From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50522) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZZyaH-0007rA-Gk for qemu-devel@nongnu.org; Thu, 10 Sep 2015 05:56:02 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZZyaD-0008Gy-9u for qemu-devel@nongnu.org; Thu, 10 Sep 2015 05:56:01 -0400 From: Wen Congyang Date: Thu, 10 Sep 2015 17:55:02 +0800 Message-ID: <1441878905-5272-3-git-send-email-wency@cn.fujitsu.com> In-Reply-To: <1441878905-5272-1-git-send-email-wency@cn.fujitsu.com> References: <1441878905-5272-1-git-send-email-wency@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain Subject: [Qemu-devel] [PATCH v3 2/5] 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 , Markus Armbruster , Alberto Garcia , Stefan Hajnoczi Cc: Kevin Wolf , qemu block , Jiang Yunhong , Dong Eddie , "Dr. David Alan Gilbert" , Gonglei , Yang Hongyang , 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 --- block.c | 52 +++++++++++++++++++++++++++++++++++++++++++++++ include/block/block.h | 5 +++++ include/block/block_int.h | 5 +++++ 3 files changed, 62 insertions(+) diff --git a/block.c b/block.c index d004bd0..682d2ec 100644 --- a/block.c +++ b/block.c @@ -4115,3 +4115,55 @@ 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 BDS %s doesn't support adding a child", + bdrv_get_device_or_node_name(parent_bs)); + return; + } + + if (child_bs->blk) { + error_setg(errp, "The BDS %s is used by the block device %s", + child_bs->node_name, blk_name(child_bs->blk)); + return; + } + + /* TODO: check if the child bs has parent */ + + 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 BDS %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 BDS %s is not the BDS %s's child", + 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 a4e31af..8480af7 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -603,4 +603,9 @@ void bdrv_io_plug(BlockDriverState *bs); void bdrv_io_unplug(BlockDriverState *bs); void bdrv_flush_io_queue(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 ca1eefa..b4d5250 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -288,6 +288,11 @@ struct BlockDriver { */ int (*bdrv_probe_geometry)(BlockDriverState *bs, HDGeometry *geo); + void (*bdrv_add_child)(BlockDriverState *parent, BlockDriverState *child, + Error **errp); + void (*bdrv_del_child)(BlockDriverState *parent, BlockDriverState *child, + Error **errp); + QLIST_ENTRY(BlockDriver) list; }; -- 2.4.3