diff mbox series

[v2,09/36] block: return value from bdrv_replace_node()

Message ID 20201127144522.29991-10-vsementsov@virtuozzo.com
State New
Headers show
Series block: update graph permissions update | expand

Commit Message

Vladimir Sementsov-Ogievskiy Nov. 27, 2020, 2:44 p.m. UTC 
Functions with errp argument are not recommened to be void-functions.
Improve bdrv_replace_node().

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 include/block/block.h |  4 ++--
 block.c               | 14 ++++++++------
 2 files changed, 10 insertions(+), 8 deletions(-)

Comments

Alberto Garcia Dec. 15, 2020, 5:30 p.m. UTC | #1 
On Fri 27 Nov 2020 03:44:55 PM CET, Vladimir Sementsov-Ogievskiy wrote:
> Functions with errp argument are not recommened to be void-functions.
> Improve bdrv_replace_node().
>
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

Reviewed-by: Alberto Garcia <berto@igalia.com>

Berto
Kevin Wolf Jan. 18, 2021, 3:40 p.m. UTC | #2 
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 <vsementsov@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 <kwolf@redhat.com>
diff mbox series

Patch

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;
 
     /* Make sure that @from doesn't go away until we have successfully attached
      * all of its parents to @to. */
@@ -4600,10 +4600,12 @@  out:
     g_slist_free(list);
     bdrv_drained_end(from);
     bdrv_unref(from);
+
+    return ret;
 }
 
-void bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
-                       Error **errp)
+int bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
+                      Error **errp)
 {
     return bdrv_replace_node_common(from, to, true, errp);
 }