[Qemu-block] [PATCH] vmdk: Fix next_cluster_sector for compressed write

[Radoslav Gerganov]

When the VMDK is streamOptimized (or compressed), the
next_cluster_sector must not be incremented by a fixed number of
sectors. Instead of this, it must be rounded up to the next consecutive
sector. Fixing this results in much smaller compressed images.

Signed-off-by: Radoslav Gerganov <address@hidden>
---
 block/vmdk.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/block/vmdk.c b/block/vmdk.c
index fbaab67..3bd5ccd 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -1324,8 +1324,12 @@ static int vmdk_write_extent(VmdkExtent *extent, int64_t 
cluster_offset,
 
     write_end_sector = DIV_ROUND_UP(write_offset + write_len, 
BDRV_SECTOR_SIZE);
 
-    extent->next_cluster_sector = MAX(extent->next_cluster_sector,
-                                      write_end_sector);
+    if (extent->compressed) {
+        extent->next_cluster_sector = write_end_sector;
+    } else {
+        extent->next_cluster_sector = MAX(extent->next_cluster_sector,
+                                          write_end_sector);
+    }
 
     if (ret != write_len) {
         ret = ret < 0 ? ret : -EIO;
-- 
1.9.1