[libvirt] [PATCH v7 01/13] virstoragefile: Add virStorageSourceGetBackingStore

[John Ferlan]

On 12/03/2015 09:35 AM, Matthias Gatto wrote:
> Create virStorageSourceGetBackingStore function in
> preparation for quorum:
> Actually, if we want to get a backing store inside a virStorageSource
> we have to do it manually(src->backingStore = backingStore).
> The problem is that with a quorum, a virStorageSource
> can contain multiple backing stores, and src->backingStore can
> be treated as a virStorageSourcePtr or a virStorageSourcePtrPtr.
> 
> Due to these reason, we need to simplify the manipulation of
> virStorageSource, and create a function to get the asked
> backingStore in a virStorageSource
> 
> For now, this function only return the backingStore field

More simply said -

Create helper virStorageSourceGetBackingStore in order to make it easier
to access the storage backingStore pointer. Future patches will adjust
the backingStore pointer to become a table or list of backingStorePtr's


[Sure you're doing it because of the quorum changes, but it's
essentially creating an accessor function]
> 
> Signed-off-by: Matthias Gatto <matthias.gatto at outscale.com>
> ---
>  src/libvirt_private.syms  |  1 +
>  src/util/virstoragefile.c | 10 ++++++++++
>  src/util/virstoragefile.h |  3 +++
>  3 files changed, 14 insertions(+)
> 
> diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
> index dd085c3..5354a4a 100644
> --- a/src/libvirt_private.syms
> +++ b/src/libvirt_private.syms
> @@ -2190,6 +2190,7 @@ virStorageSourceClear;
>  virStorageSourceCopy;
>  virStorageSourceFree;
>  virStorageSourceGetActualType;
> +virStorageSourceGetBackingStore;
>  virStorageSourceGetSecurityLabelDef;
>  virStorageSourceInitChainElement;
>  virStorageSourceIsEmpty;
> diff --git a/src/util/virstoragefile.c b/src/util/virstoragefile.c
> index 2aa1d90..016beaa 100644
> --- a/src/util/virstoragefile.c
> +++ b/src/util/virstoragefile.c
> @@ -1809,6 +1809,16 @@ virStorageSourcePoolDefCopy(const virStorageSourcePoolDef *src)
>  }
>  
>  
> +virStorageSourcePtr
> +virStorageSourceGetBackingStore(const virStorageSource *src,
> +                                size_t pos ATTRIBUTE_UNUSED)
> +{
> +    if (!src)

I think perhaps Peter's point from his review is

    if (!src || pos > 0)

IOW: range checking for pos

Eventually patch 5 will make a real check...

In order to make some progress on this series - at least the first 5 or
6 patches - I can make the change if that is what Peter had in mind...

John
> +        return NULL;
> +    return src->backingStore;
> +}
> +
> +
>  /**
>   * virStorageSourcePtr:
>   *
> diff --git a/src/util/virstoragefile.h b/src/util/virstoragefile.h
> index b98fe25..8cd4854 100644
> --- a/src/util/virstoragefile.h
> +++ b/src/util/virstoragefile.h
> @@ -289,6 +289,9 @@ struct _virStorageSource {
>  #  define DEV_BSIZE 512
>  # endif
>  
> +virStorageSourcePtr virStorageSourceGetBackingStore(const virStorageSource *src,
> +                                                    size_t pos);
> +
>  int virStorageFileProbeFormat(const char *path, uid_t uid, gid_t gid);
>  int virStorageFileProbeFormatFromBuf(const char *path,
>                                       char *buf,
>