[Qemu-block] [PATCH v3 03/14] block: Add blk_all_next()

[Max Reitz]

Some places in block/block-backend.c need to iterate over actually all
BlockBackends, so this adds a function to do so. blk_next() in contrast
only iterates over the BlockBackends which are owned by the monitor.
Right now, both do the same, but this will change as of a follow-up
patch.

Signed-off-by: Max Reitz <address@hidden>
---
 block/block-backend.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/block/block-backend.c b/block/block-backend.c
index 2146268..30decb4 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -223,11 +223,21 @@ void blk_unref(BlockBackend *blk)
     }
 }
 
+/*
+ * Behaves similarly to blk_next() but iterates over all BlockBackends, even 
the
+ * ones which are hidden (i.e. are not referenced by the monitor).
+ */
+static BlockBackend *blk_all_next(BlockBackend *blk)
+{
+    return blk ? QTAILQ_NEXT(blk, link)
+               : QTAILQ_FIRST(&blk_backends);
+}
+
 void blk_remove_all_bs(void)
 {
-    BlockBackend *blk;
+    BlockBackend *blk = NULL;
 
-    QTAILQ_FOREACH(blk, &blk_backends, link) {
+    while ((blk = blk_all_next(blk)) != NULL) {
         AioContext *ctx = blk_get_aio_context(blk);
 
         aio_context_acquire(ctx);
-- 
2.7.1