block: Mark read/write in block/io.c GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_driver_*() need to hold a reader lock for the graph. It doesn't add
the annotation to public functions yet.

For some places, we know that they will hold the lock, but we don't have
the GRAPH_RDLOCK annotations yet. In this case, add assume_graph_lock()
with a FIXME comment. These places will be removed once everything is
properly annotated.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230203152202.49054-11-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 5 insertions, 5 deletions

diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index 870be106b6..a22607d90d 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -491,10 +491,9 @@ static int count_contiguous_subclusters(BlockDriverState *bs, int nb_clusters,
     return count;
 }
 
-static int coroutine_fn do_perform_cow_read(BlockDriverState *bs,
-                                            uint64_t src_cluster_offset,
-                                            unsigned offset_in_cluster,
-                                            QEMUIOVector *qiov)
+static int coroutine_fn GRAPH_RDLOCK
+do_perform_cow_read(BlockDriverState *bs, uint64_t src_cluster_offset,
+                    unsigned offset_in_cluster, QEMUIOVector *qiov)
 {
     int ret;
 
@@ -886,7 +885,8 @@ int coroutine_fn qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
     return 0;
 }
 
-static int coroutine_fn perform_cow(BlockDriverState *bs, QCowL2Meta *m)
+static int coroutine_fn GRAPH_RDLOCK
+perform_cow(BlockDriverState *bs, QCowL2Meta *m)
 {
     BDRVQcow2State *s = bs->opaque;
     Qcow2COWRegion *start = &m->cow_start;