From: Ben Hutchings <ben@decadent.org.uk>
Date: Sat, 23 Mar 2013 03:49:53 +0000 (+0000)
Subject: efivars: pstore: Do not check size when erasing variable
X-Git-Tag: v3.4.92~76
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=1c4e6e91fec88f6a544259d5d536991e0a41f5e3;p=platform%2Fkernel%2Flinux-stable.git

efivars: pstore: Do not check size when erasing variable

commit 80a19debc2f2d398cfa57fae97bc99826748a602 upstream.

In 3.2, unlike mainline, efi_pstore_erase() calls efi_pstore_write()
with a size of 0, as the underlying EFI interface treats a size of 0
as meaning deletion.

This was not taken into account in my backport of commit d80a361d779a
'efi_pstore: Check remaining space with QueryVariableInfo() before
writing data'.  The size check should be omitted when erasing.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Rui Xiang <rui.xiang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c
index c3ac356..787cd2f 100644
--- a/drivers/firmware/efivars.c
+++ b/drivers/firmware/efivars.c
@@ -778,19 +778,21 @@ static int efi_pstore_write(enum pstore_type_id type,
 
 	spin_lock_irqsave(&efivars->lock, flags);
 
-	/*
-	 * Check if there is a space enough to log.
-	 * size: a size of logging data
-	 * DUMP_NAME_LEN * 2: a maximum size of variable name
-	 */
-
-	status = check_var_size_locked(efivars, PSTORE_EFI_ATTRIBUTES,
-					 size + DUMP_NAME_LEN * 2);
-
-	if (status) {
-		spin_unlock_irqrestore(&efivars->lock, flags);
-		*id = part;
-		return -ENOSPC;
+	if (size) {
+		/*
+		 * Check if there is a space enough to log.
+		 * size: a size of logging data
+		 * DUMP_NAME_LEN * 2: a maximum size of variable name
+		 */
+
+		status = check_var_size_locked(efivars, PSTORE_EFI_ATTRIBUTES,
+					       size + DUMP_NAME_LEN * 2);
+
+		if (status) {
+			spin_unlock_irqrestore(&efivars->lock, flags);
+			*id = part;
+			return -ENOSPC;
+		}
 	}
 
 	for (i = 0; i < DUMP_NAME_LEN; i++)