diff options
Diffstat (limited to 'block.c')
| -rw-r--r-- | block.c | 35 |
1 files changed, 35 insertions, 0 deletions
@@ -3463,6 +3463,41 @@ int64_t bdrv_get_allocated_file_size(BlockDriverState *bs) return -ENOTSUP; } +/* + * bdrv_measure: + * @drv: Format driver + * @opts: Creation options for new image + * @in_bs: Existing image containing data for new image (may be NULL) + * @errp: Error object + * Returns: A #BlockMeasureInfo (free using qapi_free_BlockMeasureInfo()) + * or NULL on error + * + * Calculate file size required to create a new image. + * + * If @in_bs is given then space for allocated clusters and zero clusters + * from that image are included in the calculation. If @opts contains a + * backing file that is shared by @in_bs then backing clusters may be omitted + * from the calculation. + * + * If @in_bs is NULL then the calculation includes no allocated clusters + * unless a preallocation option is given in @opts. + * + * Note that @in_bs may use a different BlockDriver from @drv. + * + * If an error occurs the @errp pointer is set. + */ +BlockMeasureInfo *bdrv_measure(BlockDriver *drv, QemuOpts *opts, + BlockDriverState *in_bs, Error **errp) +{ + if (!drv->bdrv_measure) { + error_setg(errp, "Block driver '%s' does not support size measurement", + drv->format_name); + return NULL; + } + + return drv->bdrv_measure(opts, in_bs, errp); +} + /** * Return number of sectors on success, -errno on error. */ |