[3.11.y.z extended stable] Patch "efi-pstore: Make efi-pstore return a unique id" has been added to staging queue

Luis Henriques luis.henriques at canonical.com
Wed Dec 11 14:41:14 UTC 2013


This is a note to let you know that I have just added a patch titled

    efi-pstore: Make efi-pstore return a unique id

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From fdef093f68a268b3c4c53443ad23ea240feb03e0 Mon Sep 17 00:00:00 2001
From: Madper Xie <cxie at redhat.com>
Date: Fri, 29 Nov 2013 15:58:57 +0800
Subject: efi-pstore: Make efi-pstore return a unique id

commit fdeadb43fdf1e7d5698c027b555c389174548e5a upstream.

Pstore fs expects that backends provide a unique id which could avoid
pstore making entries as duplication or denominating entries the same
name. So I combine the timestamp, part and count into id.

Signed-off-by: Madper Xie <cxie at redhat.com>
Cc: Seiji Aguchi <seiji.aguchi at hds.com>
Signed-off-by: Matt Fleming <matt.fleming at intel.com>
[ luis: backported to 3.11: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/firmware/efi/efi-pstore.c | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/drivers/firmware/efi/efi-pstore.c b/drivers/firmware/efi/efi-pstore.c
index 9ff01c4..b438a3a 100644
--- a/drivers/firmware/efi/efi-pstore.c
+++ b/drivers/firmware/efi/efi-pstore.c
@@ -36,6 +36,12 @@ struct pstore_read_data {
 	char **buf;
 };

+static inline u64 generic_id(unsigned long timestamp,
+			     unsigned int part, int count)
+{
+	return (timestamp * 100 + part) * 1000 + count;
+}
+
 static int efi_pstore_read_func(struct efivar_entry *entry, void *data)
 {
 	efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
@@ -54,7 +60,7 @@ static int efi_pstore_read_func(struct efivar_entry *entry, void *data)

 	if (sscanf(name, "dump-type%u-%u-%d-%lu",
 		   cb_data->type, &part, &cnt, &time) == 4) {
-		*cb_data->id = part;
+		*cb_data->id = generic_id(time, part, cnt);
 		*cb_data->count = cnt;
 		cb_data->timespec->tv_sec = time;
 		cb_data->timespec->tv_nsec = 0;
@@ -65,7 +71,7 @@ static int efi_pstore_read_func(struct efivar_entry *entry, void *data)
 		 * which doesn't support holding
 		 * multiple logs, remains.
 		 */
-		*cb_data->id = part;
+		*cb_data->id = generic_id(time, part, 0);
 		*cb_data->count = 0;
 		cb_data->timespec->tv_sec = time;
 		cb_data->timespec->tv_nsec = 0;
@@ -305,14 +311,16 @@ static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count,
 	char name[DUMP_NAME_LEN];
 	efi_char16_t efi_name[DUMP_NAME_LEN];
 	int found, i;
+	unsigned int part;

-	sprintf(name, "dump-type%u-%u-%d-%lu", type, (unsigned int)id, count,
-		time.tv_sec);
+	do_div(id, 1000);
+	part = do_div(id, 100);
+	sprintf(name, "dump-type%u-%u-%d-%lu", type, part, count, time.tv_sec);

 	for (i = 0; i < DUMP_NAME_LEN; i++)
 		efi_name[i] = name[i];

-	edata.id = id;
+	edata.id = part;
 	edata.type = type;
 	edata.count = count;
 	edata.time = time;
--
1.8.3.2





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