mounts.  So the above "and will not" was, happily, not correct.
> Could you please post a pointer to the thread?

The main commmit is
 https://github.com/systemd/systemd/commit/65e1dee7dcf1668c25c32f0238c935708dbffbcf

The link in the title leads to
  https://github.com/systemd/systemd/pull/6103
which is the discussion of the pull request.
The "Fixes" link at the bottom leads to
 https://github.com/systemd/systemd/issues/6046
which is an 'issue' that started out as "we should warn if 'bg' is used"
but became "here is a fix so bg works".

I've been wondering if we should add text to nfs.5 suggesting that
automount is often a good match for NFS, and can particularly be useful
where "bg" is currently used.  Not sure what to do about timeouts
though.
systemd currently waits for the mount command to fail, or kills it after
90 seconds.  It doesn't return an error to accesses of the mount point
(typically ENODEV) until mount exits.  I think I would prefer a shorter
timeout before the error, but a longer timeout before killing mount.
But I'm not really sure.  Does anyone have opinions?

Thanks,
NeilBrown

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 832 bytes --]