Re: [Qemu-devel] [PATCH 2/5] block/dirty-bitmaps: rename frozen predicate helper

[Eric Blake]

On 2/11/19 7:02 PM, John Snow wrote:
> "Frozen" was a good description a long time ago, but it isn't adequate now.
> Rename the frozen predicate to has_successor to make the semantics of the
> predicate more clear to outside callers.
> 
> In the process, remove some calls to frozen() that no longer semantically
> make sense. For enabled and disabled in particular, it's actually okay for
> the internals to do this but only forbidden for users to invoke them, and
> all of the QMP entry uses already check against qmp_locked.
> 
> Several other assertions really want to check that the bitmap isn't in-use
> by another operation -- use the qmp_locked function for this instead, which
> presently also checks for has_successor.
> ---

Missing S-o-b on entire series, so you have to send v2 anyway :)

> @@ -244,12 +244,16 @@ int bdrv_dirty_bitmap_create_successor(BlockDriverState 
> *bs,
>      uint64_t granularity;
>      BdrvDirtyBitmap *child;
>  
> -    if (bdrv_dirty_bitmap_frozen(bitmap)) {
> -        error_setg(errp, "Cannot create a successor for a bitmap that is "
> -                   "currently frozen");
> +    if (bdrv_dirty_bitmap_has_successor(bitmap)) {
> +        error_setg(errp, "Cannot create a successor for a bitmap that 
> already "
> +                   "has one");
> +        return -1;
> +    }
> +    if (bdrv_dirty_bitmap_user_locked(bitmap)) {
> +        error_setg(errp, "Cannot create a successor for a bitmap that is 
> in-use "
> +                   "by an operation.");
>          return -1;

No trailing dot in error_setg().

Should these two errors be swapped (check for locked before
has_successor)?  After all, having a successor is an internal detail,
whereas being in use by something I already triggered is fairly
straightforward to understand.


> @@ -325,7 +328,7 @@ BdrvDirtyBitmap 
> *bdrv_dirty_bitmap_abdicate(BlockDriverState *bs,
>  /**
>   * In cases of failure where we can no longer safely delete the parent,
>   * we may wish to re-join the parent and child/successor.
> - * The merged parent will be un-frozen, but not explicitly re-enabled.
> + * The merged parent will not be user_locked, but not explicitly re-enabled.

s/but not/nor/

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org

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