[libvirt] [PATCH 4/6] storage:dir: .resizeVol callback for ploop volume

[Nikolay Shirokovskiy]

On 09.02.2016 16:52, Olga Krishtal wrote:
> To change the size of ploop image file we use ploop resize cmd that takes
> 2 args: new size and path/to/DiskDescriptor.xml
> 
> Signed-off-by: Olga Krishtal <okrishtal at virtuozzo.com>
> ---
>  src/storage/storage_backend.c    | 28 ++++++++++++++++++++++++++++
>  src/storage/storage_backend.h    |  5 +++++
>  src/storage/storage_backend_fs.c |  2 ++
>  3 files changed, 35 insertions(+)
> 
> diff --git a/src/storage/storage_backend.c b/src/storage/storage_backend.c
> index c455908..fb4d1b9 100644
> --- a/src/storage/storage_backend.c
> +++ b/src/storage/storage_backend.c
> @@ -877,6 +877,34 @@ int virStorageBackendDeletePloop(virConnectPtr conn ATTRIBUTE_UNUSED,
>      return virFileDeleteTree(vol->target.path);
>  }
>  
> +int virStoragePloopResize(virConnectPtr conn ATTRIBUTE_UNUSED,
> +                          virStoragePoolObjPtr pool ATTRIBUTE_UNUSED,
> +                          virStorageVolDefPtr vol,
> +                          unsigned long long capacity)

we can just omit 'conn' and 'pool' in arguments

> +{
> +    int ret;

initialize to -1, then it would be easier to goto to cleanup.

> +    char *path = NULL;
> +    char *size = NULL;
> +    virCommandPtr cmd = NULL;
> +
> +    if (virAsprintf(&path, "%s/%s", vol->target.path, "DiskDescriptor.xml") < 0)
> +        return -1;
> +
> +    if (virAsprintf(&size, "%lluM", VIR_DIV_UP(capacity, 512)) < 0) {

You use suffix 'M' here thus you need to divide by 1024 * 1024 or leave the suffix.

> +        ret = -1;
> +        goto cleanup;
> +    }

use virCommandAddArgFormat to add 'path' and 'size'. And "%s/DiskDescriptor.xml")

by the way we can put all constants into #defines

> +    cmd = virCommandNewArgList("ploop", "resize", "-s", size, path, NULL);
> +
> +    ret = virCommandRun(cmd, NULL);
> +
> + cleanup:
> +    virCommandFree(cmd);
> +    VIR_FREE(path);
> +    VIR_FREE(size);
> +    return ret;
> +}
> +
>  enum {
>      QEMU_IMG_BACKING_FORMAT_NONE = 0,
>      QEMU_IMG_BACKING_FORMAT_FLAG,
> diff --git a/src/storage/storage_backend.h b/src/storage/storage_backend.h
> index 7d354c5..1de8dfe 100644
> --- a/src/storage/storage_backend.h
> +++ b/src/storage/storage_backend.h
> @@ -118,6 +118,11 @@ int virStorageBackendCreatePloop(virConnectPtr conn,
>  int virStorageBackendDeletePloop(virConnectPtr conn,
>                                   virStorageVolDefPtr vol);
>  
> +int virStoragePloopResize(virConnectPtr conn,
> +                          virStoragePoolObjPtr pool,
> +                          virStorageVolDefPtr vol,
> +                          unsigned long long capacity);
> +
>  virStorageBackendBuildVolFrom
>  virStorageBackendGetBuildVolFromFunction(virStorageVolDefPtr vol,
>                                           virStorageVolDefPtr inputvol);
> diff --git a/src/storage/storage_backend_fs.c b/src/storage/storage_backend_fs.c
> index 2290096..c2d148d 100644
> --- a/src/storage/storage_backend_fs.c
> +++ b/src/storage/storage_backend_fs.c
> @@ -1378,6 +1378,8 @@ virStorageBackendFileSystemVolResize(virConnectPtr conn ATTRIBUTE_UNUSED,
>      if (vol->target.format == VIR_STORAGE_FILE_RAW) {
>          return virStorageFileResize(vol->target.path, capacity,
>                                      vol->target.allocation, pre_allocate);
> +    } else if (vol->target.format == VIR_STORAGE_FILE_PLOOP) {
> +        return virStoragePloopResize(conn, pool, vol, capacity);
>      } else {
>          if (pre_allocate) {
>              virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
>