[PATCH 22/22] block: Add assertion for bdrv_graph_wrlock()

[Kevin Wolf]

bdrv_graph_wrlock() can't run in a coroutine (because it polls) and
requires holding the BQL. We already have GLOBAL_STATE_CODE() to assert
the latter. Assert the former as well and add a no_coroutine_fn marker.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 include/block/graph-lock.h | 3 ++-
 block/graph-lock.c         | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/include/block/graph-lock.h b/include/block/graph-lock.h
index 7e04f98ff0..6f1cd12745 100644
--- a/include/block/graph-lock.h
+++ b/include/block/graph-lock.h
@@ -116,7 +116,8 @@ void unregister_aiocontext(AioContext *ctx);
  * This function polls. Callers must not hold the lock of any AioContext other
  * than the current one and the one of @bs.
  */
-void bdrv_graph_wrlock(BlockDriverState *bs) TSA_ACQUIRE(graph_lock) 
TSA_NO_TSA;
+void no_coroutine_fn TSA_ACQUIRE(graph_lock) TSA_NO_TSA
+bdrv_graph_wrlock(BlockDriverState *bs);
 
 /*
  * bdrv_graph_wrunlock:
diff --git a/block/graph-lock.c b/block/graph-lock.c
index 58a799065f..e5525ee2db 100644
--- a/block/graph-lock.c
+++ b/block/graph-lock.c
@@ -106,12 +106,13 @@ static uint32_t reader_count(void)
     return rd;
 }
 
-void bdrv_graph_wrlock(BlockDriverState *bs)
+void no_coroutine_fn bdrv_graph_wrlock(BlockDriverState *bs)
 {
     AioContext *ctx = NULL;
 
     GLOBAL_STATE_CODE();
     assert(!qatomic_read(&has_writer));
+    assert(!qemu_in_coroutine());
 
     /*
      * Release only non-mainloop AioContext. The mainloop often relies on the
-- 
2.41.0