From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41834) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gHtBi-0008VE-TT for qemu-devel@nongnu.org; Wed, 31 Oct 2018 12:17:49 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gHtBf-0001Wq-3w for qemu-devel@nongnu.org; Wed, 31 Oct 2018 12:17:46 -0400 From: Alberto Garcia Date: Wed, 31 Oct 2018 18:16:36 +0200 Message-Id: Subject: [Qemu-devel] [PATCH 0/2] Update the inherits_from pointer after stream and commit List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Alberto Garcia , qemu-block@nongnu.org, Kevin Wolf , Max Reitz Hi all, when you open an image [A] with a few more images on the backing chain you get something like this: [E] <- [D] <- [C] <- [B] <- [A] Here you can go from [A] to [E] by following the bs->backing pointer. At the same time each one of the backing files has an 'inherits_from' attribute pointing to their parent, so you can go from [E] to [A] following the inherits_from pointer. 'inherits_from' is used on bdrv_reopen_queue_child() to decide if a node's children must be reopened together with the parent and inherit its options. If some the intermediate nodes are removed (either by block-stream or by block-commit) you end up with something like this: [E] <- [A] In this case we would expect [E] to inherit from [A], however its inherits_from pointer is NULL and trying to change its options by reopening [A] with backing.option=value fails. This patch series fixes this. See each individual patch for more details. Regards, Berto Alberto Garcia (2): block: Update BlockDriverState.inherits_from on bdrv_set_backing_hd() block: Update BlockDriverState.inherits_from on bdrv_drop_intermediate() block.c | 37 ++++++++++++ tests/qemu-iotests/161 | 137 +++++++++++++++++++++++++++++++++++++++++++++ tests/qemu-iotests/161.out | 39 +++++++++++++ tests/qemu-iotests/group | 1 + 4 files changed, 214 insertions(+) create mode 100755 tests/qemu-iotests/161 create mode 100644 tests/qemu-iotests/161.out -- 2.11.0