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: stable@vger.kernel.org Reviewed-by: Stefan Berger stefanb@linux.ibm.com
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/8244c75f-445e-b15b-9dbf-266e7ca666e2@landley.ne...
Signed-off-by: Rob Landley rob@landley.net Signed-off-by: Stefan Berger stefanb@linux.ibm.com
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 zohar@linux.ibm.com