On Tue, 2023-11-14 at 09:10 -0500, Stefan Berger wrote:
> 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.
>
> This currently does not work when root= is provided since then
> saved_root_name contains a string and initfstype= is ignored. Therefore,
> ramfs is currently always chosen when root= is provided.
>
> The current behavior for rootfs's filesystem is:
>
> root= | initfstype= | chosen rootfs filesystem
^rootfstype=
> ------------+-------------+--------------------------
> unspecified | unspecified | tmpfs
> unspecified | tmpfs | tmpfs
> unspecified | ramfs | ramfs
> provided | ignored | ramfs
>
> initfstype= should be respected regardless whether root= is given,
> as shown below:
^rootfstype=
>
> root= | initfstype= | chosen rootfs filesystem
^rootfstype=
> ------------+-------------+--------------------------
> unspecified | unspecified | tmpfs (as before)
> unspecified | tmpfs | tmpfs (as before)
> unspecified | ramfs | ramfs (as before)
> provided | unspecified | ramfs (compatibility with before)
> provided | tmpfs | tmpfs (new)
> provided | ramfs | ramfs (new)
>
> This table represents the new behavior.
>
> Fixes: 6e19eded3684 ("initmpfs: use initramfs if rootfstype= or root= specified")
> Cc: <[email protected]>
> Reviewed-by: Stefan Berger <[email protected]>
As the patch author, "Reviewed-by" is unnecessary.
Please add a reference to the original patch on which this is based.
Link: https://lore.kernel.org/lkml/[email protected]/
> Signed-off-by: Rob Landley <[email protected]>
> Signed-off-by: Stefan Berger <[email protected]>
> ---
Add Changelog as requested.
> init/do_mounts.c | 9 ++++++---
> 1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/init/do_mounts.c b/init/do_mounts.c
> index 5fdef94f0864..279ad28bf4fb 100644
> --- a/init/do_mounts.c
> +++ b/init/do_mounts.c
> @@ -510,7 +510,10 @@ 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")))
> - is_tmpfs = true;
> + if (IS_ENABLED(CONFIG_TMPFS)) {
> + if (!saved_root_name[0] && !root_fs_names)
> + is_tmpfs = true;
> + else if (root_fs_names && !!strstr(root_fs_names, "tmpfs"))
> + is_tmpfs = true;
> + }
> }
Please change all "initfstype" references to "rootfstype" in the patch
description.
Otherwise,
Reviewed-and-Tested-by: Mimi Zohar <[email protected]>
--
Thanks,
Mimi