efi_pstore: Add ctime to argument of erase callback
authorSeiji Aguchi <seiji.aguchi@hds.com>
Wed, 14 Nov 2012 20:27:28 +0000 (20:27 +0000)
committerTony Luck <tony.luck@intel.com>
Tue, 27 Nov 2012 00:02:12 +0000 (16:02 -0800)
commita9efd39cd547223597cfe7c53acec44c099b9264
tree293feed9e89d811235371d389f7787eddf2899e1
parent96480d9c8fcfd7e325e9be6a6c6846689707f8e0
efi_pstore: Add ctime to argument of erase callback

[Issue]

Currently, a variable name, which is used to identify each log entry, consists of type,
id and ctime. But an erase callback does not use ctime.

If efi_pstore supported just one log, type and id were enough.
However, in case of supporting multiple logs, it doesn't work because
it can't distinguish each entry without ctime at erasing time.

 <Example>

 As you can see below, efi_pstore can't differentiate first event from second one without ctime.

 a variable name of first event: dump-type0-1-12345678
 a variable name of second event: dump-type0-1-23456789

  type:0
  id:1
  ctime:12345678, 23456789

[Solution]

This patch adds ctime to an argument of an erase callback.

It works across reboots because ctime of pstore means the date that the record was originally stored.
To do this, efi_pstore saves the ctime to variable name at writing time and passes it to pstore
at reading time.

Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com>
Acked-by: Mike Waychison <mikew@google.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
drivers/acpi/apei/erst.c
drivers/firmware/efivars.c
fs/pstore/inode.c
fs/pstore/ram.c
include/linux/pstore.h