[Qemu-block] [PATCH v2 2/8] block: Add blk_next_inserted()

[Max Reitz]

This function skips to the next BlockBackend for which blk_is_inserted()
is true.

Signed-off-by: Max Reitz <address@hidden>
Reviewed-by: Eric Blake <address@hidden>
---
 block/block-backend.c          | 15 +++++++++++++++
 include/sysemu/block-backend.h |  1 +
 2 files changed, 16 insertions(+)

diff --git a/block/block-backend.c b/block/block-backend.c
index 7128adc..ef387f8 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -252,6 +252,21 @@ BlockBackend *blk_next(BlockBackend *blk)
 }
 
 /*
+ * Like blk_next(), but skips all non-inserted BlockBackends (that is,
+ * BlockBackends for which blk_is_inserted() returns false)
+ */
+BlockBackend *blk_next_inserted(BlockBackend *blk)
+{
+    while ((blk = blk_next(blk)) != NULL) {
+        if (blk_is_inserted(blk)) {
+            break;
+        }
+    }
+
+    return blk;
+}
+
+/*
  * Return @blk's name, a non-null string.
  * Wart: the name is empty iff @blk has been hidden with
  * blk_hide_on_behalf_of_hmp_drive_del().
diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h
index 0593231..967c768 100644
--- a/include/sysemu/block-backend.h
+++ b/include/sysemu/block-backend.h
@@ -73,6 +73,7 @@ const char *blk_name(BlockBackend *blk);
 BlockBackend *blk_by_name(const char *name);
 bool blk_name_taken(const char *name);
 BlockBackend *blk_next(BlockBackend *blk);
+BlockBackend *blk_next_inserted(BlockBackend *blk);
 
 BlockDriverState *blk_bs(BlockBackend *blk);
 void blk_remove_bs(BlockBackend *blk);
-- 
2.6.2