block: Mark preadv_snapshot/snapshot_block_status GRAPH_RDLOCK

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230203152202.49054-16-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/block/copy-before-write.c b/block/copy-before-write.c
index e223e37..646d822 100644
--- a/block/copy-before-write.c
+++ b/block/copy-before-write.c
@@ -256,7 +256,7 @@
     g_free(req);
 }
 
-static coroutine_fn int
+static int coroutine_fn GRAPH_RDLOCK
 cbw_co_preadv_snapshot(BlockDriverState *bs, int64_t offset, int64_t bytes,
                        QEMUIOVector *qiov, size_t qiov_offset)
 {
@@ -264,8 +264,6 @@
     BdrvChild *file;
     int ret;
 
-    assume_graph_lock(); /* FIXME */
-
     /* TODO: upgrade to async loop using AioTask */
     while (bytes) {
         int64_t cur_bytes;
@@ -290,7 +288,7 @@
     return 0;
 }
 
-static int coroutine_fn
+static int coroutine_fn GRAPH_RDLOCK
 cbw_co_snapshot_block_status(BlockDriverState *bs,
                              bool want_zero, int64_t offset, int64_t bytes,
                              int64_t *pnum, int64_t *map,