[libvirt] [PATCH 09/15] storage: Use VIR_AUTOFREE for storage util

[Erik Skultety]

On Wed, Feb 06, 2019 at 08:41:41AM -0500, John Ferlan wrote:
> Let's make use of the auto __cleanup capabilities cleaning up any
> now unnecessary goto paths.
>
> Signed-off-by: John Ferlan <jferlan at redhat.com>
> ---

[snip]

> @@ -3804,7 +3713,7 @@ virStorageBackendSCSINewLun(virStoragePoolObjPtr pool,
>  {
>      virStoragePoolDefPtr def = virStoragePoolObjGetDef(pool);
>      VIR_AUTOPTR(virStorageVolDef) vol = NULL;
> -    char *devpath = NULL;
> +    VIR_AUTOFREE(char *) devpath = NULL;
>      int retval = -1;
>
>      /* Check if the pool is using a stable target path. The call to
> @@ -3820,11 +3729,11 @@ virStorageBackendSCSINewLun(virStoragePoolObjPtr pool,
>          virReportError(VIR_ERR_INVALID_ARG,
>                         _("unable to use target path '%s' for dev '%s'"),
>                         NULLSTR(def->target.path), dev);
> -        goto cleanup;
> +        return -1;
>      }
>
>      if (VIR_ALLOC(vol) < 0)
> -        goto cleanup;
> +        return -1;
>
>      vol->type = VIR_STORAGE_VOL_BLOCK;
>
> @@ -3834,10 +3743,10 @@ virStorageBackendSCSINewLun(virStoragePoolObjPtr pool,
>       * just leave 'host' out
>       */
>      if (virAsprintf(&(vol->name), "unit:%u:%u:%u", bus, target, lun) < 0)
> -        goto cleanup;
> +        return -1;
>
>      if (virAsprintf(&devpath, "/dev/%s", dev) < 0)
> -        goto cleanup;
> +        return -1;
>
>      VIR_DEBUG("Trying to create volume for '%s'", devpath);
>
> @@ -3850,7 +3759,7 @@ virStorageBackendSCSINewLun(virStoragePoolObjPtr pool,
>      if ((vol->target.path = virStorageBackendStablePath(pool,
>                                                          devpath,
>                                                          true)) == NULL)
> -        goto cleanup;
> +        return -1;
>
>      if (STREQ(devpath, vol->target.path) &&
>          !(STREQ(def->target.path, "/dev") ||
> @@ -3859,34 +3768,29 @@ virStorageBackendSCSINewLun(virStoragePoolObjPtr pool,
>          VIR_DEBUG("No stable path found for '%s' in '%s'",
>                    devpath, def->target.path);
>
> -        retval = -2;
> -        goto cleanup;
> +        return -2;
>      }
>
>      /* Allow a volume read failure to ignore or skip this block file */
>      if ((retval = virStorageBackendUpdateVolInfo(vol, true,
>                                                   VIR_STORAGE_VOL_OPEN_DEFAULT,
>                                                   VIR_STORAGE_VOL_READ_NOERROR)) < 0)
> -        goto cleanup;
> +        return retval;
>
>      vol->key = virStorageBackendSCSISerial(vol->target.path,
>                                             (def->source.adapter.type ==
>                                              VIR_STORAGE_ADAPTER_TYPE_FC_HOST));
>      if (!vol->key)
> -        goto cleanup;

We're changing the logic ^here - previously if virStorageBackendUpdateVolInfo
succeeded but virStorageBackendSCSISerial returned NULL, we'd still return
retval which would have been equal to 0. To me, your change feels right, but I
want to make sure no caller was relying on 0 even though
virStorageBackendSCSISerial might have failed.

Reviewed-by: Erik Skultety <eskultet at redhat.com>