[PATCH 16/20] block-gen: assert that bdrv_co_{read/write}v_vmstate are always called with graph rdlock taken

[Emanuele Giuseppe Esposito <eesposit@redhat.com>]

The only caller of these functions is bdrv_{read/write}v_vmstate, a
generated_co_wrapper function that already takes the
graph read lock.

Protecting bdrv_co_{read/write}v_vmstate() implies that
BlockDriver->bdrv_{load/save}_vmstate() is always called with
graph rdlock taken.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
 block/io.c                       | 2 ++
 include/block/block_int-common.h | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/block/io.c b/block/io.c
index 0bf3919939..c9b451fecd 100644
--- a/block/io.c
+++ b/block/io.c
@@ -2633,6 +2633,7 @@ bdrv_co_readv_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos)
     BlockDriverState *child_bs = bdrv_primary_bs(bs);
     int ret;
     IO_CODE();
+    assert_bdrv_graph_readable();
 
     ret = bdrv_check_qiov_request(pos, qiov->size, qiov, 0, NULL);
     if (ret < 0) {
@@ -2665,6 +2666,7 @@ bdrv_co_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos)
     BlockDriverState *child_bs = bdrv_primary_bs(bs);
     int ret;
     IO_CODE();
+    assert_bdrv_graph_readable();
 
     ret = bdrv_check_qiov_request(pos, qiov->size, qiov, 0, NULL);
     if (ret < 0) {
diff --git a/include/block/block_int-common.h b/include/block/block_int-common.h
index bab0521943..568c2d3092 100644
--- a/include/block/block_int-common.h
+++ b/include/block/block_int-common.h
@@ -724,9 +724,11 @@ struct BlockDriver {
                                                  Error **errp);
     BlockStatsSpecific *(*bdrv_get_specific_stats)(BlockDriverState *bs);
 
+    /* Called with graph rdlock held. */
     int coroutine_fn (*bdrv_save_vmstate)(BlockDriverState *bs,
                                           QEMUIOVector *qiov,
                                           int64_t pos);
+    /* Called with graph rdlock held. */
     int coroutine_fn (*bdrv_load_vmstate)(BlockDriverState *bs,
                                           QEMUIOVector *qiov,
                                           int64_t pos);
-- 
2.31.1