From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57316) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ciRdL-00007D-JP for qemu-devel@nongnu.org; Mon, 27 Feb 2017 15:11:00 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ciRdK-0003Xy-J7 for qemu-devel@nongnu.org; Mon, 27 Feb 2017 15:10:59 -0500 From: Kevin Wolf Date: Mon, 27 Feb 2017 21:09:24 +0100 Message-Id: <1488226184-9044-24-git-send-email-kwolf@redhat.com> In-Reply-To: <1488226184-9044-1-git-send-email-kwolf@redhat.com> References: <1488226184-9044-1-git-send-email-kwolf@redhat.com> Subject: [Qemu-devel] [PATCH v2 23/43] block: Add BdrvChildRole.stay_at_node List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org Cc: kwolf@redhat.com, mreitz@redhat.com, jcody@redhat.com, famz@redhat.com, qemu-devel@nongnu.org When the parents' child links are updated in bdrv_append() or bdrv_replace_in_backing_chain(), this should affect all child links of BlockBackends or other nodes, but not on child links held for other purposes (like for setting permissions). This patch allows to control the behaviour per BdrvChildRole. Signed-off-by: Kevin Wolf Reviewed-by: Max Reitz --- block.c | 3 +++ include/block/block_int.h | 4 ++++ 2 files changed, 7 insertions(+) diff --git a/block.c b/block.c index a0c1886..6456917 100644 --- a/block.c +++ b/block.c @@ -2844,6 +2844,9 @@ static void change_parent_backing_link(BlockDriverState *from, BdrvChild *c, *next, *to_c; QLIST_FOREACH_SAFE(c, &from->parents, next_parent, next) { + if (c->role->stay_at_node) { + continue; + } if (c->role == &child_backing) { /* @from is generally not allowed to be a backing file, except for * when @to is the overlay. In that case, @from may not be replaced diff --git a/include/block/block_int.h b/include/block/block_int.h index 3177b9f..a0d9328 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -441,6 +441,10 @@ typedef struct BdrvAioNotifier { } BdrvAioNotifier; struct BdrvChildRole { + /* If true, bdrv_replace_in_backing_chain() doesn't change the node this + * BdrvChild points to. */ + bool stay_at_node; + void (*inherit_options)(int *child_flags, QDict *child_options, int parent_flags, QDict *parent_options); -- 1.8.3.1