This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_filter_child() need to hold a reader lock for the graph because it
accesses bs->file/backing.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 include/block/block_int-io.h | 4 ++--
 block.c                      | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/include/block/block_int-io.h b/include/block/block_int-io.h
index 4e7bf57a5e..17547a2dab 100644
--- a/include/block/block_int-io.h
+++ b/include/block/block_int-io.h
@@ -131,8 +131,8 @@ int co_wrapper_mixed_bdrv_rdlock
 bdrv_refresh_total_sectors(BlockDriverState *bs, int64_t hint);
 
 BdrvChild *bdrv_cow_child(BlockDriverState *bs);
-BdrvChild *bdrv_filter_child(BlockDriverState *bs);
-BdrvChild *bdrv_filter_or_cow_child(BlockDriverState *bs);
+BdrvChild * GRAPH_RDLOCK bdrv_filter_child(BlockDriverState *bs);
+BdrvChild * GRAPH_RDLOCK bdrv_filter_or_cow_child(BlockDriverState *bs);
 BdrvChild * GRAPH_RDLOCK bdrv_primary_child(BlockDriverState *bs);
 BlockDriverState * GRAPH_RDLOCK bdrv_skip_filters(BlockDriverState *bs);
 BlockDriverState * GRAPH_RDLOCK bdrv_backing_chain_next(BlockDriverState *bs);
diff --git a/block.c b/block.c
index bb322df7d8..499b147315 100644
--- a/block.c
+++ b/block.c
@@ -8491,8 +8491,8 @@ BdrvChild *bdrv_primary_child(BlockDriverState *bs)
     return found;
 }
 
-static BlockDriverState *bdrv_do_skip_filters(BlockDriverState *bs,
-                                              bool stop_on_explicit_filter)
+static BlockDriverState * GRAPH_RDLOCK
+bdrv_do_skip_filters(BlockDriverState *bs, bool stop_on_explicit_filter)
 {
     BdrvChild *c;
 
-- 
2.41.0

On Fri, Oct 27, 2023 at 05:53:20PM +0200, Kevin Wolf wrote:
> This adds GRAPH_RDLOCK annotations to declare that callers of
> bdrv_filter_child() need to hold a reader lock for the graph because it
> accesses bs->file/backing.
> 
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>  include/block/block_int-io.h | 4 ++--
>  block.c                      | 4 ++--
>  2 files changed, 4 insertions(+), 4 deletions(-)
>

Deceptively short compared to some of the others in this series.

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.
Virtualization:  qemu.org | libguestfs.org