From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34898) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zjtwt-0004aG-FT for qemu-devel@nongnu.org; Wed, 07 Oct 2015 15:00:24 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Zjtws-0004mi-CL for qemu-devel@nongnu.org; Wed, 07 Oct 2015 15:00:23 -0400 Date: Wed, 7 Oct 2015 20:00:11 +0100 From: "Dr. David Alan Gilbert" Message-ID: <20151007190010.GO2710@work-vm> References: <1442907862-21376-1-git-send-email-wency@cn.fujitsu.com> <1442907862-21376-2-git-send-email-wency@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1442907862-21376-2-git-send-email-wency@cn.fujitsu.com> Subject: Re: [Qemu-devel] [PATCH v5 1/4] 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: Wen Congyang Cc: Kevin Wolf , Alberto Garcia , zhanghailiang , qemu block , Jiang Yunhong , Dong Eddie , qemu devel , Markus Armbruster , Gonglei , Stefan Hajnoczi , Yang Hongyang * Wen Congyang (wency@cn.fujitsu.com) wrote: > In some cases, we want to take a quorum child offline, and take > another child online. Hi, Have you checked the output of 'info block' after adding/deleting a child? I'm using one of your older worlds (from a few months ago) and I found I had to add a bdrv_refresh_filename(bs); to get the output of 'info block' to show the new child. I don't see it in this version. Dave > > Signed-off-by: Wen Congyang > Signed-off-by: zhanghailiang > Signed-off-by: Gonglei > Reviewed-by: Eric Blake > --- > 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 e815d73..1b25e43 100644 > --- a/block.c > +++ b/block.c > @@ -4265,3 +4265,53 @@ BlockAcctStats *bdrv_get_stats(BlockDriverState *bs) > { > return &bs->stats; > } > + > +/* > + * 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 (!QLIST_EMPTY(&child_bs->parents)) { > + error_setg(errp, "The BDS %s already has 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 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, "BDS %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 ef67353..665c56f 100644 > --- a/include/block/block.h > +++ b/include/block/block.h > @@ -616,4 +616,9 @@ void bdrv_flush_io_queue(BlockDriverState *bs); > > BlockAcctStats *bdrv_get_stats(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 2f2c47b..64cbc55 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 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK