[Qemu-devel] [PATCH] block-raw: Make cache=off default again

[Kevin Wolf <kwolf@redhat.com>]

Since the patch that suggested it woudl revert qcow2 to writeback caching, in
fact none of the drivers has had cache=off as default any more. This patch
restores the desired behaviour.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/raw-posix.c |    4 ++++
 block/raw-win32.c |    8 ++++++++
 2 files changed, 12 insertions(+), 0 deletions(-)

diff --git a/block/raw-posix.c b/block/raw-posix.c
index fa1a394..513e8e8 100644
--- a/block/raw-posix.c
+++ b/block/raw-posix.c
@@ -143,6 +143,10 @@ static int raw_open_common(BlockDriverState *bs, const char *filename,
 
     /* Use O_DSYNC for write-through caching, no flags for write-back caching,
      * and O_DIRECT for no caching. */
+    if (bdrv_flags & BDRV_O_CACHE_DEF) {
+        bdrv_flags = (bdrv_flags & ~BDRV_O_CACHE_MASK) | BDRV_O_NOCACHE;
+    }
+
     if ((bdrv_flags & BDRV_O_NOCACHE))
         s->open_flags |= O_DIRECT;
     else if (!(bdrv_flags & BDRV_O_CACHE_WB))
diff --git a/block/raw-win32.c b/block/raw-win32.c
index 72acad5..5da957c 100644
--- a/block/raw-win32.c
+++ b/block/raw-win32.c
@@ -92,6 +92,10 @@ static int raw_open(BlockDriverState *bs, const char *filename, int flags)
         create_flags = OPEN_EXISTING;
     }
     overlapped = FILE_ATTRIBUTE_NORMAL;
+
+    if (flags & BDRV_O_CACHE_DEF) {
+        flags = (flags & ~BDRV_O_CACHE_MASK) | BDRV_O_NOCACHE;
+    }
     if ((flags & BDRV_O_NOCACHE))
         overlapped |= FILE_FLAG_NO_BUFFERING | FILE_FLAG_WRITE_THROUGH;
     else if (!(flags & BDRV_O_CACHE_WB))
@@ -345,6 +349,10 @@ static int hdev_open(BlockDriverState *bs, const char *filename, int flags)
     create_flags = OPEN_EXISTING;
 
     overlapped = FILE_ATTRIBUTE_NORMAL;
+
+    if (flags & BDRV_O_CACHE_DEF) {
+        flags = (flags & ~BDRV_O_CACHE_MASK) | BDRV_O_NOCACHE;
+    }
     if ((flags & BDRV_O_NOCACHE))
         overlapped |= FILE_FLAG_NO_BUFFERING | FILE_FLAG_WRITE_THROUGH;
     else if (!(flags & BDRV_O_CACHE_WB))
-- 
1.6.0.6