[Qemu-devel] [PATCH 1/5] qemu-img: Convert by cluster size if target is compressed

[Fam Zheng <famz@redhat.com>]

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>
---
 include/block/block.h | 1 +
 qemu-img.c            | 5 ++++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/include/block/block.h b/include/block/block.h
index 3560deb..169c092 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -18,6 +18,7 @@ typedef struct BlockDriverInfo {
     /* offset at which the VM state can be saved (0 if not possible) */
     int64_t vm_state_offset;
     bool is_dirty;
+    bool is_compressed;
 } BlockDriverInfo;
 
 typedef struct BlockFragInfo {
diff --git a/qemu-img.c b/qemu-img.c
index bf3fb4f..09ed9b2 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -1383,8 +1383,11 @@ static int img_convert(int argc, char **argv)
         }
     }
 
+    ret = bdrv_get_info(out_bs, &bdi);
+    if (ret == 0) {
+        compress = compress || bdi.is_compressed;
+    }
     if (compress) {
-        ret = bdrv_get_info(out_bs, &bdi);
         if (ret < 0) {
             error_report("could not get block driver info");
             goto out;
-- 
1.8.4.2