From 104b615079bd33ad75d9d3da62818a1ee6a32a7e Mon Sep 17 00:00:00 2001
From: Matthew Garrett <mjg@redhat.com>
Date: Thu, 21 Jul 2011 16:57:55 -0400
Subject: [PATCH] --- yaml --- r: 262014 b: refs/heads/master c:
 dee28e72b619b48ec80a9e5509db458dbe66f71f h: refs/heads/master v: v3

---
 [refs]                                    |  2 +-
 trunk/Documentation/ABI/testing/pstore    |  6 ++++++
 trunk/Documentation/kernel-parameters.txt |  2 ++
 trunk/fs/pstore/platform.c                | 11 +++++++++++
 4 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index d79827d85072..eb1421b97d6b 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: b94fdd077eef5e6cab56836bf62695b497946716
+refs/heads/master: dee28e72b619b48ec80a9e5509db458dbe66f71f
diff --git a/trunk/Documentation/ABI/testing/pstore b/trunk/Documentation/ABI/testing/pstore
index ddf451ee2a08..ff1df4e3b059 100644
--- a/trunk/Documentation/ABI/testing/pstore
+++ b/trunk/Documentation/ABI/testing/pstore
@@ -39,3 +39,9 @@ Description:	Generic interface to platform dependent persistent storage.
 		multiple) files based on the record size of the underlying
 		persistent storage until at least this amount is reached.
 		Default is 10 Kbytes.
+
+		Pstore only supports one backend at a time. If multiple
+		backends are available, the preferred backend may be
+		set by passing the pstore.backend= argument to the kernel at
+		boot time.
+
diff --git a/trunk/Documentation/kernel-parameters.txt b/trunk/Documentation/kernel-parameters.txt
index aa47be71df4c..8789d0c9291a 100644
--- a/trunk/Documentation/kernel-parameters.txt
+++ b/trunk/Documentation/kernel-parameters.txt
@@ -2151,6 +2151,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 			[HW,MOUSE] Controls Logitech smartscroll autorepeat.
 			0 = disabled, 1 = enabled (default).
 
+	pstore.backend=	Specify the name of the pstore backend to use
+
 	pt.		[PARIDE]
 			See Documentation/blockdev/paride.txt.
 
diff --git a/trunk/fs/pstore/platform.c b/trunk/fs/pstore/platform.c
index 49ff1de2178a..c5300ec31696 100644
--- a/trunk/fs/pstore/platform.c
+++ b/trunk/fs/pstore/platform.c
@@ -37,6 +37,8 @@
 static DEFINE_SPINLOCK(pstore_lock);
 static struct pstore_info *psinfo;
 
+static char *backend;
+
 /* How much of the console log to snapshot */
 static unsigned long kmsg_bytes = 10240;
 
@@ -131,6 +133,12 @@ int pstore_register(struct pstore_info *psi)
 		spin_unlock(&pstore_lock);
 		return -EBUSY;
 	}
+
+	if (backend && strcmp(backend, psi->name)) {
+		spin_unlock(&pstore_lock);
+		return -EINVAL;
+	}
+
 	psinfo = psi;
 	spin_unlock(&pstore_lock);
 
@@ -208,3 +216,6 @@ int pstore_write(enum pstore_type_id type, char *buf, size_t size)
 	return 0;
 }
 EXPORT_SYMBOL_GPL(pstore_write);
+
+module_param(backend, charp, 0444);
+MODULE_PARM_DESC(backend, "Pstore backend to use");