From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43891) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zk0bz-0004xv-UR for qemu-devel@nongnu.org; Wed, 07 Oct 2015 22:07:17 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Zk0by-0002WU-H7 for qemu-devel@nongnu.org; Wed, 07 Oct 2015 22:07:15 -0400 References: <1442907862-21376-1-git-send-email-wency@cn.fujitsu.com> <1442907862-21376-2-git-send-email-wency@cn.fujitsu.com> <56156562.6000909@redhat.com> From: Wen Congyang Message-ID: <5615CFB8.20803@cn.fujitsu.com> Date: Thu, 8 Oct 2015 10:06:48 +0800 MIME-Version: 1.0 In-Reply-To: <56156562.6000909@redhat.com> Content-Type: text/plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [Qemu-block] [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: Max Reitz , qemu devel , Eric Blake , Markus Armbruster , Alberto Garcia , Stefan Hajnoczi Cc: Kevin Wolf , zhanghailiang , qemu block , Jiang Yunhong , Dong Eddie , "Dr. David Alan Gilbert" , Gonglei , Yang Hongyang On 10/08/2015 02:33 AM, Max Reitz wrote: > On 22.09.2015 09:44, Wen Congyang wrote: >> 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 >> --- >> 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); > > How about we make this (BlockDriver.bdrv_del_child()) take a BdrvChild > instead of a BDS? We could even make bdrv_del_child() as a whole take a > BdrvChild parameter, but I don't suppose that would help much. bdrv_add_child() takes a BDS, so I use BDS here. Thanks Wen Congyang > > Max > >> +} >> 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; >> }; >> >> > >