From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:39347) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T1e5p-0006fb-7I for qemu-devel@nongnu.org; Wed, 15 Aug 2012 09:57:06 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1T1e5o-0000R9-2p for qemu-devel@nongnu.org; Wed, 15 Aug 2012 09:57:05 -0400 Received: from mx1.redhat.com ([209.132.183.28]:57210) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T1e5n-0000R2-Qu for qemu-devel@nongnu.org; Wed, 15 Aug 2012 09:57:03 -0400 From: Kevin Wolf Date: Wed, 15 Aug 2012 15:56:42 +0200 Message-Id: <1345039003-19186-10-git-send-email-kwolf@redhat.com> In-Reply-To: <1345039003-19186-1-git-send-email-kwolf@redhat.com> References: <1345039003-19186-1-git-send-email-kwolf@redhat.com> Subject: [Qemu-devel] [PATCH 09/10] block: Flush parent to OS with cache=unsafe List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: anthony@codemonkey.ws Cc: kwolf@redhat.com, qemu-devel@nongnu.org Commit 29cdb251 already added a comment that no unnecessary flushes to disk will occur, this patch makes the code even get to the point of the comment. This is mostly theoretical because in practice we only stack one format on top of one protocol, the former implementing flush_to_os and the latter only flush_to_disk. It starts to matter when drivers that are not on top implement flush_to_os. Signed-off-by: Kevin Wolf Reviewed-by: Stefan Hajnoczi --- block.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/block.c b/block.c index 016858b..470bdcc 100644 --- a/block.c +++ b/block.c @@ -3534,7 +3534,7 @@ int coroutine_fn bdrv_co_flush(BlockDriverState *bs) /* But don't actually force it to the disk with cache=unsafe */ if (bs->open_flags & BDRV_O_NO_FLUSH) { - return 0; + goto flush_parent; } if (bs->drv->bdrv_co_flush_to_disk) { @@ -3573,6 +3573,7 @@ int coroutine_fn bdrv_co_flush(BlockDriverState *bs) /* Now flush the underlying protocol. It will also have BDRV_O_NO_FLUSH * in the case of cache=unsafe, so there are no useless flushes. */ +flush_parent: return bdrv_co_flush(bs->file); } -- 1.7.6.5