5.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Stefan Berger <stefanb@xxxxxxxxxxxxx>
commit 21528c69a0d8483f7c6345b1a0bc8d8975e9a172 upstream.
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 rootfstype= is ignored. Therefore,
ramfs is currently always chosen when root= is provided.
The current behavior for rootfs's filesystem is:
root= | rootfstype= | chosen rootfs filesystem
------------+-------------+--------------------------
unspecified | unspecified | tmpfs
unspecified | tmpfs | tmpfs
unspecified | ramfs | ramfs
provided | ignored | ramfs
rootfstype= should be respected regardless whether root= is given,
as shown below:
root= | rootfstype= | 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@xxxxxxxxxxxxxxx>
Signed-off-by: Rob Landley <rob@xxxxxxxxxxx>
Link: https://lore.kernel.org/lkml/8244c75f-445e-b15b-9dbf-266e7ca666e2@xxxxxxxxxxx/
Reviewed-and-Tested-by: Mimi Zohar <zohar@xxxxxxxxxxxxx>
Signed-off-by: Stefan Berger <stefanb@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20231120011248.396012-1-stefanb@xxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
init/do_mounts.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
--- a/init/do_mounts.c
+++ b/init/do_mounts.c
@@ -643,7 +643,10 @@ 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;
+ }
}
