[Qemu-devel] Re: [PATCH 1/4] block: clarify the meaning of BDRV_O_NOCACHE

[Stefan Hajnoczi]

On Tue, Mar 15, 2011 at 2:11 PM, Christoph Hellwig <address@hidden> wrote:
> Change BDRV_O_NOCACHE to only imply bypassing the host OS file cache,
> but no writeback semantics.  All existing callers are changed to also
> specify BDRV_O_CACHE_WB to give them writeback semantics.
>
> Signed-off-by: Christoph Hellwig <address@hidden>

I think there is one hunk missing:
diff --git a/block/qcow2.c b/block/qcow2.c
index 75b8bec..db1931b 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -229,7 +229,7 @@ static int qcow2_open(BlockDriverState *bs, int flags)
     }

     /* alloc L2 table/refcount block cache */
-    writethrough = ((flags & BDRV_O_CACHE_MASK) == 0);
+    writethrough = ((flags & (BDRV_O_CACHE_WB | BDRV_O_NO_FLUSH)) == 0);
     s->l2_table_cache = qcow2_cache_create(bs, L2_CACHE_SIZE, writethrough);
     s->refcount_block_cache = qcow2_cache_create(bs, REFCOUNT_CACHE_SIZE,
         writethrough);

Stefan