Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.33 as permitted sender) client-ip=23.128.96.33;
Message-ID: <6dae6aa6-e6c6-89d6-f9d7-7563708f7662@landley.net>
Date:   Wed, 1 Nov 2023 06:35:37 -0500
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.10.0
Subject: Re: [RFC PATCH] rootfs: Use tmpfs for rootfs even if root= is given
Content-Language: en-US
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Stefan Berger <stefanb@linux.ibm.com>
Cc:     linux-kernel@vger.kernel.org,
        "Milton D. Miller II" <mdmii@outlook.com>,
        Jeff Layton <jlayton@kernel.org>, Jens Axboe <axboe@kernel.dk>,
        Jim Cromie <jim.cromie@gmail.com>,
        Sam Ravnborg <sam@ravnborg.org>,
        "Eric W. Biederman" <ebiederm@xmission.com>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        "H. Peter Anvin" <hpa@zytor.com>, Mimi Zohar <zohar@linux.ibm.com>
References: <20231031154417.621742-1-stefanb@linux.ibm.com>
 <2023103159-punctuate-amount-f09d@gregkh>
From:   Rob Landley <rob@landley.net>
In-Reply-To: <2023103159-punctuate-amount-f09d@gregkh>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 10/31/23 11:56, Greg Kroah-Hartman wrote:
> On Tue, Oct 31, 2023 at 11:44:17AM -0400, Stefan Berger wrote:
>> rootfs currently does not use tmpfs if the root= boot option is passed
>> even though the documentation about rootfs (added in 6e19eded3684) in
>> Documentation/filesystems/ramfs-rootfs-initramfs.rst states:
>> 
>>   If CONFIG_TMPFS is enabled, rootfs will use tmpfs instead of ramfs by
>>   default.  To force ramfs, add "rootfstype=ramfs" to the kernel command
>>   line.
> 
> At this point in time, is there even any difference between ramfs and
> tmpfs anymore?  Why would you want to choose one over the other here?

I submitted a patch to fix this to the list multiple times, which got ignored as
always. Most recently here:

https://lore.kernel.org/lkml/8244c75f-445e-b15b-9dbf-266e7ca666e2@landley.net/

Rob