[RFC v4 7/9] config: add check to block layer

[Sam Li]

Putting zoned/non-zoned BlockDrivers on top of each other is not
allowed.

Signed-off-by: Sam Li <faithilikerun@gmail.com>
---
 block.c                          | 7 +++++++
 block/file-posix.c               | 2 ++
 include/block/block_int-common.h | 5 +++++
 3 files changed, 14 insertions(+)

diff --git a/block.c b/block.c
index 2c00dddd80..0e24582c7d 100644
--- a/block.c
+++ b/block.c
@@ -7945,6 +7945,13 @@ void bdrv_add_child(BlockDriverState *parent_bs, 
BlockDriverState *child_bs,
         return;
     }
 
+    if (parent_bs->drv->is_zoned != child_bs->drv->is_zoned) {
+        error_setg(errp, "Cannot add a %s child to a %s parent",
+                   child_bs->drv->is_zoned ? "zoned" : "non-zoned",
+                   parent_bs->drv->is_zoned ? "zoned" : "non-zoned");
+        return;
+    }
+
     if (!QLIST_EMPTY(&child_bs->parents)) {
         error_setg(errp, "The node %s already has a parent",
                    child_bs->node_name);
diff --git a/block/file-posix.c b/block/file-posix.c
index 42708012ff..e9ad1d8e1e 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -3924,6 +3924,7 @@ static BlockDriver bdrv_host_device = {
     .format_name        = "host_device",
     .protocol_name        = "host_device",
     .instance_size      = sizeof(BDRVRawState),
+    .is_zoned = false,
     .bdrv_needs_filename = true,
     .bdrv_probe_device  = hdev_probe_device,
     .bdrv_parse_filename = hdev_parse_filename,
@@ -3971,6 +3972,7 @@ static BlockDriver bdrv_zoned_host_device = {
         .format_name = "zoned_host_device",
         .protocol_name = "zoned_host_device",
         .instance_size = sizeof(BDRVRawState),
+        .is_zoned = true,
         .bdrv_needs_filename = true,
         .bdrv_probe_device  = hdev_probe_device,
         .bdrv_parse_filename = hdev_parse_filename,
diff --git a/include/block/block_int-common.h b/include/block/block_int-common.h
index 6037871089..29f1ec9184 100644
--- a/include/block/block_int-common.h
+++ b/include/block/block_int-common.h
@@ -141,6 +141,11 @@ struct BlockDriver {
      */
     bool is_format;
 
+    /*
+     * Set to true if the BlockDriver is a zoned block driver.
+     */
+    bool is_zoned;
+
     /*
      * Drivers not implementing bdrv_parse_filename nor bdrv_open should have
      * this field set to true, except ones that are defined only by their
-- 
2.36.1