From: Rob Landley <rob@landley.net>
Subject: [PATCH 0/5] initmpfs: use tmpfs instead of ramfs for rootfs
To: linux-kernel@vger.kernel.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jeff Layton <jlayton@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jim Cromie <jim.cromie@gmail.com>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Stephen Warren <swarren@nvidia.com>

Use tmpfs for rootfs when CONFIG_TMPFS=y and there's no root=.
Specify rootfstype=ramfs to get the old initramfs behavior.

The previous initramfs code provided a fairly crappy root filesystem:
didn't let you --bind mount directories out of it, reported zero
size/usage so it didn't show up in "df" and couldn't run things like
rpm that query available space before proceeding, would fill up all
available memory and panic the system if you wrote too much to it...

Using tmpfs instead provides a much better root filesystem.