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>
diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
index 4300af6..ed1d8c7 100644
--- a/fs/pstore/inode.c
+++ b/fs/pstore/inode.c
@@ -49,6 +49,7 @@
struct pstore_info *psi;
enum pstore_type_id type;
u64 id;
+ int count;
ssize_t size;
char data[];
};
@@ -175,8 +176,8 @@
struct pstore_private *p = dentry->d_inode->i_private;
if (p->psi->erase)
- p->psi->erase(p->type, p->id, dentry->d_inode->i_ctime,
- p->psi);
+ p->psi->erase(p->type, p->id, p->count,
+ dentry->d_inode->i_ctime, p->psi);
return simple_unlink(dir, dentry);
}
@@ -271,7 +272,7 @@
* Load it up with "size" bytes of data from "buf".
* Set the mtime & ctime to the date that this record was originally stored.
*/
-int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id,
+int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id, int count,
char *data, size_t size, struct timespec time,
struct pstore_info *psi)
{
@@ -307,6 +308,7 @@
goto fail_alloc;
private->type = type;
private->id = id;
+ private->count = count;
private->psi = psi;
switch (type) {