[PATCH V10 04/15] iothread: introduce iothread_unsafe_get_aio_context()

[Zhang Chen <zhangckid@gmail.com>]

Normally the IOThread's AioContext is fetched using
iothread_ref_and_get_aio_context(), but there are legacy callers
without a clear ref/unref lifecycle. They cannot unref (e.g. because
they do not have an IOThread pointer), so provide an unsafe way to
fetch the AioContext without holding a reference count. This unsafe
API serves legacy callers - do not use it in new code.

Signed-off-by: Zhang Chen <zhangckid@gmail.com>
---
 blockdev.c                | 2 +-
 include/system/iothread.h | 9 +++++++++
 iothread.c                | 6 ++++++
 3 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/blockdev.c b/blockdev.c
index 6e86c6262f..baeab3a3e1 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -3683,7 +3683,7 @@ void qmp_x_blockdev_set_iothread(const char *node_name, StrOrNull *iothread,
             goto out;
         }
 
-        new_context = iothread_get_aio_context(obj);
+        new_context = iothread_unsafe_get_aio_context(obj);
     } else {
         new_context = qemu_get_aio_context();
     }
diff --git a/include/system/iothread.h b/include/system/iothread.h
index 86f02c5a7d..3cce5eeb09 100644
--- a/include/system/iothread.h
+++ b/include/system/iothread.h
@@ -78,6 +78,15 @@ IOThread *iothread_by_id(const char *id);
  * thread-safe and must be called under the Big QEMU Lock (BQL).
  */
 AioContext *iothread_get_aio_context(IOThread *iothread);
+/*
+ * Normally the IOThread's AioContext is fetched using
+ * iothread_ref_and_get_aio_context(), but there are legacy callers
+ * without a clear ref/unref lifecycle. They cannot unref (e.g. because
+ * they do not have an IOThread pointer), so provide an unsafe way to
+ * fetch the AioContext without holding a reference count. This unsafe
+ * API serves legacy callers - do not use it in new code.
+ */
+AioContext *iothread_unsafe_get_aio_context(IOThread *iothread);
 AioContext *iothread_ref_and_get_aio_context(IOThread *iothread,
                                              const IOThreadHolder *holder);
 void iothread_put_aio_context(IOThread *iothread, const IOThreadHolder *holder);
diff --git a/iothread.c b/iothread.c
index f5d4708b25..157bb4d302 100644
--- a/iothread.c
+++ b/iothread.c
@@ -449,6 +449,12 @@ void iothread_put_aio_context(IOThread *iothread, const IOThreadHolder *holder)
     iothread_unref(iothread, holder);
 }
 
+/* Recommend migrating to the new API with IOThreadHolder as much as possible */
+AioContext *iothread_unsafe_get_aio_context(IOThread *iothread)
+{
+    return iothread->ctx;
+}
+
 static int query_one_iothread(Object *object, void *opaque)
 {
     IOThreadInfoList ***tail = opaque;
-- 
2.49.0