efi_pstore: Add a sequence counter to a variable name

[Issue]

Currently, a variable name, which identifies each entry, consists of type, id and ctime.
But if multiple events happens in a short time, a second/third event may fail to log because
efi_pstore can't distinguish each event with current variable name.

[Solution]

A reasonable way to identify all events precisely is introducing a sequence counter to
the variable name.

The sequence counter has already supported in a pstore layer with "oopscount".
So, this patch adds it to a variable name.
Also, it is passed to read/erase callbacks of platform drivers in accordance with
the modification of the variable name.

  <before applying this patch>
 a variable name of first event: dump-type0-1-12345678
 a variable name of second event: dump-type0-1-12345678

  type:0
  id:1
  ctime:12345678

 If multiple events happen in a short time, efi_pstore can't distinguish them because
 variable names are same among them.

  <after applying this patch>

 it can be distinguishable by adding a sequence counter as follows.

 a variable name of first event: dump-type0-1-1-12345678
 a variable name of Second event: dump-type0-1-2-12345678

  type:0
  id:1
  sequence counter: 1(first event), 2(second event)
  ctime:12345678

In case of a write callback executed in pstore_console_write(), "0" is added to
an argument of the write callback because it just logs all kernel messages and
doesn't need to care about multiple events.

Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Mike Waychison <mikew@google.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/fs/pstore/internal.h b/fs/pstore/internal.h
index 4847f588b7d5..937d820f273c 100644
--- a/fs/pstore/internal.h
+++ b/fs/pstore/internal.h
@@ -50,7 +50,7 @@ extern struct pstore_info *psinfo;
 extern void     pstore_set_kmsg_bytes(int);
 extern void     pstore_get_records(int);
 extern int      pstore_mkfile(enum pstore_type_id, char *psname, u64 id,
-                              char *data, size_t size,
+                              int count, char *data, size_t size,
                               struct timespec time, struct pstore_info *psi);
 extern int      pstore_is_mounted(void);