From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35352) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a2CCG-0006Od-AK for qemu-devel@nongnu.org; Fri, 27 Nov 2015 01:07:53 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1a2CCF-0006We-7v for qemu-devel@nongnu.org; Fri, 27 Nov 2015 01:07:52 -0500 From: Wen Congyang Date: Fri, 27 Nov 2015 14:06:35 +0800 Message-ID: <1448604397-14975-2-git-send-email-wency@cn.fujitsu.com> In-Reply-To: <1448604397-14975-1-git-send-email-wency@cn.fujitsu.com> References: <1448604397-14975-1-git-send-email-wency@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain Subject: [Qemu-devel] [Patch v8 1/3] Add new block driver interface to add/delete a BDS's child List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu devel , Eric Blake , Alberto Garcia , Kevin Wolf , Stefan Hajnoczi Cc: qemu block , Jiang Yunhong , Dong Eddie , Markus Armbruster , "Dr. David Alan Gilbert" , Gonglei , zhanghailiang In some cases, we want to take a quorum child offline, and take another child online. Signed-off-by: Wen Congyang Signed-off-by: zhanghailiang Signed-off-by: Gonglei Reviewed-by: Eric Blake Reviewed-by: Alberto Garcia --- block.c | 50 +++++++++++++++++++++++++++++++++++++++++++++++ include/block/block.h | 5 +++++ include/block/block_int.h | 5 +++++ 3 files changed, 60 insertions(+) diff --git a/block.c b/block.c index 60ff84f..255a36e 100644 --- a/block.c +++ b/block.c @@ -4321,3 +4321,53 @@ void bdrv_refresh_filename(BlockDriverState *bs) QDECREF(json); } } + +/* + * Hot add/remove a BDS's child. So the user can take a child offline when + * it is broken and take a new child online + */ +void bdrv_add_child(BlockDriverState *parent_bs, BlockDriverState *child_bs, + Error **errp) +{ + + if (!parent_bs->drv || !parent_bs->drv->bdrv_add_child) { + error_setg(errp, "The node %s doesn't support adding a child", + bdrv_get_device_or_node_name(parent_bs)); + return; + } + + if (!QLIST_EMPTY(&child_bs->parents)) { + error_setg(errp, "The node %s already has a parent", + child_bs->node_name); + return; + } + + parent_bs->drv->bdrv_add_child(parent_bs, child_bs, errp); +} + +void bdrv_del_child(BlockDriverState *parent_bs, BlockDriverState *child_bs, + Error **errp) +{ + BdrvChild *child; + + if (!parent_bs->drv || !parent_bs->drv->bdrv_del_child) { + error_setg(errp, "The node %s doesn't support removing a child", + bdrv_get_device_or_node_name(parent_bs)); + return; + } + + QLIST_FOREACH(child, &parent_bs->children, next) { + if (child->bs == child_bs) { + break; + } + } + + if (!child) { + error_setg(errp, "The node %s is not a child of %s", + bdrv_get_device_or_node_name(child_bs), + bdrv_get_device_or_node_name(parent_bs)); + return; + } + + parent_bs->drv->bdrv_del_child(parent_bs, child_bs, errp); +} diff --git a/include/block/block.h b/include/block/block.h index d9b380c..06d3369 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -639,4 +639,9 @@ void bdrv_drained_begin(BlockDriverState *bs); */ void bdrv_drained_end(BlockDriverState *bs); +void bdrv_add_child(BlockDriverState *parent, BlockDriverState *child, + Error **errp); +void bdrv_del_child(BlockDriverState *parent, BlockDriverState *child, + Error **errp); + #endif diff --git a/include/block/block_int.h b/include/block/block_int.h index 6d7bd3b..ea20d12 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -302,6 +302,11 @@ struct BlockDriver { */ void (*bdrv_drain)(BlockDriverState *bs); + void (*bdrv_add_child)(BlockDriverState *parent, BlockDriverState *child, + Error **errp); + void (*bdrv_del_child)(BlockDriverState *parent, BlockDriverState *child, + Error **errp); + QLIST_ENTRY(BlockDriver) list; }; -- 2.5.0