SHA256
1
0
forked from pool/qemu
qemu/0043-qcow2-Set-MIN_L2_CACHE_SIZE-to-2.patch

32 lines
1.0 KiB
Diff

From 85bd20ed57493f867626fd7d5fa073b4476ae301 Mon Sep 17 00:00:00 2001
From: Max Reitz <mreitz@redhat.com>
Date: Mon, 1 Jun 2015 18:09:17 +0200
Subject: [PATCH] qcow2: Set MIN_L2_CACHE_SIZE to 2
The L2 cache must cover at least two L2 tables, because during COW two
L2 tables are accessed simultaneously.
Reported-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Tested-by: Alexander Graf <agraf@suse.de>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
---
block/qcow2.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/block/qcow2.h b/block/qcow2.h
index 422b825..2f20949 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -62,7 +62,8 @@
#define MIN_CLUSTER_BITS 9
#define MAX_CLUSTER_BITS 21
-#define MIN_L2_CACHE_SIZE 1 /* cluster */
+/* Must be at least 2 to cover COW */
+#define MIN_L2_CACHE_SIZE 2 /* clusters */
/* Must be at least 4 to cover all cases of refcount table growth */
#define MIN_REFCOUNT_CACHE_SIZE 4 /* clusters */