diff mbox

[v4,1/4] Add new block driver interface to add/delete a BDS's child

Message ID 1442571195-27116-2-git-send-email-wency@cn.fujitsu.com
State New
Headers show

Commit Message

Wen Congyang Sept. 18, 2015, 10:13 a.m. UTC 
In some cases, we want to take a quorum child offline, and take
another child online.

Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
---
 block.c                   | 50 +++++++++++++++++++++++++++++++++++++++++++++++
 include/block/block.h     |  5 +++++
 include/block/block_int.h |  5 +++++
 3 files changed, 60 insertions(+)

Comments

Eric Blake Sept. 18, 2015, 2:52 p.m. UTC | #1 
On 09/18/2015 04:13 AM, Wen Congyang wrote:
> In some cases, we want to take a quorum child offline, and take
> another child online.
> 
> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
> Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
> Signed-off-by: Gonglei <arei.gonglei@huawei.com>
> ---
>  block.c                   | 50 +++++++++++++++++++++++++++++++++++++++++++++++
>  include/block/block.h     |  5 +++++
>  include/block/block_int.h |  5 +++++
>  3 files changed, 60 insertions(+)
> 

> +void bdrv_del_child(BlockDriverState *parent_bs, BlockDriverState *child_bs,
> +                    Error **errp)
> +{
> +    BdrvChild *child;

> +    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));

Better would be:

"BDS %s is not a child of %s"

With that,
Reviewed-by: Eric Blake <eblake@redhat.com>
diff mbox

Patch

diff --git a/block.c b/block.c
index e815d73..bb7657b 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, "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 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;
 };