On Tue, Nov 14, 2023 at 09:10:30AM -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 ------------+-------------+-------------------------- unspecified | unspecified | tmpfs unspecified | tmpfs | tmpfs unspecified | ramfs | ramfs provided | ignored | ramfs

initfstype= should be respected regardless whether root= is given, as shown below:

root= | initfstype= | chosen rootfs filesystem ------------+-------------+-------------------------- 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: stable@vger.kernel.org Reviewed-by: Stefan Berger stefanb@linux.ibm.com Signed-off-by: Rob Landley rob@landley.net Signed-off-by: Stefan Berger stefanb@linux.ibm.com

---

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;
  

• }

}

2.41.0

Hi,

This is the friendly patch-bot of Greg Kroah-Hartman. You have sent him a patch that has triggered this response. He used to manually respond to these common problems, but in order to save his sanity (he kept writing the same thing over and over, yet to different people), I was created. Hopefully you will not take offence and will fix the problem in your patch and resubmit it so that it can be accepted into the Linux kernel tree.

You are receiving this message because of the following common error(s) as indicated below:

- This looks like a new version of a previously submitted patch, but you did not list below the --- line any changes from the previous version. Please read the section entitled "The canonical patch format" in the kernel file, Documentation/process/submitting-patches.rst for what needs to be done here to properly describe this.

If you wish to discuss this problem further, or you have questions about how to resolve this issue, please feel free to respond to this email and Greg will reply once he has dug out from the pending patches received from other developers.

thanks,

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