Am 27.11.2020 um 15:44 hat Vladimir Sementsov-Ogievskiy geschrieben:
> Functions with errp argument are not recommened to be void-functions.
> Improve bdrv_replace_node().
>
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
> ---
> include/block/block.h | 4 ++--
> block.c | 14 ++++++++------
> 2 files changed, 10 insertions(+), 8 deletions(-)
>
> diff --git a/include/block/block.h b/include/block/block.h
> index 5d59984ad4..8f6100dad7 100644
> --- a/include/block/block.h
> +++ b/include/block/block.h
> @@ -346,8 +346,8 @@ int bdrv_create_file(const char *filename, QemuOpts
> *opts, Error **errp);
> BlockDriverState *bdrv_new(void);
> int bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top,
> Error **errp);
> -void bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
> - Error **errp);
> +int bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
> + Error **errp);
>
> int bdrv_parse_aio(const char *mode, int *flags);
> int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough);
> diff --git a/block.c b/block.c
> index 3765c7caed..29082c6d47 100644
> --- a/block.c
> +++ b/block.c
> @@ -4537,14 +4537,14 @@ static bool should_update_child(BdrvChild *c,
> BlockDriverState *to)
> * With auto_skip=false the error is returned if from has a parent which
> should
> * not be updated.
> */
> -static void bdrv_replace_node_common(BlockDriverState *from,
> - BlockDriverState *to,
> - bool auto_skip, Error **errp)
> +static int bdrv_replace_node_common(BlockDriverState *from,
> + BlockDriverState *to,
> + bool auto_skip, Error **errp)
> {
> + int ret = -EPERM;
> BdrvChild *c, *next;
> GSList *list = NULL, *p;
> uint64_t perm = 0, shared = BLK_PERM_ALL;
> - int ret;
I think I'd prefer setting ret in each error path. This makes it more
obvious that ret has the right value and hasn't been modified between
the initialisation and the error.
>
> /* Make sure that @from doesn't go away until we have successfully
> attached
> * all of its parents to @to. */
> @@ -4600,10 +4600,12 @@ out:
Let's add an explicit ret = 0 right before the out: label.
> g_slist_free(list);
> bdrv_drained_end(from);
> bdrv_unref(from);
> +
> + return ret;
> }
With these changes:
Reviewed-by: Kevin Wolf <kw...@redhat.com>
