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Message-ID: <f9d57ae7-6dd6-4854-b9cf-1eec4cfa2a92@linux.ibm.com>
Date:   Wed, 1 Nov 2023 09:10:28 -0400
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Subject: Re: [PATCH 5/5] fix rootfstype=tmpfs
Content-Language: en-US
To:     Rob Landley <rob@landley.net>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Wolfram Sang <wsa+renesas@sang-engineering.com>
References: <b455394f-9faa-1f1a-f171-0b9d5e9ada35@landley.net>
 <8244c75f-445e-b15b-9dbf-266e7ca666e2@landley.net>
From:   Stefan Berger <stefanb@linux.ibm.com>
In-Reply-To: <8244c75f-445e-b15b-9dbf-266e7ca666e2@landley.net>
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On 2/21/23 16:04, Rob Landley wrote:
> Wire up rootfstype=tmpfs to force rootfs to be tmpfs even when you specify root=
> 
> Initramfs automatically uses tmpfs (if available) when you DON'T specify a
> root= fallback root to mount over initramfs, but some people can't NOT do
> that for some reason (old bootloaders), so let rootfstype=tmpfs override it.
> 
> My original code tried to do this 10 years ago but got the test wrong,
> and nobody's corrected it since, so here you go...
> 
> Signed-off-by: Rob Landley <rob@landley.net>

I would like to be able to have this for some work with OpenBMC and 
ideally it would propagate to one of the recent kernels with a Fixes tag 
like this?

Fixes: 6e19eded3684 ("initmpfs: use initramfs if rootfstype= or root= 
specified")

Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Tested-by: Stefan Berger <stefanb@linux.ibm.com>

> 
> See https://lkml.iu.edu/hypermail/linux/kernel/2207.3/06939.html
> ---
>   init/do_mounts.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/init/do_mounts.c b/init/do_mounts.c
> index 811e94daf0a8..01d80fb828fd 100644
> --- a/init/do_mounts.c
> +++ b/init/do_mounts.c
> @@ -665,7 +665,7 @@ struct file_system_type rootfs_fs_type = {
>   
>   void __init init_rootfs(void)
>   {
> -	if (IS_ENABLED(CONFIG_TMPFS) && !saved_root_name[0] &&
> -		(!root_fs_names || strstr(root_fs_names, "tmpfs")))
> +	if (IS_ENABLED(CONFIG_TMPFS) && (!root_fs_names ? !saved_root_name[0] :
> +		!!strstr(root_fs_names, "tmpfs")))
>   		is_tmpfs = true;
>   }