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Date:   Sun, 15 Sep 2019 09:07:22 +0200
From:   Willy Tarreau <w@1wt.eu>
To:     Lennart Poettering <mzxreary@0pointer.de>
Cc:     Linus Torvalds <torvalds@linux-foundation.org>,
        "Alexander E. Patrakov" <patrakov@gmail.com>,
        "Ahmed S. Darwish" <darwish.07@gmail.com>,
        "Theodore Y. Ts'o" <tytso@mit.edu>,
        Andreas Dilger <adilger.kernel@dilger.ca>,
        Jan Kara <jack@suse.cz>, Ray Strode <rstrode@redhat.com>,
        William Jon McCann <mccann@jhu.edu>,
        zhangjs <zachary@baishancloud.com>, linux-ext4@vger.kernel.org,
        lkml <linux-kernel@vger.kernel.org>
Subject: Re: Linux 5.3-rc8
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On Sun, Sep 15, 2019 at 09:05:41AM +0200, Lennart Poettering wrote:
> On So, 15.09.19 09:01, Willy Tarreau (w@1wt.eu) wrote:
> 
> > On Sun, Sep 15, 2019 at 08:56:55AM +0200, Lennart Poettering wrote:
> > > There's benefit in being able to wait until the pool is initialized
> > > before we update the random seed stored on disk with a new one,
> >
> > And what exactly makes you think that waiting with arms crossed not
> > doing anything else has any chance to make the situation change if
> > you already had no such entropy available when reaching that first
> > call, especially during early boot ?
> 
> That code can finish 5h after boot, it's entirely fine with this
> specific usecase.
> 
> Again: we don't delay "the boot" for this. We just delay "writing a
> new seed to disk" for this. And if that is 5h later, then that's
> totally fine, because in the meantime it's just one bg process more that
> hangs around waiting to do what it needs to do.

Didn't you say it could also happen when using encrypted swap ? If so
I suspect this could happen very early during boot, before any services
may be started ?

Willy