qemu-img: Convert by cluster size if target is compressed
If target block driver forces compression, qemu-img convert needs to
write by cluster size as well as "-c" option.
Particularly, this applies for converting to VMDK streamOptimized
format.
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
diff --git a/include/block/block.h b/include/block/block.h
index 467fb2b..27d8598 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -34,6 +34,10 @@
* opened with BDRV_O_UNMAP flag for this to work.
*/
bool can_write_zeroes_with_unmap;
+ /*
+ * True if this block driver only supports compressed writes
+ */
+ bool needs_compressed_writes;
} BlockDriverInfo;
typedef struct BlockFragInfo {
diff --git a/qemu-img.c b/qemu-img.c
index 317bc6c..04ce02a 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -1502,6 +1502,7 @@
goto out;
}
} else {
+ compress = compress || bdi.needs_compressed_writes;
cluster_sectors = bdi.cluster_size / BDRV_SECTOR_SIZE;
}
