Re: [RFC,PATCH v2] efi: Add support for a UEFI variable filesystem

From: joeyli
Date: Fri Sep 14 2012 - 22:49:28 EST


æ åï2012-09-13 æ 21:41 -0700ïH. Peter Anvin æåï
> On 09/13/2012 08:45 PM, joeyli wrote:
> > Hi Peter,
> >
> > æ åï2012-09-13 æ 09:52 -0400ïPeter Jones æåï
> >> On Thu, 2012-09-13 at 16:10 +0800, joeyli wrote:
> >>
> >>> Do we have plan to create a new kobject add to /sys/firmware/efi for
> >>> provide a fixed mount point to efivars fs?
> >>> e.g. /sys/firmware/efi/efivars
> >>>
> >>> Or we just direct reuse current /sys/firmeware/efi/vars? But, that means
> >>> we need think for the backward compatibility if choice reuse vars
> >>> folder.
> >>
> >> I'm not sure that's a terribly large concern - if you haven't updated
> >> your tools to use the new efivars, don't mount the new efivars.
> >>
> >
> > Thanks for your comment!
> >
>
> I think it is wrong. The new API should have a different path.
>
> -hpa
>

OK, so, if still keep the old API and have new mount point for UEFI
variable filesystem. Then how about add this simple patch for create new
mount point to /sys/firmware/efi/efivars.


Thanks a lot!
Joey Lee


>From 5e64382a9a4ad538dd5ca94072d19c7a70e4c650 Mon Sep 17 00:00:00 2001
From: Lee, Chun-Yi <jlee@xxxxxxxx>
Date: Sat, 15 Sep 2012 10:33:46 +0800
Subject: [PATCH] efi: add efivars kobject to efi sysfs folder

UEFI variable filesystem need a new mount point, so this patch add
efivars kobject to efi_kobj for create a /sys/firmware/efi/efivars
folder.

Signed-off-by: Lee, Chun-Yi <jlee@xxxxxxxx>
---
drivers/firmware/efivars.c | 11 +++++++++++
include/linux/efi.h | 1 +
2 files changed, 12 insertions(+), 0 deletions(-)

diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c
index 1e1aad0..7c1234e 100644
--- a/drivers/firmware/efivars.c
+++ b/drivers/firmware/efivars.c
@@ -1487,6 +1487,7 @@ void unregister_efivars(struct efivars *efivars)
sysfs_remove_bin_file(&efivars->kset->kobj, efivars->del_var);
kfree(efivars->new_var);
kfree(efivars->del_var);
+ kobject_put(efivars->kobject);
kset_unregister(efivars->kset);
}
EXPORT_SYMBOL_GPL(unregister_efivars);
@@ -1518,6 +1519,13 @@ int register_efivars(struct efivars *efivars,
goto out;
}

+ efivars->kobject = kobject_create_and_add("efivars", parent_kobj);
+ if (!efivars->kobject) {
+ pr_err("efivars: Subsystem registration failed.\n");
+ error = -ENOMEM;
+ goto err_unreg_vars;
+ }
+
/*
* Per EFI spec, the maximum storage allocated for both
* the variable name and variable data is 1024 bytes.
@@ -1562,6 +1570,9 @@ int register_efivars(struct efivars *efivars,

register_filesystem(&efivars_fs_type);

+err_unreg_vars:
+ kset_unregister(efivars->kset);
+
out:
kfree(variable_name);

diff --git a/include/linux/efi.h b/include/linux/efi.h
index 1829a97..c993f54 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -654,6 +654,7 @@ struct efivars {
spinlock_t lock;
struct list_head list;
struct kset *kset;
+ struct kobject *kobject;
struct bin_attribute *new_var, *del_var;
const struct efivar_operations *ops;
struct efivar_entry *walk_entry;
--
1.7.7



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