From: "H. Peter Anvin" <hpa@zytor.com>
To: "linux-btrfs@vger.kernel.org" <linux-btrfs@vger.kernel.org>
Subject: Formalizing the use of Boot Area B
Date: Wed, 14 May 2014 17:01:39 -0700 [thread overview]
Message-ID: <537403E3.6090902@zytor.com> (raw)
It turns out that the primary 64K "Boot Area A" is too small for some
applications and/or some architectures.
When I discussed this with Chris Mason, he pointed out that the area
beyond the superblock is also unused, up until at least the megabyte
point (from my reading of the mkfs code, it is actually slightly more
than a megabyte.)
This is present in all versions of mkfs.btrfs that has the superblock at
64K (some very early ones had the superblock at 16K, but that format is
no longer supported), so all that is needed is formalizing the specs as
to the use of this area.
My suggestion is that 64-128K is reserved for extension of the
superblock and/or any other filesystem uses, and 128-1024K is defined as
Boot Area B. However, if there may be reason to reserve more, then we
should do that. Hence requesting a formal decision as to the extent and
ownership of this area.
-hpa
next reply other threads:[~2014-05-15 0:01 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-15 0:01 H. Peter Anvin [this message]
2014-05-20 23:29 ` Formalizing the use of Boot Area B H. Peter Anvin
2014-05-20 23:37 ` Chris Mason
2014-05-20 23:39 ` H. Peter Anvin
2014-05-21 0:04 ` H. Peter Anvin
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