block: Convert bdrv_get_info() to co_wrapper_mixed

bdrv_get_info() is categorized as an I/O function, and it currently
doesn't run in a coroutine. We should let it take a graph rdlock since
it traverses the block nodes graph, which however is only possible in a
coroutine.

Therefore turn it into a co_wrapper to move the actual function into a
coroutine where the lock can be taken.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230113204212.359076-11-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/block/rbd.c b/block/rbd.c
index c127c15..5e102fe 100644
--- a/block/rbd.c
+++ b/block/rbd.c
@@ -1240,7 +1240,8 @@
 }
 #endif
 
-static int qemu_rbd_getinfo(BlockDriverState *bs, BlockDriverInfo *bdi)
+static int coroutine_fn
+qemu_rbd_co_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
 {
     BDRVRBDState *s = bs->opaque;
     bdi->cluster_size = s->object_size;
@@ -1651,7 +1652,7 @@
     .bdrv_co_create         = qemu_rbd_co_create,
     .bdrv_co_create_opts    = qemu_rbd_co_create_opts,
     .bdrv_has_zero_init     = bdrv_has_zero_init_1,
-    .bdrv_get_info          = qemu_rbd_getinfo,
+    .bdrv_co_get_info       = qemu_rbd_co_get_info,
     .bdrv_get_specific_info = qemu_rbd_get_specific_info,
     .create_opts            = &qemu_rbd_create_opts,
     .bdrv_co_getlength      = qemu_rbd_co_getlength,