Re: [PATCH v2] block/snapshot: Fix compiler warning with -Wshadow=local

[Markus Armbruster]

Thomas Huth <thuth@redhat.com> writes:

> No need to declare a new variable in the the inner code block
> here, we can re-use the "ret" variable that has been declared
> at the beginning of the function. With this change, the code
> can now be successfully compiled with -Wshadow=local again.
>
> Fixes: a32e781838 ("Mark bdrv_snapshot_fallback() and callers GRAPH_RDLOCK")
> Signed-off-by: Thomas Huth <thuth@redhat.com>
> ---
>  v2: Assign "ret" only in one spot
>
>  block/snapshot.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/block/snapshot.c b/block/snapshot.c
> index 6e16eb803a..55974273ae 100644
> --- a/block/snapshot.c
> +++ b/block/snapshot.c
> @@ -629,7 +629,6 @@ int bdrv_all_goto_snapshot(const char *name,
>      while (iterbdrvs) {
>          BlockDriverState *bs = iterbdrvs->data;
>          AioContext *ctx = bdrv_get_aio_context(bs);
> -        int ret = 0;
>          bool all_snapshots_includes_bs;
>  
>          aio_context_acquire(ctx);
> @@ -637,9 +636,8 @@ int bdrv_all_goto_snapshot(const char *name,
>          all_snapshots_includes_bs = bdrv_all_snapshots_includes_bs(bs);
>          bdrv_graph_rdunlock_main_loop();
>  
> -        if (devices || all_snapshots_includes_bs) {
> -            ret = bdrv_snapshot_goto(bs, name, errp);
> -        }
> +        ret = (devices || all_snapshots_includes_bs) ?
> +              bdrv_snapshot_goto(bs, name, errp) : 0;
>          aio_context_release(ctx);
>          if (ret < 0) {
>              bdrv_graph_rdlock_main_loop();

Better.  Unconditional assignment to @ret right before it's checked is
how we should use @ret.

Reviewed-by: Markus Armbruster <armbru@redhat.com>

And queued.  Thanks!