Messages in this thread Patch in this message | | | From | Stefan Berger <> | Subject | [PATCH] rootfs: Fix support for rootfstype= when root= is given | Date | Mon, 13 Nov 2023 16:17:35 -0500 |
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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") 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
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