efi: Add comment to avoid future expanding of sysfs systab

/sys/firmware/efi/systab shows several different values, it breaks sysfs
one file one value design.  But since there are already userspace tools
depend on it eg. kexec-tools so add code comment to alert future expanding
of this file.

Signed-off-by: Dave Young <[email protected]>
Signed-off-by: Ard Biesheuvel <[email protected]>
Reviewed-by: Greg Kroah-Hartman <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Matt Fleming <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index c3eefa126e3b0c9ee549fb1c2e077d1e3d19bfc1..557a47829d03f2b14b0c3b664e1044e7e2cb86bc 100644 (file)
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -109,6 +109,8 @@ struct kobject *efi_kobj;
 /*
  * Let's not leave out systab information that snuck into
  * the efivars driver
+ * Note, do not add more fields in systab sysfs file as it breaks sysfs
+ * one value per file rule!
  */
 static ssize_t systab_show(struct kobject *kobj,
                           struct kobj_attribute *attr, char *buf)