block: Mark bdrv_co_debug_event() GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_debug_event() need to hold a reader lock for the graph.

Unfortunately we cannot use a co_wrapper_bdrv_rdlock (i.e. make the
coroutine wrapper a no_coroutine_fn), because the function is called
(using the BLKDBG_EVENT macro) by mixed functions that run both in
coroutine and non-coroutine context (for example many of the functions
in qcow2-cluster.c and qcow2-refcount.c).

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20230504115750.54437-16-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/block.c b/block.c
index a6deaf8ad1..1bc766c778 100644
--- a/block.c
+++ b/block.c
@@ -6399,6 +6399,8 @@ BlockStatsSpecific *bdrv_get_specific_stats(BlockDriverState *bs)
 void coroutine_fn bdrv_co_debug_event(BlockDriverState *bs, BlkdebugEvent event)
 {
     IO_CODE();
+    assert_bdrv_graph_readable();
+
     if (!bs || !bs->drv || !bs->drv->bdrv_co_debug_event) {
         return;
     }