From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55880) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z5VSG-0004l7-Cs for qemu-devel@nongnu.org; Thu, 18 Jun 2015 04:45:52 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Z5VSE-00044j-SA for qemu-devel@nongnu.org; Thu, 18 Jun 2015 04:45:48 -0400 From: Wen Congyang Date: Thu, 18 Jun 2015 16:49:11 +0800 Message-ID: <1434617361-17778-7-git-send-email-wency@cn.fujitsu.com> In-Reply-To: <1434617361-17778-1-git-send-email-wency@cn.fujitsu.com> References: <1434617361-17778-1-git-send-email-wency@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain Subject: [Qemu-devel] [PATCH COLO-Block v6 06/16] Don't allow a disk use backing reference target List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu devel , Fam Zheng , Max Reitz , Paolo Bonzini Cc: Kevin Wolf , qemu block , Lai Jiangshan , Jiang Yunhong , Dong Eddie , "Dr. David Alan Gilbert" , Gonglei , Stefan Hajnoczi , Yang Hongyang , zhanghailiang Signed-off-by: Wen Congyang Signed-off-by: zhanghailiang Signed-off-by: Gonglei --- block.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/block.c b/block.c index d1ed227..0b41af4 100644 --- a/block.c +++ b/block.c @@ -1294,6 +1294,14 @@ static int bdrv_open_backing_reference_file(BlockDriverState *bs, } backing_hd = blk_bs(backing_blk); + /* Don't allow a disk use backing reference target */ + ret = blk_attach_dev(backing_hd->blk, bs); + if (ret < 0) { + error_setg(errp, "backing_hd %s is used by the other device model", + backing_name); + goto free_exit; + } + /* Backing reference itself? */ if (backing_hd == bs || bdrv_find_overlay(backing_hd, bs)) { error_setg(errp, "Backing reference itself"); @@ -2037,6 +2045,7 @@ void bdrv_close(BlockDriverState *bs) if (backing_hd->backing_hd->job) { block_job_cancel(backing_hd->backing_hd->job); } + blk_detach_dev(backing_hd->backing_hd->blk, bs); bdrv_set_backing_hd(backing_hd, NULL); bdrv_unref(backing_hd->backing_hd); } -- 2.4.3