[Qemu-devel] [PATCH 2/2] block: Handle cache=unsafe only in raw-posix/win32

[Kevin Wolf <kwolf@redhat.com>]

The expected meaning of cache=unsafe with qcow2 is that on a flush the metadata
caches are written out, but no fsync is performed.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block.c           |    4 +---
 block/raw-posix.c |    4 ++++
 block/raw-win32.c |    4 ++++
 3 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/block.c b/block.c
index 11c7f91..0b7bc06 100644
--- a/block.c
+++ b/block.c
@@ -2908,9 +2908,7 @@ static void coroutine_fn bdrv_flush_co_entry(void *opaque)
 
 int coroutine_fn bdrv_co_flush(BlockDriverState *bs)
 {
-    if (bs->open_flags & BDRV_O_NO_FLUSH) {
-        return 0;
-    } else if (!bs->drv) {
+    if (!bs->drv) {
         return 0;
     } else if (bs->drv->bdrv_co_flush) {
         return bs->drv->bdrv_co_flush(bs);
diff --git a/block/raw-posix.c b/block/raw-posix.c
index dcae88a..9a3d3af 100644
--- a/block/raw-posix.c
+++ b/block/raw-posix.c
@@ -380,6 +380,10 @@ static int raw_co_flush(BlockDriverState *bs)
         .coroutine = qemu_coroutine_self(),
     };
 
+    if (bs->open_flags & BDRV_O_NO_FLUSH) {
+        return 0;
+    }
+
     ret = fd_open(bs);
     if (ret < 0) {
         return ret;
diff --git a/block/raw-win32.c b/block/raw-win32.c
index f5f73bc..37a8bdb 100644
--- a/block/raw-win32.c
+++ b/block/raw-win32.c
@@ -156,6 +156,10 @@ static int raw_flush(BlockDriverState *bs)
     BDRVRawState *s = bs->opaque;
     int ret;
 
+    if (bs->open_flags & BDRV_O_NO_FLUSH) {
+        return 0;
+    }
+
     ret = FlushFileBuffers(s->hfile);
     if (ret == 0) {
         return -EIO;
-- 
1.7.6.4