Received-SPF: pass (google.com: best guess record for domain of linux-ext4-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Tue, 17 Sep 2019 18:23:40 +0100
From:   Matthew Garrett <mjg59@srcf.ucam.org>
To:     Willy Tarreau <w@1wt.eu>
Cc:     Linus Torvalds <torvalds@linux-foundation.org>,
        Martin Steigerwald <martin@lichtvoll.de>,
        "Ahmed S. Darwish" <darwish.07@gmail.com>,
        "Theodore Y. Ts'o" <tytso@mit.edu>,
        Vito Caputo <vcaputo@pengaru.com>,
        Lennart Poettering <mzxreary@0pointer.de>,
        Andreas Dilger <adilger.kernel@dilger.ca>,
        Jan Kara <jack@suse.cz>, Ray Strode <rstrode@redhat.com>,
        William Jon McCann <mccann@jhu.edu>,
        "Alexander E. Patrakov" <patrakov@gmail.com>,
        zhangjs <zachary@baishancloud.com>, linux-ext4@vger.kernel.org,
        lkml <linux-kernel@vger.kernel.org>
Subject: Re: Linux 5.3-rc8
Message-ID: <20190917172340.e5u7lz74rnnrlpoc@srcf.ucam.org>
References: <CAHk-=wgs65hez6ctK7J2k46BdQzvKU5avExPOTTJsZu6iqA-ow@mail.gmail.com>
 <C4F7DC65-50B9-4D70-8E9B-0A6FF5C1070A@srcf.ucam.org>
 <20190917052438.GA26923@1wt.eu>
 <2508489.jOnZlRuxVn@merkaba>
 <CAHk-=wiGg-G8JFJ=R7qf0B+UtqA_Weouk6v+McmfsLJLRq6AKA@mail.gmail.com>
 <20190917163456.alzodstm3hd4yrni@srcf.ucam.org>
 <20190917171641.GC27999@1wt.eu>
 <20190917172002.vrkudj2ejtrtl7rh@srcf.ucam.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20190917172002.vrkudj2ejtrtl7rh@srcf.ucam.org>
User-Agent: NeoMutt/20170113 (1.7.2)
Sender: linux-ext4-owner@vger.kernel.org
Precedence: bulk

On Tue, Sep 17, 2019 at 06:20:02PM +0100, Matthew Garrett wrote:

> AES keys are used for a variety of long-lived purposes (eg, disk 
> encryption).

And as an example of when we'd want to do that during early boot - swap 
is frequently encrypted with a random key generated on each boot, but 
it's still important for that key to be strong in order to avoid someone 
being able to recover the contents of swap.

-- 
Matthew Garrett | mjg59@srcf.ucam.org