[Qemu-devel] [PATCH v4 20/38] block: Add blk_insert_bs()

[Max Reitz <mreitz@redhat.com>]

This function associates the given BlockDriverState with the given
BlockBackend.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
---
 block/block-backend.c          | 16 ++++++++++++++++
 include/sysemu/block-backend.h |  1 +
 2 files changed, 17 insertions(+)

diff --git a/block/block-backend.c b/block/block-backend.c
index 99429df..723a0df 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -314,6 +314,22 @@ void blk_hide_on_behalf_of_hmp_drive_del(BlockBackend *blk)
 }
 
 /*
+ * Associates a new BlockDriverState with @blk.
+ */
+void blk_insert_bs(BlockBackend *blk, BlockDriverState *bs)
+{
+    if (bs->blk == blk) {
+        return;
+    }
+
+    assert(!blk->bs);
+    assert(!bs->blk);
+    bdrv_ref(bs);
+    blk->bs = bs;
+    bs->blk = blk;
+}
+
+/*
  * Attach device model @dev to @blk.
  * Return 0 on success, -EBUSY when a device model is attached already.
  */
diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h
index 52e35a1..9306a52 100644
--- a/include/sysemu/block-backend.h
+++ b/include/sysemu/block-backend.h
@@ -72,6 +72,7 @@ BlockBackend *blk_by_name(const char *name);
 BlockBackend *blk_next(BlockBackend *blk);
 
 BlockDriverState *blk_bs(BlockBackend *blk);
+void blk_insert_bs(BlockBackend *blk, BlockDriverState *bs);
 
 void blk_hide_on_behalf_of_hmp_drive_del(BlockBackend *blk);
 
-- 
2.4.6