From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37272) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1akQLC-0001g2-J7 for qemu-devel@nongnu.org; Mon, 28 Mar 2016 02:07:55 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1akQLB-0007Jc-2M for qemu-devel@nongnu.org; Mon, 28 Mar 2016 02:07:54 -0400 Message-ID: <56F8CA9A.7080008@cn.fujitsu.com> Date: Mon, 28 Mar 2016 14:09:30 +0800 From: Changlong Xie MIME-Version: 1.0 References: <1457578181-27111-1-git-send-email-xiecl.fnst@cn.fujitsu.com> <1457578181-27111-4-git-send-email-xiecl.fnst@cn.fujitsu.com> In-Reply-To: <1457578181-27111-4-git-send-email-xiecl.fnst@cn.fujitsu.com> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v12 3/3] qmp: add monitor command to add/remove a child List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu devel , Eric Blake , Alberto Garcia , Kevin Wolf , Max Reitz , Stefan Hajnoczi Cc: zhanghailiang , qemu block , Jiang Yunhong , Dong Eddie , Markus Armbruster , "Dr. David Alan Gilbert" , Gonglei On 03/10/2016 10:49 AM, Changlong Xie wrote: > From: Wen Congyang > > The new QMP command name is x-blockdev-change. It's just for adding/removing > quorum's child now, and doesn't support all kinds of children, all kinds of > operations, nor all block drivers. So it is experimental now. > > Signed-off-by: Wen Congyang > Signed-off-by: zhanghailiang > Signed-off-by: Gonglei > Signed-off-by: Changlong Xie > Reviewed-by: Max Reitz > --- > blockdev.c | 55 ++++++++++++++++++++++++++++++++++++++++++++++++++++ > qapi/block-core.json | 32 ++++++++++++++++++++++++++++++ > qmp-commands.hx | 54 +++++++++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 141 insertions(+) > > diff --git a/blockdev.c b/blockdev.c > index 0f20c65..435631e 100644 > --- a/blockdev.c > +++ b/blockdev.c > @@ -4017,6 +4017,61 @@ out: > aio_context_release(aio_context); > } > > +static BdrvChild *bdrv_find_child(BlockDriverState *parent_bs, > + const char *child_name) > +{ > + BdrvChild *child; > + > + QLIST_FOREACH(child, &parent_bs->children, next) { > + if (strcmp(child->name, child_name) == 0) { > + return child; > + } > + } > + > + return NULL; > +} > + > +void qmp_x_blockdev_change(const char *parent, bool has_child, > + const char *child, bool has_node, > + const char *node, Error **errp) > +{ > + BlockDriverState *parent_bs, *new_bs = NULL; > + BdrvChild *p_child; > + > + parent_bs = bdrv_lookup_bs(parent, parent, errp); > + if (!parent_bs) { > + return; > + } > + > + if (has_child == has_node) { > + if (has_child) { > + error_setg(errp, "The parameters child and node are in conflict"); > + } else { > + error_setg(errp, "Either child or node must be specified"); > + } > + return; > + } > + > + if (has_child) { > + p_child = bdrv_find_child(parent_bs, child); > + if (!p_child) { > + error_setg(errp, "Node '%s' does not have child '%s'", > + parent, child); > + return; > + } > + bdrv_del_child(parent_bs, p_child, errp); > + } > + > + if (has_node) { > + new_bs = bdrv_find_node(node); > + if (!new_bs) { > + error_setg(errp, "Node '%s' not found", node); > + return; > + } > + bdrv_add_child(parent_bs, new_bs, errp); > + } > +} > + > BlockJobInfoList *qmp_query_block_jobs(Error **errp) > { > BlockJobInfoList *head = NULL, **p_next = &head; > diff --git a/qapi/block-core.json b/qapi/block-core.json > index 9bf1b22..bc3fd0b 100644 > --- a/qapi/block-core.json > +++ b/qapi/block-core.json > @@ -2548,3 +2548,35 @@ > ## > { 'command': 'block-set-write-threshold', > 'data': { 'node-name': 'str', 'write-threshold': 'uint64' } } > + > +## > +# @x-blockdev-change > +# > +# Dynamically reconfigure the block driver state graph. It can be used > +# to add, remove, insert or replace a graph node. Currently only the > +# Quorum driver implements this feature to add or remove its child. This > +# is useful to fix a broken quorum child. > +# > +# If @node is specified, it will be inserted under @parent. @child > +# may not be specified in this case. If both @parent and @child are > +# specified but @node is not, @child will be detached from @parent. > +# > +# @parent: the id or name of the parent node. > +# > +# @child: #optional the name of a child under the given parent node. > +# > +# @node: #optional the name of the node that will be added. > +# > +# Note: this command is experimental, and its API is not stable. It > +# does not support all kinds of operations, all kinds of children, nor > +# all block drivers. > +# > +# Warning: The data in a new quorum child MUST be consistent with that of > +# the rest of the array. > +# > +# Since: 2.6 > +## > +{ 'command': 'x-blockdev-change', > + 'data' : { 'parent': 'str', > + '*child': 'str', > + '*node': 'str' } } > diff --git a/qmp-commands.hx b/qmp-commands.hx > index b629673..2a55135 100644 > --- a/qmp-commands.hx > +++ b/qmp-commands.hx > @@ -4398,6 +4398,60 @@ Example: > EQMP > > { > + .name = "x-blockdev-change", > + .args_type = "parent:B,child:B?,node:B?", > + .mhandler.cmd_new = qmp_marshal_x_blockdev_change, > + }, > + > +SQMP > +x-blockdev-change > +----------------- > + > +Dynamically reconfigure the block driver state graph. It can be used > +to add, remove, insert or replace a graph node. Currently only the > +Quorum driver implements this feature to add or remove its child. This > +is useful to fix a broken quorum child. > + > +If @node is specified, it will be inserted under @parent. @child > +may not be specified in this case. If both @parent and @child are > +specified but @node is not, @child will be detached from @parent. > + > +Arguments: > +- "parent": the id or name of the parent node (json-string) > +- "child": the name of a child under the given parent node (json-string, optional) > +- "node": the name of the node that will be added (json-string, optional) > + > +Note: this command is experimental, and not a stable API. It doesn't > +support all kinds of operations, all kinds of children, nor all block > +drivers. > + > +Warning: The data in a new quorum child MUST be consistent with that of > +the rest of the array. > + > +Example: > + > +Add a new node to a quorum > +-> { "execute": "blockdev-add", > + "arguments": { "options": { "driver": "raw", > + "node-name": "new_node", > + "id": "test_new_node", Since f21d96d04 block: Use BdrvChild in BlockBackend, if we want to create a node without BB, we should not pass " "id": "test_new_node" ", will fix in next version. Thanks -Xie > + "file": { "driver": "file", > + "filename": "test.raw" } } } } > +<- { "return": {} } > +-> { "execute": "x-blockdev-change", > + "arguments": { "parent": "disk1", > + "node": "new_node" } } > +<- { "return": {} } > + > +Delete a quorum's node > +-> { "execute": "x-blockdev-change", > + "arguments": { "parent": "disk1", > + "child": "children.1" } } > +<- { "return": {} } > + > +EQMP > + > + { > .name = "query-named-block-nodes", > .args_type = "", > .mhandler.cmd_new = qmp_marshal_query_named_block_nodes, >