From ba705a7f769b80c3ac38e31db0e3cac003fa1052 Mon Sep 17 00:00:00 2001
From: Anton Vorontsov <anton.vorontsov@linaro.org>
Date: Sat, 26 May 2012 06:07:49 -0700
Subject: [PATCH] --- yaml --- r: 311159 b: refs/heads/master c:
 201e4aca5aa179e6c69a4dcd36a3562e56b8d670 h: refs/heads/master i:   311157:
 8a09ffddba059c2cfc08bf686d49d4ab87caf97a   311155:
 5b02d97e14dd485fbfc0aff109eda85c5720b8a0   311151:
 3222b2bddc92fbf2b4e08df67891c288da8114a5 v: v3

---
 [refs]                           |  2 +-
 trunk/fs/pstore/ram.c            |  2 ++
 trunk/fs/pstore/ram_core.c       | 15 ++++++++-------
 trunk/include/linux/pstore_ram.h |  1 +
 4 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/[refs] b/[refs]
index e28f171a2de7..6dab8c015151 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 33735a94afdfb39c550b952a40f77c60afdddfa5
+refs/heads/master: 201e4aca5aa179e6c69a4dcd36a3562e56b8d670
diff --git a/trunk/fs/pstore/ram.c b/trunk/fs/pstore/ram.c
index 9123cce28c1e..16ff7332eae0 100644
--- a/trunk/fs/pstore/ram.c
+++ b/trunk/fs/pstore/ram.c
@@ -106,6 +106,8 @@ static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
 	time->tv_sec = 0;
 	time->tv_nsec = 0;
 
+	/* Update old/shadowed buffer. */
+	persistent_ram_save_old(prz);
 	size = persistent_ram_old_size(prz);
 	*buf = kmalloc(size, GFP_KERNEL);
 	if (*buf == NULL)
diff --git a/trunk/fs/pstore/ram_core.c b/trunk/fs/pstore/ram_core.c
index 31f8d184f3a0..235513c46aaf 100644
--- a/trunk/fs/pstore/ram_core.c
+++ b/trunk/fs/pstore/ram_core.c
@@ -250,23 +250,24 @@ static void notrace persistent_ram_update(struct persistent_ram_zone *prz,
 	persistent_ram_update_ecc(prz, start, count);
 }
 
-static void __init
-persistent_ram_save_old(struct persistent_ram_zone *prz)
+void persistent_ram_save_old(struct persistent_ram_zone *prz)
 {
 	struct persistent_ram_buffer *buffer = prz->buffer;
 	size_t size = buffer_size(prz);
 	size_t start = buffer_start(prz);
-	char *dest;
 
-	persistent_ram_ecc_old(prz);
+	if (!size)
+		return;
 
-	dest = kmalloc(size, GFP_KERNEL);
-	if (dest == NULL) {
+	if (!prz->old_log) {
+		persistent_ram_ecc_old(prz);
+		prz->old_log = kmalloc(size, GFP_KERNEL);
+	}
+	if (!prz->old_log) {
 		pr_err("persistent_ram: failed to allocate buffer\n");
 		return;
 	}
 
-	prz->old_log = dest;
 	prz->old_log_size = size;
 	memcpy(prz->old_log, &buffer->data[start], size - start);
 	memcpy(prz->old_log + size - start, &buffer->data[0], start);
diff --git a/trunk/include/linux/pstore_ram.h b/trunk/include/linux/pstore_ram.h
index 7ed7fd4dba49..4491e8ff36e6 100644
--- a/trunk/include/linux/pstore_ram.h
+++ b/trunk/include/linux/pstore_ram.h
@@ -75,6 +75,7 @@ struct persistent_ram_zone *persistent_ram_init_ringbuffer(struct device *dev,
 int persistent_ram_write(struct persistent_ram_zone *prz, const void *s,
 	unsigned int count);
 
+void persistent_ram_save_old(struct persistent_ram_zone *prz);
 size_t persistent_ram_old_size(struct persistent_ram_zone *prz);
 void *persistent_ram_old(struct persistent_ram_zone *prz);
 void persistent_ram_free_old(struct persistent_ram_zone *prz);