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efi_pstore: Add a sequence counter to a variable name

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[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>
This commit is contained in:
Seiji Aguchi
2012-11-26 16:07:44 -08:00
committed by Tony Luck
parent a9efd39cd5
commit 755d4fe465
7 changed files with 41 additions and 32 deletions
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8
fs/pstore/inode.c
View File

@@ -49,6 +49,7 @@ struct pstore_private {
struct pstore_info *psi;
enum pstore_type_id type;
u64 id;
int count;
ssize_t size;
char data[];
};
@@ -175,8 +176,8 @@ static int pstore_unlink(struct inode *dir, struct dentry *dentry)
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 @@ int pstore_is_mounted(void)
* 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 @@ int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id,
goto fail_alloc;
private->type = type;
private->id = id;
private->count = count;
private->psi = psi;
switch (type) {