From ae23f78646e9635ec9cbf15dbf82a717ea1b0e69 Mon Sep 17 00:00:00 2001 From: Max Reitz Date: Wed, 12 Jun 2019 22:57:15 +0200 Subject: block: Add bdrv_supports_compressed_writes() Filters cannot compress data themselves but they have to implement .bdrv_co_pwritev_compressed() still (or they cannot forward compressed writes). Therefore, checking whether bs->drv->bdrv_co_pwritev_compressed is non-NULL is not sufficient to know whether the node can actually handle compressed writes. This function looks down the filter chain to see whether there is a non-filter that can actually convert the compressed writes into compressed data (and thus normal writes). Signed-off-by: Max Reitz Reviewed-by: Andrey Shinkevich Reviewed-by: Kevin Wolf --- include/block/block.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/block') diff --git a/include/block/block.h b/include/block/block.h index 2c09b93d07..981ab5b314 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -532,6 +532,7 @@ BlockDriverState *bdrv_next(BdrvNextIterator *it); void bdrv_next_cleanup(BdrvNextIterator *it); BlockDriverState *bdrv_next_monitor_owned(BlockDriverState *bs); +bool bdrv_supports_compressed_writes(BlockDriverState *bs); void bdrv_iterate_format(void (*it)(void *opaque, const char *name), void *opaque, bool read_only); const char *bdrv_get_node_name(const BlockDriverState *bs); -- cgit v1.2.3-55-g7522